title: The effects of vasoactive intestinal peptide on human natural killer cell function.
abstract: Vasoactive intestinal peptide (VIP) can be found at nerve endings in various tissues and has recently been shown to interact with human lymphocytes through an adenylate cyclase-linked receptor. Because various neuroendocrine factors are thought to influence immune responsiveness, we studied the effect of VIP on natural killer (NK) effector function. Human lymphocytes were incubated with 51Cr-labeled K562 target cells in a 4-hr cytotoxicity assay in the absence or presence of increasing concentrations of VIP. As expected from its activation of adenylate cyclase, VIP was inhibitory at 10(-6) to 10(-10) M. Interestingly, however, when lymphocytes were preincubated with VIP for 30 or 60 min, then washed and added to target cells, a significant augmentation of NK activity ensued. Binding studies revealed that preincubation with VIP resulted in increased numbers of effector-target conjugates, whereas cytotoxic activity in agarose was not affected at the single cell level. Studies with synthetic analogs of VIP revealed that the integrity of the 14-28 C-terminal amino acid sequence was essential for its activity in cytotoxicity. These data strongly suggest a functional role for VIP in modulating immune responses during neuroendocrine interactions with the immune system.
authors.forename: M
authors.initials: M
authors.lastname: Rola-Pleszczynski
authors.forename: D
authors.initials: D
authors.lastname: Bolduc
authors.forename: S
authors.initials: S
authors.lastname: St-Pierre
mesh_terms: D002460:Cell Line; D000242:Cyclic AMP / Q000378:metabolism; D003601:Cytotoxicity Tests, Immunologic / Q000379:methods; D003602:Cytotoxicity, Immunologic / Q000187:drug effects*; D006801:Humans; D007166:Immunosuppressive Agents / Q000494:pharmacology; D007694:Killer Cells, Natural / Q000276:immunology*; D004915:Leukemia, Erythroblastic, Acute / Q000276:immunology / Q000378:metabolism; D013329:Structure-Activity Relationship; D013997:Time Factors; D014660:Vasoactive Intestinal Peptide / Q000494:pharmacology*
chemical_list: D007166:Immunosuppressive Agents; D014660:Vasoactive Intestinal Peptide; D000242:Cyclic AMP