Isolation and characterization of simian immunodeficiency virus from African white-crowned mangabey monkeys (Cercocebus torquatus lunulatus)

Abstract

Summary Forty-eight of 236 sera from seven species of African non-human primates in Kenya, including those of white-crowned mangabey monkeys (Cercocebus torquatus lunulatus) had antibodies to simian immunodeficiency viruses (SIVs). Isolates of simian lentivirus were obtained from seropositive white-crowned mangabey monkeys which are indigenous in West Africa. This virus, designated as SIV_WCM, appeared morphologically similar to HIV by electron microscopy, showed Mg²⁺-dependent reverse transcriptase activity, and induced cytopathic effects in human CD 4-positive cells. Western blotting analysis revealed thatenv products of SIV_WCM cross-reacted with those of SIV_AGM more strongly than with those of HIV-1 and SIV_MAC, and clear hybridization bands were detected with an SIV_AGM probe. For comparison of the virus sequence with those of other primate lentiviruses, part of thepol gene and the long terminal repeats (LTRs) were amplified and cloned. Sequencing showed that SIV_WCM isolates were closely related to SIV_AGM isolates. This study suggested that SIV_AGM from theCercopithecus genus and SIV_WCM from theCercocebus genus may be members of an SIV group that is genetically distinct from the SIV from a sooty mangabey monkey (SIV_SMM) of the genusCercocebus, to which the white-crowned mangabey monkey also belongs.