DIVERSITY OF NATURALLY-OCCURRING EPSTEIN-BARR-VIRUS REVEALED BY NUCLEOTIDE-SEQUENCE POLYMORPHISM IN HYPERVARIABLE DOMAINS IN THE BAMHI-K AND BAMHI-N SUBGENOMIC REGIONS

The extent of nucleotide sequence microheterogeneity varies among subg enomic: regions of Epstein-Barr virus (EBV), We examined, in EBV-carry ing lymphoid cell lines, the extent of polymorphism in EBV DNA fragmen ts amplified from the BamHI E, K, N and Z regions, and then investigat ed the diversity of the more hypervariable regions in tissues and body fluids, In cell lines, sequence dissimilarities in a genotype-specify ing fragment of the EBNA-3C gene varied from < 1-4 % within each genot ype; dissimilarities in the first intron of the BZLF-1 gene were < 2% within each genotype, By contrast, dissimilarities in a C-terminal uni que domain of the EBNA-1 gene, and in a fragment that encompasses and is upstream of the LMP-1 start codon, varied between 2 and 7% and were not genotype-specific, The sequence diversity in BamHI K and N region s was then examined in tissues and body fluids by single-strand confor mation polymorphism (SSCP) analysis and cycle sequencing. Extensive in ter-host diversity was observed, whether the host was co-infected by h uman immunodeficiency virus (HIV) or not. In the oral cavity of HIV-in fected patients, inter-compartmental EBV diversity could be demonstrat ed, even between sites that were anatomically proximate. Studies of Ba mHI K clones derived from EBV in oral lesions revealed infection by mu ltiple variants, Identification of hypermutable loci within the EBV ge nome such as those located in the BamHI K and N regions should permit fine discrimination of individual EBV variants.