Immunogenetic and Immunologic Aspects of Gliosarcoma Growth in Rats

Growth of the chemically induced, transplantable rat brain tumor gliosarcoma 9L (GS-9L) is under immunogenetic control. Both susceptible and resistant rats produce an immune response to the tumor, but the response is qualitatively different in the two groups. The intraperitoneal administration of gliosarcoma-9L cells in resistant KGH rats causes the production of cytotoxic lymphocytes and macrophages, and in susceptible F344 rats suppressor lymphocytes are produced. After gliosarcoma-9L cells were administered to (KGH x F344)F1 and backcross rats, tumor susceptibility or resistance and the nature of the immune response correlated well with the histocompatibility type, indicating the parallel genetic control of both traits. However, a second gene or gene complex, not linked to the major histocompatibility complex, may participate in the regulation of tumor growth.