Neuropeptide signaling of lymphocytes in immunological responses

Peptidergic nerves in immune organs and lymphoid tissues of the lungs and gastrointestinal tract end on or in close proximity to lymphocytes, mast cells and macrophages. Vasoactive intestinal peptide, substance P and some other neuropeptides, that are recognized by distinct sets of cell surface receptors, regulate aspects of T cell differentiation in the thymus, such as negative selection, and contribute to mediating compartmental immune responses. The latter effects include stimulating expression of adhesive proteins by lymphocytes, enhancement of lymphocyte and macrophage migration in vascular and connective tissues, and modulation of proliferative and synthetic responses of lymphocytes to diverse antigens.