A COMPARATIVE-STUDY OF HIGHER PRIMATE FOAMY VIRUSES, INCLUDING A NEW VIRUS FROM A GORILLA

Few foamy (spuma) retroviruses have been investigated in molecular det ail, despite their previous isolation from several mamalian species, i ncluding ten neutralization serotypes from various primates. Here, we have studied a new gorilla foamy virus (SFV-Gg) and investigated its f unctional and phylogenetic relationship to the human (HFV) and other p rimate foamy viruses, including that recently described in orangutans (SFV-11). Nucleotide sequencing of PCR products obtained from the R/U5 region of the LTR, gag, and pol genes revealed a close relationship b etween HFV and three chimpanzee isolates (SFV-6, SFV-7, and SN-cpz). T he SFV-Gg, SFV-11, rhesus macaque (SFV-1), and African green monkey (S FV-3) isolates were more divergent. To explore functional relationship s, primate foamy Virus transactivation of HFV LTR driven beta-galactos idase expression in a newly constructed cell line, BHLL, was investiga ted. HFV, SFV-6, and SFV-7 potently transactivated HFV LTR driven lacZ gene expression, SFV-Gg induced expression approximately 10-fold less efficiently, and SFV types 1, 2, 3, and 11 did not significantly tran sactivate the HFV LTR. It was, thus, possible to assay serum neutraliz ing activity in SFV-infected primates against HFV, SFV-6, and SFV-7 by reduction of beta-galactosidase activity following infection of the i ndicator cell line. Sera from infected chimpanzees and gorillas neutra lized, to varying degrees, each of these three viruses, whereas orangu tan sera did not. Our results, based on DNA sequences and functional a ssays, support the conclusion that HN is closely related to foamy viru ses of chimpanzee origin. (C) 1995 Academic Press, Inc.