SEQUENCE-ANALYSIS OF A HIGHLY DIVERGENT HIV-1-RELATED LENTIVIRUS ISOLATED FROM A WILD CAPTURED CHIMPANZEE

Two strains of simian immunodeficiency viruses (SIV) isolated from chi mpanzees (SIVCPZ-GAB and SIVCPZ-GAB2) originating from Gabon have prev iously been genetically characterized and shown to belong phylogenetic ally to the same lineage as the human immunodeficiency virus type 1 (H IV-1). We describe the sequence analysis of a third HIV-1-related viru s, SIVCPZ-ANT, isolated from a wild captured chimpanzee originating fr om Zaire. This virus displayed the same genetic organization as HIV-I and was found to fall on the same lineage as HIV-1 and SIVCPZ-GAB. Pro tein sequence identity with SIVCPZ-GAB ranged from 72% (Poi) to 48% (E nv) for the structural proteins, while a particularly divergent Vpu wa s found (only 25% identity to SIVCPZ-GAB). The V3 regions of the SIVCP Z isolates were exceptionally conserved in contrast to the high diverg ence of V3 among HIV-1 isolates, However, SIVCPZ-ANT did not show a gr eater degree of sequence similarity with SIVCPZ-GAB than with HIV-1 is olates and represents a guile divergent outgroup of the HIV-1 lineage. Our data suggest multiple introductions of HIV-1 in the human populat ion and shed new light on the origin of the HIV-1 pandemlc. (C) 1996 A cademic Press, Inc.