8th International AIDS Conference Amsterdam, Netherlands — July 19-24, 1992

Int Conf AIDS 1992 Jul 19-24; 8:We60 (abstract no. WeA 1079)
Muller MC, Saksena NK, Chappey C, Herve V, Nerrienet E, Durand JP, Georges AJ, Sonigo P, Barre-Sinoussi F; Institut Pasteur, Paris.

OBJECTIVE: Simian immunodeficiency viruses (SIV) are widely present in African Green monkeys (AGM) and may have evolved in parallel with their natural host species. However, information to date is limited to viruses of only three species: the vervet, the grivet and the sabaeus green monkeys. We present here a genetic study of lentiviruses of another AGM species, the tantalus. We also initiated a first study in env of SIV from sabaeus monkeys.

METHODS: SIV isolates from tantalus in Central African Republic and from sabaeus in Senegal were selected. Proviral DNA-fragments in gag-, pol- and env-regions were amplified by PCR. Env amplified fragments were sequenced directly using SIVagm-specific nested primers. The deduced aa-sequences were compared to each other and to all other SIVagms reported so far.

RESULTS: 544 bp fragments encoding for the C-terminal half of the EGP of 4 SIV isolates from tantalus and 4 viral strains from sabaeus were sequenced. The amino acid identity was always greater between the tantalus isolates themselves (greater than 78%) than between tantalus SIVs and viruses from vervet, grivet or sabaeus monkeys (less than 70%). The greatest variation was observed between one tantalus and one sabaeus strain (57.1%). In addition, alignment of entire gp120 encoding sequences revealed that the first and the fourth variable domains of SIV from tantalus are highly divergent in regard to equivalent sequences of previously published SIVagms.

CONCLUSION: This analysis confirms the existence of species specific SIVs for vervets, grivets and sabaeus monkeys and reveals a fourth distinct SIVagm group specific for tantalus. Genetic distances between these groups are significant and allow to distinguish SIV types according to each host species. However, enhancing informations on the phylogeny of SIVagms require additional sequence analysis. Such informations on genetic diversity may also be relevant for a better understanding of possible adaptation mechanisms between primate lentiviruses and their natural hosts in Africa, and their possible consequences on the lack of pathogenicity observed so far in naturally infected monkeys.

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