Infectivity of Cell Cultures by a Virus Isolated From a Mammary Carcinoma of a Rhesus Monkey<xref ref-type="fn" rid="FN2">2</xref>

Abstract

Infectivity studies of various cell lines of primate origin, inoculated with virus isolated from the monkey mammary carcinoma, were conducted by electron microscopy. The cell cultures did not show any cytopathic effect and the infectivity was demonstrated by the presence of virus particles in the infected cells. The cell cultures of rhesus monkey embryo, rhesus monkey lung, and chimpanzee lung were found to be infected. Most significantly, human embryonic cell cultures and an established human leukocyte (NC-37) culture were infected with cell-free virus. The latter is chronically infected and continues to produce new virus particles. The development of virus in these cultures was similar to that observed in the original monkey mammary tumor cells. Electron microscopy of infected cells revealed the presence of intracytoplasmic A-type and budding extracellular forms, resembling oncogenic RNA viruses.