Cell-mediated cytotoxicity in glioma-bearing patients: differential responses of peripheral blood mononuclear cells to stimulation with interleukin-2 and microbial antigen.

Peripheral blood mononuclear cells (PBMC) of malignant glioma-bearing patients were stimulated in vitro with Interleukin-2 (IL-2) or a glucomannan-protein antigen of Candida albicans (GMP) then assayed for proliferation, production of IFN-gamma, and generation of cytotoxic effectors against either K562 tumor cell line or freshly-cultured allogenic glioma cells. PBMC of healthy, age and sex-matched subjects were the controls. PBMC of glioma-bearing patients did not differ, as a whole, from PBMC of healthy donors in IL-2 or GMP-induced proliferation. However, they showed a lesser ability to produce IFN as well as a substantial inability to generate cytotoxic effectors following GMP stimulation. PBMC of glioma patients were fully responsive to IL-2 in cytotoxicity generation, as were the PBMC from normal subjects. The results suggest that glioma patients may have a defective antigen-mediated activation of natural cytotoxic effectors. This hyporesponsiveness is not accompanied by depressed lymphoproliferation and does not apparently involve a reduced response to IL-2.