[Vasoactive intestinal polypeptide influences human immunoglobulin secretion]

Blood lymphocytes from eight subjects were cultured for seven days and stimulated with Pokeweed mitogen. At the same time, vasoactive intestinal polypeptide (VIP) was added in rising concentrations (10(-12) M to 10(-6) M). Immunoglobulin concentrations were measured by ELISA in the remaining cultures. Mitogen-stimulated peripheral mononuclear cells were stimulated dose-dependent by VIP to a further significant rise of IgM secretion in six of the eight subjects. VIP had no influence in this respect on mononuclear cells that had not been prestimulated. This was, therefore, the first demonstration that VIP, in concentrations that occur in intestinal mucosa in certain circumstances, influences human immunoglobulin synthesis in vitro. These findings may provide a building stone towards a better understanding of local immunoregulatory events in the intestinal mucosa.