Increased T-cell responses to Epstein-Barr virus with high viral load in patients with Epstein-Barr virus-positive diffuse large B-cell lymphoma

Epstein-Barr virus as a potentiator of autoimmune diseases

The Epstein-Barr virus (EBV) is epidemiologically associated with development of autoimmune diseases, including systemic lupus erythematosus, Sjögren syndrome, rheumatoid arthritis and multiple sclerosis. Although there is well-established evidence for this association, the underlying mechanistic basis remains incompletely defined. In this Review, we discuss the role of EBV infection as a potentiator of autoimmune rheumatic diseases. We review the EBV life cycle, viral transcription programmes, serological profiles and lytic reactivation. We discuss the epidemiological and mechanistic associations of EBV with systemic lupus erythematosus, Sjögren syndrome, rheumatoid arthritis and multiple sclerosis. We describe the potential mechanisms by which EBV might promote autoimmunity, including EBV nuclear antigen 1-mediated molecular mimicry of human autoantigens; EBV-mediated B cell reprogramming, including EBV nuclear antigen 2-mediated dysregulation of autoimmune susceptibility genes; EBV and host genetic factors, including the potential for autoimmunity-promoting strains of EBV; EBV immune evasion and insufficient host responses to control infection; lytic reactivation; and other mechanisms. Finally, we discuss the therapeutic implications and potential therapeutic approaches to targeting EBV for the treatment of autoimmune disease.

Determination and Role of Epstein-Barr Virus in Patients With Lymphoproliferative Disorders

INTRODUCTION

Epstein-Barr virus (EBV) is associated with different types of human malignancies, including Burkitt lymphoma, nasopharyngeal carcinoma, and lymphomas. We retrospectively investigated the presence of EBV-DNA by real-time PCR in clinical samples of patients diagnosed as having hematologic malignancies while investigating the cause of lymphoproliferative disorders, and investigated its relationship to clinical manifestations.

PATIENTS AND METHODS

Fifty clinical samples sent to Gazi University's hematology clinics between November 2013 and March 2018 were included. EBV-DNA was investigated by real-time PCR method, and EBV-IgM and EBV-IgG antibodies were investigated by ELISA.

RESULTS

Fifty serum samples were investigated, and 10% (5/50) EBV-DNA positivity was determined in patients. Of the 5 patients with EBV-DNA positivity, 2 had acute lymphoblastic leukemia, 1 lymphoma, 1 T-cell lymphoma, and 1 B-cell lymphoma. Concomitant EBV-DNA and viral capsid antigen (VCA)-IgM positivity was not detected. The VCA-lgM test results of the all EBV-DNA-positive patients were negative and VCA-IgG positive (except for 1 patient). Regarding virus load, of the 5 samples, 2, 1, 1, and 1 of the samples had a virus load of 10², 10³, 10⁴, and 10⁵ copies/mL, respectively.

CONCLUSION

EBV infection is threatening in patients with hematologic malignancies and are diagnosed by serologic and molecular methods. As a result of the study, we suggest that the detection of EBV-DNA by real-time PCR in patients being admitted with lymphoproliferative diseases and diagnosed as acute lymphoblastic leukemia and lymphomas may be useful in follow-up and treatment.

Latency and lytic replication in Epstein-Barr virus-associated oncogenesis

Epstein-Barr virus (EBV) was the first tumour virus identified in humans. The virus is primarily associated with lymphomas and epithelial cell cancers. These tumours express latent EBV antigens and the oncogenic potential of individual latent EBV proteins has been extensively explored. Nevertheless, it was presumed that the pro-proliferative and anti-apoptotic functions of these oncogenes allow the virus to persist in humans; however, recent evidence suggests that cellular transformation is not required for virus maintenance. Vice versa, lytic EBV replication was assumed to destroy latently infected cells and thereby inhibit tumorigenesis, but at least the initiation of the lytic cycle has now been shown to support EBV-driven malignancies. In addition to these changes in the roles of latent and lytic EBV proteins during tumorigenesis, the function of non-coding RNAs has become clearer, suggesting that they might mainly mediate immune escape rather than cellular transformation. In this Review, these recent findings will be discussed with respect to the role of EBV-encoded oncogenes in viral persistence and the contributions of lytic replication as well as non-coding RNAs in virus-driven tumour formation. Accordingly, early lytic EBV antigens and attenuated viruses without oncogenes and microRNAs could be harnessed for immunotherapies and vaccination.

Prognostic impact of EBV serostatus in patients with lymphomas or chronic malignancies undergoing allogeneic HCT

The influence of the donor (D) and recipient (R) pre-transplant Epstein-Barr Virus (EBV) serostatus on transplant outcomes (overall survival, relapse-free survival, relapse incidence, non-relapse mortality, acute and chronic GVHD) in 12,931 patients with lymphomas or chronic malignancies undergoing allogeneic hematopoietic cell transplant (allo-HCT) between 1997-2016 was analyzed. In multivariate analysis, the risk of development of chronic GVHD was increased for EBV R+/D+ (HR = 1.26; p = 0.003), R+/D- (HR = 1.21; p = 0.044), and R-/D + (HR = 1.21; p = 0.048) in comparison to R-/D- transplants. No significance was shown for other transplant outcomes; however, in univariate analysis, EBV-seropositive patients receiving grafts from EBV-seropositive donors (EBV R+/D+transplants) had inferior transplant outcomes in comparison to EBV-seronegative recipients of grafts from EBV-seronegative donors (EBV R-/D-): inferior overall survival (59.6% vs 65.9%), inferior relapse-free survival (51.1% vs 57.5%), increased incidence of chronic GVHD (49.5% vs 41.8%), and increased incidence of de novo chronic GVHD (30.5% vs 24.0%). In conclusion, an EBV-negative recipient with lymphoma or chronic malignancy can benefit from selection of an EBV-negative donor in context of chronic GVHD, while there are no preferences in donor EBV serostatus for EBV-seropositive recipient.

Epstein-Barr virus lytic cycle involvement in diffuse large B cell lymphoma

Epstein-Barr virus (EBV)-mediated B cell transformation is achieved predominantly through the action of latent proteins, but recent evidence suggests that lytic EBV replication has also a certain pathogenic role in lymphomagenesis, at least in the early phases of cell transformation. Particularly, in diffuse large B cell lymphoma (DLBCL), the EBV lytic cycle is by and large unexplored, so to disclose lytic cell contribution to lymphomagenesis, our aim was to evaluate viral early and late lytic gene expression in relation to several immune response markers in a series of EBV+ DLBCL from Argentina. An unexpected number of cells expressed lytic transcripts, being transcribed at the BZLF1, BHRF1, and BLLF1 locus, by real-time quantitative polymerase chain reaction. This lytic antigen expression was confirmed by immunohistochemical staining for BMRF1 early lytic protein, and a positive correlation between lytic and latent genes was confirmed, revealing a close link between their expressions in EBV+ DLBCL pathogenesis. Remarkably, BZLF1 displayed a negative correlation with CD4 cell counts, and this could be in part justified by the restriction of antigen presentation previously reported. The direct correlation for the late lytic gene BLLF1 and IFNγ in this series could represent a specific response directed towards this antigen. Interleukin 10 transcripts also displayed a positive correlation with lytic expression, indicating that regulatory mechanisms could be also involved on EBV-associated DLBCL pathogenesis in our series. Complete lytic reactivation in EBV-positive tumours could potentially kill EBV-positive malignant cells, providing a tool to promote tumour cell killing mediated by EBV as a complementary treatment strategy.

Age and cellular composition influence overall survival in a collective of non-immunocompromised patients with EBV-positive diffuse large B-cell lymphoma from a German lymphoma center

We investigated 41 diffuse large B-cell lymphomas (DLBCL) diagnosed at one center harboring ≥50% of latently Epstein-Barr virus (EBV)-infected neoplastic cells occurring in 34 patients aged ≥50 years and in 7 patients younger than 50 years in the absence of any known immunodeficiency for the expression patterns of EBV latent and immediate-early proteins, for the differentiation stage of the neoplastic cells, the presence of cytogenetic alterations and a possible co-infection with the human herpes virus (HHV)-8. Here, we show that EBV-positive DLBCLs rarely arise from naïve and more frequently from post-germinal center B-cells that often contain crippling immunoglobulin gene mutations. Most of the lymphomas did not exhibit breaks in the BCL2, BCL6, and MYC genes and none of the cases investigated contained HHV-8 sequences. Patients aged <50 years performed better than older ones while in patients aged ≥50 years only the cellular composition had an impact on overall survival.

The clinical significance of EBV DNA in the plasma and peripheral blood mononuclear cells of patients with or without EBV diseases

Epstein-Barr virus (EBV) is a ubiquitous virus that establishes a latent infection within the host and in some cases can lead to the development of EBV-associated lymphomas, lymphoproliferative disorders, hemophagocytic lymphohistiocytosis, solid tumors, and other diseases. We studied the clinical significance of detecting EBV DNA in the plasma and peripheral blood mononuclear cells (PBMCs) of 2146 patients who had blood specimens sent to the Johns Hopkins Hospital clinical laboratory for viral quantitative real-time polymerase chain reaction assay over a 5-year period. Within this largely immunocompromised and hospitalized cohort, 535 patients (25%) had EBV detected in plasma or PBMCs. When EBV was detected in the absence of an EBV(+)disease (n = 402), it was present only in PBMCs in 69% of cases. Immunocompromised patients were less likely to have EBV in plasma than in PBMCs in the absence of EBV(+)disease. In patients with active, systemic EBV(+)diseases (n = 105), EBV was detected in plasma in 99% of cases but detected in PBMCs in only 54%. Across a range of copy number cutoffs, EBV in plasma had higher specificity and sensitivity for EBV(+)disease as compared with EBV in PBMCs. EBV copy number in plasma distinguished untreated, EBV(+)lymphoma from EBV(+)lymphoma in remission and EBV(-)lymphoma, and also distinguished untreated, EBV(+)posttransplantation lymphoproliferative disorder (PTLD) from EBV(+)PTLD in remission and EBV(-)PTLD. EBV copy number quantification is a useful diagnostic marker across the spectrum of EBV(+)diseases, even among immunocompromised patients, with plasma specimens more indicative of EBV(+)disease than PBMCs.

The Biology and Clinical Utility of EBV Monitoring in Blood

Epstein-Barr virus (EBV) DNA in blood can be quantified in peripheral blood mononuclear cells, in circulating cell-free (CCF) DNA specimens, or in whole blood. CCF viral DNA may be actively released or extruded from viable cells, packaged in virions or passively shed from cells during apoptosis or necrosis. In infectious mononucleosis, viral DNA is detected in each of these kinds of specimens, although it is only transiently detected in CCF specimens. In nasopharyngeal carcinoma, CCF EBV DNA is an established tumor marker. In EBV-associated Hodgkin lymphoma and in EBV-associated extranodal NK-/T-cell lymphoma, there is growing evidence for the utility of CCF DNA as a tumor marker.