title: Deficient SOCS3 expression in CD4+CD25+FoxP3+ regulatory T cells and SOCS3-mediated suppression of Treg function.
abstract: Naturally occurring CD4+CD25+FoxP3+ regulatory T cells (Treg) suppress T helper (Th) cell-mediated immune responses. The cytokines IL-2 and IL-6 are known to influence Treg function. However, their relative effects on Th cells versus Treg are not well understood. Stimulation with IL-2, and to a lesser extent, IL-6, enhanced Treg proliferation, FoxP3 and CTLA4 maintenance, and suppressive function. In contrast, when IL-2 or IL-6 were added to Treg/Th cell cocultures, suppression was inhibited. The molecule SOCS3 negatively regulates responses to IL-2 and IL-6. Interestingly, unlike Th cells, Treg were found to be deficient in SOCS3 protein expression. The significance of this finding lies in the need for Treg to rapidly respond to these cytokines to prevent unwarranted immune responses to self-antigens. Overexpression of SOCS3 in Treg decreased their proliferation, FoxP3 and CTLA-4 expression and suppressive function. Thus, up-regulation of SOCS3 expression may be a useful therapeutic approach in diseases where inhibition of Treg is desirable.
authors.affiliation: Department of Medicine, Pulmonary, Allergy and Critical Care Division, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA.
authors.forename: Brendan B L
authors.initials: BB
authors.lastname: Pillemer
authors.forename: Hui
authors.initials: H
authors.lastname: Xu
authors.forename: Timothy B
authors.initials: TB
authors.lastname: Oriss
authors.forename: Zengbiao
authors.initials: Z
authors.lastname: Qi
authors.forename: Anuradha
authors.initials: A
authors.lastname: Ray
mesh_terms: D000818:Animals; D015153:Blotting, Western; D015704:CD4 Antigens / Q000276:immunology / Q000378:metabolism; D018920:Coculture Techniques; D051858:Forkhead Transcription Factors / Q000276:immunology / Q000378:metabolism; D007376:Interleukin-2 / Q000276:immunology / Q000378:metabolism; D053645:Interleukin-2 Receptor alpha Subunit / Q000276:immunology / Q000378:metabolism; D015850:Interleukin-6 / Q000276:immunology / Q000378:metabolism; D008213:Lymphocyte Activation / Q000276:immunology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D016133:Polymerase Chain Reaction; D000071223:Suppressor of Cytokine Signaling 3 Protein; D050826:Suppressor of Cytokine Signaling Proteins / Q000276:immunology* / Q000378:metabolism; D016176:T-Lymphocyte Subsets / Q000276:immunology* / Q000378:metabolism; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology / Q000378:metabolism; D050378:T-Lymphocytes, Regulatory / Q000276:immunology* / Q000378:metabolism
chemical_list: D015704:CD4 Antigens; D051858:Forkhead Transcription Factors; C498833:Foxp3 protein, mouse; D007376:Interleukin-2; D053645:Interleukin-2 Receptor alpha Subunit; D015850:Interleukin-6; C491411:Socs3 protein, mouse; D000071223:Suppressor of Cytokine Signaling 3 Protein; D050826:Suppressor of Cytokine Signaling Proteins