Regulation of VIP production and secretion by murine lymphocytes

Vasoactive intestinal peptide (VIP) is a neuropeptide present in the lympho id microenvironment with a multiplicity of actions. Two sources for VIP hav e been described in the immune system, the terminals present in central and peripheral lymphoid organs and the immune cells. Although VIP is synthesiz ed by lymphocytes, there is no evidence demonstrating that VIP is released, and which stimuli are able to induce VIP production and secretion. In this study, we demonstrated for the first time, that agents that mediate import ant immune functions, such as proliferation and antigenic stimulation (Con A, LPS, and anti-TCR antibody), inflammation (LPS, TNF alpha, IL-6 and IL-1 beta) or apoptosis (dexamethasone) induce the production and release of VI P to the lymphoid microenvironment. We conclude that VIP is produced and se creted by lymphocytes and propose that during an immune response, the timel y release of VIP within the lymphoid organs and peritoneum should influence the differentiation and/or downregulation of the ongoing response. (C) 199 9 Elsevier Science B.V. All rights reserved.