title: Enhancement of suppressor T cell activity by lymphocyte promoting factor of Bordetella pertussis.
abstract: Lymphocyte promoting factor (LPF), a bioproduct of Bordetella pertussis shown previously to exert immunosuppressive effects, was examined for its effect on Concanavalin A (Con A) induced T lymphocyte suppressor activity by human lymphocytes. Suppressor cells (5 x 10(4) cells/well) first generated with Con A (10 micrograms/ml) for 24h were co-cultured with responder cells (5 x 10(4) cells/well) for another 72h in the presence of Con A (2.5, 5, 20 micrograms/ml). In this culture condition, LPF (20 micrograms) and/or histamine 10(-5) M or 10(-6) M/well were added for comparison. The suppressor activity was assessed by the reduction of the uptake of radioactivity of [3H] thymidine compared to that of Con A alone. Lymphocytes treated with LPF exhibited increase of suppression by 22 to 41%, while LPF and histamine (10(-5) M) together further increased the suppression by 35 to 63% compared to controls. Serial studies on cell population in the culture indicated OKT8(+) cells proliferated after day 6 in culture. These results indicated LPF exerts selective enhancement of T cell suppressor activity by 72h in culture, prior to cell expansion, and that activity can be further strengthened by sensitizing cells to histamine.
authors: Department of Pediatrics, University of Maryland School of Medicine, Baltimore 21201.
authors: S W
authors: SW
authors: Huang
mesh_terms: D001886:Bordetella pertussis / Q000276:immunology; D003208:Concanavalin A / Q000494:pharmacology; D004357:Drug Synergism; D006632:Histamine / Q000494:pharmacology; D006801:Humans; D066298:In Vitro Techniques; D008213:Lymphocyte Activation / Q000187:drug effects; D037342:Pertussis Toxin; D013491:Suppressor Factors, Immunologic / Q000494:pharmacology*; D050378:T-Lymphocytes, Regulatory / Q000187:drug effects / Q000276:immunology*; D010566:Virulence Factors, Bordetella / Q000494:pharmacology*
chemical_list: D013491:Suppressor Factors, Immunologic; D010566:Virulence Factors, Bordetella; D003208:Concanavalin A; D006632:Histamine; D037342:Pertussis Toxin