Rhesus macaques inoculated with molecularly cloned simian immunodeficiency virus

We have isolated a biologically active molecular clone of simian immunodeficiency virus (SIV), SIVmac 1A11, originally obtained from a rhesus macaque at the New England Regional Primate Research Center. Virus derived from cells transfected with this clone is cytopathic for rhesus peripheral blood mononuclear cells, replicates in cultures of rhesus macrophages, and infects rhesus macaques when inoculated intravenously. Six macaques inoculated with SIVmac 1A11 all became infected and produced antibodies to viral envelope glycoproteins that neutralized virus. Antibodies to viral core proteins were detected in only one animal. No clinical signs of disease were observed throughout 7 months postinoculation.