Changes in spleen morphology and lymphoid cell activity during tumor progression

Abstract

Morphologic alterations in the spleen and dynamic changes in the biologic activity of its cellular components occur concomitant with the neoplastic progression of a murine methylcholanthrene induced fibrosarcoma. Spleen size, weight and cell number increased with tumor growth. Using the local adoptive transfer assay (LATA), spleens from tumor bearing mice in the early and late stages of neoplastic growth were shown to possess non-specific, tumor-facilitating cells which were radioresistant, phagocytic and adherent, presumably macrophages. On the other hand, spleens from mice in the intermediate and late stages of tumorigenesis displayed specific, tumor-neutralizing cells, which were radiosensitive and Thy 1.2 positive, presumably T-cells. Thus, a balance of tumor-facilitating and neutralizing cells may determine neoplastic progression in susceptible, syngeneic hosts.