Cellmediatedcytotoxicity and cytokineproduction in peripheralbloodmononuclearcells of gliomapatients

A mannoprotein preparation (MP) from Candida albicans induced MHC-unrestricted cytotoxicity in peripheral blood mononuclear cells (PBMC) from healthy subjects, but not in those from glioma-bearing subjects. The two groups of subjects did not significantly differ in the number of cells bearing typical natural killer (NK) markers (both in resting and MP stimulated PBMC) and NK activity. However, interferon gamma (IFN-gamma) production was in tumour patients minimal or significantly reduced, as compared to healthy subjects, following PBMC stimulation by MP or phytohaemoagglutinin, respectively. In addition, minimal, if any, stimulation of interleukin-2 (IL-2) production was achieved in MP stimulated PBMC from glioma patients. Considering the pivotal role of the above cytokines in immune responses, particularly in those concerning generation of antitumour effectors, our results consistently suggest that defective cytokine production is one possible mechanism of immunological impairment in glioma patients. They also provide indirect support for a possible clinical use of IFN-gamma as an immunopotentiating agent in gliomatous subjects.