Epstein-Barr Virus (EBV)-derived BARF1 encodes CD4- and CD8-restricted epitopes as targets for T-cell immunotherapy

Combinations of radiotherapy with immunotherapy in nasopharyngeal carcinoma

BACKGROUND

The treatment of nasopharyngeal carcinoma (NPC) is currently based on concurrent chemoradiotherapy. The prognosis of early NPC is better, while the prognosis of advanced NPC is poor. Immunotherapy is becoming increasingly commonly employed in clinical practice as a new strategy for treating malignant tumors. It has shown promising results in the treatment of certain malignant tumors, making it a current clinical research hotspot.

METHODS

This review summarizes the current immunotherapy on NPC, highlighting the application of immunotherapy and radiotherapy in the treatment of NPC.

RESULTS

X-rays can either increase or suppress anti-tumor immune responses through various pathways and mechanisms. Immune checkpoint inhibitors can usually enhance X-ray-induced anti-tumor immune responses. Detecting the immune checkpoint markers and tumor mutation markers, and the functional status of effector cells in patients can aid in the development of individualized treatment that improves the treatment efficacy with reducing drug resistance and adverse reactions. The development of a multivalent vaccine for NPC will help improve the efficacy of the vaccine. Combining techniques that increase the tumor antigens release, such as radiotherapy and oncolytic virus vaccines, may enhance the ability of the immune response.

CONCLUSIONS

To shed further light on the application of immunotherapy in NPC, large pooled studies must accumulate sufficient cases with detailed exposure data.

Transcriptomics of Epstein-Barr virus aids to the classification of T-cell evasion in nasopharyngeal carcinoma

Epstein-Barr virus (EBV) contributes to oncogenesis and immune evasion in nasopharyngeal carcinoma (NPC). At present, an aggregated, higher-level view on the impact of EBV genes toward the immune microenvironment of NPC is lacking. To this end, we have interrogated tumor-derived RNA sequences of 106 treatment-naive NPC patients for 98 EBV transcripts, and captured the presence of 10 different immune cell populations as well as 23 different modes of T-cell evasion. We discovered 3 clusters of EBV genes that each associate with distinct immunophenotypes of NPC. Cluster 1 associated with gene sets related to immune cell recruitment, such as those encoding for chemoattractants and their receptors. Cluster 2 associated with antigen processing and presentation, such as interferon-related genes, whereas cluster 3 associated with presence of M1-like macrophages, absence of CD4+ T cells, and oncogenic pathways, such as the nuclear factor kappa light-chain enhancer of activated B-cell pathway. We discuss these 3 EBV clusters regarding their potential for stratification for T-cell immunity in NPC together with the next steps needed to validate such therapeutic value.

Emerging predictive biomarkers for novel therapeutics in peripheral T-cell and natural killer/T-cell lymphoma

Peripheral T-cell lymphoma (PTCL) and natural killer/T-cell lymphoma (NKTCL) are rare subtypes of non-Hodgkin's lymphoma that are typically associated with poor treatment outcomes. Contemporary first-line treatment strategies generally involve the use of combination chemoimmunotherapy, radiation and/or stem cell transplant. Salvage options incorporate a number of novel agents including epigenetic therapies (e.g. HDAC inhibitors, DNMT inhibitors) as well as immune checkpoint inhibitors. However, validated biomarkers to select patients for individualized precision therapy are presently lacking, resulting in high treatment failure rates, unnecessary exposure to drug toxicities, and missed treatment opportunities. Recent advances in research on the tumor and microenvironmental factors of PTCL and NKTCL, including alterations in specific molecular features and immune signatures, have improved our understanding of these diseases, though several issues continue to impede progress in clinical translation. In this Review, we summarize the progress and development of the current predictive biomarker landscape, highlight potential knowledge gaps, and discuss the implications on novel therapeutics development in PTCL and NKTCL.

The generation and application of antigen-specific T cell therapies for cancer and viral-associated disease

Immunotherapy with antigen-specific T cells is a promising, targeted therapeutic option for patients with cancer as well as for immunocompromised patients with virus infections. In this review, we characterize and compare current manufacturing protocols for the generation of T cells specific to viral and non-viral tumor-associated antigens. Specifically, we discuss: (1) the different methodologies to expand virus-specific T cell and non-viral tumor-associated antigen-specific T cell products, (2) an overview of the immunological principles involved when developing such manufacturing protocols, and (3) proposed standardized methodologies for the generation of polyclonal, polyfunctional antigen-specific T cells irrespective of donor source. Ex vivo expanded cells have been safely administered to treat numerous patients with virus-associated malignancies, hematologic malignancies, and solid tumors. Hence, we have performed a comprehensive review of the clinical trial results evaluating the safety, feasibility, and efficacy of these products in the clinic. In summary, this review seeks to provide new insights regarding antigen-specific T cell technology to benefit a rapidly expanding T cell therapy field.

DNA immunotherapy targeting BARF1 induces potent anti-tumor responses against Epstein-Barr-virus-associated carcinomas

Latent Epstein-Barr virus (EBV) infection is associated with several types of cancer. Several clinical studies have targeted EBV antigens as immune therapeutic targets with limited efficacy of EBV malignancies, suggesting that additional targets might be important. BamHI-A rightward frame 1 (BARF1) is an EBV antigen that is highly expressed in EBV+ nasopharyngeal carcinoma (NPC) and EBV-associated gastric carcinoma (EBVaGC). BARF1 antigen can transform human epithelial cells in vivo. BARF1-specific antibodies and cytotoxic T cells were detected in some EBV+ NPC patients. However, BARF1 has not been evaluated as an antigen in the context of therapeutic immunization. Its possible importance in this context is unclear. Here, we developed a synthetic-DNA-based expression cassette as immunotherapy targeting BARF1 (pBARF1). Immunization with pBARF1 induced potent antigen-specific humoral and T cell responses in vivo. Immunization with pBARF1 plasmid impacted tumor progression through the induction of CD8+ T cells in novel BARF1+ carcinoma models. Using an in vivo imaging system, we observed that pBARF1-immunized animals rapidly cleared cancer cells. We demonstrated that pBARF1 can induce antigen-specific immune responses that can impact cancer progression. Further study of this immune target is likely important as part of therapeutic approaches for EBV+ malignancies.

Prophylactic and Therapeutic EBV Vaccines: Major Scientific Obstacles, Historical Progress, and Future Direction

The Epstein-Barr virus (EBV) infects more than 95% of adults worldwide and is associated with various malignant tumors and immune diseases, imparting a huge disease burden on the human population. Available EBV vaccines are imminent. Prophylactic vaccines can effectively prevent the spread of infection, whereas therapeutic vaccines mainly stimulate cell-mediated immunity and kill infected cells, thus curbing the development of malignant tumors. Nevertheless, there are still no approved EBV vaccines after decades of effort. The complexity of the EBV life cycle, the lack of appropriate animal models, and the limited reports on adjuvant selection and immune responses are gravely impeding progress in EBV vaccines. The soluble gp350 vaccine could reduce the incidence of infectious mononucleosis (IM), which seemed to offer hope, but could not prevent EBV infection. Continuous research and vaccine trials provide deep insights into the structural biology of viruses, the designs for immunogenicity, and the evolving vaccine platforms. Moreover, the new vaccine candidates are expected to achieve further success via combined immunization to elicit both a dual protection of B cells and epithelial cells, and sustainable immunization against infected cells at several phases of infection.

Adoptive T-cell therapy for Hodgkin lymphoma

Although CAR T-cell therapy is US Food and Drug Administration-approved for B-cell non-Hodgkin lymphomas, the development of adoptive immunotherapy for the treatment of classic Hodgkin lymphoma (cHL) has not accelerated at a similar pace. Adoptive T-cell therapy with Epstein-Barr virus-specific cytotoxic T lymphocytes and CD30 CAR T cells have demonstrated significant clinical responses in early clinical trials of patients with cHL. Additionally, CD19 and CD123 CAR T cells that target the immunosuppressive tumor microenvironment in cHL have also been investigated. Here we discuss the landscape of clinical trials of adoptive immunotherapy for patients with cHL with a view toward current challenges and novel strategies to improve the development of CAR T-cell therapy for cHL.

Virus-specific T cells for malignancies - then, now and where to?

Purpose of Review

Virus-associated malignancies are a global health burden, constituting 10-12% of cancers worldwide. As these tumors express foreign viral antigens that can elicit specific T cell responses, virus-directed immunotherapies are a promising treatment strategy. Specifically, adoptive cell transfer of virus-specific T cells (VSTs) has demonstrated the potential to eradicate cancers associated with certain viruses.

Recent Findings

Initial studies in 1990s first showed that VSTs specific for the Epstein-Barr virus (EBVSTs) can induce complete remissions in patients with post-transplant lymphoproliferative disease. Since then, studies have validated the specificity and safety of VSTs in multiple lymphomas and solid malignancies. However, challenges remain to optimize this platform for widespread use, including enhancing potency and persistence, overcoming the immunosuppressive tumor microenvironment, and streamlining manufacturing processes that comply with regulatory requirements.

Summary

This review focuses on data from clinical trials evaluating VSTs directed against three viruses (EBV, HPV and MCPyV), as well as recent preclinical and clinical advances, and potential future directions.

Role of BamHI-A Rightward Frame 1 in Epstein-Barr Virus-Associated Epithelial Malignancies

Simple Summary

Epstein–Barr virus is a ubiquitous persistent virus, which is involved in the development of some human cancers. A licensed vaccine to prevent Epstein–Barr virus infection is lacking. BamHI-A rightward frame 1 is a viral protein specifically detected in both nasopharyngeal and Epstein–Barr virus-positive gastric cancers. It has been proposed that this viral protein confers cancer properties to infected epithelial cells and is involved in the escape of cancer cells from immune recognition. In this review, we summarize the properties of BamHI-A rightward frame 1 which confers cancer characteristics to infected epithelial cells. Thus, BamHI-A rightward frame 1 is a potential therapeutic target for the treatment of either Epstein–Barr virus (EBV)-positive nasopharyngeal or gastric cancers.

Abstract

Epstein–Barr virus (EBV) infection is associated with a subset of both lymphoid and epithelial malignancies. During the EBV latency program, some viral products involved in the malignant transformation of infected cells are expressed. Among them, the BamHI-A rightward frame 1 (BARF1) is consistently detected in nasopharyngeal carcinomas (NPC) and EBV-associated gastric carcinomas (EBVaGCs) but is practically undetectable in B-cells and lymphomas. Although BARF1 is an early lytic gene, it is expressed during epithelial EBV latency, mainly as a secreted protein (sBARF1). The capacity of sBARF1 to disrupt both innate and adaptive host antiviral immune responses contributes to the immune escape of infected cells. Additionally, BARF1 increases cell proliferation, shows anti-apoptotic effects, and promotes an increased hTERT activity and tumor formation in nude mice cooperating with other host proteins such as c-Myc and H-ras. These facts allow for the consideration of BARF1 as a key protein for promoting EBV-associated epithelial tumors. In this review, we focus on structural and functional aspects of BARF1, such as mechanisms involved in epithelial carcinogenesis and its capacity to modulate the host immune response.

Immunology of EBV-Related Lymphoproliferative Disease in HIV-Positive Individuals

Epstein-Bar virus (EBV) can directly cause lymphoproliferative disease (LPD), including AIDS-defining lymphomas such as Burkitt’s lymphoma and other non-Hodgkin lymphomas (NHL), as well as human immunodeficiency virus (HIV)-related Hodgkin lymphoma (HL). The prevalence of EBV in HL and NHL is elevated in HIV-positive individuals compared with the general population. Rates of incidence of AIDS-defining cancers have been declining in HIV-infected individuals since initiation of combination anti-retroviral therapy (cART) use in 1996. However, HIV-infected persons remain at an increased risk of cancers related to infections with oncogenic viruses. Proposed pathogenic mechanisms of HIV-related cancers include decreased immune surveillance, decreased ability to suppress infection-related oncogenic processes and a state of chronic inflammation marked by alteration of the cytokine profile and expanded numbers of cytotoxic T lymphocytes with down-regulated co-stimulatory molecules and increased expression of markers of senescence in the setting of treated HIV infection. Here we discuss the cooperation of EBV-infected B cell- and environment-associated factors that may contribute to EBV-related lymphomagenesis in HIV-infected individuals. Environment-derived lymphomagenic factors include impaired host adaptive and innate immune surveillance, cytokine dysregulation and a pro-inflammatory state observed in the setting of chronic, cART-treated HIV infection. B cell factors include distinctive EBV latency patterns and host protein expression in HIV-associated LPD, as well as B cell-stimulating factors derived from HIV infection. We review the future directions for expanding therapeutic approaches in targeting the viral and immune components of EBV LPD pathogenesis.

The Therapeutic Potential of Targeting BARF1 in EBV-Associated Malignancies

Epstein-Barr virus (EBV) is closely linked to the development of a number of human cancers. EBV-associated malignancies are characterized by a restricted pattern of viral latent protein expression which is sufficient for the virus to both initiate and sustain cell growth and to protect virus-infected cells from immune attack. Expression of these EBV proteins in malignant cells provides an attractive target for therapeutic intervention. Among the viral proteins expressed in the EBV-associated epithelial malignancies, the protein encoded by the BamHI-A rightward frame 1 (BARF1) is of particular interest. BARF1 is a viral oncoprotein selectively expressed in latently infected epithelial cancers, nasopharyngeal carcinoma (NPC) and EBV-positive gastric cancer (EBV-GC). Here, we review the roles of BARF1 in oncogenesis and immunomodulation. We also discuss potential strategies for targeting the BARF1 protein as a novel therapy for EBV-driven epithelial cancers.

Establishment and Preservation of Lymphoblastoid Cell Lines from Fresh and Frozen Whole Blood and Mononuclear Cells

Although blood cells are interesting sources for genome investigations, one of the main problems in obtaining genomic DNA from blood is the restricted amount of DNA. This obstacle can be avoided by generating Epstein-Barr virus (EBV)-induced B cell lines. This study investigates the efficiency of four different methods to generate lymphoblastoid cell lines (LCLs). Blood samples (n = 120) were obtained from donors and categorized into four groups: fresh whole blood, frozen whole blood, fresh peripheral blood mononuclear cells (PBMCs), and frozen PBMCs. The samples were followed by EBV transformation to generate LCLs. Quality control and authentication of the cells were performed using multiplex PCR and short tandem repeat (STR) analyses. Finally, we assessed the success rate and amount of time to establish the cell lines in each group. The results showed that the cells were not contaminated nor were they misidentified or cross-contaminated with other cells. The success rate of LCLs generated from the whole blood groups was lower than the PBMC groups. The freezing procedures did not have any considerable effect on the establishment of lymphoblastoid cells. These established cells have been preserved in the human and animal cell bank of the Iranian Biological Resource Center (IBRC) and are available for researchers. Due to the management and transformation of a substantial number of blood samples, we recommend that researchers freeze PBMCs for further use with high efficiency and time-saving. We suggest that whole fresh blood should be directly transformed when the volume of the blood sample is less than 0.5 ml.

Genetic risk score combining six genetic variants associated with the cellular NRF2 expression levels correlates with Type 2 diabetes in the human population

BACKGROUND

Type 2 diabetes (T2D) is known as an inflammatory disease. NRF2 (Nuclear Factor Erythroid 2 Like2) encodes a transcription factor that binds to antioxidant response elements (AREs) and regulates the expression of genes involved in many antioxidant responses.

OBJECTIVE

This study aimed to gain insight into individual anti-inflammatory activity to prevent T2D development in humans.

METHODS

We performed a genome-wide association study (GWAS) to identify genetic variants influencing NRF2 expression in LCLs (lymphoblastoid cell lines) generated from 74 different individuals. Association analyses between T2D or its related traits and genetic risk score (GRS) calculated by combining genetic variants detected from GWAS for cellular NRF2 expression were performed using data from 8715 subjects. The T2D prediction model using GRS was evaluated by measuring the area under the curve (AUC) of the receiver operating characteristics (ROC) curve.

RESULTS

Our GWAS identified six genetic variants (SNP) showing suggestive evidence of associations with cellular NRF2 expression (P < 10^- 6). Logistic regression analysis demonstrated that GRS was associated with an increased risk of T2D (P value = 0.003, OR = 1.13). In addition, linear regression analyses showed positive associations between GRS and fasting glucose (P value = 0.028, β = 0.62), 2-h glucose (P value = 0.0004, β = 1.13) and HbA1C (P value = 0.033, β = 0.03). In the T2D prediction model using GRS, the AUC of the ROC curve was 0.69.

CONCLUSION

This study highlights genetic variants associated with cellular NRF2 expression and suggests that the GRS of NRF2 expression-associated variants is likely to be a useful indicator of T2D development in the human population.