title: CD4+ Leu-8+ T cell supernatant activity that inhibits Ig production.
abstract: The subpopulation of CD4+ T cells that expresses the Leu-8 peripheral lymph node homing receptor suppresses PWM-stimulated Ig synthesis. To determine the mechanism of this suppression, the immunoregulatory activity of culture supernatants obtained from peripheral blood CD4+ Leu-8+ T cells cultured with anti-CD3 mAb and PMA (Leu-8+ supernatant) was determined. Leu-8+ supernatant suppressed PWM-stimulated Ig synthesis in cultures containing non-T cells and CD4+ Leu-8- T cells. In contrast, the supernatant from CD4+ Leu-8- T cells did not suppress Ig synthesis. The inhibitory activity of CD4+ Leu-8+ T cell supernatants could not be accounted for by a deficiency or excess of IL-2, IL-4, IFN-gamma, IL-6, or PGE2. In studies examining the effect of CD4+ Leu-8+ supernatant on T cells, the supernatant did not alter either mitogen-induced proliferation or the helper function of CD4+ Leu-8- T cells. In studies examining the effect of CD4+ Leu-8+ supernatant on B cells, the supernatant inhibited Staphylococcus aureus Cowan I strain-induced B cell Ig secretion but not B cell proliferation. The suppressor activity of Leu-8+ supernatant was eliminated by protease treatment and was eluted by HPLC in two main peaks, with molecular sizes of 44 and 12 kDa. In summary, these studies indicate that supernatants from activated CD4+ Leu-8+ T cells directly suppress B cell Ig production.
authors.affiliation: Combined Program in Pediatric Gastroenterology and Nutrition, Harvard Medical School, Massachusetts General Hospital, Boston 02114.
authors.forename: M E
authors.initials: ME
authors.lastname: Kanof
authors.forename: W
authors.initials: W
authors.lastname: Strober
authors.forename: W C
authors.initials: WC
authors.lastname: Kwan
authors.forename: N A
authors.initials: NA
authors.lastname: O'Connell
authors.forename: S P
authors.initials: SP
authors.lastname: James
mesh_terms: D000917:Antibody Formation; D001402:B-Lymphocytes / Q000166:cytology* / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D015815:Cell Adhesion Molecules / Q000032:analysis; D002454:Cell Differentiation / Q000187:drug effects; D002478:Cells, Cultured; D002851:Chromatography, High Pressure Liquid; D015232:Dinoprostone / Q000494:pharmacology; D006801:Humans; D066298:In Vitro Techniques; D007371:Interferon-gamma / Q000502:physiology; D007376:Interleukin-2 / Q000502:physiology; D015847:Interleukin-4 / Q000502:physiology; D015850:Interleukin-6 / Q000502:physiology; D019041:L-Selectin; D008213:Lymphocyte Activation / Q000187:drug effects; D008970:Molecular Weight; D012995:Solubility; D013491:Suppressor Factors, Immunologic / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D016176:T-Lymphocyte Subsets / Q000276:immunology*
chemical_list: D015815:Cell Adhesion Molecules; D007376:Interleukin-2; D015850:Interleukin-6; D013491:Suppressor Factors, Immunologic; D019041:L-Selectin; D015847:Interleukin-4; D007371:Interferon-gamma; D015232:Dinoprostone