The Effect of NO Donating Agent and Inhibitors of NO Synthase on IL-4 and IFN-Y Production

The mechanisms regulating the balance of T helper 1 (Thl) and T helper2 (Th2) immune responces are of great interest as they may determine the outcome of allergic and infectious diseases. In this study, we investigated the effect of NO on the production of Thl and Th2-associated eytokines, IL-4 and IFN-y by EU and inguinal lymph node cells of C57BL6 and BALB/C. Cytokine secretion was measured by ELISA in the presence of different doses of NO donating agent, S-Nitroso-N-Acetyl-Penicillamine (SNAP), and inhibitors of nitric oxide synthase, L-N-(l-Iminoethyl)-lysine (L-NIL) and NG-Monomethyl-Arginine (LNMMA), with mitogen, con A, and antigen, L. major, seperately. Nitric oxide was measured by Griess reaction. Results showed that SNAP decreased the secretion of IL-4 both in EU and inguinal lymph node cells, but increased the secretion of IFN-y. The reverse effect was observed with L-NIL and LNMMA.In addition, L-NIL was more potent than LNMMA. The additive effect was dependent on the dose of SNAP, L-NIL and LNMMA. Therefore, in the future, it may be possible to use NO donating agents or inhibitors of nitric oxide synthase to cure the diseases with Th1 / Th2 imbalance.