title: Gamma/delta T cells from tolerized alpha/beta-TCR-deficient mice antigen specifically inhibit contact sensitivity in vivo and IFN-gamma production in vitro.
abstract: Contact sensitivity (CS) responses to reactive hapten antigens (Ag), such as picryl chloride, are classical examples of T-cell-mediated immune responses in vivo. There is also abundant evidence that T cells exposed in vivo to high intravenous doses of Ag can downregulate CS (high-dose Ag tolerance). To clarify cell types that effect CS and mediate its downregulation, we have studied CS in mice congenitally deficient in alpha/beta T cells (alpha-/- mice). We show that alpha-/- mice cannot mount CS, implicating alpha/beta T cells as critical CS effector cells. However, after high-dose Ag tolerization, these alpha-/- mice can downregulate alpha/beta CS effector cells adoptively transferred to them. The active cells in tolerized alpha-/- mice are gamma/delta TCR+ cells which downregulate CS effector alpha/beta T cells Ag-specifically upon adoptive cell transfer. Moreover, gamma/delta cells can Ag-specifically downregulate IFN-gamma production by CS effector cells in vitro. These findings establish that gamma/delta T cells are not CS effector cells but downregulate CS, in agreement with recent reports that gamma/delta T cells downregulate IgE responses.
authors.affiliation: College of Medicine, Jagiellonian University, Krakow, Poland.
authors.forename: M
authors.initials: M
authors.lastname: Szczepanik
authors.forename: L R
authors.initials: LR
authors.lastname: Anderson
authors.forename: H
authors.initials: H
authors.lastname: Ushio
authors.forename: W
authors.initials: W
authors.lastname: Ptak
authors.forename: M J
authors.initials: MJ
authors.lastname: Owen
authors.forename: A C
authors.initials: AC
authors.lastname: Hayday
authors.forename: P W
authors.initials: PW
authors.lastname: Askenase
mesh_terms: D000818:Animals; D000941:Antigens / Q000276:immunology*; D015551:Autoimmunity; D003877:Dermatitis, Contact / Q000517:prevention & control*; D007108:Immune Tolerance; D007371:Interferon-gamma / Q000096:biosynthesis*; D051379:Mice; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000172:deficiency* / Q000502:physiology; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000502:physiology*; D013601:T-Lymphocytes / Q000502:physiology*
chemical_list: D000941:Antigens; D016693:Receptors, Antigen, T-Cell, alpha-beta; D016692:Receptors, Antigen, T-Cell, gamma-delta; D007371:Interferon-gamma