Sequence variation of latent membrane protein-1 of Epstein-Barr virus strains associated with hairy leukoplakia.

The Epstein-Barr virus (EBV) latent membrane protein (LMP)-1 is expressed in hairy leukoplakia (HL), but data on LMP-1 sequence variation of HL isolates are limited. Variation in the LMP-1 repeat region and presence of a 30-nt deletion were studied using DNA scrapings from 28 HL lesions. cDNAs from 3 different HL isolates were sequenced, 2 from lymphocyte cell lines (LCLs) generated using HL biopsy material. The deletion was found in 16 (57%) of 28 HL scraping, and multiple repeat region variants were seen in 13 scrapings (46%). HL LMP sequence were similar to those described in nasopharyngeal cancer and lymphoma tissues, including two motifs of four amino acid changes relative to B95-8 upstream and downstream of the repeat region, respectively. Generation of LCLs using HL biopsy material confirmed the ability of HL EBV strains to infect and transform lymphocytes.