Immunogenic and immunosuppressive components in soluble preparations from Moloney murine leukemia virus-induced tumor cells.

Soluble extracts from Moloney virus-induced leukemia cells were shown to contain immunogenic and immunosuppressive components. Immunogenic components were divided into two classes based on their ability to :(1) combine with humoral antibody to inhibit cytotoxic activity; or (2) stimulate blastogenesis in normal syngeneic lymphocytes. Immunosuppressive components were demonstrated by the inhibition of DNA synthesis in normal syngeneic lymphocytes and suppression of a mixed lymphocyte reaction.

Specificity of naturally occurring antibody in normal gibbon serum.

Gibbon natural antibody examined by immunoelectron microscopy reacted with the entire envelope of type C virus and with areas on the cell surface equivalent to or smaller than the diameter of a virion in gibbon and human culture cells infected with or releasing type C viruses. The antibody activity was absorbed completely by two cell cultures infected with gibbon ape leukemia virus and by the virus itself, and partially by normal gibbon spleen cells and dog thymus-derived cells infected with baboon endogenous type C virus, and fresh white blood cells obtained from a patient with chronic myelogenous leukemia in acute blastic crisis.