• 32070182 National Natural Science Foundation of China
• ZD2021049 Jiangsu Commission of Health

Stroma–cancer cell crosstalk involves a complex signaling network that contributes to tumor progression, including carcinogenesis, angiogenesis, migration, invasion, and therapy resistance in cancers. Exosomes, as extracellular membranous nanovesicles released by almost all types of cells, including tumor cells and stromal cells, play a critical role in signal delivery and material communication, in which the characteristics of their parent cells are reflected. The tumor or stroma-derived exosomes mediate cell–cell communication in the tumor microenvironment by transporting DNA, RNA, proteins, lipids, and metabolites. Recent studies on head and neck squamous cell carcinoma (HNSCC) have demonstrated that tumor-derived exosomes support various tumor biological behaviors, whereas the functional roles of stroma-derived exosomes remain largely unknown. Although these exosomes are emerging as promising targets in early diagnosis, prognostic prediction, and pharmaceutical carriers for antitumor therapy, there are still multiple hurdles to be overcome before they can be used in clinical applications. Herein, we systematically summarize the promotive roles of the epithelium and stroma-derived exosomes in HNSCC and highlight the potential clinical applications of exosomes in the treatment of HNSCC.

• extracellular vesicles
• nasopharyngeal carcinoma
• therapeutic resistance
• tumor microenvironment

• 81672761 National Natural Science Foundation of China
• 2020JJ5957 Natural Science Foundation of Hunan Province for Young Scholar

• Biological functions
• Diagnostic monitoring
• Exosomes
• Nasopharyngeal carcinoma
• Prognostic evaluation

• Exosomes
• miRNA
• nasopharyngeal carcinoma

Exosomes are nanoscale membrane vesicles, which carry biologically active substances of their cell of origin and play an important role in signal transduction and intercellular communication. At present, exosomes have been identified as a promising non-invasive liquid biopsy biomarker in the tissues and circulating blood of nasopharyngeal carcinoma (NPC) and found to participate in regulating pathophysiological process of the tumor. We here review recent insights gained into the molecular mechanisms of exosome-induced cell growth, angiogenesis, metastasis, immunosuppression, radiation resistance and chemotherapy resistance in the development and progression of NPC, as well as the clinical application of exosomes as diagnostic biomarkers and therapeutic agents. We also discuss the limitations and challenges in exosome application. We hope this review may provide some references for the use of exosomes in clinical intervention.

• NPC
• angiogenesis
• exosomes
• tumor metastasis

• Drug resistance
• EXOs
• Extracellular vesicles
• Head and neck squamous cell carcinoma
• Tumour microenvironment

• Antineoplastic Agents/pharmacology
• Antineoplastic Agents/therapeutic use
• Drug Resistance, Neoplasm
• Extracellular Vesicles/metabolism
• Head and Neck Neoplasms/drug therapy
• Head and Neck Neoplasms/metabolism
• Head and Neck Neoplasms/pathology
• Humans
• Squamous Cell Carcinoma of Head and Neck/drug therapy
• Squamous Cell Carcinoma of Head and Neck/metabolism
• Squamous Cell Carcinoma of Head and Neck/pathology
• Tumor Microenvironment

• EBV
• gastric cancer
• lncRNA
• miRNA
• nasopharyngeal carcinoma

• exosomes
• extracellular vesicles
• herpes simplex type 1
• herpesvirus
• microvesicles
• viral spread

• Animals
• Antiviral Agents/pharmacology
• Extracellular Vesicles/genetics
• Extracellular Vesicles/immunology
• Extracellular Vesicles/virology
• Herpes Simplex/genetics
• Herpes Simplex/immunology
• Herpes Simplex/virology
• Herpesvirus 1, Human/genetics
• Herpesvirus 1, Human/physiology
• Humans

• diagnostic biomarkers
• exosomes
• host response
• miRNAs
• therapeutic targets
• viral infections

• DNA Viruses/genetics
• DNA Viruses/physiology
• Exosomes/genetics
• Membrane Lipids/metabolism
• MicroRNAs/genetics
• MicroRNAs/metabolism
• RNA Viruses/physiology
• Virus Diseases/genetics

• R01 AI050875 NIAID NIH HHS
• R21 AI121700 NIAID NIH HHS

Epstein-Barr virus (EBV) is a ubiquitous human γ-herpesvirus that infects over 90% of the global population. EBV is considered a contributory factor in a variety of malignancies including nasopharyngeal carcinoma, gastric carcinoma, Burkitt lymphoma, and Hodgkin’s lymphoma. Notably, EBV was the first virus found to encode microRNAs (miRNAs). Increasing evidence indicates that EBV-encoded miRNAs contribute to the carcinogenesis and development of EBV-associated malignancies. EBV miRNAs have been shown to inhibit the expression of genes involved in cell proliferation, apoptosis, invasion, and immune signaling pathways. Therefore, EBV miRNAs perform a significant function in the complex host-virus interaction and EBV-driven carcinogenesis. However, the integrated mechanisms underlying the roles of EBV miRNAs in carcinogenesis remain to be further explored. In this review, we describe recent advances regarding the involvement of EBV miRNAs in the pathogenesis of EBV-associated malignancies and discuss their potential utility as cancer biomarkers. An in-depth investigation into the pro-carcinogenic role of EBV miRNAs will expand our knowledge of the biological processes associated with virus-driven tumors and contribute to the development of novel therapeutic strategies for the treatment of EBV-associated malignancies.

• EBV
• EBV-associated malignancies
• cancer biomarker
• cancer pathogenesis
• carcinogenesis
• microRNA

• DNA virus
• RNA virus
• extracellular vesicles
• miRNAs

• Biomarkers
• Cancer
• Circulating
• MicroRNA
• Otolaryngology

• Biomarkers, Tumor/blood
• Biomarkers, Tumor/genetics
• Circulating MicroRNA/analysis
• Head and Neck Neoplasms/blood
• Head and Neck Neoplasms/genetics
• Humans

The proliferation and metastasis ability of tumors are mediate by the "mutual dialogue" between cells in the tumor microenvironment (TME). Extracellular vesicles (EVs), mainly exosomes and microvesicles, play an important role in achieving intercellular substance transport and information transfer in the TME. Initially considered "garbage dumpsters" and later referred to as "signal boxes", EVs carry "cargo" (proteins, lipids, or nucleic acids) that can redirect the function of a recipient cell. Currently, the molecular mechanisms and clinical applications of EVs in head and neck cancers (HNCs) are still at an early stage and need to be further investigate. In this review, we provide insight into the TME of HNCs, classifying and summarizing EVs derived from different cell types and illuminating their complex signaling networks involved in mediating tumor proliferation, invasion and metastasis, vascular angiogenesis and cancer drug resistance. In addition, we highlight the application of EVs in HNCs, underlining the special pathological and physiological environment of HNCs. The application of tumor heterogeneous EVs in saliva and circulating blood diagnostics will provide a new perspective for the early screening, real-time monitoring and prognostic risk assessment of HNCs. Given the concept of precise and individual therapy, nanostructured EVs are equipped with superior characteristics of biocompatibility, low immunogenicity, loadability and modification ability, making these molecules one of the new strategies for HNCs treatment.

• Cell-to-cell communication
• Exosomes Microvesicles
• Extracellular vesicles
• Head and neck cancers
• Tumor microenvironment

• EBV
• immune response
• miRNA
• multiple sclerosis
• post-transcriptional regulation

Nasopharyngeal carcinoma (NPC) is a common malignant tumor of the head and neck region with poorly understood progression and prognosis. The present study aims at exploring whether the expression of β-catenin, TCF-4, and survivin affects clinicopathological features and prognostic significance in NPC.

We enrolled 164 patients with NPC and 70 patients with chronic nasopharyngitis (CNP) in this study. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) and immunohistochemistry (IHC) were conducted to evaluate the expression of β-catenin, TCF-4, and survivin. Spearman’s rank correlation analysis and Pearson correlation analysis were used to measure the correlation of β-catenin, TCF-4, and survivin. Risk factors for prognosis and survival conditions of NPC patients were analyzed by Cox proportional hazards model and Kaplan–Meier curves.

The results obtained revealed that mRNA and protein expression of β-catenin, TCF-4, and survivin was higher in NPC tissues than in CNP tissues. Positive correlations amongst β-catenin, TCF-4, and survivin were identified by Spearman’s rank correlation analysis and Pearson correlation analysis. There was a significant correlation in expression of β-catenin, TCF-4, and survivin with EBV DNA, EBV-VCA-IgA, EBV-EA-IgA, T stage, N stage, and clinicopathological stages. Lower overall survival (OS), distant metastasis-free survival (DMFS), local recurrence-free survival (LRFS), and disease-free survival (DFS) rates were detected in NPC patients with positive expression of β-catenin, TCF-4, and survivin, in contrast to those with negative expression. Cox proportional hazards model demonstrated that β-catenin, TCF-4, and survivin protein positive expression were independent risk factors for OS and DFS of NPC prognosis; there was an evident correlation between clinicopathological stages, TCF-4, and EBV-EA-IgA and OS, DMFS, LRFS, and DFS of NPC.

The aforementioned results indicate that β-catenin, TCF-4, and survivin proteins are highly expressed in NPC, which can be used as factors to predict the malignancy of NPC. In addition, positive expression of β-catenin, TCF-4, and survivin are potential risk factors that lead to an unfavorable prognosis of OS and DFS in NPC patients.

• Clinicopathological stages
• Nasopharyngeal carcinoma
• Survival prognosis
• Survivin
• TCF-4
• β-Catenin

The Epstein-Barr virus (EBV) produces different microRNAs (miRNA) with distinct regulatory functions within the infectious cycle. These viral miRNAs regulate the expression of viral and host genes and have been discussed as potential diagnostic markers or even therapeutic targets, provided that the expression profile can be unambiguously correlated to a specific stage of infection or a specific EBV-induced disorder. In this context, miRNA profiling becomes more important since the roles of these miRNAs in the pathogenesis of infections and malignancies are not fully understood. Studies of EBV miRNA expression profiles are sparse and have mainly focused on associated malignancies. This study is the first to examine the miRNA profiles of EBV reactivation and to use a correction step with seronegative patients as a reference. Between 2012 and 2017, we examined the expression profiles of 11 selected EBV miRNAs in 129 whole blood samples from primary infection, reactivation, healthy carriers and EBV seronegative patients. Three of the miRNAs could not be detected in any sample. Other miRNAs showed significantly higher expression levels and prevalence during primary infection than in other stages; miR-BHRF1-1 was the most abundant. The expression profiles from reactivation differed slightly but not significantly from those of healthy carriers, but a specific marker miRNA for each stage could not be identified within the selected EBV miRNA targets.

• Adolescent
• Adult
• Case-Control Studies
• Child
• Child, Preschool
• Cohort Studies
• Disease Progression
• Epstein-Barr Virus Infections/genetics
• Epstein-Barr Virus Infections/pathology
• Epstein-Barr Virus Infections/virology
• Female
• Gene Expression Profiling
• Gene Expression Regulation, Viral
• Herpesvirus 4, Human/genetics
• Humans
• Infant
• Infant, Newborn
• Male
• MicroRNAs/analysis
• MicroRNAs/genetics
• Middle Aged
• Prospective Studies
• RNA, Viral/analysis
• RNA, Viral/genetics
• Young Adult

• Bundesministerium für Bildung und Forschung

• EBV
• EBV-associated tumors
• microRNA

Cell‐free microRNA (miRNA) in biofluids released by tumors in either protein or vesicle‐bound form, represent promising minimally‐invasive cancer biomarkers. However, a highly abundant non‐tumor background in human plasma and serum complicates the discovery and detection of tumor‐selective circulating miRNAs. We performed small RNA sequencing on serum and plasma RNA from Nasopharyngeal Carcinoma (NPC) patients. Collectively, Epstein Barr virus‐encoded miRNAs, more so than endogenous miRNAs, signify presence of NPC. However, RNAseq‐based EBV miRNA profiles differ between NPC patients, suggesting inter‐tumor heterogeneity or divergent secretory characteristics. We determined with sensitive qRT‐PCR assays that EBV miRNAs BART7‐3p, BART9‐3p and BART13‐3p are actively secreted by C666.1 NPC cells bound to extracellular vesicles (EVs) and soluble ribonucleoprotein complexes. Importantly, these miRNAs are expressed in all primary NPC tumor biopsies and readily detected in nasopharyngeal brushings from both early and late‐stage NPC patients. Increased levels of BART7‐3p, BART9‐3p and particularly BART13‐3p, distinguish NPC patient sera from healthy controls. Receiver operating characteristic curve analysis using sera from endemic NPC patients, other head and neck cancers and individuals with asymptomatic EBV‐infections reveals a superior diagnostic performance of EBV miRNAs over anti‐EBNA1 IgA serology and EBV‐DNA load (AUC 0.87–0.96 vs 0.86 and 0.66 respectively). The high specificity of circulating EBV‐BART13‐3p (97%) for NPC detection is in agreement with active secretion from NPC tumor cells. We conclude EV‐bound BART13‐3p in circulation is a promising, NPC‐selective, biomarker that should be considered as part of a screening strategy to identify NPC in endemic regions.

What's new?

Analysis of DNA from human tumor viruses in patient blood is a non‐invasive screening method for individuals at risk for developing cancer. A drawback is over‐diagnosis as these sensitive methods also detect non‐cancer‐related infections. Here the authors show by RNA sequencing and PCR amplification that a microRNA (BART13‐3p) encoded by the Epstein–Barr Virus (EBV) is associated with circulating vesicles in patients with nasopharyngeal carcinoma, thus distinguishing between cancer and non‐cancer‐related EBV infections.

• BART-microRNAs
• Epstein-Barr virus
• nasopharyngeal carcinoma
• noninvasive diagnosis
• tumor markers

• exosomes
• extracellular vesicle
• herpesvirus
• microRNA
• microvesicles
• oncosomes

• Animals
• Epstein-Barr Virus Infections/complications
• Epstein-Barr Virus Infections/genetics
• Epstein-Barr Virus Infections/pathology
• Epstein-Barr Virus Infections/virology
• Extracellular Vesicles/genetics
• Extracellular Vesicles/pathology
• Extracellular Vesicles/virology
• Gene Expression Regulation, Neoplastic
• Herpesvirus 4, Human/genetics
• Humans
• MicroRNAs/analysis
• MicroRNAs/genetics
• Neoplasms/etiology
• Neoplasms/genetics
• Neoplasms/pathology
• Neoplasms/virology
• RNA, Viral/analysis
• RNA, Viral/genetics
• Tumor Microenvironment

• R01 CA204621 NCI NIH HHS

• Exosome
• Onco-virus
• Virus-associated cancer
• miRNAs

• Biomarker
• DNA
• Exosomes
• Extracellular vesicles
• Nucleic acids
• RNA

• EBV miRNAs
• anti-apoptosis
• biomarker
• immune evasion
• metastasis
• nasopharyngeal carcinoma

• Gingival keratinocytes
• HSV-1
• Herpesvirus
• Inflammation
• Transcriptome
• Viral microRNA

• Binding Sites
• Gene Expression Regulation, Viral
• Gingiva/metabolism
• Gingiva/pathology
• Gingiva/virology
• Herpesvirus 1, Human/genetics
• Herpesvirus 1, Human/pathogenicity
• Herpesvirus 8, Human/genetics
• Herpesvirus 8, Human/pathogenicity
• Humans
• Keratinocytes/metabolism
• Keratinocytes/virology
• MicroRNAs/genetics
• Periodontal Diseases/genetics
• Periodontal Diseases/virology
• RNA, Viral/genetics
• Transcriptome/genetics
• Virus Diseases/genetics
• Virus Diseases/virology

• R03 DE027147 NIDCR NIH HHS
• R21 DE026259 NIDCR NIH HHS
• R01 DE02105201A1 NIDCR NIH HHS
• R21 DE026259-01A1 NIDCR NIH HHS

• Epstein-Barr virus
• nasopharyngeal carcinoma
• tumor microenvironment

The concentration and distribution of rare earth elements (REE) in nasopharyngeal carcinoma (NPC) were measured to investigate connections with tumor size, lymph node metastasis, clinical stages, and Epstein-Barr virus (EBV) infection. There were 30 patients with NPC who met the criteria for inclusion in the present study. The EBV copy number, as well as the concentration and distribution of REE, was analyzed. EBV was detected using reverse transcription-polymerase chain reaction, with the concentrations of REE in NPC tissues measured using inductively coupled plasma-tandem mass spectrometry. The mean values were used when comparing concentrations of REE in NPC tissues as the standard deviation of this parameter was the lowest. Light REE had the highest concentrations, followed by medium, and then heavy REE. The concentrations of REE decreased with increasing tumor size and with the presence of lymph node metastasis. The concentrations of REE gradually increased between stage II and IVa, but markedly decreased thereafter. The elements that exhibited the greatest decreases were terbium, holmium and ytterbium. Furthermore, the concentrations of REE in NPC were not associated with sex (r=0.301, P=0.106) or age (r=−0.011, P=0.955), and were negatively associated with EBV (r=−0.744, P<0.001). By contrast, the EBV copy number increased alongside advancements in clinical stage. Changes in the concentrations of REE in NPC were more prominent for medium and heavy elements. Additionally, alterations in the concentrations of heavy REE may affect the occurrence and development of NPC.

• Epstein-Barr virus
• concentration
• correlation
• nasopharyngeal carcinoma
• rare earth element

• Nasopharyngeal carcinoma
• chemoradioresistance
• exosomes
• miRNA
• non-coding RNA
• tumor microenvironment

• A549 Cells
• Cells, Cultured
• Cytokines/metabolism
• Epithelial Cells/cytology
• Epithelial Cells/immunology
• Exosomes/genetics
• Exosomes/immunology
• High-Throughput Nucleotide Sequencing/methods
• Humans
• Immunity, Innate
• Models, Biological
• Respiratory Syncytial Virus Infections/genetics
• Respiratory Syncytial Virus Infections/immunology
• Respiratory Syncytial Virus Infections/virology
• Respiratory Syncytial Virus, Human/genetics
• Respiratory Syncytial Virus, Human/immunology
• Respiratory System/cytology
• Respiratory System/immunology
• Sequence Analysis, RNA/methods

• P01 AI062885 NIAID NIH HHS
• P30 ES006676 NIEHS NIH HHS
• R01 AI079246 NIAID NIH HHS

Epstein–Barr virus (EBV) infection is detected in various epithelial malignancies, such as nasopharyngeal carcinoma (NPC) and gastric cancer (GC). EBV comprises some unique molecular features and encodes viral genes and microRNAs (miRNAs) by its own DNA sequence. EBV genes are required to maintain latency and contribute to oncogenic property. miRNAs encoded by EBV have been shown to contribute to initiation and progression of EBV‐related malignancies. By a number of genomic profiling studies, some EBV miRNAs were confirmed to be highly expressed in EBV‐associated gastric cancer (EBVaGC) samples and cell lines. The majority host targets of the EBV miRNAs are important for promoting cell growth and inhibiting apoptosis, facilitating cell survival and immune evasion. However, the integrated molecular mechanisms related to EBV miRNAs remain to be investigated. In this review, we summarized the crucial role of EBV miRNAs in epithelial malignancies, especially in EBVaGC. Collectively, EBV miRNAs play a significant role in the viral and host gene regulation network. Understanding the comprehensive potential targets and relevant functions of EBV miRNAs in gastric carcinogenesis might provide better clinical translation.

• Epstein-Barr virus
• gastric cancer
• microRNA

Epstein-Barr virus (EBV) is an oncogenic virus that ubiquitously establishes life-long persistence in humans. To ensure its survival and maintain its B cell transformation function, EBV has developed powerful strategies to evade host immune responses. Emerging evidence has shown that microRNAs (miRNAs) are powerful regulators of the maintenance of cellular homeostasis. In this review, we summarize current progress on how EBV utilizes miRNAs for immune evasion. EBV encodes miRNAs targeting both viral and host genes involved in the immune response. The miRNAs are found in two gene clusters, and recent studies have demonstrated that lack of these clusters increases the CD4⁺ and CD8⁺ T cell response of infected cells. These reports strongly indicate that EBV miRNAs are critical for immune evasion. In addition, EBV is able to dysregulate the expression of a variety of host miRNAs, which influence multiple immune-related molecules and signaling pathways. The transport via exosomes of EBV-regulated miRNAs and viral proteins contributes to the construction and modification of the inflammatory tumor microenvironment. During EBV immune evasion, viral proteins, immune cells, chemokines, pro-inflammatory cytokines, and pro-apoptosis molecules are involved. Our increasing knowledge of the role of miRNAs in immune evasion will improve the understanding of EBV persistence and help to develop new treatments for EBV-associated cancers and other diseases.

• Epstein-Barr virus (EBV)
• carcinogenesis
• exosomes
• immune evasion
• microRNAs

• Cancer diagnosis
• Circulating ncRNA
• Exosome
• Noncoding RNA

• EBV
• Exosome
• Extracellular vesicle
• HCMV
• HSV
• Herpesvirus
• Infection
• KSHV
• Pathogenesis
• Viral assembly

• Adoptive T cell immunotherapy
• Burkitt lymphoma
• EBV latency
• Exosome
• Hodgkin lymphoma
• In vivo experimental models
• Latent membrane protein 1 (LMP1)
• Lytic viral replication
• Mass spectrometry
• Patho-epigenetics
• RNA-seq
• Telomere
• Tumorigenesis

• Epstein–Barr virus
• Exosomes
• Lymphoblastoid cell lines
• lncRNA
• miRNA

• Epstein-Barr virus
• circulating micro-RNA
• miR-BART2-5p
• nasal natural killer/T-cell lymphoma

• Exosome
• Next-generation sequencing
• Pancreatic cancer

• Biomarkers, Tumor/analysis
• Biomarkers, Tumor/genetics
• Exosomes/chemistry
• Exosomes/genetics
• Exosomes/metabolism
• Exosomes/pathology
• High-Throughput Nucleotide Sequencing/methods
• Humans
• MicroRNAs/analysis
• MicroRNAs/genetics
• Neoplasms/diagnosis
• Neoplasms/genetics
• Neoplasms/metabolism
• Neoplasms/pathology

Epstein-Barr virus (EBV)-related micoRNAs (miRNAs), BamHI-A rightward transcripts (BART)-miRNAs, are released in a stable form from viable cells, which are abundant in patients with EBV-positive nasopharyngeal carcinoma (NPC). We estimated copy numbers of circulating miR-BART2-5p, miR-BART17-5p, and miR-BART18-5p as well as BamHI-W DNA as biomarkers.

Serums from 31 EBV-positive (confirmed by in situ hybridization for EBV-encoded small RNAs) NPC patients and 40 non-NPC controls were analyzed. Among the 31 NPC patients, serums at the initial diagnosis and three months after treatment were obtained from 20 patients, and serums only at three months after treatment were obtained from 11 patients.

The sensitivity/specificity of circulating BamHI-W DNA, miR-BART2-5p, miR-BART17-5p, and miR-BART18-5p for the diagnosis of NPC before treatment were 100 / 100, 85 / 85, 60 / 95, and 25 / 100%, respectively. For BamHI-W DNA, NPC patients with stage IV disease had significantly higher copy numbers than those with I-III. Copy numbers decreased significantly post-treatment. In contrast, copy numbers of the three BART-miRNAs showed no significant correlation with the clinical stage at diagnosis or any significant post-treatment change. After treatment, BamHI-W DNA and miR-BART17-5p were detected in 5 and 6 cases out of 11 patients with recurrent or residual tumors, respectively. However, BamHI-W DNA and miR-BART17-5p were absent in all 20 patients without relapse or residual tumors.

The copy number of circulating BamHI-W DNA is a more useful biomarker for the initial diagnosis of NPC than the three BART-miRNAs examined. Post-treatment detection of miR-BART17-5p is a potential biomarker of a poor prognosis.

• the Ministry of Education, Science, Sports, Culture and Technology of Japan

• Blotting, Western
• Cell Line, Tumor
• Exosomes/genetics
• Exosomes/metabolism
• Exosomes/ultrastructure
• Exosomes/virology
• Herpesviridae/genetics
• High-Throughput Nucleotide Sequencing
• Humans
• Lymphoma/genetics
• Lymphoma/metabolism
• Lymphoma/virology
• MicroRNAs/genetics
• Microscopy, Electron
• Polymerase Chain Reaction
• Reverse Transcriptase Polymerase Chain Reaction

• Japan Agency for Medical Research and Development
• Japan Society for the Promotion of Science

Cellular immune reactions against non-self-epitopes require activation of cytotoxic CD8⁺ T-cells via cross-presentation of MHC class I-restricted peptides by professional antigen presenting cells (pAPCs), with the consequent detection and elimination of cells expressing the same antigens via the endogenous (direct) pathway. The source of peptides for the endogenous pathway is constituted of alternative mRNA translation products; however, it is still unclear which source of peptides is used for cross-presentation. Furthermore, the presentation of non-canonical translation products, produced during a non-conventional translation event, on class I molecules of tumor cells has been reported but how these peptides are generated, presented to pAPCs, and their capacity to stimulate CD8⁺ T cells is still not known. Here, we report that pioneer translation peptides (PTPs) derived from intron or exon pre-mRNAs can serve as tumor-associated antigens (TA-PTPs) and are delivered from the producing tumor cells to pAPCs via exosomes where they are processed by the cytosolic pathway. Injection of TA-PTPs and tumor-derived exosomes efficiently induce CD8⁺ T-cell proliferation and prevent tumor growth in mice. Our results show that TA-PTPs represent an efficient source of antigenic peptides for CD8⁺ T cell activation and that full-length proteins are not required for cross-presentation. These findings can have interesting implications for generating tolerance and for designing vectors to generate vaccines.

• Exosomes
• MHC-I antigen cross presentation
• pioneer translation products
• tumor rejection
• vaccines

MicroRNAs (miRNAs) are small non-coding RNAs important in gene regulation. They are able to regulate mRNA translation through base-pair complementarity. Cellular miRNAs have been involved in the regulation of nearly all cellular pathways, and their deregulation has been associated with several diseases such as cancer. Given the importance of microRNAs to cell homeostasis, it is no surprise that viruses have evolved to take advantage of this cellular pathway. Viruses have been reported to be able to encode and express functional viral microRNAs that target both viral and cellular transcripts. Moreover, viral inhibition of key proteins from the microRNA pathway and important changes in cellular microRNA pool have been reported upon viral infection. In addition, viruses have developed multiple mechanisms to avoid being targeted by cellular microRNAs. This complex interaction between host and viruses to control the microRNA pathway usually favors viral infection and persistence by either reducing immune detection, avoiding apoptosis, promoting cell growth, or promoting lytic or latent infection. One of the best examples of this virus-host-microRNA interplay emanates from members of the Herperviridae family, namely the herpes simplex virus type 1 and type 2 (HSV-1 and HSV-2), human cytomegalovirus (HCMV), human herpesvirus 8 (HHV-8), and the Epstein–Barr virus (EBV). In this review, we will focus on the general functions of microRNAs and the interactions between herpesviruses, human hosts, and microRNAs and will delve into the related mechanisms that contribute to infection and pathogenesis.

• herpesvirus
• immune evasion
• latency
• microRNAs
• oncogenesis
• pathogenesis

• Gene Expression Regulation
• Herpesviridae/immunology
• Herpesviridae/pathogenicity
• Herpesviridae Infections/immunology
• Herpesviridae Infections/pathology
• Host-Pathogen Interactions
• Humans
• MicroRNAs/metabolism

• BARTs
• EBERs
• Viral noncoding RNA
• miRNA target
• microRNA

Epstein-Barr virus (EBV) was the first virus identified to encode microRNAs (miRNAs). Both of viral and human cellular miRNAs are important in EBV infection. However, the dynamic expression profile of miRNAs during primary EBV infection was unknown. This study aimed to investigate the dynamic expression profile of viral and cellular miRNAs in infectious mononucleosis (IM) caused by primary EBV infection.

The levels of viral and cellular miRNAs were measured in fifteen pediatric IM patients at three different time-points. Fifteen healthy children who were seropositive for EBV were enrolled in the control group. Relative expression levels of miRNAs were detected by quantitative real-time PCR (qPCR) assay.

EBV-miR-BHRF1-1, 1-2-3P, miR-BART13-1, 19-3p, 11-3P, 12–1, and 16–1 in IM patients of early phase were significantly higher than in healthy children. Most cellular miRNAs of B cells, such as hsa-miR-155-5p, −34a-5p, −18b-5p, −181a-5p, and −142-5p were up-regulated; while most of cellular miRNAs of CD8 + T cells, such as hsa-miR-223, −29c-3p, −181a, −200a-3p, miR-155-5p, −146a, and −142-5p were down-regulated in IM patients. With disease progression, nearly all of EBV-miRNAs decreased, especially miR-BHRF1, but at a slower rate than EBV DNA loads. Most of the cellular miRNAs of B cells, including hsa-miR-134-5p, −18b-5p, −34a-5p, and -196a-5p increased with time. However, most of the cellular miRNAs of CD8 + T cells, including hsa-let-7a-5p, −142-3p, −142-5p, and −155-5p decreased with time. Additionally, hsa-miR-155-5p of B cells and hsa-miR-18b-5p of CD8+ T cells exhibited a positive correlation with miR-BHRF1-2-5P and miR-BART2-5P (0.96 ≤ r ≤ 0.99, P < 0.05). Finally, hsa-miR-181a-5p of B cells had positive correlation with miR-BART4-3p, 4-5P, 16–1, and 22 (0.97 ≤ r ≤ 0.99, P < 0.05).

Our study is the first to describe the expression profile of viral and cellular miRNAs in IM caused by primary EBV infection. These results might be the basis of investigating the pathogenic mechanism of EBV-related diseases and bring new insights into their diagnosis and treatment.

• TAR RNA
• cytokinesis
• exosome (vesicle)
• human immunodeficiency virus (HIV)
• macrophage
• protein kinase RNA-activated (PKR)
• toll-like receptor (TLR)

Infections that result in natural or manmade spread of lethal biological agents are a concern and require national and focused preparedness. In this manuscript, as part of an early diagnostics and pathogen treatment strategy, we have focused on extracellular vesicles (EVs) that arise following infections. Although the field of biodefense does not currently have a rich resource in EVs literature, none the less, similar pathogens belonging to the more classical emerging and non-emerging diseases have been studied in their EV/exosomal contents and function. These exosomes are formed in late endosomes and released from the cell membrane in almost every cell type in vivo. These vesicles contain proteins, RNA, and lipids from the cells they originate from and function in development, signal transduction, cell survival, and transfer of infectious material. The current review focuses on how different forms of infection exploit the exosomal pathway and how exosomes can be exploited artificially to treat infection and disease and potentially also be used as a source of vaccine. Virally-infected cells can secrete viral as well as cellular proteins and RNA in exosomes, allowing viruses to cause latent infection and spread of miRNA to nearby cells prior to a subsequent infection. In addition to virally-infected host cells, bacteria, protozoa, and fungi can all release small vesicles that contain pathogen-associated molecular patterns, regulating the neighboring uninfected cells. Examples of exosomes from both virally and bacterially infected cells point toward a re-programming network of pathways in the recipient cells. Finally, many of these exosomes contain cytokines and miRNAs that in turn can effect gene expression in the recipient cells through the classical toll-like receptor and NFκB pathway. Therefore, although exosomes do not replicate as an independent entity, they however facilitate movement of infectious material through tissues and may be the cause of many pathologies seen in infected hosts.

• bacteria
• exosome
• extracellular vesicle
• parasite
• pathogen
• protozoa
• virus

• Carcinogenesis
• Class I Phosphatidylinositol 3-Kinases
• CpG Islands
• DNA Methylation
• DNA-Binding Proteins
• Epstein-Barr Virus Infections/virology
• Gene Expression Regulation, Neoplastic
• Herpesvirus 4, Human/genetics
• Herpesvirus 4, Human/physiology
• Humans
• MicroRNAs
• Mutation
• Nuclear Proteins/genetics
• Phosphatidylinositol 3-Kinases/genetics
• Stomach Neoplasms/genetics
• Stomach Neoplasms/pathology
• Stomach Neoplasms/physiopathology
• Stomach Neoplasms/virology
• Transcription Factors/genetics