title: IL-4 suppression of in vivo T cell activation and antibody production.
abstract: Injection of mice with a foreign anti-IgD Ab stimulates B and T cell activation that results in large cytokine and Ab responses. Because most anti-IgD-activated B cells die before they can be stimulated by activated T cells, and because IL-4 prolongs the survival of B cells cultured with anti-Ig, we hypothesized that treatment with IL-4 at the time of anti-IgD Ab injection would decrease B cell death and enhance anti-IgD-induced Ab responses. Instead, IL-4 treatment before or along with anti-IgD Ab suppressed IgE and IgG1 responses, whereas IL-4 injected after anti-IgD enhanced IgE responses. The suppressive effect of early IL-4 treatment on the Ab response to anti-IgD was associated with a rapid, short-lived increase in IFN-gamma gene expression but decreased CD4+ T cell activation and decreased or delayed T cell production of other cytokines. We examined the possibilities that IL-4 stimulation of IFN-gamma production, suppression of IL-1 or IL-2 production, or induction of TNF-alpha or Fas-mediated apoptosis could account for IL-4's suppressive effect. The suppressive effect of IL-4 was not reversed by IL-1, IL-2, or anti-TNF-alpha or anti-IFN-gamma mAb treatment, or mimicked by treatment with anti-IL-2Ralpha (CD25) and anti-IL-2Rbeta (CD122) mAbs. Early IL-4 treatment failed to inhibit anti-IgD-induced Ab production in Fas-defective lpr mice; however, the poor responsiveness of lpr mice to anti-IgD made this result difficult to interpret. These observations indicate that exposure to IL-4, while T cells are first being activated by Ag presentation, can inhibit T cells activation or promote deletion of responding CD4+ T cells.
authors.affiliation: Department of Internal Medicine, Division of Immunology, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA. morrissc@email.uc.edu
authors.forename: S C
authors.initials: SC
authors.lastname: Morris
authors.forename: W C
authors.initials: WC
authors.lastname: Gause
authors.forename: F D
authors.initials: FD
authors.lastname: Finkelman
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000008:administration & dosage; D005260:Female; D006041:Goats; D007072:Immunoglobulin D / Q000008:administration & dosage; D007073:Immunoglobulin E / Q000096:biosynthesis* / Q000097:blood; D007074:Immunoglobulin G / Q000096:biosynthesis* / Q000097:blood; D007166:Immunosuppressive Agents / Q000008:administration & dosage; D007275:Injections, Intravenous; D007371:Interferon-gamma / Q000276:immunology; D007375:Interleukin-1 / Q000037:antagonists & inhibitors / Q000096:biosynthesis; D007376:Interleukin-2 / Q000037:antagonists & inhibitors / Q000096:biosynthesis; D015847:Interleukin-4 / Q000008:administration & dosage / Q000502:physiology*; D008213:Lymphocyte Activation / Q000276:immunology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D019463:Mice, Inbred MRL lpr; D015375:Receptors, Interleukin-2 / Q000037:antagonists & inhibitors; D013601:T-Lymphocytes / Q000276:immunology*; D014409:Tumor Necrosis Factor-alpha / Q000502:physiology
chemical_list: D000911:Antibodies, Monoclonal; D007072:Immunoglobulin D; D007074:Immunoglobulin G; D007166:Immunosuppressive Agents; D007375:Interleukin-1; D007376:Interleukin-2; D015375:Receptors, Interleukin-2; D014409:Tumor Necrosis Factor-alpha; D015847:Interleukin-4; D007073:Immunoglobulin E; D007371:Interferon-gamma