IMMUNOMODULATORY ROLE OF PHAGOCYTE-DERIVED CHLORAMINES INVOLVING LYMPHOCYTE GLUTATHIONE

THIS study shows that human lymphocytes markedly decrease chloramines (long-lived oxidants) generated by polymorphonuclear neutrophils (PMN) after stimulation by phorbol-myristate-acetate or opsonized zymosan. In a cell-free model, reduced glutathione (GSH) scavenged chloramines, giving rise to oxidized glutathione (GSSG). In the cell system, treat ment of lymphocytes with autologous PMN-derived chloramines induced a profound decrease in their total and reduced glutathione (GSH) content and markedly inhibited their proliferate responses to concanavalin-A and, to a lesser extent, phytohaemagglutinin. It is concluded that (i) lymphocytes may play a defensive role against phagocyte-derived oxida tive stress by scavenging chloramines, and (ii) as this effect which i s mediated by GSH affects lymphocyte proliferative responses, it may h elp to elucidate the still obscure mechanisms of oxidative stress asso ciated immunodeficiency.