NEUROIMMUNOMODULATION OF NATURAL-KILLER (NK) CELLS BY ERGOT ALKALOID DERIVATIVES

Ergot alkaloids (EAs), products of Claviceps spp., are widely used in various fields of clinical medicine (neurology, psychiatry, endocrinol ogy). In the present work we studied the neuroimmunomodulative effect of EAs on activation of NK cells and their signalling pathways. Furthe rmore, the killing capability of rat NK cells in vitro was examined in the presence of glycosidic derivatives of elymoclavine, agroclavine, and liposome-encapsulated EAs. The engagement of appropriate NK cell m embrane receptors by EAs cause an indirect enhancement of adenylyl cyc lase system through inhibition of G-protein alpha 1,2-subunit (up to 5 0 % of control values). All of the tested EAs enhanced the rat NK cell -mediated cytotoxic activity in vitro, particularly against target cel ls of astrocyte origin (C-6 glioma). The present results argue for a p ossible EA immunomodulatory role of cell-mediated immunity in tumour r egression processes.