PEPTIDE CYTOKINES IN CNS AND THE IMMUNE-SYSTEM

This study describes the effects of cytokine peptides released into th e supernatant during an early allogeneic reaction (AR) of mouse spleen lymphocytes or brain cortex cells which differ in their major histoco mpatibility complex (MHC). The peptides were isolated by ultrafiltrati on, liquid chromatography and HPLC. We found that both peptides stimul ated the cell surface Na+,K+-ATPase and Ca2+-ATPase activities of quie scent spleen lymphocytes in vitro and mimicked early allogeneic cell i nteractions. Both brain and spleen AR peptides inhibited Concanavalin A-stimulated spleen lymphocyte proliferation, whereas H-3-TdR incorpor ation into DNA of the E7 neuroblastoma cell line was stimulated by the se peptides. The peptide isolated from the supernatant of the allogene ic brain cell reaction inhibited phagocytosis in phorbol myristate-sti mulated LA5-9/8 mouse macrophage cell line. Immunosuppressive activity of spleen AR peptide is supported by inhibition of spontaneous E rose tte formation by lymphocytes. The immunosuppressive effect of isolated peptide cytokines on lectin-activated lymphocytes was comparable with the serum thymic factor (FTS, Lenfant et al. 1983). These changes dem onstrate the pleiotropic cytokine actions mediated by plasma membrane of immune system and brain cells.