Sequence analysis of the new human T cell leukemia/lymphoma virus type I isolate (HTLV-I) in Israel

Recent studies have established the presence of human T cell leukemia/lymphoma virus type I (HTLV-I) in Israel. The entire nucleotide sequence of HTLV-I virus from a previously described HE isolate of a Mashadi Jewish Iranian patient was determined. To further characterize the LTR and env genes from the HTLV-I isolate we employed polymerase chain reaction amplification with subsequent cloning and sequencing of the amplified products on both strands. Sequence analyses of amplified LTR regions of this variant showed marked nucleotide homology of 98% compared to Japanese isolates, while African and Indo-Malay (Papua, New Guinea) and Solomon Island isolates showed more divergence with sequence homology of 95% and 91%. Higher homology of 98-99% was conserved in the amplified HTLV-env gene. In this respect the Iranian isolate was most similar to the African and Japanese isolate and divergent from the Melanesian HTLV-I variant, supporting the theory that HTLV-I may have originated in Africa and reached the Far East by overland trade routes.