Virus particles morphologically similar to the known oncogenic RNA-type viruses have been isolated and cultured from a spontaneous mammary carcinoma of a rhesus monkey. The virus was initially isolated by cocultivation of tumor tissues with monkey embryonic cell cultures but was later found to be transmissible as a cell-free filtrate.
The virus is approximately 110 mµ in diameter and has a buoyant density between 1.14 and 1.16. Preliminary host-range studies thus far have shown the virus to replicate in rhesus monkey mixed embryo, embryonic lung, chimpanzee lung, and human mixed embryo cell cultures, and in an established human leukocyte culture, NC-37. Virus did not replicate in hamster kidney, mouse bone marrow, rhesus or African green monkey kidney cells, or baboon or chimpanzee leukocyte cultures.
This study was conducted under USPHS contracts PH 43-66-98 (NIH 70-2080) and PH 43-67-1176 within the Special Virus-Leukemia Program of the National Cancer Institute, Bethesda, Md.