Isolation of a primate type‐C virus from a lymphomatous baboon

Abstract
A type-C RNA virus has been isolated from various tissues of a lymphomatous baboon (sp. P. hamadryas). Virus isolations were made by co-cultivating baboon cells from the inguinal and mesenteric lymph nodes, testes, kidneys and spleen with cells of canine or human origin. The isolated virus grew in canine, bat, rhesus and human cells but not in cells of mouse, rat, cat or rabbit origin. The baboon isolate resembled a type-C virus when infected cells were examined by thin section in the electron microscope. In addition, the virus was capable of providing helper function by rescuing and transmitting the Moloney and Kirsten sarcoma virus genome from non-productively transformed cells. Antibody directed against the RD114 virus reverse transcriptase was very effective in inhibiting the baboon virus polymerase while anti-mouse and woolly type-C virus polymerase antibodies had no significant inhibitory activity. Further analysis by immunodiffusion and competitive radioimmune assay revealed a close immunological relationship between this virus, RD114 and another type-C virus isolated from the placenta of a different species of baboon. Finally, three different classes of interspecies antigenic determinants have been demonstrated in mammalian type-C viruses.