Pro-oncogenic, intra host viral quasispecies in Diffuse large B cell lymphoma patients with occult Hepatitis B Virus infection

Mahua Sinha,Vikas Asati,Linu A Jacob,Kshitish K Acharya,Sravanthi Davuluri,Akhilesh Kumar Bajpai,Keerthana Sundar,Dinesh Velayutham,C S Premalata,Alka Murali,Govind Babu K,Dharam Nandan,R S Jayshree,K C Lakshmaiah,Sibnarayan Datta

doi:10.1038/s41598-019-51157-1

Abstract

Non Hodgkin lymphoma, predominantly Diffuse Large B-cell Lymphoma (DLBCL) has been reported to have a significant association with Hepatitis B virus (HBV). We investigated the presence of different gene segments of HBV in plasma, B-cells and tumor tissues from DLBCL patients and explored the genetic variability of HBV within and across different compartments in a host using Next Generation Sequencing. Despite all 40 patients being HBV seronegative, 68% showed evidence of occult HBV. Sequencing of these gene segments revealed inter-compartment viral variants in 26% of them, each with at least one non-synonymous mutation. Between compartments, core gene variants revealed Arg94Leu, Glu86Arg and Ser41Thr while X gene variants revealed Phe73Val, Ala44Val, Ser146Ala and Ser147Pro. In tumor compartments per se, several mis-sense mutations were detected, notably the classic T1762A/A1764G mutation in the basal core promoter. In addition, a virus surface antigen mis-sense mutation resulting in M125T was detected in all the samples and could account for surface antigen negativity and occult HBV status. It would be interesting to further explore if a temporal accumulation of viral variants within a favored niche, like patients’ lymphocytes, could bestow survival advantage to the virus, and if certain pro-oncogenic HBV variants could drive lymphomagenesis in DLBCL.

Highlights

Diffuse large B cell lymphoma (DLBCL) is predominant among the Non-Hodgkin’s Lymphoma (NHL) subtypes, accounting for nearly 60% of NHLs1
We explore the possibility that long-term persistence of pro-oncogenic viral quasispecies in such occultly infected B lymphocytes, probably in the presence of other pro-oncogenic co-factors, can eventually lead to B cell lymphomas
Serological studies have shown that Hepatitis B virus (HBV)-infected patients have a higher risk of developing B-cell NHL, typically Diffuse Large B-cell Lymphoma (DLBCL), than non-infected patients, and the viral infection may play an etiopathologic role in oncogenesis in these subtypes of lymphomas[2,3,4,5,6,7,8,15]

Summary

Introduction

Diffuse large B cell lymphoma (DLBCL) is predominant among the Non-Hodgkin’s Lymphoma (NHL) subtypes, accounting for nearly 60% of NHLs1. Risk of B-cell subtypes of NHL, especially DLBCL has been documented to be significantly elevated with an odds ratio of 3.3 in HBV infected patients[2,5,6,7,8]. These studies were predominantly on HBV seropositive cases. Selection pressure exerted by the host immune surveillance, the virus’ error-prone replication and resulting mutations propel evolution of HBV quasispecies, which accumulate within the host and get compartmentalized in immunologically preferred sites. The aim of this study was to investigate occult HBV infection in DLBCL patients and to identify viral quasispecies or variants within the host using Generation Sequencing (NGS)

Objectives

Methods

Results

Conclusion