COMPLETE NUCLEOTIDE-SEQUENCE OF AN AMERINDIAN HUMAN T-CELL LYMPHOTROPIC VIRUS TYPE-II (HTLV-II) ISOLATE - IDENTIFICATION OF A VARIANT HTLV-II SUBTYPE-B FROM A GUAYMI INDIAN

The complete nucleotide sequence of a human T-cell lymphotropic virus type II (HTLV-II) isolate from a Panamanian Guaymi Indian was determin ed and analyzed. When this new viral isolate (HTLV-II(G12)) was compar ed with prototypic HTLV-II(MoT), the overall nucleotide sequence simil arity was 95.4%, while the predicted amino acid sequence similarity wa s 97.5%. Although the overall percentage of nucleotide and amino acid identity with prototypic HTLV-II(MoT) (subtype a) was high, HTLV-II(G1 2) displayed several distinctive features that defined it as an HTLV-I I subtype b. However, there were several characteristics unique to thi s isolate, which included a cluster of nucleotide substitutions in the pre-gag region and changes in restriction enzyme sites within the pre -gag region and the gag, pol, env, and pX genes. In addition, two nucl eotide changes in the C terminus of the Tax protein coding sequence in serted an Arg residue for a stop codon and appeared to result in a lar ger tax gene product in HTLV-II(G12). Although the HTLV-II(G12) isolat e appears to be a variant of the prototypic HTIV-IIb, this information represents the first complete nucleotide sequence of any HTLV-II subt ype b. These data will allow further studies on the evolutionary relat ionships between the HTLV-II subtypes and between HTLV-I and HTLV-II.