title: Immunomodulation by two potent analogs of met-enkephalin.
abstract: Met-enkephalin (Tyr-Gly-Gly-Phe-Met) and its more stable analogs, Tyr-D-Ala-Gly-MePhe-Met-NHC3H gamma-iso (1) and Tyr-D-Ala-Gly-MePhe-Gly-NHC3H gamma-iso (2) significantly enhanced human T-cell proliferation in vitro after 5 days of incubation in the absence of mitogen. The activity was completely inhibited by naloxone, an opioid antagonist. These peptides significantly enhanced human active T-cell rosette (CD2R) also on in vitro treatment. Furthermore, these analogs stimulated interleukin-2 production by human peripheral blood mononuclear cells in vitro which was completely inhibited by naloxone. These observations suggest that human T-cells bear receptors for Met-enkephalin on their surface. Such findings may provide a link between the central nervous system and the immune system.
authors.affiliation: Department of Immunology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, India.
authors.forename: K
authors.initials: K
authors.lastname: Bajpai
authors.forename: V K
authors.initials: VK
authors.lastname: Singh
authors.forename: V C
authors.initials: VC
authors.lastname: Dhawan
authors.forename: W
authors.initials: W
authors.lastname: Haq
authors.forename: K B
authors.initials: KB
authors.lastname: Mathur
authors.forename: S S
authors.initials: SS
authors.lastname: Agarwal
mesh_terms: D000276:Adjuvants, Immunologic / Q000494:pharmacology*; D004744:Enkephalin, Methionine / Q000031:analogs & derivatives* / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D006801:Humans; D007376:Interleukin-2 / Q000096:biosynthesis; D008213:Lymphocyte Activation / Q000187:drug effects*; D009270:Naloxone / Q000494:pharmacology; D009292:Narcotic Antagonists / Q000494:pharmacology; D009842:Oligopeptides / Q000494:pharmacology*; D013268:Stimulation, Chemical; D013601:T-Lymphocytes / Q000187:drug effects* / Q000276:immunology
chemical_list: D000276:Adjuvants, Immunologic; D007376:Interleukin-2; D009292:Narcotic Antagonists; D009842:Oligopeptides; D009270:Naloxone; D004744:Enkephalin, Methionine