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Session 35 Poster Session HIV and SIV Diversity Session Time: 4:30-6:30 pm Room 4E-F

131-M. SIVcpz Infection in Wild Chimpanzees M. Santiago*1, C. Rodenburg1, S. Kamenya2, F. Bibollet-Ruche1, F. Gao1, E. Bailes3, B. Fahey4, M. Muller4, H. McClure5, J. Heeney6, A. Pusey7, D. Collins2, C. Boesch8, R. Wrangham4, J. Goodall9, P. Sharp3, G. Shaw1, and B. Hahn1 1Univ. of Alabama, Birmingham; 2Gombe Stream Res. Ctr., Kigoma, Tanzania; 3Univ. of Nottingham, UK; 4Harvard Univ., Cambridge, MA; 5Yerkes Regional Primate Res. Ctr., Atlanta, GA; 6Biomed. Primate Res. Ctr., Rijswijk, The Netherlands; 7Univ. of Minnesota, St.Paul; 8Max-Planck Inst. for Evolutionary Anthropology, Leipzig, Germany; and 9Jane Goodall Inst., Silver Spring, MD Background: West-central African chimpanzees (Pan troglodytes troglodytes) are known to harbor strains of SIVcpz that are closely related to all 3 groups of HIV-1 (M, N, and O) and have thus been implicated as a reservoir for human infection. Yet, because all SIVcpz strains identified to date have been derived from captive chimpanzees, little is known about the prevalence, geographic distribution, and evolutionary relationships of SIVcpz in the wild. Such information is critical for elucidating the origins of HIV-1 and current human zoonotic risk. Methods: Non-invasive methods were developed to detect and molecularly identify SIVcpz in wild chimpanzees by analyzing fecal and urine samples for SIVcpz antibodies and virion RNA. We studied a total of 58 chimpanzees from 3 wild communities outside the P.t.troglodytes range: 28 P. t. verus from the Taï Forest, Cote d’Ivoire, 24 P. t. schweinfurthii from Kibale National Park, Uganda, and 6 P. t. schweinfurthii from Gombe National Park, Tanzania. Results: Out of 58 chimpanzees studied, only 1, from Gombe National Park, was positive for SIVcpz infection. Each of 2 urine samples from this individual contained HIV-1 cross-reactive antibodies recognizing gp160, p66, p55, p51, gp41, p31, and p24 antigens in an ultrasensitive Western blot assay, and each of 3 fecal samples contained SIVcpz virion RNA detectable by RT-PCR methods. Sequence analysis of diagnostic RT-PCR products revealed a highly divergent SIVcpz strain (SIVcpzTAN1). A near full-length sequence of SIVcpzTAN1 (8912 bp) was subsequently derived from 12 overlapping PCR fragments amplified from fecal RNA, and phylogenetic analyses revealed a deep, but significant clustering of SIVcpzTAN1 with SIVcpzANT, the only other known SIVcpz strain from a P. t. schweinfurthii. Conclusions: The discovery of SIVcpzTAN1 in a wild-living Gombe chimpanzee extends the geographic boundaries for SIVcpz from Gabon and Cameroon in west-central Africa to the eastern-most limit of the chimpanzee range in Tanzania. It also indicates that both P. t. troglodytes and P. t. schweinfurthii are naturally infected by SIVcpz. However, the considerable divergence of SIVcpzTAN1 and SIVcpzANT from HIV-1 groups M, N, and O indicates that P. t. schweinfurthii did not serve as the zoonotic source for epidemic HIV-1.

©2002 9th Conference on Retroviruses and Opportunistic Infections