title: Influence of beta-endorphin on phytohemagglutinin-induced lymphocyte proliferation and on the expression of mononuclear cell surface antigens in vitro.
abstract: Recent evidence suggests that opiates can modulate the immune responses. In particular it has been shown that beta-endorphin and morphine are able to depress some T lymphocyte functions in humans. In the present study, experiments were designed to evaluate the effect of beta-endorphin phytohemagglutinin-induced lymphocyte proliferation and determine the mechanism of this action. The ability of naloxone to block the effect of beta-endorphin was also investigated, and the influence of beta-endorphin on the expression of mononuclear cell surface antigens using the OKT3, OKT4, OKT8, anti-HLA-DR and anti-beta 2-microglobulin monoclonal antibodies was evaluated. Phytohemagglutinin-induced lymphocyte proliferation was significantly inhibited by beta-endorphin. This effect occurred when beta-endorphin was added to cells at the beginning of the culture period (30 min before, simultaneously or 30 min after phytohemagglutinin), but not when added after 48 h of incubation. The preincubation of cells with BEP for 1 h, 4 h or 24 h did not affect lymphocyte activation by phytohemagglutinin. A ten-fold excess of naloxone, added to cultures 30 min prior to beta-endorphin, did not block the inhibitory effect. Incubation with beta-endorphin had different effects on each surface antigen tested. The OKT8+ and beta 2-microglobulin+ cells did not show significant variations. The OKT4+ cells significantly decreased, after 4 h of incubation with beta-endorphin, both in mononuclear cell and in purified T lymphocyte cultures and, after 24 h, in mononuclear cell cultures only. The OKT3+ cells decreased, in mononuclear cell cultures only, after 24 h beta-endorphin incubation.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.forename: F
authors.initials: F
authors.lastname: Puppo
authors.forename: G
authors.initials: G
authors.lastname: Corsini
authors.forename: P
authors.initials: P
authors.lastname: Mangini
authors.forename: L
authors.initials: L
authors.lastname: Bottaro
authors.forename: T
authors.initials: T
authors.lastname: Barreca
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology; D000954:Antigens, Surface; D004723:Endorphins / Q000494:pharmacology*; D006684:HLA-DR Antigens; D000949:Histocompatibility Antigens Class II; D006801:Humans; D066298:In Vitro Techniques; D008213:Lymphocyte Activation / Q000187:drug effects*; D008264:Macrophages / Q000187:drug effects / Q000276:immunology; D010835:Phytohemagglutinins / Q000494:pharmacology; D013601:T-Lymphocytes / Q000187:drug effects* / Q000276:immunology; D006377:T-Lymphocytes, Helper-Inducer / Q000187:drug effects / Q000276:immunology; D001615:beta-Endorphin
chemical_list: D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; D004723:Endorphins; D006684:HLA-DR Antigens; D000949:Histocompatibility Antigens Class II; D010835:Phytohemagglutinins; D001615:beta-Endorphin