EBNA3B-deficient EBV promotes B cell lymphomagenesis in humanized mice and is found in human tumors
Robert E. White, … , Christian Münz, Martin J. Allday
Robert E. White, … , Christian Münz, Martin J. Allday
Published March 12, 2012
Citation Information: J Clin Invest. 2012;122(4):1487-1502. https://doi.org/10.1172/JCI58092.
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Research Article Oncology

EBNA3B-deficient EBV promotes B cell lymphomagenesis in humanized mice and is found in human tumors

Abstract

Epstein-Barr virus (EBV) persistently infects more than 90% of the human population and is etiologically linked to several B cell malignancies, including Burkitt lymphoma (BL), Hodgkin lymphoma (HL), and diffuse large B cell lymphoma (DLBCL). Despite its growth transforming properties, most immune-competent individuals control EBV infection throughout their lives. EBV encodes various oncogenes, and of the 6 latency-associated EBV-encoded nuclear antigens, only EBNA3B is completely dispensable for B cell transformation in vitro. Here, we report that infection with EBV lacking EBNA3B leads to aggressive, immune-evading monomorphic DLBCL-like tumors in NOD/SCID/γc–/– mice with reconstituted human immune system components. Infection with EBNA3B-knockout EBV (EBNA3BKO) induced expansion of EBV-specific T cells that failed to infiltrate the tumors. EBNA3BKO-infected B cells expanded more rapidly and secreted less T cell–chemoattractant CXCL10, reducing T cell recruitment in vitro and T cell–mediated killing in vivo. B cell lines from 2 EBV-positive human lymphomas encoding truncated EBNA3B exhibited gene expression profiles and phenotypic characteristics similar to those of tumor-derived lines from the humanized mice, including reduced CXCL10 secretion. Screening EBV-positive DLBCL, HL, and BL human samples identified additional EBNA3B mutations. Thus, EBNA3B is a virus-encoded tumor suppressor whose inactivation promotes immune evasion and virus-driven lymphomagenesis.

Authors

Robert E. White, Patrick C. Rämer, Kikkeri N. Naresh, Sonja Meixlsperger, Laurie Pinaud, Cliona Rooney, Barbara Savoldo, Rita Coutinho, Csaba Bödör, John Gribben, Hazem A. Ibrahim, Mark Bower, Jamie P. Nourse, Maher K. Gandhi, Jaap Middeldorp, Fathima Z. Cader, Paul Murray, Christian Münz, Martin J. Allday

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Figure 4

PTLD-derived LCLs lacking EBNA3B phenotypically resemble those derived from infected mice.

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PTLD-derived LCLs lacking EBNA3B phenotypically resemble those derived f...
(A) Relative gene expression levels, measured by qPCR using Taqman low-density arrays, normalized against 4 endogenous controls, and plotted on a log2 scale as the distance from the geometric mean expression for that gene across all cell lines. Data are mean ± SEM for the EBNA3BKO and combined wtBAC and EBNA3Brev cell lines. Also shown are expression levels in the patient-derived cell lines, for which error bars indicate expression values of the 2 TRL1 lines. Data points are connected to clarify data trends. (B) Flow cytometry profiles for LAIR1 and CD11a expression in ex vivo–expanded cells from 2 mouse experiments and EBNA3B mutant PTLD patients (ptLCLs). Each plot contains the same number of gated events to facilitate comparison of samples within the same experiment. (C) Principal component correlation analysis of cell lines based on gene expression data from qPCR analysis of the 48 genes shown in Supplemental Figure 3. Samples are identified by the infecting virus (color) and whether the LCLs were established in vitro or ex vivo (shape). Groups by virus and LCL type are indicated by overlaid icosahedrons colored by virus type; wtBAC and EBNA3Brev were considered as a single group, and TRL1 and TRL595 lines were separated. Percent contribution of each principal component to total variation is indicated on the respective axis.