%0 Journal Article
%@ 0009-9104
%A Raghavendra, V
%A Singh, V
%A Shaji, A V
%A Vohra, H
%A Kulkarni, S K
%A Agrewala, J N
%D 2001
%F open:864
%I wiley
%J Clinical and experimental immunology
%K B cells and macrophages;CD4+ T cells;melatonin;unprimed Th1 and Th2 cells 
%N 3
%P 414-22
%T Melatonin provides signal 3 to unprimed CD4(+) T cells but failed to stimulate LPS primed B cells.
%U http://crdd.osdd.net/open/864/
%V 124
%X Growing evidence has supported the conclusion that melatonin, a pineal hormone, modulates the immune function. In our previous study, we evaluated in vivo the potential role of melatonin in the regulation of the antigen specific T and B cells. In the present study, we observe that melatonin down-regulated the expression of the co-stimulatory molecule B7-1 but not B7-2 on macrophages. Further, melatonin encouraged the proliferation of anti-CD3 antibody activated CD4(+) T cells only in the presence of antigen-presenting cells and promoted the production of Th2-like cytokines. Furthermore, it failed to influence the activity of B cells in a T-independent manner. Melatonin suppressed the release of TNF-alpha by LPS or IFN-gamma activated macrophages but failed to inhibit nitric oxide (NO) release. Thus the study shows that melatonin can engineer the growth of unprimed CD4(+) T cells if both the signals are provided by antigen-presenting cells. However, it could not regulate the function of B cells.
%Z Copyright of this article belongs to Wiley.