title: Interleukin-10 induces a long-term antigen-specific anergic state in human CD4+ T cells.
abstract: Human CD4+ T cells, activated by allogeneic monocytes in a primary mixed lymphocyte reaction in the presence of exogenous interleukin (IL) 10, specifically failed to proliferate after restimulation with the same alloantigens. A comparable state of T cell unresponsiveness could be induced by activation of CD4+ T cells by cross-linked anti-CD3 monoclonal antibodies (mAbs) in the presence of exogenous IL-10. The anergic T cells failed to produce IL-2, IL-5, IL-10, interferon gamma, tumor necrosis factor alpha, and granulocyte/macrophage colony-stimulating factor. The IL-10-induced anergic state was long-lasting. T cell anergy could not be reversed after restimulation of the cells with anti-CD3 and anti-CD28 mAbs, although CD3 and CD28 expression was normal. In addition, restimulation of anergized T cells with anti-CD3 mAbs induced normal Ca2+ fluxes and resulted in increased CD3, CD28, and class II major histocompatibility complex expression, indicating that calcineurin-mediated signaling occurs in these anergic cells. However, the expression of the IL-2 receptor alpha chain was not upregulated, which may account for the failure of exogenous IL-2 to reverse the anergic state. Interestingly, anergic T cells and their nonanergic counterparts showed comparable levels of proliferation and cytokine production after activation with phorbol myristate acetate and Ca2+ ionophore, indicating that a direct activation of a protein kinase C-dependent pathway can overcome the tolerizing effect of IL-10. Taken together, these data demonstrate that IL-10 induces T cell anergy and therefore may play an important role in the induction and maintenance of antigen-specific T cell tolerance.
authors.affiliation: Human Immunology Department, DNAX Research Institute of Molecular and Cellular Biology, Inc., Palo Alto, California 94304-1104, USA.
authors.forename: H
authors.initials: H
authors.lastname: Groux
authors.forename: M
authors.initials: M
authors.lastname: Bigler
authors.forename: J E
authors.initials: JE
authors.lastname: de Vries
authors.forename: M G
authors.initials: MG
authors.lastname: Roncarolo
mesh_terms: D018106:CD28 Antigens / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D002118:Calcium / Q000502:physiology; D002478:Cells, Cultured; D017635:Clonal Anergy; D016207:Cytokines / Q000378:metabolism; D006801:Humans; D016753:Interleukin-10 / Q000502:physiology*; D007376:Interleukin-2 / Q000276:immunology; D007959:Lymphocyte Culture Test, Mixed; D009000:Monocytes / Q000276:immunology; D011948:Receptors, Antigen, T-Cell / Q000502:physiology; D015375:Receptors, Interleukin-2 / Q000378:metabolism; D015398:Signal Transduction; D013997:Time Factors
chemical_list: D018106:CD28 Antigens; D016207:Cytokines; D007376:Interleukin-2; D011948:Receptors, Antigen, T-Cell; D015375:Receptors, Interleukin-2; D016753:Interleukin-10; D002118:Calcium