Biochemical characteristics of receptors for vasoactive intestinal polypeptide in nervous, endocrine, and immune systems.

Neuropeptides have recently been shown to modulate the immune response. Vasoactive intestinal polypeptide (VIP) modulates lymphocyte migration to Peyer's patches and inhibits natural killer cell activity. VIP receptors have been characterized on lymphocytes and have been compared with the VIP receptor in nervous tissue and in tissues of the gastrointestinal tract. The evidence supports the existence of at least two classes of high-affinity VIP receptors as well as a low-affinity receptor. The development of tissue-specific agonists and antagonists to the VIP receptor may thus be feasible.