Cell-mediated and humoral immunity studies of murine and hamster sarcoma virus-induced producer and non-producer tumors in syngeneic animals.

Abstract

AbstractMurine sarcoma virus (MSV)‐induced transformed tumor cells, which are releasers and non‐releasers of virus, were investigated by transplantation immunity and a variety of serological assays. Transplantation immunity demonstrated that tumor‐associated transplantation antigens could be detected on producer cells and were also apparent, but to a lesser degree, on non‐releaser cells of BALB/c mouse origin. Some lymphocyte microcytotoxicity tests employing hamster MSV tumors failed to detect any in vitro immunity. Studies employing immunofluorescence, complement fixation and virus focus neutralization tests demonstrated that Harvey‐MSV producer cells of hamster origin were strongly immunogenic in inducing antibody formation in syngeneic hamsters. By contrast, no antibody could usually be detected by these techniques following immunization with non‐producer Harvey‐MSV or immunization with either Moloney‐MSV non‐producer cells or those non‐producer cells that had been made releasers by treatment with IUDR in syngeneic hosts. The results suggest that humoral antibody, as detected by the techniques employed, is probably produced largely in response to infectious MSV contained by producer tumor cells and is not directed against new cell neoantigens, whereas transplantation immunity is probably, in part, a response to non‐virion neoantigens.