The neuropeptide vasoactive intestinal peptide: direct effects on immune cells and involvement in inflammatory and autoimmune diseases.

Neuropeptides represent an important category of endogenous contributors to the establishment and maintenance of immune deviation in immune privileged organs such as the CNS, and in the control of acute inflammation in the peripheral immune organs. Vasoactive intestinal peptide (VIP) is a major immunoregulatory neuropeptide widely distributed in the central and peripheral nervous system. In addition to neurons, VIP is synthesized by immune cells which also express VIP receptors. Here we review the current information on VIP production and VIP receptor mediated effects in the immune system, the role of endogenous and exogenous VIP in inflammatory and autoimmune disorders, and present and future VIP therapeutic approaches.