Complete nucleotide sequences of the genomes of two Brazilian specimens of human T lymphotropic virus type 2 (HTLV-2).

We report the complete nucleotide sequences of the genomes of two human T cell lymphotropic viruses type 2 (HTLV-2) isolated from a Kayapó Indian (K96 isolate) and from an inhabitant of an urban region in the south of Brazil (RP329 isolate). The general structure of the K96 and RP329 genomes did not differ from that of other HTLV-2 genomes described in the literature. The K96 genome consisted of 8955 bp and the RP329 genome consisted of 8964 bp. The general similarity between the nucleotide sequences of the K96 and RP329 genomes was 99.4%. Comparison between the nucleotide sequences of the K96 and RP329 genomes and the nucleotide sequences of isolates considered to be HTLV-2 prototypes of subtype 2a (Mo isolate), 2b (NRA isolate), and 2d (Efe2 isolate) showed a global similarity of 98.8, 95.6, and 93.3%, respectively, for the RP329 isolate, and of 99.1, 95.6, and 93.3%, respectively, for the K96 isolate. Phylogenetic analysis permitted the classification of the K96 and RP329 isolates as HTLV-2 subtype 2a. Detailed phylogenetic analyses of the LTR, env, and Tax regions showed that the Brazilian isolates tend to form a distinct phylogenetic subgroup within subtype 2a, previously called HTLV-2c, which differs from the subtype 2a isolates found in North America, Europe, and Africa. The K96 genome is the first HTLV-2 genome obtained from a Brazilian Indian that was completely sequenced, whereas the RP329 genome represents the first specimen derived from an inhabitant of a Brazilian urban region who was not coinfected with HIV-1.