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Singer ZS, Pabón J, Huang H, Sun W, Luo H, Grant KR, Obi I, Coker C, Rice CM, Danino T. Engineered bacteria launch and control an oncolytic virus. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2025:2023.09.28.559873. [PMID: 37808855 PMCID: PMC10557668 DOI: 10.1101/2023.09.28.559873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/10/2023]
Abstract
The ability of bacteria and viruses to selectively replicate in tumors has led to synthetic engineering of new microbial therapies. Here we design a cooperative strategy whereby S. typhimurium bacteria transcribe and deliver the Senecavirus A RNA genome inside host cells, launching a potent oncolytic viral infection. "Encapsidated" by bacteria, the viral genome can further bypass circulating antiviral antibodies to reach the tumor and initiate replication and spread within immune mice. Finally, we engineer the virus to require a bacterially delivered protease to achieve virion maturation, demonstrating bacterial control over the virus. This work extends bacterially delivered therapeutics to viral genomes, and shows how a consortium of microbes can achieve a cooperative aim.
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Swain B, Powell CT, Curtiss R. Virulence, immunogenicity and live vaccine potential of aroA and phoP mutants of Edwardsiella piscicida in zebrafish. Microb Pathog 2021; 162:105355. [PMID: 34902537 DOI: 10.1016/j.micpath.2021.105355] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 11/28/2021] [Accepted: 12/07/2021] [Indexed: 12/21/2022]
Abstract
Vaccination remains the most effective approach for prevention and control of infectious diseases in aquaculture. Edwardsiella piscicida is a causative agent of edwardsiellosis leading to mass mortality in a variety of fish species, leading to huge economic losses in the aquaculture industry. In this study, we have deleted the aroA and phoP genes in E. piscicida and investigated the phenotype, degrees of attenuation, immunogenicity, and ability to confer immune protection in zebrafish host. Our vaccine strain χ16028 with genotype ΔaroA11 ΔphoP12, showed significantly reduced growth, motility, biofilm formation and intracellular replication compared to the wild-type strain J118. In this regard, χ16028 exhibited retarded colonization and attenuation phenotype in zebrafish. Studies showed that χ16028 induced TLR4 and TLR5 mediated NF-kB pathway and upregulated cytokine gene expression i.e., TNF-α, IL-1β, IL-6, IL-8 and type-I IFN in zebrafish. Zebrafish immunized by intracoelomic injection (i.c.) with χ16028 showed systemic and mucosal IgM responses and protection against the wild-type E. piscicida i.c. injection challenge. However, the protection was only 25% in zebrafish following i.c. challenge. We speculate that our vaccine strain might be very attenuated; a booster dose may trigger better immune response and increase the percentage of survival to a more significant level.
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Affiliation(s)
- Banikalyan Swain
- University of Florida, Department of Infectious Diseases & Immunology, College of Veterinary Medicine, Gainesville, FL, 32608, USA.
| | - Cole T Powell
- University of Florida, Department of Infectious Diseases & Immunology, College of Veterinary Medicine, Gainesville, FL, 32608, USA
| | - Roy Curtiss
- University of Florida, Department of Infectious Diseases & Immunology, College of Veterinary Medicine, Gainesville, FL, 32608, USA
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3
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Enhancing the tropism of bacteria via genetically programmed biosensors. Nat Biomed Eng 2021; 6:94-104. [PMID: 34326488 DOI: 10.1038/s41551-021-00772-3] [Citation(s) in RCA: 80] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Accepted: 06/25/2021] [Indexed: 01/01/2023]
Abstract
Engineered bacteria for therapeutic applications would benefit from control mechanisms that confine the growth of the bacteria within specific tissues or regions in the body. Here we show that the tropism of engineered bacteria can be enhanced by coupling bacterial growth with genetic circuits that sense oxygen, pH or lactate through the control of the expression of essential genes. Bacteria that were engineered with pH or oxygen sensors showed preferential growth in physiologically relevant acidic or oxygen conditions, and reduced growth outside the permissive environments when orally delivered to mice. In syngeneic mice bearing subcutaneous tumours, bacteria engineered with both hypoxia and lactate biosensors coupled through an AND gate showed increased tumour specificity. The multiplexing of genetic circuits may be more broadly applicable for enhancing the localization of bacteria to specified niches.
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4
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Li Q, Lv Y, Li YA, Du Y, Guo W, Chu D, Wang X, Wang S, Shi H. Live attenuated Salmonella enterica serovar Choleraesuis vector delivering a conserved surface protein enolase induces high and broad protection against Streptococcus suis serotypes 2, 7, and 9 in mice. Vaccine 2020; 38:6904-6913. [PMID: 32907758 DOI: 10.1016/j.vaccine.2020.08.062] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Revised: 07/11/2020] [Accepted: 08/25/2020] [Indexed: 01/03/2023]
Abstract
Streptococcus suis, a major zoonotic pathogen in swine, can be classified into 35 serotypes. However, no universal vaccine against the multiple serotypes of S. suis is available, though some studies have shown homologous protection. Hence, developing an effective universal vaccine to protect pigs against multiple S. suis serotypes is necessary, or at the very least, to protect pigs against diseases caused by the dominant pathogenic serotypes. Enolase, a highly conserved surface protein, is present in all of the described S. suis serotypes. rSC0016 is an improved recombinant attenuated S. Choleraesuis vaccine vector, combining a sopB mutation with regulated delayed systems, achieving an adequate balance between host safety and immunogenicity. In order to develop a universal vaccine against the multiple serotypes of S. suis, a novel recombinant vaccine strain rSC0016 that carries a heterologous antigen enolase was developed in this study. According, it was found that the recombinant vaccine strain rSC0016(pS-Enolase) exhibited better colonization compared to the vaccine control strain rSC0018(pYA3493). In addition, a mouse model immunized with the strain rSC0016(pS-Enolase) elicited significant IgG antibody responses against both enolase and Salmonella antigens, while inducing good mucosal, humoral, and cellular immune responses against enolase. Finally, immunization with rSC0016(pS-Enolase) was shown to confer 100%, 80%, and 100% protection against the serotypes of SS2, SS7, and SS9, respectively, and significantly reduced histopathological lesions in mice. Overall, this study provides a promising universal vaccine candidate for use against the multiple serotypes of S. suis.
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Affiliation(s)
- Quan Li
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, Jiangsu, China; Jiangsu Co-innovation Center for the Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China.
| | - Yifan Lv
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, Jiangsu, China; Jiangsu Co-innovation Center for the Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China
| | - Yu-An Li
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, Jiangsu, China; Jiangsu Co-innovation Center for the Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China
| | - Yuanzhao Du
- Yebio Bioengineering Co., Ltd of Qingdao, Qingdao 266114, China
| | - Weiwei Guo
- Yebio Bioengineering Co., Ltd of Qingdao, Qingdao 266114, China
| | - Dianfeng Chu
- Yebio Bioengineering Co., Ltd of Qingdao, Qingdao 266114, China.
| | - Xiaobo Wang
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, Jiangsu, China; Jiangsu Co-innovation Center for the Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China.
| | - Shifeng Wang
- Department of Infectious Diseases and Immunology, College of Veterinary Medicine, University of Florida, Gainesville, FL 32611-0880, USA.
| | - Huoying Shi
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, Jiangsu, China; Jiangsu Co-innovation Center for the Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China; Key Laboratory of Animal Infectious Diseases, Ministry of Agriculture, Yangzhou University, China; Jiangsu Key Laboratory of Preventive Veterinary Medicine, Yangzhou University, China.
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5
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Harimoto T, Singer ZS, Velazquez OS, Zhang J, Castro S, Hinchliffe TE, Mather W, Danino T. Rapid screening of engineered microbial therapies in a 3D multicellular model. Proc Natl Acad Sci U S A 2019; 116:9002-9007. [PMID: 30996123 PMCID: PMC6500119 DOI: 10.1073/pnas.1820824116] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Synthetic biology is transforming therapeutic paradigms by engineering living cells and microbes to intelligently sense and respond to diseases including inflammation, infections, metabolic disorders, and cancer. However, the ability to rapidly engineer new therapies far outpaces the throughput of animal-based testing regimes, creating a major bottleneck for clinical translation. In vitro approaches to address this challenge have been limited in scalability and broad applicability. Here, we present a bacteria-in-spheroid coculture (BSCC) platform that simultaneously tests host species, therapeutic payloads, and synthetic gene circuits of engineered bacteria within multicellular spheroids over a timescale of weeks. Long-term monitoring of bacterial dynamics and disease progression enables quantitative comparison of critical therapeutic parameters such as efficacy and biocontainment. Specifically, we screen Salmonella typhimurium strains expressing and delivering a library of antitumor therapeutic molecules via several synthetic gene circuits. We identify candidates exhibiting significant tumor reduction and demonstrate high similarity in their efficacies, using a syngeneic mouse model. Last, we show that our platform can be expanded to dynamically profile diverse microbial species including Listeria monocytogenes, Proteus mirabilis, and Escherichia coli in various host cell types. This high-throughput framework may serve to accelerate synthetic biology for clinical applications and for understanding the host-microbe interactions in disease sites.
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Affiliation(s)
- Tetsuhiro Harimoto
- Department of Biomedical Engineering, Columbia University, New York, NY 10027
| | - Zakary S Singer
- Department of Biomedical Engineering, Columbia University, New York, NY 10027
| | - Oscar S Velazquez
- Department of Biomedical Engineering, Columbia University, New York, NY 10027
| | - Joanna Zhang
- Department of Biomedical Engineering, Columbia University, New York, NY 10027
| | - Samuel Castro
- Department of Biomedical Engineering, Columbia University, New York, NY 10027
| | - Taylor E Hinchliffe
- Department of Biomedical Engineering, Columbia University, New York, NY 10027
| | - William Mather
- BioCircuits Institute, University of California, San Diego, La Jolla, CA 92093
| | - Tal Danino
- Department of Biomedical Engineering, Columbia University, New York, NY 10027;
- Data Science Institute, Columbia University, New York, NY 10027
- Herbert Irving Comprehensive Cancer Center, Columbia University, New York, NY 10027
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Das S, Mohakud NK, Suar M, Sahu BR. Vaccine development for enteric bacterial pathogens: Where do we stand? Pathog Dis 2019; 76:5040763. [PMID: 30052916 DOI: 10.1093/femspd/fty057] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 06/19/2018] [Indexed: 01/06/2023] Open
Abstract
Gut infections triggered by pathogenic bacteria lead to most frequently occurring diarrhea in humans accounting for million deaths annually. Currently, only a few licensed vaccines are available against these pathogens for mostly travelers moving to diarrheal endemic areas. Besides commercialized vaccines, there are many formulations that are either under clinical or pre-clinical stages of development and despite several efforts to improve safety, immunogenicity and efficacy, none of them can confer long-term protective immunity, for which repeated booster doses are always recommended. Further in many countries, financial, social and political constraints have jeopardized vaccine development program against these pathogens that enforce us to gather knowledge on safety, tolerability, immunogenicity and protective efficacy regarding the same. In this review, we analyze safety and efficacy issues of vaccines against five major gut bacteria causing enteric infections. The article also simultaneously describes several barriers for vaccine development and further discusses possible strategies to enhance immunogenicity and efficacy.
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Affiliation(s)
- Susmita Das
- Infection Biology Lab, KIIT School of Biotechnology, Campus XI, Bhubaneswar 751024, India
| | - Nirmal K Mohakud
- Department of Pediatrics, Kalinga Institute of Medical Sciences, Patia, Bhubaneswar 751024, India
| | - Mrutyunjay Suar
- Infection Biology Lab, KIIT School of Biotechnology, Campus XI, Bhubaneswar 751024, India
| | - Bikash R Sahu
- Infection Biology Lab, KIIT School of Biotechnology, Campus XI, Bhubaneswar 751024, India
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7
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Abstract
BACKGROUND Typhoid fever and paratyphoid fever continue to be important causes of illness and death, particularly among children and adolescents in south-central and southeast Asia. Two typhoid vaccines are widely available, Ty21a (oral) and Vi polysaccharide (parenteral). Newer typhoid conjugate vaccines are at varying stages of development and use. The World Health Organization has recently recommended a Vi tetanus toxoid (Vi-TT) conjugate vaccine, Typbar-TCV, as the preferred vaccine for all ages. OBJECTIVES To assess the effects of vaccines for preventing typhoid fever. SEARCH METHODS In February 2018, we searched the Cochrane Infectious Diseases Group Specialized Register, CENTRAL, MEDLINE, Embase, LILACS, and mRCT. We also searched the reference lists of all included trials. SELECTION CRITERIA Randomized and quasi-randomized controlled trials (RCTs) comparing typhoid fever vaccines with other typhoid fever vaccines or with an inactive agent (placebo or vaccine for a different disease) in adults and children. Human challenge studies were not eligible. DATA COLLECTION AND ANALYSIS Two review authors independently applied inclusion criteria and extracted data, and assessed the certainty of the evidence using the GRADE approach. We computed vaccine efficacy per year of follow-up and cumulative three-year efficacy, stratifying for vaccine type and dose. The outcome addressed was typhoid fever, defined as isolation of Salmonella enterica serovar Typhi in blood. We calculated risk ratios (RRs) and efficacy (1 - RR as a percentage) with 95% confidence intervals (CIs). MAIN RESULTS In total, 18 RCTs contributed to the quantitative analysis in this review: 13 evaluated efficacy (Ty21a: 5 trials; Vi polysaccharide: 6 trials; Vi-rEPA: 1 trial; Vi-TT: 1 trial), and 9 reported on adverse events. All trials but one took place in typhoid-endemic countries. There was no information on vaccination in adults aged over 55 years of age, pregnant women, or travellers. Only one trial included data on children under two years of age.Ty21a vaccine (oral vaccine, three doses)A three-dose schedule of Ty21a vaccine probably prevents around half of typhoid cases during the first three years after vaccination (cumulative efficacy 2.5 to 3 years: 50%, 95% CI 35% to 61%, 4 trials, 235,239 participants, moderate-certainty evidence). These data include patients aged 3 to 44 years.Compared with placebo, this vaccine probably does not cause more vomiting, diarrhoea, nausea or abdominal pain (2 trials, 2066 participants; moderate-certainty evidence), headache, or rash (1 trial, 1190 participants; moderate-certainty evidence); however, fever (2 trials, 2066 participants; moderate-certainty evidence) is probably more common following vaccination.Vi polysaccharide vaccine (injection, one dose)A single dose of Vi polysaccharide vaccine prevents around two-thirds of typhoid cases in the first year after vaccination (year 1: 69%, 95% CI 63% to 74%; 3 trials, 99,979 participants; high-certainty evidence). In year 2, trial results were more variable, with the vaccine probably preventing between 45% and 69% of typhoid cases (year 2: 59%, 95% CI 45% to 69%; 4 trials, 194,969 participants; moderate-certainty evidence). These data included participants aged 2 to 55 years of age.The three-year cumulative efficacy of the vaccine may be around 55% (95% CI 30% to 70%; 11,384 participants, 1 trial; low-certainty evidence). These data came from a single trial conducted in South Africa in the 1980s in participants aged 5 to 15 years.Compared with placebo, this vaccine probably did not increase the incidence of fever (3 trials, 132,261 participants; moderate-certainty evidence) or erythema (3 trials, 132,261 participants; low-certainty evidence); however, swelling (3 trials, 1767 participants; moderate-certainty evidence) and pain at the injection site (1 trial, 667 participants; moderate-certainty evidence) were more common in the vaccine group.Vi-rEPA vaccine (two doses)Administration of two doses of the Vi-rEPA vaccine probably prevents between 50% and 96% of typhoid cases during the first two years after vaccination (year 1: 94%, 95% CI 75% to 99%; year 2: 87%, 95% CI 56% to 96%, 1 trial, 12,008 participants; moderate-certainty evidence). These data came from a single trial with children two to five years of age conducted in Vietnam.Compared with placebo, both the first and the second dose of this vaccine increased the risk of fever (1 trial, 12,008 and 11,091 participants, low-certainty evidence) and the second dose increase the incidence of swelling at the injection site (one trial, 11,091 participants, moderate-certainty evidence).Vi-TT vaccine (two doses)We are uncertain of the efficacy of administration of two doses of Vi-TT (PedaTyph) in typhoid cases in children during the first year after vaccination (year 1: 94%, 95% CI -1% to 100%, 1 trial, 1625 participants; very low-certainty evidence). These data come from a single cluster-randomized trial in children aged six months to 12 years and conducted in India. For single dose Vi-TT (Typbar-TCV), we found no efficacy trials evaluating the vaccine with natural exposure.There were no reported serious adverse effects in RCTs of any of the vaccines studied. AUTHORS' CONCLUSIONS The licensed Ty21a and Vi polysaccharide vaccines are efficacious in adults and children older than two years in endemic countries. The Vi-rEPA vaccine is just as efficacious, although data is only available for children. The new Vi-TT vaccine (PedaTyph) requires further evaluation to determine if it provides protection against typhoid fever. At the time of writing, there were only efficacy data from a human challenge setting in adults on the Vi-TT vaccine (Tybar), which clearly justify the ongoing field trials to evaluate vaccine efficacy.
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Affiliation(s)
- Rachael Milligan
- Liverpool School of Tropical MedicineCochrane Infectious Diseases GroupPembroke PlaceLiverpoolUKL3 5QA
| | - Mical Paul
- Rambam Health Care CampusDivision of Infectious DiseasesHa‐aliya 8 StHaifaIsrael33705
| | - Marty Richardson
- Liverpool School of Tropical MedicineCochrane Infectious Diseases GroupPembroke PlaceLiverpoolUKL3 5QA
| | - Ami Neuberger
- Rambam Health Care Campus and The Ruth and Bruce Rappaport Faculty of Medicine, Technion – Israel Institute of TechnologyDivision of Infectious DiseasesTel AvivIsrael
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8
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Tiwari S, Jamal SB, Hassan SS, Carvalho PVSD, Almeida S, Barh D, Ghosh P, Silva A, Castro TLP, Azevedo V. Two-Component Signal Transduction Systems of Pathogenic Bacteria As Targets for Antimicrobial Therapy: An Overview. Front Microbiol 2017; 8:1878. [PMID: 29067003 PMCID: PMC5641358 DOI: 10.3389/fmicb.2017.01878] [Citation(s) in RCA: 140] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2017] [Accepted: 09/14/2017] [Indexed: 12/12/2022] Open
Abstract
The bacterial communities in a wide range of environmental niches sense and respond to numerous external stimuli for their survival. Primarily, a source they require to follow up this communication is the two-component signal transduction system (TCS), which typically comprises a sensor Histidine kinase for receiving external input signals and a response regulator that conveys a proper change in the bacterial cell physiology. For numerous reasons, TCSs have ascended as convincing targets for antibacterial drug design. Several studies have shown that TCSs are essential for the coordinated expression of virulence factors and, in some cases, for bacterial viability and growth. It has also been reported that the expression of antibiotic resistance determinants may be regulated by some TCSs. In addition, as a mode of signal transduction, phosphorylation of histidine in bacteria differs from normal serine/threonine and tyrosine phosphorylation in higher eukaryotes. Several studies have shown the molecular mechanisms by which TCSs regulate virulence and antibiotic resistance in pathogenic bacteria. In this review, we list some of the characteristics of the bacterial TCSs and their involvement in virulence and antibiotic resistance. Furthermore, this review lists and discusses inhibitors that have been reported to target TCSs in pathogenic bacteria.
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Affiliation(s)
- Sandeep Tiwari
- Laboratório de Genética Celular e Molecular, Departamento de Biologia Geral, Instituto de Ciências Biológicas (ICB), Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Syed B. Jamal
- Laboratório de Genética Celular e Molecular, Departamento de Biologia Geral, Instituto de Ciências Biológicas (ICB), Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Syed S. Hassan
- Laboratório de Genética Celular e Molecular, Departamento de Biologia Geral, Instituto de Ciências Biológicas (ICB), Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
- Biochemistry Group, Department of Chemistry, Islamia College University, Peshawar, Pakistan
| | - Paulo V. S. D. Carvalho
- Laboratório de Genética Celular e Molecular, Departamento de Biologia Geral, Instituto de Ciências Biológicas (ICB), Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Sintia Almeida
- Laboratório de Genética Celular e Molecular, Departamento de Biologia Geral, Instituto de Ciências Biológicas (ICB), Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Debmalya Barh
- Laboratório de Genética Celular e Molecular, Departamento de Biologia Geral, Instituto de Ciências Biológicas (ICB), Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
- Centre for Genomics and Applied Gene Technology, Institute of Integrative Omics and Applied Biotechnology, Purba Medinipur, India
| | - Preetam Ghosh
- Department of Computer Science, Virginia Commonwealth University, Richmond, VA, United States
| | - Artur Silva
- Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, Brazil
| | - Thiago L. P. Castro
- Laboratório de Genética Celular e Molecular, Departamento de Biologia Geral, Instituto de Ciências Biológicas (ICB), Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
- Instituto de Ciências da Saúde, Universidade Federal da Bahia, Salvador, Brazil
| | - Vasco Azevedo
- Laboratório de Genética Celular e Molecular, Departamento de Biologia Geral, Instituto de Ciências Biológicas (ICB), Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
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9
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Ren J, Sang Y, Lu J, Yao YF. Protein Acetylation and Its Role in Bacterial Virulence. Trends Microbiol 2017; 25:768-779. [PMID: 28462789 DOI: 10.1016/j.tim.2017.04.001] [Citation(s) in RCA: 103] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2017] [Revised: 03/21/2017] [Accepted: 04/04/2017] [Indexed: 12/13/2022]
Abstract
Protein acetylation is a universal post-translational modification which is found in both eukaryotes and prokaryotes. This process is achieved enzymatically by the protein acetyltransferase Pat, and nonenzymatically by metabolic intermediates (e.g., acetyl phosphate) in bacteria. Protein acetylation plays a role in bacterial chemotaxis, metabolism, DNA replication, and other cellular processes. Recently, accumulating evidence has suggested that protein acetylation might be involved in bacterial virulence because a number of bacterial virulence factors are acetylated. In this review, we summarize the progress in understanding bacterial protein acetylation and discuss how it mediates bacterial virulence.
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Affiliation(s)
- Jie Ren
- Laboratory of Bacterial Pathogenesis, Department of Microbiology and Immunology, Institutes of Medical Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Yu Sang
- Laboratory of Bacterial Pathogenesis, Department of Microbiology and Immunology, Institutes of Medical Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Jie Lu
- Department of Infectious Diseases, Shanghai Ruijin Hospital, Shanghai 200025, China
| | - Yu-Feng Yao
- Laboratory of Bacterial Pathogenesis, Department of Microbiology and Immunology, Institutes of Medical Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China; Department of Laboratory Medicine, Shanghai East Hospital, Tongji University School of Medicine, Shanghai 200120, China.
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10
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Zhang M, Sun C, Gu J, Yan X, Wang B, Cui Z, Sun X, Tong C, Feng X, Lei L, Han W. Salmonella Typhimurium strain expressing OprF-OprI protects mice against fatal infection by Pseudomonas aeruginosa. Microbiol Immunol 2016; 59:533-44. [PMID: 26249788 DOI: 10.1111/1348-0421.12291] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Revised: 07/29/2015] [Accepted: 08/02/2015] [Indexed: 01/16/2023]
Abstract
Pseudomonas aeruginosa poses a major threat to human health and to the mink industry. Thus, development of vaccines that elicit robust humoral and cellular immunity against P. aeruginosa is greatly needed. In this study, a recombinant attenuated Salmonella vaccine (RASV) that expresses the outer membrane proteins fusion OprF190-342 -OprI21-83 (F1I2) from P. aeruginosa was constructed and the potency of this vaccine candidate assessed by measuring F1I2-specific humoral immune responses upon vaccination through s.c. or oral routes. S.C. administration achieved higher serum IgG titers and IgA titers in the intestine and induced stronger F1I2-specific IgG and IgA titers in lung homogenate than did oral administration, which resulted in low IgG titers and no local IgA production. High titers of IFN-γ, IL-4, and T-lymphocyte subsets induced a mixed Th1/Th2 response in mice immunized s.c., indicating elicitation of cellular immunity. Importantly, when immunized mice were challenged with P. aeruginosa by the intranasal route 30 days after the initial immunization, s.c. vaccination achieved 77.78% protection, in contrast to 41.18% via oral administration and 66.67% via Escherichia coli-expressed F1I2 (His-F1I2) vaccination. These results indicate that s.c. vaccination provides a better protective response against P. aeruginosa infection than do oral administration and the His-F1I2 vaccine.
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Affiliation(s)
| | | | | | - Xinwu Yan
- College of Animal Science, Jilin University, No. 5333, Xi'an Street, Changchun, Jilin, 130062
| | | | | | | | | | | | | | - Wenyu Han
- College of Veterinary Medicine.,Jiangsu Co-innovation Center for the Prevention and Control of Important Animal Infectious Disease and Zoonoses, Yangzhou, 225009, People's Republic of China
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11
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Brannon JR, Hadjifrangiskou M. The arsenal of pathogens and antivirulence therapeutic strategies for disarming them. Drug Des Devel Ther 2016; 10:1795-806. [PMID: 27313446 PMCID: PMC4890686 DOI: 10.2147/dddt.s98939] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Pathogens deploy an arsenal of virulence factors (VFs) to establish themselves within their infectious niche. The discovery of antimicrobial compounds and their development into therapeutics has made a monumental impact on human and microbial populations. Although humans have used antimicrobials for medicinal and agricultural purposes, microorganism populations have developed and shared resistance mechanisms to persevere in the face of classical antimicrobials. However, a positive substitute is antivirulence therapy; antivirulence therapeutics prevent or interrupt an infection by counteracting a pathogen's VFs. Their application can reduce the use of broad-spectrum antimicrobials and dampen the frequency with which resistant strains emerge. Here, we summarize the contribution of VFs to various acute and chronic infections. In correspondence with this, we provide an overview of the research and development of antivirulence strategies.
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Affiliation(s)
- John R Brannon
- Division of Molecular Pathogenesis, Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Maria Hadjifrangiskou
- Division of Molecular Pathogenesis, Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN, USA
- Department of Urologic Surgery, Vanderbilt University School of Medicine, Nashville, TN, USA
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12
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Principi N, Esposito S. Preventing invasive salmonellosis in children through vaccination. Expert Rev Vaccines 2016; 15:897-905. [PMID: 27140662 DOI: 10.1080/14760584.2016.1183484] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
INTRODUCTION Vaccination is an important strategy to control endemic enteric fever (EF) and to interrupt transmission during outbreaks. The main aim of this paper is to discuss the efficacy of available EF vaccines in children and to highlight novel vaccination possibilities against EF and non-typhoid invasive salmonelloses. AREAS COVERED Two types of typhoid vaccines are presently available in the industrialized world. One of these vaccines is administered parenterally and is based on the virulence-associated (Vi) capsular polysaccaride of Salmonella typhi. The second vaccine is based on a live attenuated strain of the pathogen and is given orally. In addition, a Vi-tetanus toxoid conjugated vaccine is currently licensed in India; however, it is not available anywhere else. Expert commentary: Unfortunately, only typhoid fever is addressed by the currently licensed typhoid vaccines. Moreover, they are unsuitable for infants and remain a possible aid for reducing the risk of EF only in older subjects. They should be used in developing countries with endemic EF. New vaccines able to confer long-term protection to subjects in the first years of life and those with immature immune systems could significantly reduce incidence rates of EF in younger children. Vi-conjugate preparations are promising solutions in this regard.
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Affiliation(s)
- Nicola Principi
- a Paediatric Highly Intensive Care Unit, Department of Pathophysiology and Transplantation , Università degli Studi di Milano, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico , Milan , Italy
| | - Susanna Esposito
- a Paediatric Highly Intensive Care Unit, Department of Pathophysiology and Transplantation , Università degli Studi di Milano, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico , Milan , Italy
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Dalebroux ZD, Edrozo MB, Pfuetzner RA, Ressl S, Kulasekara BR, Blanc MP, Miller SI. Delivery of cardiolipins to the Salmonella outer membrane is necessary for survival within host tissues and virulence. Cell Host Microbe 2016; 17:441-51. [PMID: 25856753 DOI: 10.1016/j.chom.2015.03.003] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Revised: 01/05/2015] [Accepted: 02/27/2015] [Indexed: 12/22/2022]
Abstract
The outer membrane (OM) of Gram-negative bacteria is an asymmetric lipid bilayer that serves as a barrier to the environment. During infection, Gram-negative bacteria remodel their OM to promote survival and replication within host tissues. Salmonella rely on the PhoPQ two-component regulators to coordinate OM remodeling in response to environmental cues. In a screen for mediators of PhoPQ-regulated OM remodeling in Salmonella Typhimurium, we identified PbgA, a periplasmic domain-containing transmembrane protein, which binds cardiolipin glycerophospholipids near the inner membrane and promotes their PhoPQ-regulated trafficking to the OM. Purified-PbgA oligomers are tetrameric, and the periplasmic domain contains a globular region that binds to the OM in a PhoPQ-dependent manner. Thus, PbgA forms a complex that may bridge the envelope for regulated cardiolipin delivery. PbgA globular region-deleted mutant bacteria are severely attenuated for pathogenesis, suggesting that increased cardiolipin trafficking to the OM is necessary for Salmonella to survive within host tissues that activate PhoPQ.
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Affiliation(s)
- Zachary D Dalebroux
- Department of Microbiology, University of Washington, Seattle, WA 98195, USA
| | - Mauna B Edrozo
- Department of Microbiology, University of Washington, Seattle, WA 98195, USA
| | - Richard A Pfuetzner
- Department of Microbiology, University of Washington, Seattle, WA 98195, USA
| | - Susanne Ressl
- Department of Molecular and Cellular Biochemistry, Indiana University Bloomington, 212 S. Hawthrone Drive, Bloomington, IN 47401, USA
| | | | - Marie-Pierre Blanc
- Department of Microbiology, University of Washington, Seattle, WA 98195, USA
| | - Samuel I Miller
- Department of Microbiology, University of Washington, Seattle, WA 98195, USA; Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA; Department of Medicine, University of Washington, Seattle, WA 98195, USA.
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Lin IYC, Van TTH, Smooker PM. Live-Attenuated Bacterial Vectors: Tools for Vaccine and Therapeutic Agent Delivery. Vaccines (Basel) 2015; 3:940-72. [PMID: 26569321 PMCID: PMC4693226 DOI: 10.3390/vaccines3040940] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Revised: 10/30/2015] [Accepted: 10/30/2015] [Indexed: 12/14/2022] Open
Abstract
Genetically attenuated microorganisms, including pathogenic and commensal bacteria, can be engineered to carry and deliver heterologous antigens to elicit host immunity against both the vector as well as the pathogen from which the donor gene is derived. These live attenuated bacterial vectors have been given much attention due to their capacity to induce a broad range of immune responses including localized mucosal, as well as systemic humoral and/or cell-mediated immunity. In addition, the unique tumor-homing characteristics of these bacterial vectors has also been exploited for alternative anti-tumor vaccines and therapies. In such approach, tumor-associated antigen, immunostimulatory molecules, anti-tumor drugs, or nucleotides (DNA or RNA) are delivered. Different potential vectors are appropriate for specific applications, depending on their pathogenic routes. In this review, we survey and summarize the main features of the different types of live bacterial vectors and discussed the clinical applications in the field of vaccinology. In addition, different approaches for using live attenuated bacterial vectors for anti-cancer therapy is discussed, and some promising pre-clinical and clinical studies in this field are outlined.
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Affiliation(s)
- Ivan Y C Lin
- School of Applied Sciences, RMIT University, Plenty Road, Bundoora VIC-3083, Australia.
| | - Thi Thu Hao Van
- School of Applied Sciences, RMIT University, Plenty Road, Bundoora VIC-3083, Australia.
| | - Peter M Smooker
- School of Applied Sciences, RMIT University, Plenty Road, Bundoora VIC-3083, Australia.
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15
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What Makes A Bacterial Oral Vaccine a Strong Inducer of High-Affinity IgA Responses? Antibodies (Basel) 2015. [DOI: 10.3390/antib4040295] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
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Ji Z, Shang J, Li Y, Wang S, Shi H. Live attenuated Salmonella enterica serovar Choleraesuis vaccine vector displaying regulated delayed attenuation and regulated delayed antigen synthesis to confer protection against Streptococcus suis in mice. Vaccine 2015; 33:4858-67. [PMID: 26238722 DOI: 10.1016/j.vaccine.2015.07.063] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Revised: 07/18/2015] [Accepted: 07/21/2015] [Indexed: 01/29/2023]
Abstract
Salmonella enterica serotype Choleraesuis (S. Choleraesuis) and Streptococcus suis (S. suis) are important swine pathogens. Development of a safe and effective attenuated S. Choleraesuis vaccine vector would open a new window to prevent and control pig diseases. To achieve this goal, the mannose and arabinose regulated delayed attenuated systems (RDAS), Δpmi and ΔPcrp::TT araC PBADcrp, were introduced into the wild type S. Choleraesuis strain C78-3. We also introduced ΔrelA::araC PBADlacI TT to achieve regulated delayed antigen synthesis and ΔasdA to constitute a balanced-lethal plasmid system. The safety and immunogenicity of the resulted RDAS S. Choleraesuis strain rSC0011 carrying 6-phosphogluconate dehydrogenase (6-PGD) of S. suis serotype 2 (SS2) were evaluated in vitro and in vivo. Compared with the wild type parent strain C78-3 and vaccine strain C500, a live attenuated S. Choleraesuis vaccine licensed for piglet in China, the results showed that the survival curves of the vaccine strain rSC0011 were similar to those of strains C78-3 and C500 at the early stage of infection, but lower than those of C78-3 and higher than those of C500 at the later stage in both porcine alveolar macrophages and peripheral porcine monocytes. The LD50 of the RDAS strains rSC0011 by oral route in mice was close to that of C500 and 10,000-fold higher than that of C78-3. Similar results were achieved by intraperitoneal (i.p.) route, suggesting that the RDAS strains rSC0011 achieved similar attenuation as C500. However, the RDAS strain rSC0011 was superior to C500 in colonization of Peyer's patches. Adult mice orally immunized with strain rSC0011 carrying a plasmid expression 6-phosphogluconate dehydrogenase (6-PGD) gene from SS2 developed strong immune responses against 6-PGD and Salmonella antigens, and conferred high protection against i.p. challenge with SS2.
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Affiliation(s)
- Zhenying Ji
- College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu 225009, China; Co-Innovation Center of Jiangsu for the Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, Jiangsu 225009, China
| | - Jing Shang
- College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu 225009, China; Co-Innovation Center of Jiangsu for the Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, Jiangsu 225009, China
| | - Yuan Li
- College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu 225009, China; Co-Innovation Center of Jiangsu for the Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, Jiangsu 225009, China
| | - Shifeng Wang
- Center for Infectious Diseases and Vaccinology, The Biodesign Institute and School of Life Sciences, Arizona State University, Tempe, AZ 85287-5401, USA; Department of Infectious Diseases and Pathology, College of Veterinary Medicine, University of Florida, Gainesville, FL 32611-0880, USA
| | - Huoying Shi
- College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu 225009, China; Co-Innovation Center of Jiangsu for the Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, Jiangsu 225009, China.
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Galen JE, Curtiss R. The delicate balance in genetically engineering live vaccines. Vaccine 2014; 32:4376-4385. [PMID: 24370705 PMCID: PMC4069233 DOI: 10.1016/j.vaccine.2013.12.026] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2013] [Revised: 11/26/2013] [Accepted: 12/10/2013] [Indexed: 11/24/2022]
Abstract
Contemporary vaccine development relies less on empirical methods of vaccine construction, and now employs a powerful array of precise engineering strategies to construct immunogenic live vaccines. In this review, we will survey various engineering techniques used to create attenuated vaccines, with an emphasis on recent advances and insights. We will further explore the adaptation of attenuated strains to create multivalent vaccine platforms for immunization against multiple unrelated pathogens. These carrier vaccines are engineered to deliver sufficient levels of protective antigens to appropriate lymphoid inductive sites to elicit both carrier-specific and foreign antigen-specific immunity. Although many of these technologies were originally developed for use in Salmonella vaccines, application of the essential logic of these approaches will be extended to development of other enteric vaccines where possible. A central theme driving our discussion will stress that the ultimate success of an engineered vaccine rests on achieving the proper balance between attenuation and immunogenicity. Achieving this balance will avoid over-activation of inflammatory responses, which results in unacceptable reactogenicity, but will retain sufficient metabolic fitness to enable the live vaccine to reach deep tissue inductive sites and trigger protective immunity. The breadth of examples presented herein will clearly demonstrate that genetic engineering offers the potential for rapidly propelling vaccine development forward into novel applications and therapies which will significantly expand the role of vaccines in public health.
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Affiliation(s)
- James E Galen
- Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, MD 21201, USA; Division of Geographic Medicine, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
| | - Roy Curtiss
- Center for Infectious Diseases and Vaccinology, The Biodesign Institute and School of Life Sciences, Arizona State University, Tempe, AZ 85287, USA
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Cheng X, Zhang X, Zhou Y, Zhang C, Hua ZC. A Salmonella Typhimurium mutant strain capable of RNAi delivery: higher tumor-targeting and lower toxicity. Cancer Biol Ther 2014; 15:1068-76. [PMID: 24842165 DOI: 10.4161/cbt.29185] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Bacteria are highly versatile and useful tools that could deliver short interfering RNA. In this study, a phoP/phoQ double-deleted Salmonella Typhimurium named VNP(PhoP/Q(-)) based on the genetic background of VNP20009. The biological safety and function of VNP(PhoP/Q(-)) were also analyzed. Our study revealed the following results: (1) VNP(PhoP/Q(-)) exhibited lower titers in tumor-free livers and spleens than VNP20009, (2) The survival of VNP(PhoP/Q(-)) in macrophages and 4T1 tumor cells was significantly reduced compared with that of VNP20009, (3) The tumor-targeting ability of VNP(PhoP/Q(-)) was significantly enhanced compared with that of VNP20009, and the anticancer effects of VNP(pPhoP/Q(-)) and VNP20009 on tumor-bearing mice were similar, (4) VNP(PhoP/Q(-)) could release an shRNA-expressing plasmid and express the EGFP reporter gene in tumor tissue. Therefore, VNP(PhoP/Q(-)) exhibited a better safety level in tumor-free mice and elicited an anti-tumor effect on tumor-bearing mice. Moreover, VNP(PhoP/Q(-)) could release an shRNA-expressing plasmid into the cytoplasm of host cells to silence targeted genes.
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Affiliation(s)
- Xiawei Cheng
- The State Key Laboratory of Pharmaceutical Biotechnology; School of Life Science and School of Stomatology; Affiliated Stomatological Hospital; Nanjing University; Nanjing, Jiangsu, PR China
| | - Xiaoxin Zhang
- The State Key Laboratory of Pharmaceutical Biotechnology; School of Life Science and School of Stomatology; Affiliated Stomatological Hospital; Nanjing University; Nanjing, Jiangsu, PR China
| | - Yuqiang Zhou
- The State Key Laboratory of Pharmaceutical Biotechnology; School of Life Science and School of Stomatology; Affiliated Stomatological Hospital; Nanjing University; Nanjing, Jiangsu, PR China
| | - Chunmei Zhang
- The State Key Laboratory of Pharmaceutical Biotechnology; School of Life Science and School of Stomatology; Affiliated Stomatological Hospital; Nanjing University; Nanjing, Jiangsu, PR China
| | - Zi-Chun Hua
- The State Key Laboratory of Pharmaceutical Biotechnology; School of Life Science and School of Stomatology; Affiliated Stomatological Hospital; Nanjing University; Nanjing, Jiangsu, PR China; Changzhou High-Tech Research Institute of Nanjing University and Jiangsu TargetPharma Laboratories Inc.; Changzhou, Jiangsu, PR China
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MacLennan CA, Martin LB, Micoli F. Vaccines against invasive Salmonella disease: current status and future directions. Hum Vaccin Immunother 2014; 10:1478-93. [PMID: 24804797 PMCID: PMC4185946 DOI: 10.4161/hv.29054] [Citation(s) in RCA: 162] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Though primarily enteric pathogens, Salmonellae are responsible for a considerable yet under-appreciated global burden of invasive disease. In South and South-East Asia, this manifests as enteric fever caused by serovars Typhi and Paratyphi A. In sub-Saharan Africa, a similar disease burden results from invasive nontyphoidal Salmonellae, principally serovars Typhimurium and Enteritidis. The existing Ty21a live-attenuated and Vi capsular polysaccharide vaccines target S. Typhi and are not effective in young children where the burden of invasive Salmonella disease is highest. After years of lack of investment in new Salmonella vaccines, recent times have seen increased interest in the area led by emerging-market manufacturers, global health vaccine institutes and academic partners. New glycoconjugate vaccines against S. Typhi are becoming available with similar vaccines against other invasive serovars in development. With other new vaccines under investigation, including live-attenuated, protein-based and GMMA vaccines, now is an exciting time for the Salmonella vaccine field.
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Affiliation(s)
- Calman A MacLennan
- Novartis Vaccines Institute for Global Health; Siena, Italy; Medical Research Council Centre for Immune Regulation and Clinical Immunology Service; Institute of Biomedical Research, School of Immunity and Infection; College of Medicine and Dental Sciences; University of Birmingham; Birmingham, UK
| | - Laura B Martin
- Novartis Vaccines Institute for Global Health; Siena, Italy
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Sahastrabuddhe S, Carbis R, Wierzba TF, Ochiai RL. Increasing rates of Salmonella Paratyphi A and the current status of its vaccine development. Expert Rev Vaccines 2014; 12:1021-31. [PMID: 24053396 DOI: 10.1586/14760584.2013.825450] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Enteric fever caused by Salmonella enterica serovar Typhi and Salmonella enterica serovar Paratyphi is still a major disease burden mainly in developing countries. Previously, S. Typhi was believed to be the major cause of enteric fever. The real situation is now becoming clear with reports emerging from many Asian countries of S. Paratyphi, mostly S. Paratyphi A, causing a substantial number of cases of enteric fever. Although there have been advances in the use of the currently available typhoid vaccines and in the development of newer typhoid vaccines, paratyphoid vaccine development is lagging behind. Since the disease caused by S. Typhi and S. Paratyphi are clinically indistinguishable and are commonly termed 'enteric' fever, it will be necessary to have a vaccine available against both S. Typhi and S. Paratyphi A as a bivalent 'enteric fever vaccine'.
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Affiliation(s)
- Sushant Sahastrabuddhe
- International Vaccine Institute, San 4-8, Nakseongdae-dong, Gwanak-gu, Seoul, 151-919, Korea
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Dalebroux ZD, Miller SI. Salmonellae PhoPQ regulation of the outer membrane to resist innate immunity. Curr Opin Microbiol 2014; 17:106-13. [PMID: 24531506 DOI: 10.1016/j.mib.2013.12.005] [Citation(s) in RCA: 140] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Revised: 12/23/2013] [Accepted: 12/30/2013] [Indexed: 11/25/2022]
Abstract
Salmonellae sense host cues to regulate properties important for bacterial survival and replication within host tissues. The PhoPQ two-component regulatory system senses phagosome acidification and cationic antimicrobial peptides (CAMP) to regulate the protein and lipid contents of the bacterial envelope that comprises an inner and outer membrane. PhoPQ-regulated lipid components of the outer membrane include lipopolysaccharides and glycerophospholipids. Envelope proteins regulated by PhoPQ, include: components of virulence associated secretion systems, the flagellar apparatus, membrane transport systems, and proteins that are likely structural components of the outer membrane. PhoPQ alteration of the bacterial surface results in increased bacterial resistance to CAMP and decreased detection by the innate immune system. This review details the molecular complexity of the bacterial cell envelope and highlights the outer membrane lipid bilayer as an environmentally regulated bacterial organelle.
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Affiliation(s)
- Zachary D Dalebroux
- Department of Microbiology, University of Washington, Seattle, WA, United States
| | - Samuel I Miller
- Department of Microbiology, University of Washington, Seattle, WA, United States; Department of Genome Sciences, University of Washington, Seattle, WA, United States; Department of Immunology, University of Washington, Seattle, WA, United States; Department of Medicine, University of Washington, Seattle, WA, United States.
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Daudel D, Weidinger G, Spreng S. Use of attenuated bacteria as delivery vectors for DNA vaccines. Expert Rev Vaccines 2014; 6:97-110. [PMID: 17280482 DOI: 10.1586/14760584.6.1.97] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Live, attenuated bacterial vaccines (LBV) are promising candidates for the induction of a broad-based immune response directed at recombinant heterologous antigens and the corresponding pathogen. LBVs allow vaccination through the mucosal surfaces and specific targeting of professional antigen-presenting cells located at the inductive sites of the immune system. A novel approach exploits attenuated intracellular bacteria as delivery vectors for eukaryotic antigen-expression plasmids (so-called DNA vaccines). Candidate carrier bacteria include attenuated strains of Gram-positive and Gram-negative bacteria. These bacteria have been shown to deliver DNA vaccines to human cells in vitro and have also proven their in vivo efficacy in several experimental animal models of infectious diseases and different cancers. The clinical assessment of the safety, immunogenicity and efficacy of these candidate strains will be the next challenging step towards live bacterial DNA vaccines.
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Affiliation(s)
- Damini Daudel
- Berna Biotech AG, Rehhagstrasse 79, CH-3018 Berne, Switzerland.
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Abstract
BACKGROUND Typhoid fever and paratyphoid fever continue to be important causes of illness and death, particularly among children and adolescents in south-central and southeast Asia. Two typhoid vaccines are commercially available, Ty21a (oral) and Vi polysaccharide (parenteral), but neither is used routinely. Other vaccines, such as a new, modified, conjugated Vi vaccine called Vi-rEPA, are in development. OBJECTIVES To evaluate the efficacy and adverse effects of vaccines used to prevent typhoid fever. SEARCH METHODS In June 2013, we searched the Cochrane Infectious Diseases Group Specialized Register, CENTRAL, MEDLINE, EMBASE, LILACS, and mRCT. We also searched relevant conference proceedings up to 2013 and scanned the reference lists of all included trials. SELECTION CRITERIA Randomized and quasi-randomized controlled trials (RCTs) comparing typhoid fever vaccines with other typhoid fever vaccines or with an inactive agent (placebo or vaccine for a different disease). DATA COLLECTION AND ANALYSIS Two review authors independently applied inclusion criteria and extracted data. We computed vaccine efficacy per year of follow-up and cumulative three-year efficacy, stratifying for vaccine type and dose. The outcome addressed was typhoid fever, defined as isolation of Salmonella typhi in blood. We calculated risk ratios (RRs) and efficacy (1-RR as a percentage) with 95% confidence intervals (CIs). MAIN RESULTS In total, 18 RCTs were included in this review; 12 evaluated efficacy (Ty21a: five trials; Vi polysaccharide: six trials; Vi-rEPA: one trial), and 11 reported on adverse events. Ty21a vaccine (oral vaccine, three doses) A three-dose schedule of Ty21a vaccine prevents around one-third to one-half of typhoid cases in the first two years after vaccination (Year 1: 35%, 95% CI 8% to 54%; Year 2: 58%, 95% CI 40% to 71%; one trial, 20,543 participants; moderate quality evidence; data taken from a single trial conducted in Indonesia in the 1980s). No benefit was detected in the third year after vaccination. Four additional cluster-RCTs have been conducted, but the study authors did not adjust for clustering.Compared with placebo, this vaccine was not associated with more participants with vomiting, diarrhoea, nausea or abdominal pain (four trials, 2066 participants; moderate quality evidence) headache, or rash (two trials, 1190 participants; moderate quality evidence); however, fever (four trials, 2066 participants; moderate quality evidence) was more common in the vaccine group. Vi polysaccharide vaccine (injection, one dose) A single dose of Vi polysaccharide vaccine prevents around two-thirds of typhoid cases in the first year after vaccination (Year 1: 69%, 95% CI 63% to 74%; three trials, 99,979 participants; high quality evidence). In Year 2, the trial results were more variable, with the vaccine preventing between 45% and 69% of typhoid cases (Year 2: 59%, 95% CI 45% to 69%; four trials, 194,969 participants; moderate quality evidence). The three-year cumulative efficacy of the vaccine is around 55% (95% CI 30% to 70%; 11,384 participants, one trial; moderate quality evidence). These data are taken from a single trial in South Africa in the 1980s.Compared with placebo, this vaccine was not associated with more participants with fever (four trials, 133,038 participants; moderate quality evidence) or erythema (three trials, 132,261 participants; low quality evidence); however, swelling (three trials, 1767 participants; moderate quality evidence) and pain at the injection site (one trial, 667 participants; moderate quality evidence) were more common in the vaccine group. Vi-rEPA vaccine (two doses) Administration of two doses of the Vi-rEPA vaccine prevents between 50% and 96% of typhoid cases during the first two years after vaccination (Year 1: 94%, 95% CI 75% to 99%; Year 2: 87%, 95% CI 56% to 96%; one trial, 12,008 participants; moderate quality evidence). These data are taken from a single trial with children 2 to 5 years of age conducted in Vietnam.Compared with placebo, the first and second doses of this vaccine were not associated with increased risk of adverse events. The first dose of this vaccine was not associated with fever (2 studies, 12,209 participants; low quality evidence), erythema (two trials, 12,209 participants; moderate quality evidence) or swelling at the injection site (two trials, 12,209 participants; moderate quality evidence). The second dose of this vaccine was not associated with fever (two trials, 11,286 participants; low quality evidence), erythema (two trials, 11,286 participants; moderate quality evidence) and swelling at the injection site (two trials, 11,286 participants; moderate quality evidence). AUTHORS' CONCLUSIONS The licensed Ty21a and Vi polysaccharide vaccines are efficacious. The new and unlicensed Vi-rEPA vaccine is as efficacious and may confer longer immunity.
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Affiliation(s)
- Elspeth Anwar
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, UK
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Waddington CS, Darton TC, Pollard AJ. The challenge of enteric fever. J Infect 2014; 68 Suppl 1:S38-50. [DOI: 10.1016/j.jinf.2013.09.013] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/20/2013] [Indexed: 11/27/2022]
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Pati NB, Vishwakarma V, Selvaraj SK, Dash S, Saha B, Singh N, Suar M. Salmonella Typhimurium TTSS-2 deficient mig-14 mutant shows attenuation in immunocompromised mice and offers protection against wild-type Salmonella Typhimurium infection. BMC Microbiol 2013; 13:236. [PMID: 24148706 PMCID: PMC3819739 DOI: 10.1186/1471-2180-13-236] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Accepted: 09/24/2013] [Indexed: 01/06/2023] Open
Abstract
Background Development of Salmonella enterica serovar Typhimurium (S. Typhimurium) live attenuated vaccine carrier strain to prevent enteric infections has been a subject of intensive study. Several mutants of S. Typhimurium have been proposed as an effective live attenuated vaccine strain. Unfortunately, many such mutant strains failed to successfully complete the clinical trials as they were suboptimal in delivering effective safety and immunogenicity. However, it remained unclear, whether the existing live attenuated S. Typhimurium strains can further be attenuated with improved safety and immune efficacy or not. Results We deleted a specific non-SPI (Salmonella Pathogenicity Island) encoded virulence factor mig-14 (an antimicrobial peptide resistant protein) in ssaV deficient S. Typhimurium strain. The ssaV is an important SPI-II gene involved in Salmonella replication in macrophages and its mutant strain is considered as a potential live attenuated strain. However, fatal systemic infection was previously reported in immunocompromised mice like Nos2−/− and Il-10−/− when infected with ssaV deficient S. Typhimurium. Here we reported that attenuation of S. Typhimurium ssaV mutant in immunocompromised mice can further be improved by introducing additional deletion of gene mig-14. The ssaV, mig-14 double mutant was as efficient as ssaV mutant, with respect to host colonization and eliciting Salmonella-specific mucosal sIgA and serum IgG response in wild-type C57BL/6 mice. Interestingly, this double mutant did not show any systemic infection in immunocompromised mice. Conclusions This study suggests that ssaV, mig-14 double mutant strain can be effectively used as a potential vaccine candidate even in immunocompromised mice. Such attenuated vaccine strain could possibly used for expression of heterologous antigens and thus for development of a polyvalent vaccine strain.
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Affiliation(s)
| | | | | | | | | | | | - Mrutyunjay Suar
- School of Biotechnology, KIIT University, Bhubaneswar 751024, Odisha, India.
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Recombinant Salmonella enterica serovar Typhimurium as a vaccine vector for HIV-1 Gag. Viruses 2013; 5:2062-78. [PMID: 23989890 PMCID: PMC3798890 DOI: 10.3390/v5092062] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2013] [Revised: 08/05/2013] [Accepted: 08/22/2013] [Indexed: 01/30/2023] Open
Abstract
The HIV/AIDS epidemic remains a global health problem, especially in Sub-Saharan Africa. An effective HIV-1 vaccine is therefore badly required to mitigate this ever-expanding problem. Since HIV-1 infects its host through the mucosal surface, a vaccine for the virus needs to trigger mucosal as well as systemic immune responses. Oral, attenuated recombinant Salmonella vaccines offer this potential of delivering HIV-1 antigens to both the mucosal and systemic compartments of the immune system. So far, a number of pre-clinical studies have been performed, in which HIV-1 Gag, a highly conserved viral antigen possessing both T- and B-cell epitopes, was successfully delivered by recombinant Salmonella vaccines and, in most cases, induced HIV-specific immune responses. In this review, the potential use of Salmonella enterica serovar Typhimurium as a live vaccine vector for HIV-1 Gag is explored.
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Danino T, Prindle A, Hasty J, Bhatia S. Measuring growth and gene expression dynamics of tumor-targeted S. typhimurium bacteria. J Vis Exp 2013:e50540. [PMID: 23851642 DOI: 10.3791/50540] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The goal of these experiments is to generate quantitative time-course data on the growth and gene expression dynamics of attenuated S. typhimurium bacterial colonies growing inside tumors. We generated model xenograft tumors in mice by subcutaneous injection of a human ovarian cancer cell line, OVCAR-8 (NCI DCTD Tumor Repository, Frederick, MD). We transformed attenuated strains of S. typhimurium bacteria (ELH430:SL1344 phoPQ- (1)) with a constitutively expressed luciferase (luxCDABE) plasmid for visualization(2). These strains specifically colonize tumors while remaining essentially non-virulent to the mouse(1). Once measurable tumors were established, bacteria were injected intravenously via the tail vein with varying dosage. Tumor-localized, bacterial gene expression was monitored in real time over the course of 60 hours using an in vivo imaging system (IVIS). At each time point, tumors were excised, homogenized, and plated to quantitate bacterial colonies for correlation with gene expression data. Together, this data yields a quantitative measure of the in vivo growth and gene expression dynamics of bacteria growing inside tumors.
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Affiliation(s)
- Tal Danino
- Health Sciences and Technology, Massachusetts Institute of Technology
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Pascual DW, Suo Z, Cao L, Avci R, Yang X. Attenuating gene expression (AGE) for vaccine development. Virulence 2013; 4:384-90. [PMID: 23652809 PMCID: PMC3714130 DOI: 10.4161/viru.24886] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Live attenuated vaccines are adept in stimulating protective immunity. Methods for generating such vaccines have largely adopted strategies used with Salmonella enterica. Yet, when similar strategies were tested in other gram-negative bacteria, the virulence factors or genes responsible to incapacitate Salmonella often failed in providing the desired outcome. Consequently, conventional live vaccines rely on prior knowledge of the pathogen's virulence factors to successfully attenuate them. This can be problematic since such bacterial pathogens normally harbor thousands of genes. To circumvent this problem, we found that overexpression of bacterial appendages, e.g., fimbriae, capsule, and flagella, could successfully attenuate wild-type (wt) Salmonella enterica serovar Typhimurium. Further analysis revealed these attenuated Salmonella strains conferred protection against wt S. Typhimurium challenge as effectively as genetically defined Salmonella vaccines. We refer to this strategy as attenuating gene expression (AGE), a simple efficient approach in attenuating bacterial pathogens, greatly facilitating the construction of live vaccines.
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Affiliation(s)
- David W Pascual
- Department of Infectious Diseases and Pathology, College of Veterinary Medicine, University of Florida, Gainesville, FL USA.
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Evaluation of regulated delayed attenuation strategies for Salmonella enterica serovar Typhi vaccine vectors in neonatal and infant mice. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2013; 20:931-44. [PMID: 23616408 DOI: 10.1128/cvi.00003-13] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
We developed regulated delayed attenuation strategies for Salmonella vaccine vectors. In this study, we evaluated the combination of these strategies in recombinant attenuated Salmonella enterica serovar Typhi and Salmonella enterica serovar Typhimurium vaccine vectors with similar genetic backgrounds in vitro and in vivo. Our goal is to develop a vaccine to prevent Streptococcus pneumoniae infection in newborns; thus, all strains delivered a pneumococcal antigen PspA and the impact of maternal antibodies was evaluated. The results showed that all strains with the regulated delayed attenuated phenotype (RDAP) displayed an invasive ability stronger than that of the S. Typhi vaccine strain, Ty21a, but weaker than that of their corresponding wild-type parental strains. The survival curves of different RDAP vaccine vectors in vitro and in vivo exhibited diverse regulated delayed attenuation kinetics, which was different from S. Typhi Ty21a and the wild-type parental strains. Under the influence of maternal antibody, the persistence of the S. Typhimurium RDAP strain displayed a regulated delayed attenuation trend in nasal lymphoid tissue (NALT), lung, and Peyer's patches, while the persistence of S. Typhi RDAP strains followed the curve only in NALT. The bacterial loads of S. Typhi RDAP strains were lower in NALT, lung, and Peyer's patches in mice born to immune mothers than in those born to naive mothers. In accordance with these results, RDAP vaccine strains induced high titers of IgG antibodies against PspA and against Salmonella lipopolysaccharides. Immunization of mothers with S. Typhi RDAP strains enhanced the level of vaginal mucosal IgA, gamma interferon (IFN-γ), and interleukin 4 (IL-4) and resulted in a higher level of protection against S. pneumoniae challenge.
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Abstract
PURPOSE OF REVIEW This review summarizes the recent advances in vaccination against Salmonella enterica serovar Typhi and highlights the data supporting the development of next generation vaccines to address paratyphoid fever and invasive nontyphoidal Salmonella (iNTS) disease. RECENT FINDINGS There has been increasing awareness of the disease burden caused by S. Typhi particularly in Africa and greater recognition of S. Paratyphi A's contribution to enteric fever episodes throughout Asia. Groups have been working to improve the existing typhoid vaccines and provide comprehensive data on the feasibility of their implementation in endemic settings. These data have resulted in modifications to the recommendations for typhoid vaccination in traveller markets and endemic settings, and has also led to the development of S. Paratyphi A vaccine components that can be combined with existing typhoid vaccines to generate bivalent formulations against enteric fever. The epidemiology of iNTS serovars as cause of appreciable morbidity and mortality in Africa, and the need for vaccines, has also become more widely appreciated. SUMMARY Current typhoid vaccines, although moderately effective for short periods of time, cannot be used in all age groups and only target one of the clinically relevant Salmonella serovars. Greater effort must be placed on the development and implementation of improved vaccines for the disease burden resulting from Typhi, Paratyphi A or iNTS infections.
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New technologies in developing recombinant attenuated Salmonella vaccine vectors. Microb Pathog 2012; 58:17-28. [PMID: 23142647 DOI: 10.1016/j.micpath.2012.10.006] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2012] [Revised: 10/29/2012] [Accepted: 10/30/2012] [Indexed: 01/01/2023]
Abstract
Recombinant attenuated Salmonella vaccine (RASV) vectors producing recombinant gene-encoded protective antigens should have special traits. These features ensure that the vaccines survive stresses encountered in the gastrointestinal tract following oral vaccination to colonize lymphoid tissues without causing disease symptoms and to result in induction of long-lasting protective immune responses. We recently described ways to achieve these goals by using regulated delayed in vivo attenuation and regulated delayed in vivo antigen synthesis, enabling RASVs to efficiently colonize effector lymphoid tissues and to serve as factories to synthesize protective antigens that induce higher protective immune responses. We also developed some additional new strategies to increase vaccine safety and efficiency. Modification of lipid A can reduce the inflammatory responses without compromising the vaccine efficiency. Outer membrane vesicles (OMVs) from Salmonella-containing heterologous protective antigens can be used to increase vaccine efficiency. A dual-plasmid system, possessing Asd+ and DadB+ selection markers, each specifying a different protective antigen, can be used to develop multivalent live vaccines. These new technologies have been adopted to develop a novel, low-cost RASV synthesizing multiple protective pneumococcal protein antigens that could be safe for newborns/infants and induce protective immunity to diverse Streptococcus pneumoniae serotypes after oral immunization.
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Danino T, Lo J, Prindle A, Hasty J, Bhatia SN. In Vivo Gene Expression Dynamics of Tumor-Targeted Bacteria. ACS Synth Biol 2012; 1:465-470. [PMID: 23097750 PMCID: PMC3477096 DOI: 10.1021/sb3000639] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2012] [Indexed: 01/29/2023]
Abstract
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The engineering of bacteria to controllably deliver therapeutics
is an attractive application for synthetic biology. While most synthetic
gene networks have been explored within microbes, there is a need
for further characterization of in vivo circuit behavior
in the context of applications where the host microbes are actively
being investigated for efficacy and safety, such as tumor drug delivery.
One major hurdle is that culture-based selective pressures are absent in vivo, leading to strain-dependent instability of plasmid-based
networks over time. Here, we experimentally characterize the dynamics
of in vivo plasmid instability using attenuated strains
of S. typhimurium and real-time monitoring of luminescent
reporters. Computational modeling described the effects of growth
rate and dosage on live-imaging signals generated by internal bacterial
populations. This understanding will allow us to harness the transient
nature of plasmid-based networks to create tunable temporal release
profiles that reduce dosage requirements and increase the safety of
bacterial therapies.
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Affiliation(s)
- Tal Danino
- Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, Massachusetts
02139, United States
| | - Justin Lo
- Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, Massachusetts
02139, United States
| | | | | | - Sangeeta N. Bhatia
- Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, Massachusetts
02139, United States
- Broad Institute of Harvard and MIT, Cambridge, Massachusetts 02142,
United States
- Department
of Medicine, Brigham and Women’s Hospital, Boston, Massachusetts
02115, United States
- Electrical
Engineering and Computer
Science and David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Massachusetts
02139, United States
- Howard Hughes Medical Institute, Chevy Chase, Maryland 20815, United States
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Prindle A, Selimkhanov J, Danino T, Samayoa P, Goldberg A, Bhatia SN, Hasty J. Genetic Circuits in Salmonella typhimurium. ACS Synth Biol 2012; 1:458-464. [PMID: 23097749 PMCID: PMC3477097 DOI: 10.1021/sb300060e] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2012] [Indexed: 01/31/2023]
Abstract
Synthetic biology has rapidly progressed over the past decade and is now positioned to impact important problems in health and energy. In the clinical arena, the field has thus far focused primarily on the use of bacteria and bacteriophages to overexpress therapeutic gene products. The next generation of multigene circuits will control the triggering, amplitude, and duration of therapeutic activity in vivo. This will require a host organism that is easy to genetically modify, leverages existing successful circuit designs, and has the potential for use in humans. Here, we show that gene circuits that were originally constructed and tested in Escherichia coli translate to Salmonella typhimurium, a therapeutically relevant microbe with attenuated strains that have exhibited safety in several human clinical trials. These strains are essentially nonvirulent, easy to genetically program, and specifically grow in tumor environments. Developing gene circuits on this platform could enhance our ability to bring sophisticated genetic programming to cancer therapy, setting the stage for a new generation of synthetic biology in clinically relevant microbes.
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Affiliation(s)
- Arthur Prindle
- Department of Bioengineering, University of California, San Diego, San Diego, California,
United States
| | - Jangir Selimkhanov
- Department of Bioengineering, University of California, San Diego, San Diego, California,
United States
| | - Tal Danino
- Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, Massachusetts
02139, United States
| | - Phillip Samayoa
- Bioinformatics
Program, University of California, San Diego, La Jolla, California,
United States
| | - Anna Goldberg
- Department of Bioengineering, University of California, San Diego, San Diego, California,
United States
| | - Sangeeta N. Bhatia
- Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, Massachusetts
02139, United States
| | - Jeff Hasty
- Department of Bioengineering, University of California, San Diego, San Diego, California,
United States
- Bioinformatics
Program, University of California, San Diego, La Jolla, California,
United States
- BioCircuits
Institute, University of California, San Diego, San Diego, California,
United States
- Molecular
Biology Section, Division
of Biological Science, University of California, San Diego, La Jolla, California 92093, United States
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Unnikrishnan M, Rappuoli R, Serruto D. Recombinant bacterial vaccines. Curr Opin Immunol 2012; 24:337-42. [PMID: 22541723 DOI: 10.1016/j.coi.2012.03.013] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2012] [Accepted: 03/19/2012] [Indexed: 01/09/2023]
Abstract
Vaccines are currently available for many infectious diseases caused by several microbes and the prevention of disease and death by vaccination has profoundly improved public health globally. However, vaccines are not yet licensed for use against many other infectious diseases and new or improved vaccines are needed to replace suboptimal vaccines, and against newly emerging pathogens. Most of the vaccines currently licensed for human use include live attenuated and inactivated or killed microorganisms. Only a small subset is based on purified components and even fewer are recombinantly produced. Novel approaches in recombinant DNA technology, genomics and structural biology have revolutionized the way vaccine candidates are developed and will make a significant impact in the generation of safer and more effective vaccines.
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Affiliation(s)
- Meera Unnikrishnan
- Novartis Vaccines and Diagnostics, Via Fiorentina 1, 53100, Siena, Italy
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Galen JE, Simon R, Ernst RK. Salmonella expressing detoxified lipopolysaccharide is immunogenic and protective both as an attenuated vaccine and for delivery of foreign antigens. Expert Rev Vaccines 2012; 10:1679-82. [PMID: 22085171 DOI: 10.1586/erv.11.155] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The construction of safe and protective vaccines, derived from human pathogens that have been genetically modified to remove pathogenicity, is often easier to accomplish on paper than it is in the laboratory. Kong and colleagues have pursued a clever strategy to reduce the reactogenicity of attenuated Salmonella oral vaccines by genetically modifying the surface lipopolysaccharide to lower endotoxic activity. The resulting candidate vaccine strains were highly reduced in virulence yet were able to confer protection in a mouse model against challenge with virulent Salmonella. Remarkably, these strains could also be further modified to present foreign antigens from unrelated human pathogens and again confer protection against heterologous challenge. This work brings important new tools to bear on solving the problem of creating efficacious attenuated bacterial vaccines that maximize both safety and immunogenicity in clinical trials.
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Affiliation(s)
- James E Galen
- Center for Vaccine Development, University of Maryland, Baltimore, MD 21201, USA.
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36
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Kawasaki K. Complexity of lipopolysaccharide modifications in Salmonella enterica: Its effects on endotoxin activity, membrane permeability, and resistance to antimicrobial peptides. Food Res Int 2012. [DOI: 10.1016/j.foodres.2011.01.026] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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Abstract
Salmonella enterica is an invasive, facultative intracellular gastrointestinal pathogen causing human diseases such as gastroenteritis and typhoid fever. Virulence-attenuated strains of this pathogen have interesting capacities for the generation of live vaccines. Attenuated live typhoidal and nontyphoidal Salmonella strains can be used for vaccination against Salmonella infections and to target tumor tissue. Such strains may also serve as live carriers for the development of vaccination strategies against other bacterial, viral or parasitic pathogens. Various strategies have been developed to deploy regulatory circuits and protein secretion systems for efficient expression and delivery of foreign antigens by Salmonella carrier strains. One prominent example is the use of type III secretion systems to translocate recombinant antigens into antigen presenting cells. In this review, we will describe the recent developments in strategies that utilize live attenuated Salmonella as vaccine carriers for prophylactic vaccination against infectious diseases and therapeutic vaccination against tumors. Considerations for generating safe, attenuated carrier strains, designing stable expression systems and the use of adjuvants for live carrier strategies are discussed.
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Affiliation(s)
- Wael Abdel Halim Hegazy
- Abteilung Mikrobiologie, Fachbereich Biologie/Chemie, Universität Osnabrück Barbarastrasse 11, 49076 Osnabrück, Germany
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Sun W, Roland KL, Curtiss R. Developing live vaccines against plague. J Infect Dev Ctries 2011; 5:614-27. [PMID: 21918302 PMCID: PMC3932668 DOI: 10.3855/jidc.2030] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2011] [Revised: 05/20/2011] [Accepted: 05/22/2011] [Indexed: 12/13/2022] Open
Abstract
Three great plague pandemics caused by the gram-negative bacterium Yersinia pestis have killed nearly 200 million people and it has been linked to biowarfare in the past. Plague is endemic in many parts of the world. In addition, the risk of plague as a bioweapon has prompted increased research to develop plague vaccines against this disease. Injectable subunit vaccines are being developed in the United States and United Kingdom. However, the live attenuated Y. pestis-EV NIIEG strain has been used as a vaccine for more than 70 years in the former Soviet Union and in some parts of Asia and provides a high degree of efficacy against plague. This vaccine has not gained general acceptance because of safety concerns. In recent years, modern molecular biological techniques have been applied to Y. pestis to construct strains with specific defined mutations designed to create safe, immunogenic vaccines with potential for use in humans and as bait vaccines to reduce the load of Y. pestis in the environment. In addition, a number of live, vectored vaccines have been reported using attenuated viral vectors or attenuated Salmonella strains to deliver plague antigens. Here we summarize the progress of live attenuated vaccines against plagu.
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Affiliation(s)
- Wei Sun
- Center for Infectious Disease and Vaccinology, The Biodesign Institute and School of Life Sciences, Arizona State University, Tempe, AZ 85287-5401 , USA
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Homology modeling, molecular dynamics and QM/MM study of the regulatory protein PhoP from Corynebacterium pseudotuberculosis. J Mol Model 2011; 18:1219-27. [PMID: 21701810 DOI: 10.1007/s00894-011-1145-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2011] [Accepted: 06/01/2011] [Indexed: 10/18/2022]
Abstract
Corynebacterium pseudotuberculosis is a facultatively intracellular Gram-positive bacterium that causes caseous lymphadenitis, principally in sheep and goats, though sometimes in other species of animals, leading to considerable economic losses. This pathogen has a TCS known as PhoPR, which consists of a sensory histidine kinase protein (PhoR) and an intracellular response regulator protein (PhoP). This system is involved in the regulation of proteins present in various processes, including virulence. The regulation is activated by PhoP protein phosphorylation, an event that requires a magnesium (Mg(2+)) ion. Here we describe the 3D structure of the regulatory response protein (PhoP) of C. pseudotuberculosis through molecular modeling by homology. The model generated provides the first structural information on a full-length member of the OmpR/PhoP subfamily. Classical molecular dynamics was used to investigate the stability of the model. In addition, we used quantum mechanical/molecular mechanical techniques to perform (internal, potential) energy optimizations to determine the interaction energy between the Mg(2+) ion and the structure of the PhoP protein. Analysis of the interaction energy residue by residue shows that Asp-16 and Asp-59 play an important role in the protein-Mg(2+) ion interactions. These results may be useful for the future development of a new vaccine against tuberculosis based on genetic attenuation via a point mutation that results in the polar residue Asp-16 and/or Asp-59 being replaced with a nonpolar residue in the DNA-binding domain of PhoP of C. pseudotuberculosis.
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Liu CJ, Jin JD, Lv TD, Wu ZZ, Ha XQ. Keratinocyte growth factor gene therapy ameliorates ulcerative colitis in rats. World J Gastroenterol 2011; 17:2632-40. [PMID: 21677832 PMCID: PMC3110926 DOI: 10.3748/wjg.v17.i21.2632] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2010] [Revised: 03/23/2011] [Accepted: 03/30/2011] [Indexed: 02/06/2023] Open
Abstract
AIM: To investigate the effect of keratinocyte growth factor (KGF) gene therapy in acetic acid-induced ulcerative colitis in rat model.
METHODS: The colitis of Sprague-Dawley rats was induced by intrarectal infusion of 1 mL 5% (v/v) acetic acid. Twenty-four hours after exposed to acetic acid, rats were divided into three experimental groups: control group, attenuated Salmonella typhimurium Ty21a strain (SP) group and SP strain carrying human KGF gene (SPK) group, and they were separately administered orally with 10% NaHCO3, SP or SPK. Animals were sacrificed and colonic tissues were harvested respectively on day 3, 5, 7 and 10 after administration. Weights of rats, colonic weight/length ratio and stool score were evaluated. Histological changes of colonic tissues were examined by hematoxylin and eosin (HE) staining method. The expression of KGF, KGF receptor (KGFR) and TNF-α were measured either by enzyme-linked immunosorbent assay or Western blotting. Immunohistochemistry was used to detect the cellular localization of KGFR and Ki67. In addition, superoxide dismutase (SOD) activity and malondialdehyde (MDA) contents in the homogenate were measured.
RESULTS: Body weight and colonic weight/length ratio were declined in SPK group compared with SP and control groups (body weight: 272.78 ± 17.92 g vs 243.72 ± 14.02 g and 240.68 ± 12.63 g, P < 0.01; colonic weight/length ratio: 115.76 ± 7.47 vs 150.32 ± 5.99 and 153.67 ± 5.50 mg/cm, P < 0.01). Moreover, pathological changes of damaged colon were improved in SPK group as well. After administration of SPK strain, KGF expression increased markedly from the 3rd d, and remained at a high level till the 10th d. Furthermore, KGFR expression and Ki67 expression elevated, whereas TNF-α expression was inhibited in SPK group. In the group administered with SPK, SOD activity increased significantly (d 5: 26.18 ± 5.84 vs 18.12 ± 3.30 and 18.79 ± 4.74 U/mg, P < 0.01; d 7: 35.48 ± 3.35 vs 22.57 ± 3.44 and 21.69 ± 3.94 U/mg, P < 0.01; d 10: 46.10 ± 6.23 vs 25.35 ± 4.76 and 27.82 ± 6.42 U/mg, P < 0.01) and MDA contents decreased accordingly (d 7: 7.40 ± 0.88 vs 9.81 ± 1.21 and 10.45 ± 1.40 nmol/mg, P < 0.01; d 10: 4.36 ± 0.62 vs 8.41 ± 0.92 and 8.71 ± 1.27 nmol/mg, P < 0.01), compared with SP and control groups.
CONCLUSION: KGF gene therapy mediated by attenuated Salmonella ameliorates ulcerative colitis induced by acetic acids, and it may be a safe and effective treatment for ulcerative colitis.
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Comparison of a regulated delayed antigen synthesis system with in vivo-inducible promoters for antigen delivery by live attenuated Salmonella vaccines. Infect Immun 2010; 79:937-49. [PMID: 21134969 DOI: 10.1128/iai.00445-10] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Induction of strong immune responses against a vectored antigen in hosts immunized with live attenuated Salmonella vaccines is related in part to the amount of antigen delivered and the overall fitness of the Salmonella vector in relation to its ability to stimulate the host immune system. Constitutive high-level antigen synthesis causes a metabolic burden to the vaccine vector strain that can reduce the vaccine strain's ability to interact with host lymphoid tissues, resulting in a compromised immune response. A solution to this problem is the use of systems that regulate antigen gene expression, permitting high levels of antigen synthesis only after the vaccine strain has reached its target tissues. In vivo-inducible promoters (IVIPs) are often used to accomplish this. We recently developed an alternative strategy, a regulated delayed antigen synthesis (RDAS) system, in which the LacI-repressible P(trc) promoter controls antigen gene expression by adding arabinose. In this paper, we compared the RDAS system with two commonly used IVIPs, P(ssaG) and P(pagC). Three nearly identical plasmids, differing only in the promoter used to direct transcription of the pneumococcal pspA gene, P(trc), P(ssaG), or P(pagC), were constructed and introduced into isogenic Salmonella vaccine strains with or without arabinose-inducible LacI synthesis. Mice immunized with the RDAS strain developed slightly higher titers of mucosal and serum anti-PspA antibodies than P(pagC)-immunized mice, while titers in mice immunized with the P(ssaG) strain were 100-fold lower. Both the RDAS and P(pagC) strains conferred similar levels of protection against Streptococcus pneumoniae challenge, significantly greater than those for the P(ssaG) strain or controls. Thus, RDAS provides another choice for inclusion in the live vaccine design to increase immunogenicity.
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Abstract
Salmonella enterica are Gram-negative enteric pathogens that cause typhoid fever and gastroenteritis in humans. Many bacteria, including Salmonella, use signal transduction cascades such as two-component regulatory systems to detect and respond to stimuli in the local microenvironment. During infection, environmental sensing allows bacteria to regulate gene expression to evade host immune defenses and thrive in vivo. Activation of the Salmonella two-component regulatory systems PhoP-PhoQ and PmrA-PmrB and the RcsC-RcsD-RcsB phosphorylay by specific environmental signals in the intestine and within host cells leads to several lipopolysaccharide modifications that promote bacterial survival, cationic antimicrobial peptide resistance and virulence. Many pathogens encode orthologs to Salmonella two-component regulatory systems and also modify the lipopolysaccharide to escape killing by the host immune response. However, these organisms often regulate their virulence genes, including those responsible for lipopolysaccharide modification, in ways that differ from Salmonella. Further examination of bacterial virulence gene regulation and lipopolysaccharide modifications may lead to improved antimicrobial therapies and vaccines.
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Shi H, Santander J, Brenneman KE, Wanda SY, Wang S, Senechal P, Sun W, Roland KL, Curtiss R. Live recombinant Salmonella Typhi vaccines constructed to investigate the role of rpoS in eliciting immunity to a heterologous antigen. PLoS One 2010; 5:e11142. [PMID: 20585446 PMCID: PMC2887840 DOI: 10.1371/journal.pone.0011142] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2010] [Accepted: 05/27/2010] [Indexed: 11/18/2022] Open
Abstract
We hypothesized that the immunogenicity of live Salmonella enterica serovar Typhi vaccines expressing heterologous antigens depends, at least in part, on its rpoS status. As part of our project to develop a recombinant attenuated S. Typhi vaccine (RASTyV) to prevent pneumococcal diseases in infants and children, we constructed three RASTyV strains synthesizing the Streptococcus pneumoniae surface protein PspA to test this hypothesis. Each vector strain carried ten engineered mutations designed to optimize safety and immunogenicity. Two S. Typhi vector strains (chi9639 and chi9640) were derived from the rpoS mutant strain Ty2 and one (chi9633) from the RpoS(+) strain ISP1820. In chi9640, the nonfunctional rpoS gene was replaced with the functional rpoS gene from ISP1820. Plasmid pYA4088, encoding a secreted form of PspA, was moved into the three vector strains. The resulting RASTyV strains were evaluated for safety in vitro and for immunogenicity in mice. All three RASTyV strains were similar to the live attenuated typhoid vaccine Ty21a in their ability to survive in human blood and human monocytes. They were more sensitive to complement and were less able to survive and persist in sewage and surface water than their wild-type counterparts. Adult mice intranasally immunized with any of the RASTyV strains developed immune responses against PspA and Salmonella antigens. The RpoS(+) vaccines induced a balanced Th1/Th2 immune response while the RpoS(-) strain chi9639(pYA4088) induced a strong Th2 immune response. Immunization with any RASTyV provided protection against S. pneumoniae challenge; the RpoS(+) strain chi9640(pYA4088) provided significantly greater protection than the ISP1820 derivative, chi9633(pYA4088). In the pre-clinical setting, these strains exhibited a desirable balance between safety and immunogenicity and are currently being evaluated in a Phase 1 clinical trial to determine which of the three RASTyVs has the optimal safety and immunogenicity profile in human hosts.
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Affiliation(s)
- Huoying Shi
- Center for Infectious Diseases and Vaccinology, The Biodesign Institute and School of Life Sciences, Arizona State University, Tempe, Arizona, United States of America
| | - Javier Santander
- Center for Infectious Diseases and Vaccinology, The Biodesign Institute and School of Life Sciences, Arizona State University, Tempe, Arizona, United States of America
| | - Karen E. Brenneman
- Center for Infectious Diseases and Vaccinology, The Biodesign Institute and School of Life Sciences, Arizona State University, Tempe, Arizona, United States of America
| | - Soo-Young Wanda
- Center for Infectious Diseases and Vaccinology, The Biodesign Institute and School of Life Sciences, Arizona State University, Tempe, Arizona, United States of America
| | - Shifeng Wang
- Center for Infectious Diseases and Vaccinology, The Biodesign Institute and School of Life Sciences, Arizona State University, Tempe, Arizona, United States of America
| | | | - Wei Sun
- Center for Infectious Diseases and Vaccinology, The Biodesign Institute and School of Life Sciences, Arizona State University, Tempe, Arizona, United States of America
| | - Kenneth L. Roland
- Center for Infectious Diseases and Vaccinology, The Biodesign Institute and School of Life Sciences, Arizona State University, Tempe, Arizona, United States of America
| | - Roy Curtiss
- Center for Infectious Diseases and Vaccinology, The Biodesign Institute and School of Life Sciences, Arizona State University, Tempe, Arizona, United States of America
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Abstract
RNAi is a powerful research tool for specific gene silencing and may also lead to promising novel therapeutic strategies. However, the development of RNAi-based therapies has been slow due to the lack of targeted delivery methods. The biggest challenge in the use of siRNA-based therapies is the delivery to target cells. There are many additional obstacles to in vivo delivery of siRNAs, such as degradation by endogenous enzymes and interaction with blood components leading to nonspecific uptake into cells, which govern biodistribution and availability of siRNA in the body. Naked unmodified synthetic siRNA including plasmid-carried-shRNA-expression constructs cannot penetrate cellular membranes, and therefore, systemic application is unlikely to be successful. The success of gene therapy by siRNAs relies on the development of safe, economical, and efficacious in vivo delivery systems into the target cells. Attenuated Salmonella have been employed recently as vectors to deliver silencing hairpin RNA (shRNA) expression plasmids into mammalian cells. This approach has achieved gene silencing in vitro and in vivo. The facultative anaerobic, invasive Salmonella have a natural tropism for solid tumors including metastatic tumors. Genetically modified, attenuated Salmonella have been used recently both as potential antitumor agents by themselves, and to deliver specific tumoricidal therapies. This chapter describes the use of attenuated bacteria as tumor-targeting delivery systems for cancer therapy.
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Evaluation of new generation Salmonella enterica serovar Typhimurium vaccines with regulated delayed attenuation to induce immune responses against PspA. Proc Natl Acad Sci U S A 2008; 106:593-8. [PMID: 19114649 DOI: 10.1073/pnas.0811697106] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Increasing the immunogenicity to delivered antigens by recombinant attenuated Salmonella vaccines (RASV) has been the subject of intensive study. With this goal in mind, we have designed and constructed a new generation of RASV that exhibit regulated delayed attenuation. These vaccine strains are phenotypically wild type at the time of immunization and become attenuated after colonization of host tissues. The vaccine strains are grown under conditions that allow expression of genes required for optimal invasion and colonization of host tissues. Once established in the host, these virulence genes are turned off, fully attenuating the vaccine strain. In this study, we compared 2 of our newly developed regulated delayed attenuation Salmonella enterica serovar Typhimurium strains chi9088 and chi9558 with the Deltacya Deltacrp Deltaasd strain chi8133, for their abilities to express and present a secreted form of the alpha-helical region of pneumococcal surface protein A (PspA) to the mouse immune system. All 3 strains induced high levels of serum antibodies specific for PspA as well as to Salmonella antigens in orally immunized mice. However, both RASVs expressing delayed attenuation elicited significantly greater anti-PspA immune responses, including serum IgG and T cell secretion of IL-4 and IFN-gamma, than other groups. Also, vaccination with delayed attenuation strains resulted in a greater degree of protection against Streptococcus pneumoniae challenge than in mice vaccinated with chi8133 (71-86% vs. 21% survival, P </= 0.006). Together, the results demonstrate that the regulated attenuation strategy results in highly immunogenic antigen delivery vectors for oral vaccination.
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A sopB deletion mutation enhances the immunogenicity and protective efficacy of a heterologous antigen delivered by live attenuated Salmonella enterica vaccines. Infect Immun 2008; 76:5238-46. [PMID: 18765737 DOI: 10.1128/iai.00720-08] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
SopB is a virulence factor of Salmonella encoded by SPI-5. Salmonella sopB deletion mutants are impaired in their ability to cause local inflammatory responses and fluid secretion into the intestinal lumen and also can enhance the immunogenicity of a vectored antigen. In this study, we evaluated the effects on immunogenicity and the efficacy of a sopB deletion mutation on two Salmonella enterica serovar Typhimurium vaccine strains with different attenuating mutations expressing a highly antigenic alpha-helical region of the Streptococcus pneumoniae surface protein PspA from an Asd(+)-balanced lethal plasmid. After oral administration to mice, the two pairs of strains induced high levels of serum antibodies specific for PspA as well as to Salmonella antigens. The levels of antigen-specific serum immunoglobulin G (IgG) and mucosal IgA were higher in mice immunized with sopB mutants. Enzyme-linked immunospot assay results indicated that the spleen cells from mice immunized with a sopB mutant showed higher interleukin-4 and gamma interferon secretion levels than did the mice immunized with the isogenic sopB(+) strain. The sopB mutants also induced higher numbers of CD4(+) CD44(hi) CD62L(hi) and CD8(+) CD44(hi) CD62L(hi) central memory T cells. Eight weeks after primary oral immunization, mice were challenged with 100 50% lethal doses of virulent S. pneumoniae WU2. Immunization with either of the sopB mutant strains led to increased levels of protection compared to that with the isogenic sopB(+) parent. Together, these results demonstrate that the deletion of sopB leads to an overall enhancement of the immunogenicity and efficacy of recombinant attenuated Salmonella vaccine strains.
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Wahid R, Salerno-Gonçalves R, Tacket CO, Levine MM, Sztein MB. Generation of specific effector and memory T cells with gut- and secondary lymphoid tissue- homing potential by oral attenuated CVD 909 typhoid vaccine in humans. Mucosal Immunol 2008; 1:389-98. [PMID: 19079203 PMCID: PMC3215293 DOI: 10.1038/mi.2008.30] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Induction of effective memory T cells is likely to be critical to the level and duration of protection elicited by novel live oral typhoid vaccines. Using cells from volunteers who ingested Salmonella Typhi vaccine strain CVD 909, we characterized the induction of interferon (IFN)-gamma-secreting central (T(CM), CD45RO(+)CD62L(+)) and effector (T(EM), CD45RO(+)CD62L(-)) memory T populations, and their gut-homing potential based on integrin alpha4/beta7 expression. Both CD4(+) T(EM) and T(CM) populations secreted IFN-gamma. However, although CD4(+) T(EM) expressed, or not, integrin alpha(4)/beta(7), CD4(+) T(CM) cells were predominantly integrin alpha(4)/beta(7)(+). In contrast, IFN-gamma-secreting CD8(+) cells were predominantly classical T(EM) and CD45RA(+) T(EM) (T(EMRA), CD45RO(-)CD62L(-)) subsets. However, although CD8(+) T(EM) expressed, or not, integrin alpha(4)/beta(7), CD8(+) T(EMRA) were predominantly integrin alpha(4)/beta(7)(+). This is the first demonstration that oral immunization of humans with S. Typhi elicits diverse IFN-gamma-secreting CD4(+) and CD8(+) T(CM) and T(EM) subsets able to migrate to the gut and other lymphoid tissues.
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Affiliation(s)
- R Wahid
- Department of Pediatrics, Center for Vaccine Development, University of Maryland, Baltimore, Maryland, USA
| | - R Salerno-Gonçalves
- Department of Pediatrics, Center for Vaccine Development, University of Maryland, Baltimore, Maryland, USA
| | - CO Tacket
- Department of Medicine, University of Maryland, Baltimore, Maryland, USA
| | - MM Levine
- Department of Pediatrics, Center for Vaccine Development, University of Maryland, Baltimore, Maryland, USA
- Department of Medicine, University of Maryland, Baltimore, Maryland, USA
| | - MB Sztein
- Department of Pediatrics, Center for Vaccine Development, University of Maryland, Baltimore, Maryland, USA
- Department of Medicine, University of Maryland, Baltimore, Maryland, USA
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Domínguez-Bernal G, Tierrez A, Bartolomé A, Martínez-Pulgarín S, Salguero FJ, Orden JA, de la Fuente R. Salmonella enterica serovar Choleraesuis derivatives harbouring deletions in rpoS and phoP regulatory genes are attenuated in pigs, and survive and multiply in porcine intestinal macrophages and fibroblasts, respectively. Vet Microbiol 2008; 130:298-311. [PMID: 18313237 DOI: 10.1016/j.vetmic.2008.01.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2007] [Revised: 01/16/2008] [Accepted: 01/18/2008] [Indexed: 10/22/2022]
Abstract
Live attenuated Salmonella enterica strains have been extensively studied as potential vectors for the oral delivery of heterologous antigens. Due to its ability to target immune cells, its specific mechanism for crossing the intestinal barrier, and its swine-restricted tropism, S. enterica subspecies enterica serovar Choleraesuis (S. Choleraesuis) has attracted a great deal of interest for the production of bacterial-based oral carriers specifically adapted to swine. In this study, two mutants of S. Choleraesuis were constructed and their attenuation and intracellular fate analysed with the purpose of engineering new attenuated live strains with improved properties as oral vaccine carriers. Those strains harboured a specific deletion either within the phoP or rpoS genes, which encode virulence-related regulators in S. Typhimurium. In comparison to the wild-type parental S. Choleraesuis, the mutant strains, especially DeltaphoP, were extremely low in virulence in the murine model and in the natural host, the pig. Moreover, when compared with a commercial live vaccine strain, SC-54, the two mutants showed a higher level of attenuation in mice and DeltaphoP also in pigs. In addition, DeltarpoS and DeltaphoP presented a proliferation and survival phenotype within swine intestinal primary fibroblast and macrophage cell cultures, respectively. Collectively, the present results indicate that the DeltarpoS and DeltaphoP strains of S. Choleraesuis gather adequate features to be potential candidates for vaccine vectors for the specific delivery of heterologous antigens adapted to pigs.
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Affiliation(s)
- Gustavo Domínguez-Bernal
- Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad Complutense de Madrid, Avda Puerta de Hierro s/n, Madrid, Spain.
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Lee HY, Cho SA, Lee IS, Park JH, Seok SH, Baek MW, Kim DJ, Lee SH, Hur SJ, Ban SJ, Lee YK, Han YK, Cho YK, Park JH. Evaluation of phoP and rpoS mutants of Salmonella enterica serovar Typhi as attenuated typhoid vaccine candidates: virulence and protective immune responses in intranasally immunized mice. ACTA ACUST UNITED AC 2007; 51:310-8. [PMID: 17725620 DOI: 10.1111/j.1574-695x.2007.00307.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The attenuation and immunoenhancing effects of rpoS and phoP Salmonella enterica serovar strain Typhi (Salmonella typhi) mutants have not been compared. Here, three S. typhi deletion mutants (phoP, rpoS, and rpoS-phoP double mutant) are constructed and these mutants are characterized with respect to invasiveness, virulence, and protective immune response compared with wild-type Ty2. It was found that phoP and phoP-rpoS deletion mutants are less invasive to HT-29 cells than the wild-type Ty2 and the rpoS single-deleted strain. The LD(50) of immunized mice was higher for phoP than for rpoS mutants, and the highest for the phoP-rpoS double mutant. In addition, all S. typhi mutants showed an increase in the specific serum IgG levels and T-cell-mediated immunity, and showed equal protection abilities against a wild-type Ty2 challenge after two rounds of immunization in BALB/c mice. It is concluded that phoP genes appear to play a more important role than rpoS genes in both cellular invasion and virulence of S. typhi, but not in immunogenicity in mice. Furthermore, the data indicate that the phoP-rpoS double mutant may show promise as a candidate for an attenuated typhoid vaccine.
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Affiliation(s)
- Hui-Young Lee
- Department of Laboratory Animal Medicine, College of Veterinary Medicine, Seoul National University, Gwanak-gu, Seoul, Korea
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