REGULATION OF SECRETION OF IL-4 AND IGG1 ISOTYPE BY MELATONIN-STIMULATED OVALBUMIN-SPECIFIC T-CELLS

In the present study, we describe the potential role of melatonin, a p ineal hormone, in regulating the activation of the antigen-specific T cell response. Melatonin encouraged the proliferation of Th cells and improved their ability to secrete IL-4, but down-regulated the levels of IL-2 and interferon-gamma (IFN-gamma). Melatonin, however, could no t exert any influence on the T cells of unprimed mice. On studying the regulation of subclass of IgG isotype, melatonin specifically enhance d the secretion of antigen-specific IgG1 antibodies and decreased the yield of IgG2a isotype. The results suggest that melatonin possibly ac ts by selectively activating a Th2-like immune response.