Antibody-epitope conjugates (AECs) proved to be a promising new therapeutic strategy to redirect virus-specific CD8+ T cells toward cancer cells by delivering T-cell epitopes. To be able to redirect a larger fraction of the virus-specific T-cell population, it is beneficial to deliver a broader selection of T-cell epitopes. We investigated two different methods to generate AECs with two distinct virus-specific T-cell epitopes fused to one antibody. Epitopes were either placed in a tandem-like fashion at the C-terminus of the AEC (t-AEC) or bispecific-AECs (bs-AECs) were generated via controlled Fab-arm exchange to generate bs-AECs with two identical antigen binding domains, but two distinct epitopes on each Fab-arm. Our study revealed that maintaining a free epitope terminus was required for efficient delivery of the virus-specific T-cell epitopes. Consequently, viral-epitope delivery using t-AECs was suboptimal as the concatenated epitopes were less effectively delivered to the target cells. However, well-defined bs-AECs containing both CMV and EBV epitopes were successfully generated and both in vitro and in vivo efficacy was evaluated. Our results demonstrate that bispecific-AECs can efficiently deliver EBV and CMV epitopes simultaneously to multiple cancer cell lines from different origins, thereby redirecting and activating two distinct populations of virus-specific T cells. Furthermore, our in vivo findings indicate that when both virus-specific T-cell populations are present and tumor cells express the proteases required for efficient epitope delivery, bs-AECs exhibit similar efficacy in reducing tumor burden compared to AECs. To conclude, our study demonstrates the feasibility of redirecting two groups of virus-specific T cells using a single antibody and highlights the potential of bs-AECs both in vitro and in vivo.

Haematological malignancies are one of the most common tumors, with a rising incidence noted over recent decades. Viral infections play significant roles in the pathogenesis of these malignancies globally. This review delves into the contributions of various known viruses-specifically Epstein-Barr virus (EBV), human immunodeficiency virus (HIV), human T-cell leukemia virus type 1 (HTLV-1), Kaposi's sarcoma-associated herpesvirus (KSHV), human cytomegalovirus (HCMV), hepatitis B virus (HBV), hepatitis C virus (HCV), and human papillomavirus (HPV)-in the development of haematological malignancies. These viruses are shown to drive tumorigenesis through mechanisms, such as metabolic reprogramming, epigenetic modifications, and remodeling of the immune microenvironment. By directly disrupting fundamental cellular functions and altering metabolic and epigenetic pathways, these viruses foster an immune milieu that supports both viral persistence and tumor growth. A thorough understanding of these viral oncogenic processes is crucial not only for etiological discovery but also for developing targeted interventions. This review emphasizes the need for continued research into the specific ways these viruses manipulate the host cell's metabolic and epigenetic environments, aiming to provide insights that could guide future advancements in treatment modalities.

To identify nasopharyngeal carcinoma (NPC)-relevant T cell receptors (TCRs), we profile the repertoires of peripheral blood TCRβ chains from 228 NPC patients, 241 at-risk controls positive for serum Epstein-Barr virus (EBV) VCA-IgA antibody, and 251 seronegative controls. We develop a TCR-based signature (T-score) based on 208 NPC-enriched CDR3β sequences, which accurately diagnoses NPC in both the original and independent validation cohorts. Notably, a higher T-score, associated with a shorter time interval to NPC diagnosis, effectively identifies early-stage NPC among EBV-seropositive at-risk individuals prior to clinical diagnosis. These NPC-enriched TCRs react against not only EBV-specific antigens but also non-EBV antigens expressed by NPC cells, indicating a broad range of specificities. Moreover, the abundance of NPC-enriched CD8+ T cells in blood correlates with the infiltration of non-exhausted T cell counterparts in tumors and predicts prolonged survival, suggesting that these NPC-enriched T cells have significant potential for disease monitoring and therapeutic applications.

Epstein-Barr virus (EBV), a human herpes virus, presents significant risks to hematopoietic stem cell transplant (HSCT) recipients due to immunosuppressive treatments. Two genotypes of EBV can infect humans: EBV1 and EBV2. These genotypes differ in their latent genes. One important latent protein is EBNA3, which plays a crucial role in immune evasion and pathogenesis of EBV.

This study characterizes EBV genotypes among HSCT recipients in Jordan and examines the relationship between EBV positivity and demographic factors.

A retrospective observational study was conducted at the Jordanian Royal Medical Services Hospital (JRMS) from January to October 2024. Blood samples were collected from the virology department, and plasma was separated. EBV-DNA detection was performed using quantitative real-time PCR, while conventional PCR targeted EBNA3C genes for genotyping.

Out of 93 EBV-positive HSCT recipients, 31 underwent genotyping analysis. The findings revealed a predominance of EBV2, detected in 26 samples (84%), while 5 samples (16%) exhibited mixed infections. Notably, EBV1 was not identified in any samples. A significant association was found between EBV positivity and male recipients, with a markedly higher prevalence in individuals under 18 years of age (P<0.0001).

EBV2 was the predominant genotype among HSCT recipients in Jordan, with coinfections of EBV1 and EBV2. Understanding the prevalent genotypes in transplant patients is crucial for managing EBV-related complications, ultimately improving patient outcomes. This study highlights the need for continuous monitoring and characterization of EBV genotypes in immunocompromised populations.

Epstein-Barr virus (EBV), a ubiquitous human herpesvirus, has been robustly linked to the pathogenesis of nasopharyngeal carcinoma (NPC). The mechanism of EBV-induced NPC involves complex interactions between viral proteins and host cell pathways. This review aims to comprehensively outline the mechanism of EBV-induced NPC and the latest advances in targeted EBV vaccines for prophylaxis and treatment. This review explores the intricate molecular mechanisms by which EBV contributes to NPC pathogenesis, highlighting viral latency, genetic and epigenetic alterations, and immune evasion strategies. It emphasizes the pivotal role of key viral proteins, including EBNA1, LMP1, and LMP2A, in carcinogenesis. Subsequently, the discussion shifts towards the development of targeted EBV vaccines, including preventive vaccines aimed at preventing primary EBV infection and therapeutic vaccines aimed at treating diagnosed EBV-related NPC. The review underscores the challenges and future directions in the field, stressing the importance of developing innovative vaccine strategies and combination therapies to improve efficacy. This review synthesizes current insights into the molecular mechanisms of EBV-induced NPC and the development of EBV-targeted vaccines, highlighting the potential use of mRNA vaccines for NPC treatment.

Although viral infections are one of the common clinical manifestations in patients with inborn errors of immunity (IEIs), little is known about the epidemiology, susceptibility genes, and clinical status of viral infections in patients with IEIs.

The demographic information, clinical diagnoses, and laboratory findings of 931 IEI patients who underwent viral testing from January 2016 to December 2022 were collected and analyzed.

In total, 47.15% (439/931) patients with IEI tested positive for at least one virus during hospitalization. There were a total of 640 viral infections during the study period, mainly from EBV 131 (20.47%), HRV 102(15.94%), CMV 100(15.63%), and RV 84(13.13%). CMV and RV infections were more common in the combined immunodeficiencies (IEI_I) group during the infant stage, whereas EBV infection was more common in the immune dysregulation (IEI_IV) group during the preschool stage. Mutations in SH2D1A (57.14%), PIK3CD (56.41%) and LRBA (50%) make individuals susceptible to EBV infection; mutations in WAS (30%) make individuals susceptible to CMV infection; and mutations in IL2RG (56.52%) and RAG1 (37.5%) make individuals susceptible to RV infection. Joinpoint analysis revealed trends in viral positivity in different years.

These data suggest that it is possible to target the prevention, treatment, and management of IEI patients who are infected with a virus by accounting for the age at infection, type of IEI, and mutant genes, but special attention needs to be paid to viral infections in IEI_I and IEI_IV patients during the infant stage.

Inborn errors of immunity (IEIs) represent unique in natura models that uncover key components of immunity in humans, in particular those that predispose to infections. Epstein-Barr virus (EBV) is one of the most common opportunistic infectious agents in humans and is responsible for several diseases, including infectious mononucleosis, nonmalignant and malignant lymphoproliferative disorders, hemophagocytic lymphohistiocytosis, and smooth muscle and epithelial tumors. For most individuals, EBV infection persists for life without pathological consequences. IEIs that do not predispose to EBV infection suggest that innate and humoral responses are not necessary or redundant for the immune response to EBV. IEIs associated with high susceptibility to EBV infection provide unequivocal genetic proof of the central role of CD8+ T cell responses in immunity to EBV. They also highlight the distinct steps and pathways required for, on the one hand, the effector cytotoxic functions of CD8+ T cells and, on the other hand, the expansion and maturation of cytotoxic CD8+ T cells.

Here, we analyze the viral landscape in blood and tissue from 4918 metastatic cancer patients across 38 solid cancer types from the Hartwig Medical Foundation (HMF) cohort, the largest pan-cancer study on metastatic cancer. Using a coverage-based filtering approach, we detected 25 unique viral genera across 32 different cancer types, with a total of 747 unique virus-positive tissue samples. We detected 336 virus-positive blood samples across 29 cancer types, dominated by Torque teno virus and Alphatorquevirus. The tissue samples were dominated by Alphapapillomavirus and Roseolovirus. Alphapapillomavirus was significantly enriched in genital, anal, and colorectal cancers and was associated with host mutational signatures and transcriptional programs related to immunity and DNA repair. Host genes with Alphapapillomavirus integration tended to be more highly expressed and samples with HPV integration had higher somatic mutation rates and higher number of extrachromosomal DNA elements. Alphapapillomavirus was also detected in a significant proportion of blood samples from cervix and anal cancers, suggesting a potential blood-based biomarker.

Epstein-Barr virus-positive mucocutaneous ulcer (EBVMCU) is a rare condition characterized by skin or mucosal lesions resulting from defective immune surveillance of EBV due to immunosuppression, which can be iatrogenic or age-related. It represents a benign lymphoproliferative disorder that clinically may mimic malignant tumors. However, EBVMCU typically progresses slowly and often resolves spontaneously without specific treatment, emphasizing the critical need for differential diagnosis from malignancies. In this study, we report a case of EBVMCU in an elderly patient demonstrating ulcers on the oral mucosa, buccal area, and maxillary mucosa, with associated bone destruction, which was initially suspected to be an oral malignancy but was confirmed as EBVMCU through biopsy. This case underscores the importance of considering EBVMCU in elderly patients with unexplained persistent mucosal ulcers to exclude malignancies. In addition, attention should be given to unhealthy lifestyle habits such as smoking and drinking, as well as poor oral hygiene, which are potential factors that increase the risk of this disease and contribute to worse prognoses.

The field of cancer immunotherapy has experienced remarkable advancements in the treatment of human cancers over recent decades. Therapeutic cancer vaccines have been employed to elicit antitumor immune responses through the generation of specific reactions against tumor-associated antigens. Although preclinical studies have demonstrated hopeful results and at least one product is approved for clinical use, the overall efficacy of cancer vaccines remains restricted. The co-administration of anti-checkpoint antibodies alongside cancer vaccines is proposed as a potential strategy to enhance the clinical efficacy of immunotherapies. Among the various anti-checkpoint agents, monoclonal antibodies targeting CD127, OX40, and CD40 have been further investigated in combined administration with cancer vaccines, demonstrating a synergistic impact on disease outcomes in both animal models and human subjects. This combinational approach has been shown to suppress tumor regression, improve survival rates, and promote the efficacy of cancer vaccines via multiple mechanisms, including the augmentation of generation, activation, and expansion of CD8+ T cells, as well as the production of tumor-inhibitory cytokines. Importantly, the impact of the concurrent administration of anti-checkpoint agents and cancer vaccines surpass those observed with the sole vaccine, indicating that this strategy may offer significant advantages for clinical application in cancer patients. In this review, we aim to provide a comprehensive overview of the significance and therapeutic potential of the combined administration of checkpoint agonist/antagonist antibodies and cancer vaccines for human tumors.

Chronic active Epstein-Barr Virus disease is a kind of Epstein-Barr Virus associated T/NK cell lymphoproliferative disease. At present, there is still a lack of standard therapeutic regimen for its treatment, but its basic treatment principles include controlling inflammatory response, anti-tumor proliferation, and immune reconstitution. Hematopoietic stem cell transplantation is currently the only method that can cure this disease. In recent years, immunotherapy has developed rapidly and is widely used in the treatment of various hematological malignancies; various immunotherapy drugs, including PD-1 inhibitors, have also demonstrated their safety and efficacy in CAEBV, while immune cell therapies such as Epstein- Barr virus-specific T cells have also displayed their unique advantages in CAEBV.

To investigate the diagnostic value of peripheral blood lymphocyte testing in children with infectious mononucleosis (IM).

A total of 135 children with IM as the IM group and 100 healthy volunteers as the healthy group were included in this retrospective study. Peripheral blood lymphocyte subsets marked as CD3+, CD4+, CD8+, CD16 + CD56+, and CD19 + in the peripheral blood were quantified using flow cytometry. Statistical analysis was performed using the chi-square test, Kruskal-Wallis test, AUROC curve, and Kappa consistency test to assess the diagnostic value of these markers in IM.

The AUROC curve for CD8 + cells and for CD4+/CD8 + ratios both achieved a value of 1 with the sensitivity and specificity of 100% (P<0.001). The Kappa coefficients were 1 for CD8+, CD4+/CD8 + ratios and the combined EBV analysis, indicating a 100% consistency with the clinical diagnosis. Significant differences were also observed in the CD3+, CD4+, CD16 + CD56+, and CD19 + lymphocyte subsets between the IM group and the healthy group (P<0.05).

The evaluation of CD8 + and CD4+/CD8 + ratios in peripheral blood lymphocytes represents a significant advancement in the diagnosis of IM. Peripheral blood lymphocyte testing offers a reliable, sensitive, and specific diagnostic tool to enhance the clinical management of children with IM.

Numerous studies have demonstrated the importance of the Epstein-Barr Virus (EBV), which was initially identified in 1964 while studying Burkitt's lymphoma, in the development of a number of cancers, including nasopharyngeal carcinoma, Hodgkin's lymphoma, Burkitt's lymphoma, and EBV-associated gastric carcinoma. Gammaherpesvirus EBV is extremely common; by adulthood, over 90 % of people worldwide have been infected. Usually, the virus causes a permanent latent infection in B cells, epithelial cells, and NK/T cells. It then contributes to oncogenesis by inhibiting apoptosis and promoting unchecked cell proliferation through its latent proteins, which include EBNA-1, LMP1, and LMP2A. Tumor progression further accelerated by EBV's capacity to transition between latent and lytic phases, especially in cases of nasopharyngeal carcinoma. Although our understanding of the molecular underpinnings of EBV has advanced, there are still difficulties in identifying latent infections and creating targeted therapeutics. To tackle EBV-associated malignancies, current research efforts are concentrated on developing vaccines, developing better diagnostic tools, and developing targeted treatments. In order to improve treatment approaches and lower the incidence of EBV-related cancers worldwide, more research into the relationship between EBV and immune evasion and cancer formation is necessary.

Epstein-Barr virus (EBV) is a highly successful pathogen that infects ~95% of the adult population and is associated with diverse cancers and autoimmune diseases. The most abundant viral factor in latently infected cells is not a protein but a noncoding RNA called EBV-encoded RNA 1 (EBER1). Even though EBER1 is highly abundant and was discovered over forty years ago, the function of EBER1 has remained elusive. EBER1 interacts with the ribosomal protein L22, which normally suppresses the expression of its paralog L22-like 1 (L22L1). Here we show that when L22 binds EBER1, it cannot suppress L22L1, resulting in L22L1 being expressed and incorporated into ribosomes. We further show that L22L1-containing ribosomes preferentially translate mRNAs involved in the oxidative phosphorylation pathway. Moreover, upregulation of L22L1 is indispensable for growth transformation and immortalization of resting B cells upon EBV infection. Taken together, our results suggest that the function of EBER1 is to modulate host gene expression at the translational level, thus bypassing the need for dysregulating host gene transcription.

Epstein-Barr virus (EBV) is a highly successful pathogen that infects ~95% of the adult population and is associated with diverse cancers and autoimmune diseases. The most abundant viral factor in latently infected cells is not a protein but a noncoding RNA called EBV-encoded RNA 1 (EBER1). Even though EBER1 is highly abundant and was discovered over forty years ago, the function of EBER1 has remained elusive. EBER1 interacts with the ribosomal protein L22, which normally suppresses the expression of its paralog L22-like 1 (L22L1). Here we show that when L22 binds EBER1, it cannot suppress L22L1, resulting in L22L1 being expressed and incorporated into ribosomes. We further show that L22L1-containing ribosomes preferentially translate mRNAs involved in the oxidative phosphorylation pathway. Moreover, upregulation of L22L1 is indispensable for growth transformation and immortalization of resting B cells upon EBV infection. Taken together, our results suggest that the function of EBER1 is to modulate host gene expression at the translational level, thus bypassing the need for dysregulating host gene transcription.

Infection with the Epstein-Barr virus (EBV) elicits a complex T-cell response against a broad range of viral proteins. Hence, identifying potential differences in the cellular immune response of patients with different EBV-associated diseases or different courses of the same disorder requires interrogation of a maximum number of EBV antigens. Here, we tested three novel EBV-derived antigen formulations for their ability to reactivate virus-specific T cells ex vivo in patients with EBV-associated infectious mononucleosis (IM).

We comparatively analyzed EBV-specific CD4+ and CD8+ T-cell responses to three EBV-derived antigen formulations in 20 pediatric patients during the early phase of IM: T-activated EBV proteins (BZLF1, EBNA3A) and EBV-like particles (EB-VLP), both able to induce CD4+ and CD8+ T-cell responses ex vivo, as well as an EBV-derived peptide pool (PP) covering 94 well-characterized CD8+ T-cell epitopes. We assessed the specificity, magnitude, kinetics, and functional characteristics of EBV-specific immune responses at two sequential time points (v1 and v2) within the first six weeks after IM symptom onset (Tonset).

All three tested EBV-derived antigen formulations enabled the detection of EBV-reactive T cells during the early phase of IM without prior T-cell expansion in vitro. EBV-reactive CD4+ and CD8+ T cells were mainly mono-functional (CD4+: mean 64.92%, range 56.15-71.71%; CD8+: mean 58.55%, range 11.79-85.22%) within the first two weeks after symptom onset (v1) with IFN-γ and TNF-secreting cells representing the majority of mono-functional EBV-reactive T cells. By contrast, PP-reactive CD8+ T cells were primarily bi-functional (>60% at v1 and v2), produced IFN-γ and TNF and had more tri-functional than mono-functional components. We observed a moderate correlation between viral load and EBNA3A, EB-VLP, and PP-reactive CD8+ T cells (rs = 0.345, 0.418, and 0.356, respectively) within the first two weeks after Tonset, but no correlation with the number of detectable EBV-reactive CD4+ T cells.

All three EBV-derived antigen formulations represent innovative and generic recall antigens suitable for monitoring EBV-specific T-cell responses ex vivo. Their combined use facilitates a thorough analysis of EBV-specific T-cell immunity and allows the identification of functional T-cell signatures linked to disease development and severity.

Kaposi sarcoma associated herpesvirus (KSHV) is associated with around 1% of all human tumors, including the B cell malignancy primary effusion lymphoma (PEL), in which co-infection with the Epstein Barr virus (EBV) can almost always be found in malignant cells. Here, we demonstrate that KSHV/EBV co-infection of mice with reconstituted human immune systems (humanized mice) leads to IgM responses against both latent and lytic KSHV antigens, and expansion of central and effector memory CD4+ and CD8+ T cells. Among these, KSHV/EBV dual-infection allows for the priming of CD8+ T cells that are specific for the lytic KSHV antigen K6 and able to kill KSHV/EBV infected B cells. This suggests that K6 may represent a vaccine antigen for the control of KSHV and its associated pathologies in high seroprevalence regions, such as Sub-Saharan Africa.

Epstein-Barr virus (EBV) is a likely prerequisite for multiple sclerosis (MS) but the underlying mechanisms are unknown. We investigated antibody and T cell responses to EBV in persons with MS (pwMS), healthy EBV-seropositive controls (HC) and post-infectious mononucleosis (POST-IM) individuals up to 6 months after disease resolution. The ability of EBV-specific T cell responses to target antigens from the central nervous system (CNS) was also investigated.

Untreated persons with relapsing-remitting MS, POST-IM individuals and HC were, as far as possible, matched for gender, age and HLA-DRB1*15:01. EBV load was determined by qPCR, and IgG responses to key EBV antigens were determined by ELISA, immunofluorescence and Western blot, and tetanus toxoid antibody responses by multiplex bead array. EBV-specific T cell responses were determined ex vivo by intracellular cytokine staining (ICS) and cross-reactivity of in vitro-expanded responses probed against 9 novel Modified Vaccinia Ankara (MVA) viruses expressing candidate CNS autoantigens.

EBV load in peripheral blood mononuclear cells (PBMC) was unchanged in pwMS compared to HC. Serologically, while tetanus toxoid responses were unchanged between groups, IgG responses to EBNA1 and virus capsid antigen (VCA) were significantly elevated (EBNA1 p = 0.0079, VCA p = 0.0298) but, importantly, IgG responses to EBNA2 and the EBNA3 family antigens were also more frequently detected in pwMS (EBNA2 p = 0.042 and EBNA3 p = 0.005). In ex vivo assays, T cell responses to autologous EBV-transformed B cells and to EBNA1 were largely unchanged numerically, but significantly increased IL-2 production was observed in response to certain stimuli in pwMS. EBV-specific polyclonal T cell lines from both MS and HC showed high levels of autoantigen recognition by ICS, and several neuronal proteins emerged as common targets including MOG, MBP, PLP and MOBP.

Elevated serum EBV-specific antibody responses in the MS group were found to extend beyond EBNA1, suggesting a larger dysregulation of EBV-specific antibody responses than previously recognised. Differences in T cell responses to EBV were more difficult to discern, however stimulating EBV-expanded polyclonal T cell lines with 9 candidate CNS autoantigens revealed a high level of autoreactivity and indicate a far-reaching ability of the virus-induced T cell compartment to damage the CNS.

Allogeneic hematopoietic cell transplantation (alloHCT) provides a potential curative treatment for haematological malignancies. The therapeutic Graft-versus-Leukaemia (GvL) effect is induced by donor T cells attacking patient hematopoietic (malignant) cells. However, if healthy non-hematopoietic tissues are targeted, Graft-versus-Disease (GvHD) may develop. After HLA-matched alloHCT, GvL and GvHD are induced by donor T cells recognizing polymorphic peptides presented by HLA on patient cells, so-called minor histocompatibility antigens (MiHAs). The balance between GvL and GvHD depends on the tissue distribution of MiHAs and T-cell frequencies targeting these MiHAs. T cells against broadly expressed MiHAs induce GvL and GvHD, whereas those targeting MiHAs with hematopoietic-restricted expression induce GvL without GvHD. Recently, the MiHA repertoire identified in natural immune responses after alloHCT was expanded to 159 total HLA-I-restricted MiHAs, including 14 hematopoietic-restricted MiHAs. This review explores their potential relevance to predict, monitor, and manipulate GvL and GvHD for improving clinical outcome after HLA-matched alloHCT.

Acquired aplastic anemia is a bone marrow failure syndrome characterized by hypocellular bone marrow and peripheral blood pancytopenia. Frequent clinical responses to calcineurin inhibition and antithymocyte globulin strongly suggest critical roles for hematopoietic stem/progenitor cell-reactive T-cell clones in disease pathophysiology; however, their exact contribution and antigen specificities remain unclear. We determined differentiation states and targets of dominant T-cell clones along with their potential to eliminate hematopoietic progenitor cells in the bone marrow of 15 patients with acquired aplastic anemia. Single-cell sequencing and immunophenotyping revealed oligoclonal expansion and effector differentiation of CD8+ T-cell compartments. We reexpressed 28 dominant T-cell receptors (TCRs) of 9 patients in reporter cell lines to determine reactivity with (1) in vitro-expanded CD34+ bone marrow, (2) CD34- bone marrow, or (3) peptide pools covering immunodominant epitopes of highly prevalent viruses. Besides 5 cytomegalovirus-reactive TCRs, we identified 3 TCRs that recognized antigen presented on hematopoietic progenitor cells. T cells transduced with these TCRs eliminated hematopoietic progenitor cells of the respective patients in vitro. One progenitor cell-reactive TCR (11A5) also recognized an epitope of the Epstein-Barr virus-derived latent membrane protein 1 (LMP1) presented on HLA-A∗02:01. We identified 2 LMP1-related mimotopes within the human proteome as activating targets of TCR 11A5, providing proof of concept that molecular mimicry of viral and self-epitopes can drive T cell-mediated elimination of hematopoietic progenitor cells in aplastic anemia.

Multiple sclerosis (MS) is a chronic autoimmune disease of the central nervous system (CNS). MS results from an inflammatory process leading to the loss of neural tissue and increased disability over time. The role of Epstein Barr Virus (EBV), as one of the most common global viruses, in MS development has been the subject of several studies. However, many related questions are still unanswered. This study aimed to review the connection between MS and EBV and provide a quick outline of MS prevention using EBV vaccination.

For this narrative review, an extensive literature search using specific terms was conducted across online databases, including PubMed/Medline, Scopus, Web of Science, and Google Scholar, to identify pertinent studies.

Several studies proved that almost 100% of people with MS showed a history of EBV infection, and there was an association between high titers of EBV antibodies and an increased risk of MS development. Various hypotheses are proposed for how EBV may contribute to MS directly and indirectly: (1) Molecular Mimicry, (2) Mistaken Self, (3) Bystander Damage, and (4) Autoreactive B cells infected with EBV.

Given the infectious nature of EBV and its ability to elude the immune system, EBV emerges as a strong candidate for being the underlying cause of MS. The development of an EBV vaccine holds promise for preventing MS; however, overcoming the challenge of creating a safe and efficacious vaccine presents a significant obstacle.

EBV+ lymphomas constitute a significant cause of morbidity and mortality in recipients of allogeneic hematopoietic cell (HCT) and solid organ transplants (SOT). Phase I and II trials have shown that in HCT recipients, adoptive transfer of EBV-specific T-cells from the HCT donor can safely induce durable remissions of EBV+ lymphomas including 70->90% of patients who have failed to respond to treatment with Rituximab. More recently, EBV-specific T-cells generated from allogeneic 3rd party donors have also been shown to induce durable remission of EBV+ lymphomas in Rituximab refractory HCT and SOT recipients. In this review, we compare results of phase I and II trials of 3rd party and donor derived EBV-specific T-cells. We focus on the attributes and limitations of each product in terms of access, safety, responses achieved and durability. The limited data available regarding donor and host factors contributing to T cell persistence is also described. We examine factors contributing to treatment failures and approaches to prevent or salvage relapse. Lastly, we summarize strategies to further improve results for virus-specific immunotherapies for post-transplant EBV lymphomas.

Antibody-mediated delivery of immunogenic viral CD8+ T-cell epitopes to redirect virus-specific T cells toward cancer cells is a promising new therapeutic avenue to increase the immunogenicity of tumors. Multiple strategies for viral epitope delivery have been shown to be effective. So far, most of these have relied on a free C-terminus of the immunogenic epitope for extracellular delivery. Here, we demonstrate that antibody-epitope conjugates (AECs) with genetically fused epitopes to the N-terminus of the antibody can also sensitize tumors for attack by virus-specific CD8+ T cells. AECs carrying epitopes genetically fused at the N-terminus of the light chains of cetuximab and trastuzumab demonstrate an even more efficient delivery of the T-cell epitopes compared to AECs with the epitope fused to the C-terminus of the heavy chain. We demonstrate that this increased efficiency is not caused by the shift in location of the cleavage site from the N- to the C-terminus, but by its increased proximity to the cell surface. We hypothesize that this facilitates more efficient epitope delivery. These findings not only provide additional insights into the mechanism of action of AECs but also broaden the possibilities for genetically fused AECs as an avenue for the redirection of multiple virus-specific T cells toward tumors.

Antibody-mediated delivery of immunogenic epitopes to redirect virus-specific CD8+ T-cells towards cancer cells is an emerging and promising new therapeutic strategy. These so-called antibody-epitope conjugates (AECs) rely on the proteolytic release of the epitopes close to the tumor surface for presentation by HLA class I molecules to eventually redirect and activate virus-specific CD8+ T-cells towards tumor cells. We fused the immunogenic EBV-BRLF1 epitope preceded by a protease cleavage site to the C-terminus of the heavy and/or light chains of cetuximab and trastuzumab. We evaluated these AECs and found that, even though all AECs were able to redirect the EBV-specific T-cells, AECs with an epitope fused to the C-terminus of the heavy chain resulted in higher levels of T-cell activation compared to AECs with the same epitope fused to the light chain of an antibody. We observed that all AECs were depending on the presence of the antibody target, that the level of T-cell activation correlated with expression levels of the antibody target, and that our AECs could efficiently deliver the BRLF1 epitope to cancer cell lines from different origins (breast, ovarian, lung, and cervical cancer and a multiple myeloma). Moreover, in vivo, the AECs efficiently reduced tumor burden and increased the overall survival, which was prolonged even further in combination with immune checkpoint blockade. We demonstrate the potential of these genetically fused AECs to redirect the potent EBV-specific T-cells towards cancer in vitro and in vivo.

Epstein-Barr virus (EBV) infection in humans is associated with a wide range of diseases including malignancies of different origins, most prominently B cells. Several EBV latent genes are thought to act together in B cell immortalization, but a minimal set of EBV genes sufficient for transformation remains to be identified.

Here, we addressed this question by transducing human peripheral B cells from EBV-negative donors with retrovirus expressing the latent EBV genes encoding Latent Membrane Protein (LMP) 1 and 2A and Epstein-Barr Nuclear Antigen (EBNA) 2.

LMP1 together with EBNA2, but not LMP1 alone or in combination with LMP2A was able to transform human primary B cells. LMP1/EBNA2-immortalized cell lines shared surface markers with EBV-transformed lymphoblastoid cell lines (LCLs). They showed sustained growth for more than 60 days, albeit at a lower growth rate than EBV-transformed LCLs. LMP1/EBNA2-immortalized cell lines generated tumors when transplanted subcutaneously into severely immunodeficient NOG mice.

Our results identify a minimal set of EBV proteins sufficient for B cell transformation.

Infection with West Nile virus (WNV) drives a wide range of responses, from asymptomatic to flu-like symptoms/fever or severe cases of encephalitis and death. To identify cellular and molecular signatures distinguishing WNV severity, we employed systems profiling of peripheral blood from asymptomatic and severely ill individuals infected with WNV. We interrogated immune responses longitudinally from acute infection through convalescence employing single-cell protein and transcriptional profiling complemented with matched serum proteomics and metabolomics as well as multi-omics analysis. At the acute time point, we detected both elevation of pro-inflammatory markers in innate immune cell types and reduction of regulatory T cell activity in participants with severe infection, whereas asymptomatic donors had higher expression of genes associated with anti-inflammatory CD16+ monocytes. Therefore, we demonstrated the potential of systems immunology using multiple cell-type and cell-state-specific analyses to identify correlates of infection severity and host cellular activity contributing to an effective anti-viral response.

The avidity of the T-cell receptor (TCR) for antigenic peptides presented by the MHC (pMHC) on cells is an essential parameter for efficient T cell-mediated immunity. Yet, whether the TCR-ligand avidity can drive the clonal evolution of virus antigen-specific CD8 T cells, and how this process is determined in latent Cytomegalovirus (CMV)- against Epstein-Barr virus (EBV)-mediated infection remains largely unknown.

To address these issues, we quantified monomeric TCR-pMHC dissociation rates on CMV- and EBV-specific individual TCRαβ clonotypes and polyclonal CD8 T cell populations in healthy donors over a follow-up time of 15-18 years. The parameters involved during the long-term persistence of virus-specific T cell clonotypes were further evaluated by gene expression profiling, phenotype and functional analyses.

Within CMV/pp65-specific T cell repertoires, a progressive contraction of clonotypes with high TCR-pMHC avidity and low CD8 binding dependency was observed, leading to an overall avidity decline during long-term antigen exposure. We identified a unique transcriptional signature preferentially expressed by high-avidity CMV/pp65-specific T cell clonotypes, including the inhibitory receptor LILRB1. Interestingly, T cell clonotypes of high-avidity showed higher LILRB1 expression than the low-avidity ones and LILRB1 blockade moderately increased T cell proliferation. Similar findings were made for CD8 T cell repertoires specific for the CMV/IE-1 epitope. There was a gradual in vivo loss of high-avidity T cells with time for both CMV specificities, corresponding to virus-specific CD8 T cells expressing enhanced LILRB1 levels. In sharp contrast, the EBV/BMFL1-specific T cell clonal composition and distribution, once established, displayed an exceptional stability, unrelated to TCR-pMHC binding avidity or LILRB1 expression.

These findings reveal an overall long-term avidity decline of CMV- but not EBV-specific T cell clonal repertoires, highlighting the differing role played by TCR-ligand avidity over the course of these two latent herpesvirus infections. Our data further suggest that the inhibitor receptor LILRB1 potentially restricts the clonal expansion of high-avidity CMV-specific T cell clonotypes during latent infection. We propose that the mechanisms regulating the long-term outcome of CMV- and EBV-specific memory CD8 T cell clonotypes in humans are distinct.

Allogeneic stem cell transplantation is used to cure hematologic malignancies or deficiencies of the hematopoietic system. It is associated with severe immunodeficiency of the host early after transplant and therefore early reactivation of latent herpesviruses such as CMV and EBV within the first 100 days are frequent. Small studies and case series indicated that application of herpes virus specific T cells can control and prevent disease in this patient population.

We report the results of a randomized controlled multi centre phase I/IIa study (MULTIVIR-01) using a newly developed T cell product with specificity for CMV and EBV derived from the allogeneic stem cell grafts used for transplantation. The study aimed at prevention and preemptive treatment of both viruses in patients after allogeneic stem cell transplantation targeting first infusion on day +30. Primary endpoints were acute transfusion reaction and acute-graft versus-host-disease after infusion of activated T cells.

Thirty-three patients were screened and 9 patients were treated with a total of 25 doses of the T cell product. We show that central manufacturing can be achieved successfully under study conditions and the product can be applied without major side effects. Overall survival, transplant related mortality, cumulative incidence of graft versus host disease and number of severe adverse events were not different between treatment and control groups. Expansion of CMV/EBV specific T cells was observed in a fraction of patients, but overall there was no difference in virus reactivation.

Our study results indicate peptide stimulated epitope specific T cells derived from stem cell grafts can be administered safely for prevention and preemptive treatment of reactivation without evidence for induction of acute graft versus host disease.

https://clinicaltrials.gov, identifier NCT02227641.

Epstein-Barr virus (EBV), one of the most common human viruses, has been associated with both lymphoid and epithelial cancers. Undifferentiated nasopharyngeal carcinoma (NPC), EBV associated gastric cancer (EBVaGC) and lymphoepithelioma-like carcinoma (LELC) are amongst the few common epithelial cancers that EBV has been associated with. The pathogenesis of EBV-associated NPC has been well described, however, the same cannot be said for primary pulmonary LELC (PPLELC) owing to the rarity of the cancer. In this review, we outline the pathogenesis of EBV-associated NPC and EBVaGCs and their recent advances. By drawing on similarities between NPC and PPLELC, we then also postulated the pathogenesis of PPLELC. A deeper understanding about the pathogenesis of EBV enables us to postulate the pathogenesis of other EBV associated cancers such as PPLELC.

Concomitant malignant lymphoma at the time of transplantation is usually considered a contraindication to liver transplantation (LT). We report a case of Epstein-Barr virus (EBV)-associated malignant lymphoma that was latent preoperatively and rapidly became aggravated after LT. A 69-year-old man was referred to our hospital with an exacerbation of abdominal distension due to polycystic liver. As cystic infection, ascites, and deteriorated liver reserve function occurred after hepatic artery embolization, he underwent living-donor LT with his daughter as the donor. His respiratory condition worsened, and he was moved to the intensive care unit on postoperative day 34. Histopathologic examination of the excised liver returned around the same time revealed findings suggestive of EBV-associated malignant lymphoma in lymph nodes near the gallbladder. Subsequent computed tomography scans showed apparent neoplastic lesions in the abdominal cavity and worsening pleural effusion and ascites. Numerous atypical lymphocytes were observed in the pleural effusion and ascites, and the patient was diagnosed with exacerbation of EBV-associated malignant lymphoma. He was treated unsuccessfully with rituximab and died 66 days after LT. Caution should be exercised in elderly immunocompromised transplant candidates who may have comorbid EBV-associated lymphoproliferative disease.

Epstein-Barr virus (EBV) is a ubiquitous human tumor virus associated with various malignancies, including B-lymphoma, NK and T-lymphoma, and epithelial carcinoma. It infects B lymphocytes and epithelial cells within the oropharynx and establishes persistent infection in memory B cells. With a balanced virus-host interaction, most individuals carry EBV asymptomatically because of the lifelong surveillance by T cell immunity against EBV. A stable anti-EBV T cell repertoire is maintained in memory at high frequency in the blood throughout persistent EBV infection. Patients with impaired T cell immunity are more likely to develop life-threatening lymphoproliferative disorders, highlighting the critical role of T cells in achieving the EBV-host balance. Recent studies reveal that the EBV protein, LMP1, triggers robust T-cell responses against multiple tumor-associated antigens (TAAs) in B cells. Additionally, EBV-specific T cells have been identified in EBV-unrelated cancers, raising questions about their role in antitumor immunity. Herein, we summarize T-cell responses in EBV-related cancers, considering latency patterns, host immune status, and factors like human leukocyte antigen (HLA) susceptibility, which may affect immune outcomes. We discuss EBV-induced TAA-specific T cell responses and explore the potential roles of EBV-specific T cell subsets in tumor microenvironments. We also describe T-cell immunotherapy strategies that harness EBV antigens, ranging from EBV-specific T cells to T cell receptor-engineered T cells. Lastly, we discuss the involvement of γδ T-cells in EBV infection and associated diseases, aiming to elucidate the comprehensive interplay between EBV and T-cell immunity.

EBV is a lymphotropic virus, member of the Herpesviridae family that asymptomatically infects more than 90% of the human population, establishing a latent infection in memory B cells. EBV exhibits complex survival and persistence dynamics, replicating its genome through the proliferation of infected B cells or production of the lytic virions. Many studies have documented the infection of T/NK cells by EBV in healthy individuals during and after primary infection. This feature has been confirmed in humanized mouse models. Together these results have challenged the hypothesis that the infection of T/NK cells per se by EBV could be a triggering event for lymphomagenesis. Extranodal NK/T-cell lymphoma (ENKTCL) and Epstein-Barr virus (EBV)-positive nodal T- and NK-cell lymphoma (NKTCL) are two EBV-associated lymphomas of T/NK cells. These two lymphomas display different clinical, histological and molecular features. However, they share two intriguing characteristics: the association with EBV and a geographical prevalence in East Asia and Latin America. In this review we will discuss the genetic characteristics of EBV in order to understand the possible role of this virus in the oncogenesis of ENKTCL and NKTCL. In addition, the main immunohistological, molecular, cytogenetic and epigenetic differences between ENKTCL and NKTCL will be discussed, as well as EBV differences in latency patterns and other viral molecular characteristics.

The recent emergence of a causal link between Epstein-Barr virus (EBV) and multiple sclerosis has generated considerable interest in the development of an effective vaccine against EBV. Here we describe a vaccine formulation based on a lymph node targeting Amphiphile vaccine adjuvant, Amphiphile-CpG, admixed with EBV gp350 glycoprotein and an engineered EBV polyepitope protein that includes 20 CD8+ T cell epitopes from EBV latent and lytic antigens. Potent gp350-specific IgG responses are induced in mice with titers >100,000 in Amphiphile-CpG vaccinated mice. Immunization including Amphiphile-CpG also induces high frequencies of polyfunctional gp350-specific CD4+ T cells and EBV-specific CD8+ T cells that are 2-fold greater than soluble CpG and are maintained for >7 months post immunization. This combination of broad humoral and cellular immunity against multiple viral determinants is likely to provide better protection against primary infection and control of latently infected B cells leading to protection against the development of EBV-associated diseases.

Multiple immunopathological responses to viruses are observed in infectious mononucleosis (IM), a manifestation of primary infection with Epstein-Barr virus (EBV). Protective effects of the negative immunoregulatory molecule interleukin-37 (IL-37) have been observed in various bacterial and viral infections. However, the function of IL-37 in IM remains unknown.

Flow cytometry and enzyme-linked immunosorbent assay (ELISA) were used to determine the expression of IL-37 in the peripheral blood of patients diagnosed with IM, and the variation of lymphocyte subsets. Furthermore, the associations between IL-37 expression and the percentage of lymphocyte subgroups were analyzed.

Patients with IM had severe immune dysfunction. The control group had a lower expression of IL-37 than the patients with IM. There were significant associations between IL-37 expression and both the proportion of CD3⁺T cells and the ratio of CD3⁺CD4⁺ to CD3⁺CD8⁺T cells. Patients with higher levels of IL-37 expression had lower levels of the liver inflammation indicators, alanine aminotransferase (ALT) and aspartate aminotransferase (AST).

IL-37 may affect the immune pathogenesis of patients with IM infected with EBV, and may have immunotherapeutic benefit for EBV-associated illnesses.