Epstein-Barr virus strain variation and cancer

Construction of rBCG carrying the IL-2-BZLF1 fusion gene and its immunological function

In this research, a recombinant Bacillus Calmette Guerin (rBCG) vector vaccine carrying a human IL-2 and EBV BZLF1 fusion gene (IL-2-BZLF1-rBCG) was constructed. The IL-2-BZLF1-rBCG construct was successfully generated and stably expressed the IL-2 and BZLF1 proteins. IL-2-BZLF1-rBCG activated the immune system and promoted the secretion of IFN-γ and TNF-α by CD4+ and CD8+ T cells. IL-2-BZLF1-rBCG activated lymphocytes to effectively kill EBV-positive NPC cells in vitro. Additionally, IL-2-BZLF1-rBCG stimulated the proliferation of NK cells and lymphocytes in vivo, activated related immune responses, and effectively treated EBV-positive NPC. The immune response to and pharmacological effect of IL-2-BZLF1-rBCG were explored in vitro and in vivo to provide a theoretical and experimental basis for the prevention and treatment of EBV-positive tumors with an rBCG vector vaccine. KEY POINTS: • rBCG with human IL-2 and BZLF1 of EB virus was constructed • The IL-2-BZLF1 fusion gene was stably expressed with rBCG • rBCG with IL-2-BZLF1 has an obvious immune response in vitro and in vivo.

dbEBV: A database of Epstein-Barr virus variants and their correlations with human health

Since Epstein-Barr virus (EBV) was discovered in 1964, it has been reported to be associated with various malignancies as well as benign diseases, and the pathogenicity of EBV has been widely studied. Several databases have been established to provide comprehensive information on the virus and its relation to diseases and introduce convenient analysis tools. Although they have greatly facilitated the analysis of EBV at the genome, gene, protein, or epitope level, they did not provide enough insight into the genomic variants of EBV, which have been suggested as relevant to diseases by multiple studies. Here, we introduce dbEBV, a comprehensive database of EBV genomic variation landscape, which contains 942 EBV genomes with 109,893 variants from different tissues or cell lines in 24 countries. The database enables the visualization of information with varying global frequencies and their relationship with the human health of each variant. It also supports phylogenetic analysis at the genome or gene level in subgroups of different characteristics. Information of interest can easily be reached with functions such as searching, browsing, and filtering. In conclusion, dbEBV is a convenient resource for exploring EBV genomic variants, freely available at http://dbebv.omicsbio.info.

Demonstration of Epstein-Barr Virus by In Situ Hybridization in Papillary Thyroid Carcinomas Developing on Background of Hashimoto's Thyroiditis

AIM

This study aimed to demonstrate the role of Epstein-Barr Virus (EBV) in papillary thyroid carcinomas (PTC) developing on the background of Hashimoto's thyroiditis (HT).

METHODS

The presence of EBV in tumoral tissue, lymphocytes, and peritumoral normal thyroid tissue was investigated using the in situ hybridization method in paraffin blocks. The subtypes of PTC, tumor diameter, TNM stage, multifocality, invasion of thyroid capsule, perineural invasion, and muscular tissue invasion were identified and compared according to EBV involvement.

RESULTS

Eighty-one patients with HT diagnosis, with 93.8% (n=76) female and 6.2% (n=5) male, were included in the study. Papillary microcarcinoma was the pathological diagnosis in 24.2% (n=15) of the cases. EBV was identified in 58.06% (n=36) of the tumor cells nuclei, 58.06% (n=36) in the tumor cell cytoplasm, 16.12% (n=10) in tumor infiltrative lymphocytes, and 53.2% (n=33) in normal parenchymal follicle epithelial cells (NPFEC). In the T2 stage, the rate of EBV nuclear positivity in patients was significantly higher (p=0.034). The classic variant of papillary carcinoma was accompanied by a significantly higher rate of EBV-negative NPFEC (67.6%, p=0.049). In multifocal tumors, EBV positivity was found to be significantly higher in lymphocytes in the surrounding tissues (58.3%, p=0.034).

CONCLUSION

A significant increase in EBV positivity in the surrounding tissue lymphocytes was observed in multifocal PTC developing on a background of HT. This suggests a possible association between HT and EBV.

Adaptive natural killer cell expression in response to cytomegalovirus infection in blood and solid cancer

Natural Killer (NK) cells are conventionally thought to be an indefinite part of innate immunity. However, in a specific subset of NK cells, recent data signify an extension of their "duties" in immune surveillance and response, having characteristics of adaptive immunity, in terms of persistence and cytotoxicity. These cells are known as the adaptive or memory-like NK cells, where human cytomegalovirus (HCMV) infection has been shown to drive the expansion of adaptive NKG2C+ NK cells. HCMV is a ubiquitous pathogen whose prevalence differs worldwide with respect to the socioeconomic status of countries. The adaptive NK cell subpopulation is often characterized by the upregulated expression of NKG2C, CD16, and CD2, and restricted expression of NKG2A, FCεRγ and killer immunoglobulin-like receptors (KIR), although these phenotypes may differ in different disease groups. The reconfiguration of these receptor distributions has been linked to epigenetic factors. Hence, this review attempts to appraise literature reporting markers associated with adaptive or memory-like NK cells post-HCMV infection, in relation to solid cancers and hematological malignancies. Adaptive NK cells, isolated and subjected to ex vivo modifications, have the potential to enhance anti-tumor response which can be a promising strategy for adoptive immunotherapy.

Evolutionary analysis of LMP-1 genetic diversity in EBV-associated nasopharyngeal carcinoma: Bioinformatic insights into oncogenic potential

EBV latent membrane protein 1 (LMP-1) is an important oncogene involved in the induction and maintenance of EBV infection and the activation of several cell survival and proliferative pathways. The genetic diversity of LMP-1 has an important role in immunogenicity and tumorigenicity allowing escape from host cell immunity and more metastatic potential of LMP-1 variants. This study explored the evolutionary of LMP-1 in EBV-infected patients at an advanced stage of nasopharyngeal carcinoma (NPC). Detection of genetic variability in LMP-1 genes was carried out using Sanger sequencing. Bioinformatic analysis was conducted for translation and nucleotide alignment. Phylogenetic analysis was used to construct a Bayesian tree for a deeper understanding of the genetic relationships, evolutionary connections, and variations between sequences. Genetic characterization of LMP-1 in NPC patients revealed the detection of polymorphism in LMP-1 Sequences. Motifs were identified within three critical LMP-1 domains, such as PQQAT within CTAR1 and YYD within CTAR2. The presence of the JACK3 region at specific sites within CTAR3, as well as repeat regions at positions (122-132) and (133-143) within CTAR3, was also annotated. Additionally, several mutations were detected including 30 and 69 bp deletions, 33 bp repeats, and 15 bp insertion. Although LMP-1 strains appear to be genetically diverse, they are closely related to 3 reference strains: prototype B95.8, Med- 30 bp deletion, and Med + 30 bp deletion. In our study, one of the strains harboring the 30 bp deletion had both bone and bone marrow metastasis which could be attributed to the fact that LMP-1 is involved in tumor metastasis, evasion and migration of NPC cells. This study provided valuable insights into genetic variability in LMP-1 sequences of EBV in NPC patients. Further functional studies would provide a more comprehensive understanding of the molecular characteristics, epidemiology, and clinical implications of LMP-1 polymorphisms in EBV-related malignancies.

Herpesvirus Infection of Endothelial Cells as a Systemic Pathological Axis in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

Understanding the pathophysiology of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is critical for advancing treatment options. This review explores the novel hypothesis that a herpesvirus infection of endothelial cells (ECs) may underlie ME/CFS symptomatology. We review evidence linking herpesviruses to persistent EC infection and the implications for endothelial dysfunction, encompassing blood flow regulation, coagulation, and cognitive impairment-symptoms consistent with ME/CFS and Long COVID. This paper provides a synthesis of current research on herpesvirus latency and reactivation, detailing the impact on ECs and subsequent systemic complications, including latent modulation and long-term maladaptation. We suggest that the chronicity of ME/CFS symptoms and the multisystemic nature of the disease may be partly attributable to herpesvirus-induced endothelial maladaptation. Our conclusions underscore the necessity for further investigation into the prevalence and load of herpesvirus infection within the ECs of ME/CFS patients. This review offers conceptual advances by proposing an endothelial infection model as a systemic mechanism contributing to ME/CFS, steering future research toward potentially unexplored avenues in understanding and treating this complex syndrome.

The viral etiology of EBV-associated gastric cancers contributes to their unique pathology, clinical outcomes, treatment responses and immune landscape

Epstein-Barr virus (EBV) is a pathogen known to cause a number of malignancies, often taking years for them to develop after primary infection. EBV-associated gastric cancer (EBVaGC) is one such malignancy, and is an immunologically, molecularly and pathologically distinct entity from EBV-negative gastric cancer (EBVnGC). In comparison with EBVnGCs, EBVaGCs overexpress a number of immune regulatory genes to help form an immunosuppressive tumor microenvironment (TME), have improved prognosis, and overall have an "immune-hot" phenotype. This review provides an overview of the histopathology, clinical features and clinical outcomes of EBVaGCs. We also summarize the differences between the TMEs of EBVaGCs and EBVnGCs, which includes significant differences in cell composition and immune infiltration. A list of available EBVaGC and EBVnGC gene expression datasets and computational tools are also provided within this review. Finally, an overview is provided of the various chemo- and immuno-therapeutics available in treating gastric cancers (GCs), with a focus on EBVaGCs.

The IPTA Nashville Consensus Conference on Post-Transplant lymphoproliferative disorders after solid organ transplantation in children: III - Consensus guidelines for Epstein-Barr virus load and other biomarker monitoring

The International Pediatric Transplant Association convened an expert consensus conference to assess current evidence and develop recommendations for various aspects of care relating to post-transplant lymphoproliferative disorders after solid organ transplantation in children. In this report from the Viral Load and Biomarker Monitoring Working Group, we reviewed the existing literature regarding the role of Epstein-Barr viral load and other biomarkers in peripheral blood for predicting the development of PTLD, for PTLD diagnosis, and for monitoring of response to treatment. Key recommendations from the group highlighted the strong recommendation for use of the term EBV DNAemia instead of "viremia" to describe EBV DNA levels in peripheral blood as well as concerns with comparison of EBV DNAemia measurement results performed at different institutions even when tests are calibrated using the WHO international standard. The working group concluded that either whole blood or plasma could be used as matrices for EBV DNA measurement; optimal specimen type may be clinical context dependent. Whole blood testing has some advantages for surveillance to inform pre-emptive interventions while plasma testing may be preferred in the setting of clinical symptoms and treatment monitoring. However, EBV DNAemia testing alone was not recommended for PTLD diagnosis. Quantitative EBV DNAemia surveillance to identify patients at risk for PTLD and to inform pre-emptive interventions in patients who are EBV seronegative pre-transplant was recommended. In contrast, with the exception of intestinal transplant recipients or those with recent primary EBV infection prior to SOT, surveillance was not recommended in pediatric SOT recipients EBV seropositive pre-transplant. Implications of viral load kinetic parameters including peak load and viral set point on pre-emptive PTLD prevention monitoring algorithms were discussed. Use of additional markers, including measurements of EBV specific cell mediated immunity was discussed but not recommended though the importance of obtaining additional data from prospective multicenter studies was highlighted as a key research priority.

The Role of LMP1 in Epstein-Barr Virus-associated Gastric Cancer

EBV promotes many cancers such as lymphoma, nasopharyngeal carcinoma, and gastric; Latent Membrane Protein 1 (LMP1) is considered to be a major oncogenic protein encoded by Epstein- Barr virus (EBV). LMP1 functions as a carcinogen in lymphoma and nasopharyngeal carcinoma, and LMP1 may also promote gastric cancer. The expression level of LMP1 in host cells is a key determinant in tumorigenesis and maintenance of virus specificity. By promoting cell immortalization and cell transformation, promoting cell proliferation, affecting immunity, and regulating cell apoptosis, LMP1 plays a crucial tumorigenic role in epithelial cancers. However, very little is currently known about LMP1 in Epstein-Barr virus-associated gastric cancer (EBVaGC); the main reason is that the expression level of LMP1 in EBVaGC is comparatively lower than other EBV-encoded proteins, such as The Latent Membrane Protein 2A (LMP2A), Epstein-Barr nuclear antigen 1 (EBNA1) and BamHI-A rightward frame 1 (BARF1), to date, there are few studies related to LMP1 in EBVaGC. Recent studies have demonstrated that LMP1 promotes EBVaGC by affecting The phosphatidylinositol 3-kinase- Akt (PI3K-Akt), Nuclear factor-kappa B (NF-κB), and other signaling pathways to regulate many downstream targets such as Forkhead box class O (FOXO), C-X-C-motif chemokine receptor (CXCR), COX-2 (Cyclooxygenase-2); moreover, the gene methylation induced by LMP1 in EBVaGC has become one of the characteristics that distinguish this gastric cancer (GC) from other types of gastric cancer and LMP1 also promotes the formation of the tumor microenvironment (TME) of EBVaGC in several ways. This review synthesizes previous relevant literature, aiming to highlight the latest findings on the mechanism of action of LMP1 in EBVaGC, summarize the function of LMP1 in EBVaGC, lay the theoretical foundation for subsequent new research on LMP1 in EBVaGC, and contribute to the development of novel LMP1-targeted drugs.

Involvement of CXC chemokines (CXCL1-CXCL17) in gastric cancer: Prognosis and therapeutic molecules

Gastric cancer (GC) is the fifth-most prevalent and second-most deadly cancer worldwide. Due to the late onset of symptoms, GC is frequently treated at a mature stage. In order to improve the diagnostic and clinical decision-making processes, it is necessary to establish more specific and sensitive indicators valuable in the early detection of the disease whenever a cancer is asymptomatic. In this work, we gathered information about CXC chemokines and GC by using scientific search engines including Google Scholar, PubMed, SciFinder, and Web of Science. Researchers believe that GC chemokines, small proteins, class CXC chemokines, and chemokine receptors promote GC inflammation, initiation, and progression by facilitating angiogenesis, tumor transformation, invasion, survival, metastatic spread, host response safeguards, and inter-cell interaction. With our absolute best professionalism, the role of CXC chemokines and their respective receptors in GC diagnosis and prognosis has not been fully explained. This review article updates the general characteristics of CXC chemokines, their unique receptors, their function in the pathological process of GC, and their potential application as possible indicators for GC. Although there have only recently been a few studies focusing on the therapeutic efficacy of CXC chemokine inhibitors in GC, growing experimental evidence points to the inhibition of CXC chemokines as a promising targeted therapy. Therefore, further translational studies are warranted to determine whether specific antagonists or antibodies designed to target CXC chemokines alone or in combination with chemotherapy are useful for diagnosing advanced GC.

Epstein-Barr Virus: Human Interactome Reveals New Molecular Insights into Viral Pathogenesis for Potential Therapeutics and Antiviral Drug Discovery

Host-virus Protein-Protein Interactions (PPIs) play pivotal roles in biological processes crucial for viral pathogenesis and by extension, inform antiviral drug discovery and therapeutics innovations. Despite efforts to develop the Epstein-Barr virus (EBV)-host PPI network, there remain significant knowledge gaps and a limited number of interacting human proteins deciphered. Furthermore, understanding the dynamics of the EBV-host PPI network in the distinct lytic and latent viral stages remains elusive. In this study, we report a comprehensive map of the EBV-human protein interactions, encompassing 1752 human and 61 EBV proteins by integrating data from the public repository HPIDB (v3.0) as well as curated high-throughput proteomic data from the literature. To address the stage-specific nature of EBV infection, we generated two detailed subset networks representing the latent and lytic stages, comprising 747 and 481 human proteins, respectively. Functional and pathway enrichment analysis of these subsets uncovered the profound impact of EBV proteins on cancer. The identification of highly connected proteins and the characterization of intrinsically disordered and cancer-related proteins provide valuable insights into potential therapeutic targets. Moreover, the exploration of drug-protein interactions revealed notable associations between hub proteins and anticancer drugs, offering novel perspectives for controlling EBV pathogenesis. This study represents, to the best of our knowledge, the first comprehensive investigation of the two distinct stages of EBV infection using high-throughput datasets. This makes a contribution to our understanding of EBV-host interactions and provides a foundation for future drug discovery and therapeutic interventions.

Targeting EBV-encoded products: Implications for drug development in EBV-associated diseases

Epstein-Barr virus, a human gamma-herpesvirus, has a close connection to the pathogenesis of cancers and other diseases, which are a burden for public health worldwide. So far, several drugs or biomolecules have been discovered that can target EBV-encoded products for treatment, such as Silvestrol, affinity toxin, roscovitine, H20, H31, curcumin, thymoquinone, and ribosomal protein L22. These drugs activate or inhibit the function of some biomolecules, affecting subsequent signalling pathways by acting on the products of EBV. These drugs usually target LMP1, LMP2; EBNA1, EBNA2, EBNA3; EBER1, EBER2; Bam-HI A rightward transcript and BHRF1. Additionally, some promising findings in the fields of vaccines, immunological, and cellular therapies have been established. In this review, we mainly summarise the function of drugs mentioned above and unique mechanisms, hoping that we can help giving insight to the design of drugs for the treatment of EBV-associated diseases.

The programed death-1/programed death ligand-1 axis and its potential as a therapeutic target for virus-associated tumours

As an important and serious condition impacting human health, the diagnosis, and treatment of tumours is clinically vital because tumour cell immune escape sustains tumour development. Programed death ligand-1 (PD-L1) on tumour cell surfaces binds to the programed death-1 (PD-1), inhibits T cell activation, and induces apoptosis, and incapacitates cells. This allows tumour cells to evade recognition and clearance by the immune system, thereby permitting tumour occurrence, and development and poor prognosis outcomes in patients with tumours. Currently, anti-PD-1/PD-L1 immunotherapy has become pivotal in tumour treatment. Pathogens, especially viruses, are important factors which induce many tumours. In this article, we examine associations between Epstein-Barr virus, human papilloma virus, hepatitis B virus, hepatitis C virus, and human immunodeficiency virus type 1-related tumours and PD-1/PD-L1 axis.

Recent Advances in Assessing the Clinical Implications of Epstein-Barr Virus Infection and Their Application to the Diagnosis and Treatment of Nasopharyngeal Carcinoma

Reports about the oncogenic mechanisms underlying nasopharyngeal carcinoma (NPC) have been accumulating since the discovery of Epstein-Barr virus (EBV) in NPC cells. EBV is the primary causative agent of NPC. EBV-host and tumor-immune system interactions underlie the unique representative pathology of NPC, which is an undifferentiated cancer cell with extensive lymphocyte infiltration. Recent advances in the understanding of immune evasion and checkpoints have changed the treatment of NPC in clinical settings. The main EBV genes involved in NPC are LMP1, which is the primary EBV oncogene, and BZLF1, which induces the lytic phase of EBV. These two multifunctional genes affect host cell behavior, including the tumor-immune microenvironment and EBV behavior. Latent infections, elevated concentrations of the anti-EBV antibody and plasma EBV DNA have been used as biomarkers of EBV-associated NPC. The massive infiltration of lymphocytes in the stroma suggests the immunogenic characteristics of NPC as a virus-infected tumor and, at the same time, also indicates the presence of a sophisticated immunosuppressive system within NPC tumors. In fact, immune checkpoint inhibitors have shown promise in improving the prognosis of NPC patients with recurrent and metastatic disease. However, patients with advanced NPC still require invasive treatments. Therefore, there is a pressing need to develop an effective screening system for early-stage detection of NPC in patients. Various modalities, such as nasopharyngeal cytology, cell-free DNA methylation, and deep learning-assisted nasopharyngeal endoscopy for screening and diagnosis, have been introduced. Each modality has its advantages and disadvantages. A reciprocal combination of these modalities will improve screening and early diagnosis of NPC.

Why does the herpes simplex 1 virus-encoded UL49.5 protein fail to inhibit the TAP-dependent antigen presentation?

Herpes simplex virus 1 (HSV-1) is a well-studied herpesvirus that causes various human diseases. Like other herpesviruses, HSV-1 produces the transmembrane glycoprotein N (gN/UL49.5 protein), which has been extensively studied, but its function in HSV-1 remains largely unknown. The amino-acid sequences and lengths of UL49.5 proteins differ between herpesvirus species. It is, therefore, crucial to determine whether and to what extent the spatial structure of UL49.5 orthologs that are transporter associated with antigen processing (TAP) inhibitors (i.e., of bovine herpesvirus 1; BoHV-1) differ from that of non-TAP inhibitors (i.e., of HSV-1). Our study aimed to examine the 3D structure of the HSV-1-encoded UL49.5 protein in an advanced model of the endoplasmic reticulum (ER) membrane using circular dichroism, 2D nuclear magnetic resonance, and multiple-microsecond all-atom molecular dynamics simulations in an ER membrane mimetic environment. According to our findings, the N-terminus of the HSV-1-encoded UL49.5 adopts a highly flexible, unordered structure in the extracellular part due to the presence of a large number of proline and glycine residues. In contrast to the BoHV-1-encoded homolog, the transmembrane region of the HSV-1-encoded UL49.5 is formed by a single long transmembrane α-helix, rather than two helices oriented perpendicularly, while the cytoplasmic part of the protein (C-terminus) has a short unordered structure. Our findings provide valuable experimental structural information on the HSV-1-encoded UL49.5 protein and offer, based on the obtained structure, insight into its lack of biological activity in inhibiting the TAP-dependent antigen presentation pathway.

Unique synapomorphies and high diversity in South American Raji-related Epstein-Barr virus genomes

BACKGROUND

Epstein-Barr virus (EBV) is a human gammaherpesvirus etiologically linked to several benign and malignant diseases. EBV-associated malignancies exhibit an unusual global distribution that might be partly attributed to virus and host genetic backgrounds.

OBJECTIVES

To assemble a new genome of EBV (CEMO3) from a paediatric Burkitt's lymphoma from Rio de Janeiro State (Southeast Brazil). In addition, to perform global phylogenetic analysis using complete EBV genomes, including CEMO3, and investigate the genetic relationship of some South American (SA) genomes through EBV subgenomic targets.

METHODS

CEMO3 was sequenced through next generation sequencing and its coverage and gaps were corrected through the Sanger method. CEMO3 and 67 EBV genomes representing diverse geographic regions were evaluated through maximum likelihood phylogenetic analysis. Further, the polymorphism of subgenomic regions of some SA EBV genomes were assessed.

FINDINGS

The whole bulk tumour sequencing yielded 23,217 reads related to EBV, which 172,713 base pairs of the newly EBV genome CEMO3 was assembled. The CEMO3 and most SA EBV genomes clustered within the SA subclade closely related to the African Raji strain, forming the South American/Raji clade. Notably, these Raji-related genomes exhibit significant genetic diversity, characterised by distinctive synapomorphies at some gene levels absent in the original Raji strain.

CONCLUSION

The CEMO3 represents a new South American EBV genome assembled. Albeit the majority of EBV genomes from SA are Raji-related, it harbours a high diversity different from the original Raji strain.

Predictive Biomarkers for Immunotherapy in Gastric Cancer: Current Status and Emerging Prospects

Gastric cancer presents substantial management challenges, and the advent of immunotherapy has ignited renewed hope among patients. Nevertheless, a significant proportion of patients do not respond to immunotherapy, and adverse events associated with immunotherapy also occur on occasion, underscoring the imperative to identify suitable candidates for treatment. Several biomarkers, including programmed death ligand-1 expression, tumor mutation burden, mismatch repair status, Epstein-Barr Virus infection, circulating tumor DNA, and tumor-infiltrating lymphocytes, have demonstrated potential in predicting the effectiveness of immunotherapy in gastric cancer. However, the quest for the optimal predictive biomarker for gastric cancer immunotherapy remains challenging, as each biomarker carries its own limitations. Recently, multi-omics technologies have emerged as promising platforms for discovering novel biomarkers that may help in selecting gastric cancer patients likely to respond to immunotherapy. The identification of reliable predictive biomarkers for immunotherapy in gastric cancer holds the promise of enhancing patient selection and improving treatment outcomes. In this review, we aim to provide an overview of clinically established biomarkers of immunotherapy in gastric cancer. Additionally, we introduce newly reported biomarkers based on multi-omics studies in the context of gastric cancer immunotherapy, thereby contributing to the ongoing efforts to refine patient stratification and treatment strategies.

Contribution of the Epstein-Barr virus to the oncogenesis of mature T-cell lymphoproliferative neoplasms

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.

Comparison of first-line immunotherapy efficacy between advanced lung squamous cell carcinoma and pulmonary lymphoepithelioma-like carcinoma: A propensity score matching multicenter study

Background

Compared with other lung squamous cell carcinomas (LUSC), pulmonary lymphoepithelioma-like carcinoma (pLELC) is closely associated with Epstein-Barr virus (EBV) infections with a unique molecular profile and immune microenvironment. This study was thus established to compare the treatment response and effectiveness of immunotherapy between pLELC and LUSC.

Material and Methods

We enrolled 31 patients with pLELC and 116 with LUSC receiving first-line immunotherapy at three centers in China and compared the treatment response and effectiveness of immunotherapy. Propensity score matching (PSM) was used to balance the differences in baseline data between the two groups.

Results

Before PSM, progression-free survival and overall survival were longer in the pLELC group than in the LUSC group (progression-free survival: hazard ratio (HR), 1.67, 95% CI: 1.05-2.63, P = 0.028; overall survival: HR, 1.90, 95% CI: 1.06-3.40, P = 0.028). This remained unchanged after PSM (progression-free survival: HR, 1.79, 95% CI: 1.02-3.15, P = 0.044; overall survival: HR, 2.20; 95% CI: 1.10-4.37, P = 0.022).

Conclusion

pLELC showed a clinically meaningful survival benefit compared with traditional LUSC following immunotherapy. Subsequent studies should consider the role of the EBV in the tumor immune microenvironment of pLELC.

Extranodal NK-/T-cell lymphoma, nasal type: what advances have been made in the last decade?

Extranodal NK-/T-cell lymphoma (ENKTCL) is a rare and highly aggressive malignancy with significant racial and geographic variations worldwide. In addition to the formerly "nasal-type" initial description, these lymphomas are predominantly extranodal in origin and typically cause vascular damage and tissue destruction, and although not fully understood, Epstein-Barr virus (EBV) has an important role in its pathogenesis. Initial assessment must include a hematopathology review of representative and viable tumor areas without necrosis for adequate immunohistochemistry studies, including EBV-encoded small RNA (EBER) in situ hybridization (ISH). Positron emission tomography with 18-fluorodeoxyglucose (¹⁸F-FDG-PET/CT) for accurate staging is essential, and most patients will have localized disease (IE/IIE) at diagnosis. Apart from other T-cell malignancies, the best treatment even for localized cases is combined modality therapy (chemotherapy plus radiotherapy) with non-anthracycline-based regimens. For advanced-stage disease, l-asparaginase-containing regimens have shown improved survival, but relapsed and refractory cases have very poor outcomes. Nowadays, even with a better understanding of pathogenic pathways, up-front therapy is completely based on chemotherapy and radiotherapy, and treatment-related mortality is not low. Future strategies targeting signaling pathways and immunotherapy are evolving, but we need to better identify those patients with dismal outcomes in a pre-emptive way. Given the rarity of the disease, international collaborations are urgently needed, and clinical trials are the way to change the future.

Circulating tumor DNA in NK/T and peripheral T cell lymphoma

Natural killer (NK)/T-cell lymphomas (NK/TCL) and peripheral T-cell lymphomas (PTCL) are aggressive hematological malignancies. With the development of next-generation sequencing, circulating tumor DNA (ctDNA) can be detected by several techniques with clinical implications. So far, the effect of ctDNA in pretreatment prognosis prediction, longitudinal monitoring of treatment response and surveillance of long-term remission or relapse in NK/TCL and PTCL has been reported in several researches.

Hemoglobinopathies, merozoite surface protein-2 gene polymorphisms, and acquisition of Epstein Barr virus among infants in Western Kenya

BACKGROUND

Epstein Barr virus (EBV)-associated endemic Burkitt's Lymphoma pediatric cancer is associated with morbidity and mortality among children resident in holoendemic Plasmodium falciparum regions in western Kenya. P. falciparum exerts strong selection pressure on sickle cell trait (SCT), alpha thalassemia (-α^3.7/αα), glucose-6-phosphate dehydrogenase (G6PD), and merozoite surface protein 2 (MSP-2) variants (FC27, 3D7) that confer reduced malarial disease severity. The current study tested the hypothesis that SCT, (-α^3.7/αα), G6PD mutation and (MSP-2) variants (FC27, 3D7) are associated with an early age of EBV acquisition.

METHODS

Data on infant EBV infection status (< 6 and ≥ 6-12 months of age) was abstracted from a previous longitudinal study. Archived infant DNA (n = 81) and mothers DNA (n = 70) samples were used for genotyping hemoglobinopathies and MSP-2. The presence of MSP-2 genotypes in maternal DNA samples was used to indicate infant in-utero malarial exposure. Genetic variants were determined by TaqMan assays or standard PCR. Group differences were determined by Chi-square or Fisher's analysis. Bivariate regression modeling was used to determine the relationship between the carriage of genetic variants and EBV acquisition.

RESULTS

EBV acquisition for infants < 6 months was not associated with -α^3.7/αα (OR = 1.824, P = 0.354), SCT (OR = 0.897, P = 0.881), or G6PD [Viangchan (871G > A)/Chinese (1024 C > T) (OR = 2.614, P = 0.212)] and [Union (1360 C > T)/Kaiping (1388G > A) (OR = 0.321, P = 0.295)]. There was no relationship between EBV acquisition and in-utero exposure to either FC27 (OR = 0.922, P = 0.914) or 3D7 (OR = 0.933, P = 0.921). In addition, EBV acquisition in infants ≥ 6-12 months also showed no association with -α^3.7/αα (OR = 0.681, P = 0.442), SCT (OR = 0.513, P = 0.305), G6PD [(Viangchan (871G > A)/Chinese (1024 C > T) (OR = 0.640, P = 0.677)], [Mahidol (487G > A)/Coimbra (592 C > T) (OR = 0.948, P = 0.940)], [(Union (1360 C > T)/Kaiping (1388G > A) (OR = 1.221, P = 0.768)], African A (OR = 0.278, P = 0.257)], or in utero exposure to either FC27 (OR = 0.780, P = 0.662) or 3D7 (OR = 0.549, P = 0.241).

CONCLUSION

Although hemoglobinopathies (-α^3.7/αα, SCT, and G6PD mutations) and in-utero exposure to MSP-2 were not associated with EBV acquisition in infants 0-12 months, novel G6PD variants were discovered in the population from western Kenya. To establish that the known and novel hemoglobinopathies, and in utero MSP-2 exposure do not confer susceptibility to EBV, future studies with larger sample sizes from multiple sites adopting genome-wide analysis are required.

Lymphoproliferative disorder during temozolomide therapy; a representative case of a formidable complication and management challenges

BACKGROUND

Lymphoproliferative disorder represents a heterogeneous clinicopathological spectrum characterized by uncontrolled proliferation of lymphocytes. Immunodeficiency is a major trigger of its development. While induction of immunodeficiency is a well-known adverse effect of temozolomide therapy, development of lymphoproliferative disorder following temozolomide therapy has not previously been described.

CASE PRESENTATION

A patient with brainstem glioma developed constitutional symptoms, pancytopenia, splenomegaly and generalized lymphadenopathy during the 2nd cycle of maintenance therapy following induction therapy with temozolomide. Epstein-Barr virus-infected lymphocytes were observed histopathologically and "other iatrogenic immunodeficiency-associated lymphoproliferative disorder" (OIIA-LPD) was diagnosed. Although discontinuation of temozolomide led to rapid remission, relapse was observed 4 months later. CHOP chemotherapy was induced, resulting in secondary remission. Vigilant follow-up for another 14 months showed radiologically stable brainstem glioma and no further recurrence of OIIA-LPD.

CONCLUSIONS

This is the first report documenting OIIA-LPD during temozolomide administration. Timely diagnosis of the disease and discontinuation of the causative agent were considered to be the management of choice. Close monitoring for relapse should be continued. Finding a balance between glioma management and controlling the remission of OIIA-LPD remains to be clarified.

Epstein-Barr virus variation in people living with human immunodeficiency virus in southeastern China

BACKGROUND

Patients infected with HIV are at high risk of developing Epstein-Barr Virus (EBV)-related diseases. The genotype and viral biological behavior of EBV infection in patients with human immunodeficiency virus-1 (HIV) in China remain unclear. This study analyzed the characteristics of EBV in patients infected with HIV in southeastern China.

METHODS

A total of 162 HIV-infected patients and 52 patients without HIV were enrolled in this study. EBV viral load in blood was determined by fluorescence quantitative PCR. EBV typing was performed using saliva according to polymorphisms in the EBNA3C region. EBV LMP-1 carboxy terminus (C-ter) was sequenced, and compared with the epidemic strains in the world.

RESULTS

Among HIV infected patients, the EBV strain variant was mainly EBV-1, while EBV-2 had a higher viral load than EBV-1 (P = 0.001) and EBV-1/2 (P = 0.002). HIV infected patients had higher active virus replication. The EBV LMP-1 variants were mainly the China1 variant. HIV-infected patients had different nucleic acid positions of 30-bp deletion (del30) and had a higher incidence of high 33-bp tandem repeats (rep33) copies than non-HIV-infected patients. There was a difference in the mutations of EBV LMP-1 C-ter del30 and ins15 between HIV infected patients and the control group (P < 0.001).

CONCLUSION

In southeastern China, EBV in HIV-infected patients had higher active virus replication; EBV infection was mainly EBV-1, and EBV-2 infection has higher EBV virus load; hotspot mutations of LMP-1 C-ter were different between HIV-infected patients and non-HIV-infected patients.

TRIAL REGISTRATION

This study was approved by the ethics committee of the First Affiliated Hospital of Zhejiang University School of Medicine (Approval No. 2018764), and registered in Chinese Clinical Trial Registry on 3 June 2019 (ChiCTR, ChiCTR1900023600, http://www.chictr.org.cn/usercenter.aspx ).

Advancing therapeutic strategies for Epstein-Barr virus-associated malignancies through lytic reactivation

Epstein-Barr virus (EBV) is a widespread human herpes virus associated with lymphomas and epithelial cell cancers. It establishes two separate infection phases, latent and lytic, in the host. Upon infection of a new host cell, the virus activates several pathways, to induce the expression of lytic EBV antigens and the production of infectious virus particles. Although the carcinogenic role of latent EBV infection has been established, recent research suggests that lytic reactivation also plays a significant role in carcinogenesis. In this review, we summarize the mechanism of EBV reactivation and recent findings about the role of viral lytic antigens in tumor formation. In addition, we discuss the treatment of EBV-associated tumors with lytic activators and the targets that may be therapeutically effective in the future.

Immunodeficiency-Associated Epstein-Barr Virus-Positive B-cell Lymphoproliferative Disorders

Sources of immune deficiency and dysregulation (IDD) are being increasingly recognized and defined, as are IDD-related B-cell lymphoproliferative lesions and lymphomas occurring in these patients. In this review, basic biology of Epstein-Barr virus (EBV) as it relates to classification of EBV-positive B-cell lymphoproliferative disorders (LPDs) is reviewed. Also discussed is the new paradigm of classification of IDD-related LPDs adopted by the fifth edition World Health Organization classification. IDD-related EBV-positive B-cell hyperplasias, LPDs, and lymphomas are discussed with particular attention to unifying and unique features that assist with recognition of these IDD-related lesions and their classification scheme.

Viral vectors and extracellular vesicles: innate delivery systems utilized in CRISPR/Cas-mediated cancer therapy

Gene editing-based therapeutic strategies grant the power to override cell machinery and alter faulty genes contributing to disease development like cancer. Nowadays, the principal tool for gene editing is the clustered regularly interspaced short palindromic repeats-associated nuclease 9 (CRISPR/Cas9) system. In order to bring this gene-editing system from the bench to the bedside, a significant hurdle remains, and that is the delivery of CRISPR/Cas to various target cells in vivo and in vitro. The CRISPR-Cas system can be delivered into mammalian cells using various strategies; among all, we have reviewed recent research around two natural gene delivery systems that have been proven to be compatible with human cells. Herein, we have discussed the advantages and limitations of viral vectors, and extracellular vesicles (EVs) in delivering the CRISPR/Cas system for cancer therapy purposes.

LMP1-EBV Gene Deletion Mutations and HLA Genotypes of Nasopharyngeal Cancer Patients in Vietnam

Nasopharyngeal carcinoma (NPC) is the most common cancer among head and neck cancers in Vietnam. We aimed to identify the rate of a 30 bp deletion mutation of the LMP1-EBV gene in nasopharyngeal biopsy tissue samples, the HLA genotypes of NPC patients, and the relationship between these two targets. Patients with NPC at Can Tho Oncology Hospital from September 2014 to December 2018 were selected. A length of 30 bp of the del-LMP1-EBV gene was analyzed using a PCR technique, and the HLA genotypes in patients' blood samples were analyzed with PCR-SSO technology. HLA-B*15 gene carriers had the highest risk of 30 bp LMP1-EBV gene deletion mutation, which was found in 51 out of 70 patients (72.9%). Carriers of the HLA-B*15 allele had a 4.6-fold increased risk of a 30 bp del-LMP1-EBV gene compared with non-carriers of this allele. The initial identification of NPC was related to the 30 bp del-LMP1-EBV gene and high frequencies of the -A*02, -B*15, -DRB1*12, -DQB1*03, and -DQA1*01 HLA alleles. Our study results suggest an association of the 30 bp del-LMP1-EBV gene and the HLA-B*15 allele with NPC susceptibility.

Immunotherapeutic approaches in EBV-associated nasopharyngeal carcinoma

Epstein-Barr virus (EBV) was the first tumor virus in humans. Nasopharyngeal carcinoma (NPC) accounts for approximately 60% of the 200,000 new tumor cases caused by EBV infection worldwide each year. NPC has an insidious onset and is highly malignant, with more than 70% of patients having intermediate to advanced disease at the time of initial diagnosis, and is strongly implicated in epithelial cancers as well as malignant lymphoid and natural killer/T cell lymphomas. Over 90% of patients with confirmed undifferentiated NPC are infected with EBV. In recent decades, much progress has been made in understanding the molecular mechanisms of NPC and developing therapeutic approaches. Radiotherapy and chemotherapy are the main treatment options for NPC; however, they have a limited efficacy in patients with locally advanced or distant metastatic tumors. Tumor immunotherapy, including vaccination, adoptive cell therapy, and immune checkpoint blockade, represents a promising therapeutic approach for NPC. Significant breakthroughs have recently been made in the application of immunotherapy for patients with recurrent or metastatic NPC (RM-NPC), indicating a broad prospect for NPC immunotherapy. Here, we review important research findings regarding immunotherapy for NPC patients and provide insights for future research.

GMP development and preclinical validation of CAR-T cells targeting a lytic EBV antigen for therapy of EBV-associated malignancies

Introduction

Epstein-Barr virus (EBV) is a widely spread pathogen associated with lymphoproliferative diseases, B/ T/ NK cell lymphomas, nasopharyngeal carcinoma (NPC) and gastric carcinoma (GC). EBV lytic reactivations contribute to the genomic instability, inflammation and tumorigenesis of NPC, promoting cancer progression. Patients with NPC refractory to standard therapies show dismal survival. EBV gp350 is an envelope protein detectable in NPC specimens intracellularly and on the cell membrane of malignant cells, and is a potential viral antigen for T cell-directed immunotherapies. The potency of T cells engineered with a chimeric antigen receptor (CAR) targeting gp350 against EBV⁺ lymphoproliferative disease was previously shown.

Methods

Here, we advanced towards preclinical and non-clinical developments of this virus-specific CAR-T cell immunotherapy against NPC. Different gp350CAR designs were inserted into a lentiviral vector (LV) backbone.

Results

A construct expressing the scFv 7A1-anti-gp350 incorporating the CD8 transmembrane and CD28.CD3ζ signaling domain (ZT002) was selected. High titer ZT002 (~1x10⁸ TU/ml) was manufactured in HEK 293T/17 suspension cells in serum free media as large-scale production under good manufacturing practices (GMP). A LV multiplicity of infection (MOI) of 1 resulted in high frequencies of functional gp350CAR⁺ T cells (>70%) at a low (<2) vector copy numbers in the genome. ZT002 was therefore used to establish gp350CAR-T batch run production methods. GMP upscaling and validation of T cell transduction and expansion in several runs resulted in average 3x10⁹ gp350CAR-T cells per batch. >80% CD3⁺ gp350CAR-T cells bound to purified gp350 protein. In vitro cytotoxicity and cytokine secretion assays (IFN-γ and TNF-α) confirmed the specificity of gp350CAR-T cells against gp350⁺ NPC, GC and lymphoma cell targets. Immunocompromised B-NDG mice (NOD.CB17-PrkdcscidIl2rgtm1/Bcgen) were challenged s.c. with a EBV⁺ NPC C666.1 cell line expressing gp350 and then treated with escalating doses of gp350CAR-T cells or with non-transduced T cells. gp350CAR-T cells promoted antitumor responses, bio-distributed in several tissues, infiltrated in tumors and rejected gp350⁺ tumor cells.

Discussion

These results support the use of gp350CAR-T cells generated with ZT002 as an Innovative New Drug to treat patients with solid and liquid EBV-associated malignancies.

Epstein-Barr virus and multiple sclerosis

Epstein-Barr virus (EBV) is a ubiquitous human lymphotropic herpesvirus with a well-established causal role in several cancers. Recent studies have provided compelling epidemiological and mechanistic evidence for a causal role of EBV in multiple sclerosis (MS). MS is the most prevalent chronic inflammatory and neurodegenerative disease of the central nervous system and is thought to be triggered in genetically predisposed individuals by an infectious agent, with EBV as the lead candidate. How a ubiquitous virus that typically leads to benign latent infections can promote cancer and autoimmune disease in at-risk populations is not fully understood. Here we review the evidence that EBV is a causal agent for MS and how various risk factors may affect EBV infection and immune control. We focus on EBV contributing to MS through reprogramming of latently infected B lymphocytes and the chronic presentation of viral antigens as a potential source of autoreactivity through molecular mimicry. We consider how knowledge of EBV-associated cancers may be instructive for understanding the role of EBV in MS and discuss the potential for therapies that target EBV to treat MS.

Development of dynamical network biomarkers for regulation in Epstein-Barr virus positive peripheral T cell lymphoma unspecified type

Background: This study was performed to identify key regulatory network biomarkers including transcription factors (TFs), miRNAs and lncRNAs that may affect the oncogenesis of EBV positive PTCL-U. Methods: GSE34143 dataset was downloaded and analyzed to identify differentially expressed genes (DEGs) between EBV positive PTCL-U and normal samples. Gene ontology and pathway enrichment analyses were performed to illustrate the potential function of the DEGs. Then, key regulators including TFs, miRNAs and lncRNAs involved in EBV positive PTCL-U were identified by constructing TF-mRNA, lncRNA-miRNA-mRNA, and EBV encoded miRNA-mRNA regulatory networks. Results: A total of 96 DEGs were identified between EBV positive PTCL-U and normal tissues, which were related to immune responses, B cell receptor signaling pathway, chemokine activity. Pathway analysis indicated that the DEGs were mainly enriched in cytokine-cytokine receptor interaction and chemokine signaling pathway. Based on the TF network, hub TFs were identified regulate the target DEGs. Afterwards, a ceRNA network was constructed, in which miR-181(a/b/c/d) and lncRNA LINC01744 were found. According to the EBV-related miRNA regulatory network, CXCL10 and CXCL11 were found to be regulated by EBV-miR-BART1-3p and EBV-miR-BHRF1-3, respectively. By integrating the three networks, some key regulators were found and may serve as potential network biomarkers in the regulation of EBV positive PTCL-U. Conclusion: The network-based approach of the present study identified potential biomarkers including transcription factors, miRNAs, lncRNAs and EBV-related miRNAs involved in EBV positive PTCL-U, assisting us in understanding the molecular mechanisms that underlie the carcinogenesis and progression of EBV positive PTCL-U.

Designing a vaccine-based therapy against Epstein-Barr virus-associated tumors using immunoinformatics approach

Epstein-Barr virus (EBV) is widely known due to its role in the etiology of infectious mononucleosis. However, it is the first oncovirus that was identified and has been implicated in the etiology of several types of cancers. Globally, EBV infection is associated with more than 200, 000 new cancer cases and 150, 000 deaths yearly. A prophylactic or therapeutic vaccine targeting tumors associated with EBV infection is currently lacking. Therefore, this study aimed to develop a multiepitope-based polyvalent vaccine against EBV-associated tumors using immunoinformatics approach. The latency-associated proteins (LAP) of three strains of the virus were used in this study. Potential epitopes predicted from the proteins were analyzed and selected based on several predicted properties. Thirty viable B-cell and T-cell epitopes were selected and conjugated using various linkers alongside beta-defensin 3 as an adjuvant and pan HLA DR-binding epitope (PADRE) sequence to improve the immunogenicity of the vaccine construct. Molecular docking studies of the vaccine construct against toll-like receptors (TLRs) showed it is capable of inducing immune response via recognition by TLRs while immune simulation studies showed it could induce both cellular and humoral immune responses. Furthermore, molecular dynamics study of the complex formed by the vaccine candidate and TLR-4 showed that the complex was stable. Ultimately, the designed vaccine showed desirable properties based on in silico evaluation; however, experimental studies are needed to validate the efficacy of the vaccine against EBV-associated tumors.

Ryabova T, A. Kalashnikova A. Recombinant Interferon Gamma: Influence on the Cytotoxic Activity of NK Cells in Patients with Chronic Epstein-Barr Virus Infection

NK cells play an important role in combating viral infections. In this study, we examined the effect of therapy with recombinant interferon gamma (Ingaron) on cytotoxic activity of NK cells. Sixty patients with chronic Epstein-Barr virus infection (CEBVI) were examined. All patients were treated with Ingaron at a dose of 500,000 IU every other day IM. Initially, they received 10 injections of Ingaron followed by a 10-day break to assess the dynamics of clinical and laboratory parameters. Then, the treatment was continued with five injections of Ingaron. In total, each patient received 15 injections or a total dose of 7,500,000 IU. The administration of recombinant interferon gamma at a total dose of 5,000,000 IU stimulated spontaneous and induced degranulation of NK cells in patients with CEBVI. After a full course of 7,500,000 IU of recombinant interferon gamma, CD107a expression on NK cells decreased but remained higher than before the onset of therapy and exceeded reference values. Thus, the maximum activity of NK cells in the peripheral blood of patients with CEBVI was reached 10 days after the administration of Ingaron at a total dose of 5,000,000 IU.

The Role of Codon Usage, tRNA Availability, and Cell Proliferation in EBV Latency and (Re)Activation

Epstein–Barr nuclear antigen 1 (EBNA1) protein synthesis is inhibited during Epstein–Barr virus (EBV) latency and is resumed in EBV (re)activation. In analyzing the molecular mechanisms underpinning the translation of EBNA1 in the human host, this article deals with two orders of data. First, it shows that the heavily biased codon usage of the EBNA1 open reading frame cannot be translated due to its noncompliance with the human codon usage pattern and the corresponding tRNA pool. The EBNA1 codon bias resides in the sequence composed exclusively of glycine and alanine, i.e., the Gly-Ala repeat (GAR). Removal of the nucleotide sequence coding for GAR results in an EBNA1 codon usage pattern with a lower codon bias, thus conferring translatability to EBNA1. Second, the data bring cell proliferation to the fore as a conditio sine qua non for qualitatively and quantitatively modifying the host's tRNA pool as required by the translational needs of EBNA1, thus enabling viral reactivation. Taken together, the present work provides a biochemical mechanism for the pathogen's shift from latency to (re)activation and confirms the role of human codon usage as a first-line tool of innate immunity in inhibiting pathogens' expression. Immunologically, this study cautions against using codon optimization and proliferation-inducing substances such as glucocorticoids and adjuvants, which can (re)activate the otherwise quiescent, asymptomatic, and innocuous EBV infection. Lastly, the data pose the question whether the causal pathogenic role attributed to EBV should instead be ascribed to the carcinogenesis-associated cellular proliferation.

EBV-associated NK and T-cell lymphoid neoplasms

PURPOSE OF REVIEW

Epstein-Barr virus (EBV)-associated neoplasms derived from natural killer (NK) or T cells comprise a group of clinically and biologically heterogenous disorders affecting children and adults, which are overall rare but more prevalent in Asia and South America. This review focuses on neoplasms presenting in the adulthood, addressing recent genomic discoveries as well as therapeutic developments in these highly aggressive disorders.

RECENT FINDINGS

Distinct molecular subtypes of extranodal NK/T-cell lymphomas (ENKTCLs) have been described, with differences in cell of origin, EBV pattern, genomic alterations, clinical characteristics, response to asparaginase-based therapies and to more recent approaches targeting molecular aberrations of the lymphoma. For the last two decades, progress in the clinical management of ENKTCL was based on L-asapraginase containing combinations and the incoroperation of radiotherapy. A subset of cases with PDL1-2 structural alterations may be more responsive to treatment with immune checkpoint inhibitors. Primary nodal EBV+ lymphomas derived from T or NK cells have distinctive features separating them from both peripheral T-cell lymphoma not otherwise specified and ENKTCL. Treatment algorithms correspond to those for advanced ENKTCL.

SUMMARY

With better understanding of lymphomagenesis, genomic landscape and immunologic aspects of the diseases, future treatment options will include targeted therapies including immune checkpoint inhibitors and novel antibodies.

Effects of Exosomal Viral Components on the Tumor Microenvironment

Simple Summary

Oncogenic viral infection may lead to cancers, such as nasopharyngeal carcinoma, hepatocellular carcinoma, and cervical cancer. In addition to the tumor cells themselves, the tumor microenvironment also plays a decisive role in tumor evolution. Oncogenic viruses can affect the tumor microenvironment via exosomes influencing the occurrence and development of tumors by encapsulating and transporting viral components. This review focuses on the effects of virus-infected cancer exosomes on tumor microenvironment and tumor progression.

Abstract

Exosomes are extracellular membrane vesicles with a diameter of 30–100 nm, produced by different eukaryotic cells that contain multitudinous lipids, nucleic acids, and proteins. They transfer membrane components and nucleic acids between cells, thereby performing an information exchange between cells. Many studies have shown that a variety of tumor-associated viruses can exert their biological functions through exosomes. The tumor microenvironment (TME) is very important in the occurrence, development, and chemoresistance of tumors. It is composed of tumor cells, fibroblasts, endothelial cells, immune cells, stromal cells, and acellular components, such as exosomes and cytokines. This review focuses on the effects of virus-related components secreted by tumor cells over the TME in several virus-associated cancers.

Circulating lymphocyte subsets are prognostic factors in patients with nasopharyngeal carcinoma

BACKGROUND

Nasopharyngeal carcinoma (NPC) is a geographically and racially variable disease that has a high incidence in Southeast China. According to previous studies on tumor immunity, we compared multiple clinical parameters and blood indexes with outcomes regarding to Epstein-Barr virus (EBV) status in NPC patients.

METHODS

According to the EBV load at diagnosis, 220 NPC patients who received concurrent chemoradiotherapy (CRT) were divided into two groups: EBV DNA ≥ 1500 copies/mL and EBV DNA < 1500 copies/mL, respectively. We compared clinical parameters with peripheral blood mononuclear cells, lymphocyte subsets and biochemical indexes. We also analyzed distant metastases and the overall survival rate regarding to these characteristics.

RESULTS

In most cases, the two groups showed the same trends. Most blood indexes were decreased during CRT and the decrease of the absolute count was more significant than the percentage. Patients with younger age showed the higher CD3+ and CD3 + CD8+ percentages. Patients whose EBV DNA ≥ 1500 copies/mL showed a higher N classification than those with EBV DNA < 1500 copies/mL at first diagnosis. Within patients with EBV DNA ≥ 1500 copies/mL, a higher CD3 + CD8+ percentage or lower CD3-CD56+ percentage had better OS rates, and the CD3 + CD8+ percentage was an independent prognostic factor by multivariate survival analyses.

CONCLUSIONS

CRT caused an overall decrease of blood cells in NPC patients. Among all the blood indexes, the CD3 + CD8+ percentage showed a correlation with age and was an independent prognostic factor in patients with EBV DNA ≥ 1500 copies/mL at first diagnosis, which is worthy for further large cohort study.

The implications of cell-free DNAs derived from tumor viruses as biomarkers of associated cancers

Cancer is still ranked as a leading cause of death according to estimates from the World Health Organization (WHO) and the strong link between tumor viruses and human cancers have been proved for almost six decades. Cell-free DNA (cfDNA) has drawn enormous attention for its dynamic, instant, and noninvasive advantages as one popular type of cancer biomarker. cfDNAs are mainly released from apoptotic cells and exosomes released from cancer cells, including those infected with viruses. Although cfDNAs are present at low concentrations in peripheral blood, they can reflect tumor load with high sensitivity. Considering the relevance of the tumor viruses to the associated cancers, cfDNAs derived from viruses may serve as good biomarkers for the early screening, diagnosis, and treatment monitoring. In this review, we summarize the methods and newly developed analytic techniques for the detection of cfDNAs from different body fluids, and discuss the implications of cfDNAs derived from different tumor viruses in the detection and treatment monitoring of virus-associated cancers. A better understanding of cfDNAs derived from tumor viruses may help formulate novel anti-tumoral strategies to decrease the burden of cancers that attributed to viruses. This article is protected by copyright. All rights reserved.

Characterization of the Prognostic Values of CXCL Family in Epstein-Barr Virus Associated Gastric Cancer

Background

CXCL family is a class of secreted growth factors signaling through G-protein-coupled receptors, and abnormal expression is associated with the growth and progression of many tumors. However, their prognostic value has been poorly studied in Epstein-Barr virus- (EBV-) associated gastric cancer (EBVaGC). Therefore, it is of great significance to explore the prognostic value of the CXCL family in EBVaGC.

Methods

CXCL family mRNA expression was analyzed in STAD data from The Cancer Genome Atlas (TCGA). Kaplan-Meier Plotter was used to assess the prognostic value of the CXCL family. Transcription factors (TFs) and miRNAs associated with the CXCL family were identified by TFCheckpoint, miRWalk, and ViRBase databases. The prognostic model was evaluated using the EBVaGC patient cohort GSE51575.

Results

The mRNA expression of CXCL1/3/5/6/8/9/10/11/16 was significantly upregulated, while the expression of CXCL12/14 was downregulated in EBVaGC compared with normal tissues from TCGA-STAD. The mRNA expressions of CXCL9, CXCL10, CXCL11, and CXCL17 in EBVaGCs were higher than those in EBVnGCs, but the mRNA expressions of CXCL6, CXCL12, and CXCL17 were lower than those in EBVnGCs. The mRNA expression levels of CXCL9, CXCL10, and CXCL11 in EBVaGCs were higher than those in EBVnGCs regardless of the tumor stage. High mRNA expression of CXCL8 was associated with better OS in patients with EBVaGC, while high expression of CXCL9 was associated with better OS in patients with EBVnGC. We obtained 10 candidate potential transcription factors (TFs) associated with CXCLs: OTOP3, NKX6-2, NKX2-2, FEV, SMYD1, TRIMSO, TBX10, CDX1, SLC26A3, and ARC. 576 miRNA-mRNA interactions were obtained. Among them, 65 miRNAs were predicted to be correlated with CXCL6, CXCL9, CXCL10, and CXCL11. Similar to the results of TCGA-STAD, the GSE51575 dataset also showed that the mRNA expression levels of CXCL1/3/9/10/11/16 were markedly enhanced in EBVaGC tissues compared with corresponding normal gastric mucosa tissues, while the mRNA expression levels of CXCL12/14 were significantly reduced. The mRNA expression levels of CXCL3/9/10/11/13/17 were increased in EBVaGC compared with EBVnGC tissues.

Conclusions

The expression differences of CXCL family members are closely associated with the progression of EBVaGC. Expression of CXCL9/10/11/17 mRNA may be a promising prognostic indicator for EBVaGC patients.

Molecular fusion events in carcinogenic organisms: a bioinformatics study for the detection of fused proteins between viruses, bacteria and eukaryotes

Molecular fusion events have a prominent role in the initial steps of carcinogenesis. In this study, a bioinformatics analysis was performed between four organisms that are known to induce cancer development in humans: two viruses, Human Herpesvirus 4, and Human T-cell leukaemia virus, one bacterium, Helicobacter Pylori, and one trematode, Schistosoma mansoni. The annotated proteomes from these organisms were analysed using the SAFE software to identify protein fusion events, which may provide insight into protein function similarities and possible merging events during the course of evolution. Based on the results, five fused proteins with very similar functions were detected, whereas proteins with different functions that might act in the same molecular complex or biochemical pathway were not found. Thus, this study analysed the above four well-known cancer-related organisms with de novo bioinformatics programs and provided useful information on protein fusion events, hopefully leading to deeper understanding of carcinogenenesis.

Comparison of Immunotherapy, Chemotherapy, and Chemoimmunotherapy in Advanced Pulmonary Lymphoepithelioma-Like Carcinoma： A Retrospective Study

Pulmonary lymphoepithelioma-like carcinoma (pLELC) is a rare subtype of lung cancer that is associated with the Epstein-Barr virus in Asia. Due to the lack of prospective studies, the best first-line treatment and survival outcomes remain unclear. Herein, This study investigated the efficacy and safety of different treatment regimens for advanced pLELC. This retrospective study included 68 patients with advanced pLELC from two centers in China. Patients were divided into three groups according to different first-line treatments: chemotherapy (n=49, 72.1%), immunotherapy (n=7, 10.3%), and chemoimmunotherapy (n=12,17.6%). The primary endpoint of this study was the 2-year progression-free survival (PFS) of each group. The results show that the median PFS was 6.9 months (range, 2.3–not estimable) in the chemotherapy group, 11.0 months (range, 2–not estimable) in the immunotherapy group, and 11.8 months (range, 6–not estimable) in the chemoimmunotherapy group. There was a significant difference in 2-year PFS between the chemoimmunotherapy group and the chemotherapy group (hazard ratio, 0.38, 95% confidence interval: 0.18-0.78, log-rank P=0.007). The most frequent grade 3-4 adverse event in the chemotherapy and chemoimmunotherapy groups was myelosuppression (10/49 [22.4%] and 4/12 [33.3%], respectively). The most frequent grade 3-4 adverse events in the immunotherapy group were diarrhea (1/7, 14.8%) and hepatotoxicity (1/7, 14.8%). Chemoimmunotherapy had the highest 2-year PFS as a first-line treatment for advanced pLELC compared to chemotherapy and immunotherapy. This study suggests that chemoimmunotherapy may be the best first-line treatment for patients with advanced pLELC.

Epstein–Barr Virus (EBV) Genotypes Associated with the Immunopathological Profile of People Living with HIV-1: Immunological Aspects of Primary EBV Infection

Background: The aim of the present study was to evaluate the immunological profile of adult HIV-1+ patients coinfected with primary Epstein–Barr virus (EBV) infection who were free of antiretroviral drugs and inhabitants of the Brazilian Amazon region. Materials and methods: Primary EBV infection was screened by the semiquantitative detection of IgM and IgG anti-VCA. Genotypes were determined by conventional PCR. EBV and HIV viral load (VL) were quantified by real-time PCR. Cytokine dosage and cell quantification were performed by cytometry. Results: Only HIV-1+ individuals had primary EBV infection (7.12%). The EBV-1 genotype was the most prevalent (47.37%). The VL of HIV-1 was lower in the HIV/EBV-2 group. CD4+ T lymphocytes were inversely proportional to the VL of EBV in HIV/EBV-1/2 multi-infected patients. The HIV/EBV-2 group had the lowest cytokine levels, especially IFN-γ and IL-4. Different correlations were proposed for each coinfection. The late search for specific care related to HIV infection directly affected the cytokine profile and the number of CD8+ T lymphocytes. Symptoms were associated with the increase in VL of both viruses and cytokine profile. Conclusions: Different immunological profiles were associated with EBV genotypes in primary infection, with EBV-2 being more frequent in patients with low levels of HIV viral load. With late infection monitoring and consequent delay in the initiation of HAART, clinical changes and effects on the maintenance of the immune response were observed.

ViMIC: a database of human disease-related virus mutations, integration sites and cis-effects

Molecular mechanisms of virus-related diseases involve multiple factors, including viral mutation accumulation and integration of a viral genome into the host DNA. With increasing attention being paid to virus-mediated pathogenesis and the development of many useful technologies to identify virus mutations (VMs) and viral integration sites (VISs), much research on these topics is available in PubMed. However, knowledge of VMs and VISs is widely scattered in numerous published papers which lack standardization, integration and curation. To address these challenges, we built a pilot database of human disease-related Virus Mutations, Integration sites and Cis-effects (ViMIC), which specializes in three features: virus mutation sites, viral integration sites and target genes. In total, the ViMIC provides information on 31 712 VMs entries, 105 624 VISs, 16 310 viral target genes and 1 110 015 virus sequences of eight viruses in 77 human diseases obtained from the public domain. Furthermore, in ViMIC users are allowed to explore the cis-effects of virus-host interactions by surveying 78 histone modifications, binding of 1358 transcription regulators and chromatin accessibility on these VISs. We believe ViMIC will become a valuable resource for the virus research community. The database is available at http://bmtongji.cn/ViMIC/index.php.

EBV-associated diseases: Current therapeutics and emerging technologies

EBV is a prevalent virus, infecting >90% of the world's population. This is an oncogenic virus that causes ~200,000 cancer-related deaths annually. It is, in addition, a significant contributor to the burden of autoimmune diseases. Thus, EBV represents a significant public health burden. Upon infection, EBV remains dormant in host cells for long periods of time. However, the presence or episodic reactivation of the virus increases the risk of transforming healthy cells to malignant cells that routinely escape host immune surveillance or of producing pathogenic autoantibodies. Cancers caused by EBV display distinct molecular behaviors compared to those of the same tissue type that are not caused by EBV, presenting opportunities for targeted treatments. Despite some encouraging results from exploration of vaccines, antiviral agents and immune- and cell-based treatments, the efficacy and safety of most therapeutics remain unclear. Here, we provide an up-to-date review focusing on underlying immune and environmental mechanisms, current therapeutics and vaccines, animal models and emerging technologies to study EBV-associated diseases that may help provide insights for the development of novel effective treatments.

iCAV: an integrative database of cancer-associated viruses

To date, various studies have found that the occurrence of cancer may be related to viral infections. Therefore, it is important to explore the relationship between viruses and diseases. The International Agency for Research on Cancer has defined six types of viruses as Class 1 human carcinogens, including Epstein–Barr virus, hepatitis C virus, hepatitis B virus, human T-cell lymphotropic virus, human herpesvirus 8 and human papillomavirus, while Merkel cell polyomavirus is classified as ‘probably carcinogenic to humans’ (Group 2A). Therefore, in-depth research on these viruses will help clarify their relationship with diseases, and substantial efforts have been made to sequence their genomes. However, there is no complete database documenting these cancer-associated viruses, and researchers are not able to easily access and retrieve the published genomes. In this study, we developed iCAV, a database that integrates the genomes of cancer-related viruses and the corresponding phenotypes. We collected a total of 18 649 genome sequences from seven human disease-related viruses, and each virus was further classified by the associated disease, sample and country. iCAV is a comprehensive resource of cancer-associated viruses that provides browse and download functions for viral genomes.

Database URL: http://icav.omicsbio.info/