Neuropeptides have recently been shown to modulate the immune response
. Vasoactive intestinal peptide (VIP) released from nerve endings and
from immune cells modulates the mobility and adherence of lymphocytes
and macrophages, phagocytic cell functions (phagocytosis and free radi
cal production), the lymphocyte proliferative response, lymphokine and
immunoglobulin production and the natural killer cell activity, with
opposite effects in vitro on these immune cell functions. The VIP rece
ptor heterogeneity and the different action mechanisms of VIP-mediated
immunoregulation could explain, at least in part, the different VIP e
ffects observed on lymphoid and phagocytic cells. The evidence support
s the theory that VIP acts not as an inhibitor, but as a modulator of
immune functions, as previously thought, and that this neuropeptide ma
y play a relevant role in vivo. Copyright (C) 1996 Elsevier Science Lt
d.