INITIAL CHARACTERIZATION OF VIRAL SEQUENCES FROM A SHIV-INOCULATED PIG-TAILED MACAQUE THAT DEVELOPED AIDS

In this study, we report on the derivation of a pathogenic SIV-HIV chi meric virus (SHIV) and the initial characterization of the viral seque nces from the first (macaque PPc) of a series of pig-tailed macaques t hat developed CD4(+) T cell loss and AIDS. Viral genes were amplified by PCR from the brain, lymphoid, and kidney tissues and their sequence s compared to the original SHIV used to initiate passages in macaques. Our results show that the vpu gene, which was nonfunctional in the or iginal SHIV, now coded for functional protein in macaque PPc. The tat and rev genes had no consensus changes but the nef gene had 4-5 consen sus changes, depending on the tissue examined. The gp 120 gene had the highest number of nucleotide and amino acid substitution rates that v aried from 0.64% to 1.44% and 1.17% to 3.71%, respectively, again depe nding on the tissue examined. These results suggest that a constellati on of changes accumulated at the genomic level during the derivation o f a SHIV that was pathogenic for pig-tailed macaques.