Tissue specific distribution of Epstein-Barr virus (EBV) BZLF1 gene variants in nasopharyngeal carcinoma (NPC) bearing patients

Using EBV BNLF1 gene polymorphism, we have recently shown that, in NPC bear ing patients, lymphocytes and tumor cells of the same individual were infec ted by different viruses. It appeared as a rule that EBV infection was by m ultiple strains in these immunocompetent, HIV negative patients. Our data d id not detect any evident association between tumor cells and a particular BNLF1 variant. In the present paper, we extend our analysis to the BZLF1 ge ne of the viruses present in different sites of the same patients. Only two main variants of the BZLF1 gene were identified. Despite this very weak po lymorphism of this locus, our results entirely confirm the very frequent oc currence of multistrain infections in these patients, and the presence of d ifferent EBV strains in tumor cells and lymphocytes from the same individua l. However, in contrast to our results concerning the BNLF1 gene, the BZLF1 variants appeared to be cell type specific, one being associated mainly wi th epithelial or tumor cells and the other with lymphocytes. The possible r easons for this distribution are discussed. (C) 2001 Elsevier Science B.V. All rights reserved.