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.

SOXC and MiR17-92 gene expression profiling defines two subgroups with different clinical outcome in mantle cell lymphoma.

Mantle cell lymphoma (MCL) is a heterogeneous B-cell lymphoid malignancy where most patients follow an aggressive clinical course whereas others are associated with an indolent performance. SOX4, SOX11, and SOX12 belong to SOXC family of transcription factors involved in embryonic neurogenesis and tissue remodeling. Among them, SOX11 has been found aberrantly expressed in most aggressive MCL patients, being considered a reliable biomarker in the pathology. Several studies have revealed that microRNAs (miRs) from the miR-17-92 cluster are among the most deregulated miRNAs in human cancers, still little is known about this cluster in MCL. In this study we screened the transcriptional profiles of 70 MCL patients for SOXC cluster and miR17, miR18a, miR19b and miR92a, from the miR-17-92 cluster. Gene expression analysis showed higher SOX11 and SOX12 levels compared to SOX4 (P ≤ 0.0026). Moreover we found a negative correlation between the expression of SOX11 and SOX4 (P < 0.0001). miR17-92 cluster analysis showed that miR19b and miR92a exhibited higher levels than miR17 and miR18a (P < 0.0001). Unsupervised hierarchical clustering revealed two subgroups with significant differences in relation to aggressive MCL features, such as blastoid morphological variant (P = 0.0412), nodal presentation (P = 0.0492), CD5(+) (P = 0.0004) and shorter overall survival (P < 0.0001). Together, our findings show for the first time an association between the differential expression profiles of SOXC and miR17-92 clusters in MCL and also relate them to different clinical subtypes of the disease adding new biological information that may contribute to a better understanding of this pathology. © 2016 Wiley Periodicals, Inc.

Cytotoxic response against Epstein Barr virus coexists with diffuse large B-cell lymphoma tolerogenic microenvironment: clinical features and survival impact.

Epstein-Barr Virus (EBV) is present in neoplastic cells of 15% of Asian and Latin-American diffuse large B-cell lymphoma (DLBCL) patients. Even though a tolerogenic microenvironment was recently described in DLBCL, little is known concerning immunomodulatory features induced by EBV. As suggested in Hodgkin lymphoma, EBV-specific cytotoxic T-cells are increased but showing immune exhaustion features. Hence, host immunity suppression may play a critical role in tumor progression. This study aimed to investigate, whether an association between tumor microenvironment features and EBV presence is taking place, and its clinical correlate. The incidence of EBV+DLBCL NOS was 12.6% in this cohort. Cytokine and chemokine transcripts expression and immunophenotype analysis showed that EBV infection was associated with increased gene expression of immunosuppressive cytokine (IL-10) together with increased CD8+ T-cells and granzyme B+ cytotoxic effector cells. However, this specific response coexists with a tolerogenic milieu, by PD-1 expression, in EBV+ and EBV-DLBCL cases. High PD-1+ cell counts, EBV presence and low CCL22 expression were associated with worse survival, supporting our hypothesis that EBV-specific response is mounted locally and its inhibition by, for example PD-1+ cells, may negatively affect outcome. The better understanding of the interplay between lymphoma cells and microenvironment in a viral framework could thereby facilitate the discovery of new targets for innovative anti-lymphoma treatment strategies.