Epstein-Barr Virus Nuclear Antigen 1 Sequences in Endemic and Sporadic Burkitt’s Lymphoma Reflect Virus Strains Prevalent in Different Geographic Areas

Abstract

The Epstein-Barr virus (EBV) nuclear antigen EBNA1 is the only viral protein detectably expressed in virus genome-positive Burkitt’s lymphoma (BL); recent work has suggested that viral strains with particular EBNA1 sequence changes are preferentially associated with this tumor and that, within a patient, the tumor-associated variant may have arisen de novo as a rare mutant of the dominant preexisting EBV strain (K. Bhatia, A. Raj, M. J. Gutierrez, J. G. Judde, G. Spangler, H. Venkatesh, and I. T. Magrath, Oncogene 13:177–181, 1996). In the present work we first study 12 BL patients and show that the virus strain in the tumor is identical in EBNA1 sequence and that it is matched at several other polymorphic loci to the dominant strain rescued in vitro from the patient’s normal circulating B cells. We then analyze BL-associated virus strains from three different geographic areas (East Africa, Europe, and New Guinea) alongside virus isolates from geographically matched control donors by using sequence changes in two separate regions of the EBNA1 gene (N-terminal codons 1 to 60 and C-terminal codons 460 to 510) to identify the EBNA1 subtype of each virus. Different geographic areas displayed different spectra of EBNA1 subtypes, with only limited overlap between them; even type 2 virus strains, which tended to be more homogeneous than their type 1 counterparts, showed geographic differences at the EBNA1 locus. Most importantly, within any one area the EBNA1 subtypes associated with BL were also found to be prevalent in the general population. We therefore find no evidence that Burkitt lymphomagenesis involves a selection for EBV strains with particular EBNA1 sequence changes.

Analysis of Epstein–Barr virus latent gene expression in endemic Burkitt's lymphoma and nasopharyngeal carcinoma tumour cells by using quantitative real-time PCR assays

“…1 also shows the data from two atypical BL lines, Oku-BL and Ava-BL. We have shown previously that these BL lines exhibit a novel form of infection (termed Wp-restricted latency) that is characterized by Wp-driven expression of EBNA1, -3A, -3B, -3C and -LP in the absence of EBNA2 or the LMPs (Habeshaw et al, 1999;Kelly et al, 2002). These earlier findings are in agreement with the results of the real-time RT-PCR analyses (Fig.…”

“…In the next series of experiments, we asked whether the quantitative assays might provide new information about EBV gene expression in primary tumour material. In the first case, we examined a collection of endemic BL tumour biopsies from the West Nile region of Uganda (Habeshaw et al, 1999) for which enough material was available to study by both RT-PCR and immunoblotting. All but one case showed a similar pattern of EBNA transcription, characterized by abundant QUK-spliced EBNA1 transcripts (at levels similar to those seen in the reference Rael BL cells) in the absence of significant Wp-, Cp-or YUK-spliced signals (Fig.…”

Epstein–Barr virus latent gene sequences as geographical markers of viral origin: unique EBNA3 gene signatures identify Japanese viruses as distinct members of the Asian virus family

“…The four main allelic variants of the EBNA1 sequence, known from earlier work (Bhatia et al, 1996), differ by up to 20 codon changes from the prototype B95.8 strain but are named after signature changes at codon 487. The A 487 (B95.8) and T 487 alleles are common among European isolates, the T 487 and L 487 alleles are common in Africa and the V 487 allele are common in China (Bhatia et al, 1996;Habeshaw et al, 1999;Sandvej et al, 2000). Fig.…”

Proposed guidelines for diagnosing chronic active Epstein‐Barr virus infection

“…To date, no disease-specific virus has been isolated or recognized, although some variants were reported including variants of EBNA-1, EBNA-2, or latent membrane protein (LMP)-1 coding regions, or lytic viral strains [1,2]. Regarding virus variants, when data are available from diseasederived virus strains in the absence of geographically matched control isolates, caution must be exercised to confirm the disease-specific virus [32].…”