Paul Arnstein

Demonstration of two immunologically distinct xenotropic type C RNA viruses of mouse cells

Abstract Several independent type C virus isolates were obtained by transplantation of human tumor cell lines into immunosuppressed NIH Swiss mice. Each isolate appeared to be of mouse origin as determined by the antigenicity of its major virion polypeptide, p30. The virus isolates were indistinguishable from each other in serologic and host range properties and also closely resembled BALB:virus-2, one endogenous virus of BALB c mouse cells. However, in immunoassays for a highly type-specific virion polypeptide, designated p12, every isolate was found to differ from BALB: virus-2. These results provide evidence for the existence of immunologically distinct xenotropic viruses of mouse cells.

Transformation of Baboon Cells with Feline Sarcoma Virus

Testes cells from two baboons have been transformed by the Snyder-Theilen (ST) and Gardner-Arnstein (GA) strains of feline sarcoma virus (FeSV). The resulting cell cultures formed tumors in immunosuppressed mice, but not in the autologous baboons. The cells transformed by GA FeSV contained more feline gs antigen than those transformed by ST FeSV. Conversely, the cells transformed by ST FeSV produced more type-C virus. Unlike FeSV, which has a predilection for feline cells, the virus from baboon cells transformed by ST FeSV replicated in baboon and beagle embryo cells, but not in feline embryo cells, suggesting that this virus is different from FeSV.