Rous Sarcoma Virus Infection of Chicken Buffy Goat Macrophage. ∗

Abstract

Summary

Over 50% of RSV treated chicken buffy coat macrophage cultures induced tumors when the cells were tested in 2-day-old chicks. Some of these cultures were positive when tested as late as 4 months after infection. Sarcoma virus from the tumors and red vascular lesions were observed in many of the tumor bearing animals. The macrophage cultures lacked detectable fibro-blastic elements. Free virus was absent in the supernatant fluid of most of the virus treated macrophage cultures. More than one-half of the cultures whose cells induced tumors did not contain free virus at any time when their supernatant fluids were tested. Whenever detected, the titre of free virus was less than 10² v.f.u./ml of supernatant fluid. This value was about 1/1000 that of the free virus in infected fibroblast cultures which had a titre of 10⁴ to 10⁵ v.f.u. per ml of supernatant fluid. Sarcoma virus antigens were not observed in the virus treated macrophage cultures when tested by the fluorescent antibody staining technique including cell samples from macrophage cultures positive for tumor induction.