title: Role of interleukin-4 in down-regulation of contact sensitivity by gammadelta T cells from tolerized T-cell receptor alpha-/- mice.
abstract: Contact sensitivity (CS) is a classical example of an in vivo T-cell-mediated immune response that is under regulation. Such down-regulation can be mediated by alphabeta T cells in mice that are tolerized by prior exposure to high doses of antigen. In contrast, we demonstrated previously that such high-dose antigen tolerance in T-cell receptor (TCR) alpha-/- H-2d mice induced antigen-specific, apparently major histocompatibility complex-unrestricted, CD4- CD8- gammadelta T cells, that also could down-regulate CS responses antigen-specifically in vivo, and also inhibited in vitro production of IFN-gamma. In the present experiments we employed H-2b-deficient TCRalpha-/- and TCRbeta-/- mice, owing to different molecular constructs than were used previously, and confirmed that tolerized gammadelta T cells in these different H-2b alphabeta TCR-/- mice down-regulated CS. Thus, gammadelta T-cell suppressor function was not limited to mice bearing a special transgenic TCRalpha-/- DNA construct. Furthermore, employing monoclonal antibody and complement depletion in vitro and adoptive transfer in vivo, characterized the phenotype of these gammadelta down-regulatory T cells as: CD3+, CD28+, CD40-ligand+, Fas+, FcgammaR+ and NK1.1-. Also, in vitro antigen desensitization of these trinitrophenyl (TNP)-specific TCRgammadelta+ down-regulatory cells was achieved with soluble TNP-bovine serum albumin (BSA), but not with oxazolone-BSA, showing that these suppressive gammadelta T cells have antigen-specific receptors. Moreover, employing monoclonal antibody blocking of gammadelta suppressors in vitro, and of recipients in vivo, we showed that interleukin-4 (IL-4) was involved in this down-regulation of CS by gammadelta T cells, while IL-10 and transforming growth factor-beta2 were not. In summary, generation of antigen-specific, double-negative, gammadelta suppressor cells, by tolerance of high antigen doses in TCRalpha-/- mice, appears to be a general phenomenon, and IL-4 production is involved in their down-regulation of the T helper type 1 cells that mediate CS.
authors.affiliation: Department of Immunology, Jagiellonian University College of Medicine, Krakow, Poland.
authors.forename: M
authors.initials: M
authors.lastname: Szczepanik
authors.forename: W
authors.initials: W
authors.lastname: Ptak
authors.forename: P W
authors.initials: PW
authors.lastname: Askenase
mesh_terms: D019264:Adoptive Transfer; D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D016207:Cytokines / Q000276:immunology; D003877:Dermatitis, Contact / Q000276:immunology*; D015536:Down-Regulation; D005260:Female; D007108:Immune Tolerance; D015847:Interleukin-4 / Q000502:physiology*; D051379:Mice; D008807:Mice, Inbred BALB C; D016693:Receptors, Antigen, T-Cell, alpha-beta; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000276:immunology*; D018417:Th1 Cells / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D016207:Cytokines; D016693:Receptors, Antigen, T-Cell, alpha-beta; D016692:Receptors, Antigen, T-Cell, gamma-delta; D015847:Interleukin-4