title: Biological characteristics of an immunoregulatory activity secreted by an autoreactive CD4+ T cell clone that suppresses autoimmune diabetes in non-obese diabetic mice.
abstract: We previously reported the generation and characterization of a panel of CD4(+) autoreactive T cell clones that suppress development of autoimmune diabetes in non-obese diabetic (NOD) mice. We showed that the protective capacity of the T cell clones correlated with secretion of an activity that potently inhibits allogeneic mixed lymphocyte reaction (allo-MLR). In this report, we describe the biological characteristics of the allo-MLR inhibitory activity (MLR-IA, short for mixed lymphocyte reaction inhibitory activity) secreted by the protective T cell clone, NOD-5. MLR-IA has little effect on initiation of proliferation in an allo-MLR, but it potently inhibits the maintenance and amplification of the proliferative response. MLR-IA is also capable of inhibiting concanavalin A (Con A) stimulated splenic responder T cell proliferation. MLR-IA is reversible in vitro and is not restricted by MHC class I or II proteins. MLR-IA does not affect IL-2 receptor expression of responding T cells and has no effect on IL-2-dependent proliferation of CTLL-20 T cells. Partially purified MLR-IA inhibits IL-2 production in a primary allo-MLR, and decreases IFN-gamma production during secondary allo-MLR and Con A activation, whereas it enhances IL-4 production in both primary and secondary Con A activation. MLR-IA is not neutralized by combination of antibodies specific for transforming growth factor-beta, IL-10, tumor necrosis factor-alpha/beta or IFN-gamma, suggestive of a novel activity. MLR-IA is ammonium sulfate precipitable, sensitive to protease digestion and is destroyed by boiling, indicating that a protein moiety is part of its active structure. Our work suggests that a potentially novel immunoregulatory activity, capable of inhibiting T lymphocyte proliferation and IFN-gamma production, and stimulating IL-4 production, may regulate development of autoimmune diabetes in NOD mice.
authors.affiliation: Laboratory of Immunopathology and Division of Pediatric Oncology, Dana-Farber Cancer Institute, Boston, MA 02115, USA.
authors.forename: K N
authors.initials: KN
authors.lastname: Tan
authors.forename: H K
authors.initials: HK
authors.lastname: Min
authors.forename: L
authors.initials: L
authors.lastname: Pan
authors.forename: J L
authors.initials: JL
authors.lastname: Ferrara
authors.forename: K V
authors.initials: KV
authors.lastname: Myrick
mesh_terms: D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000737:chemistry* / Q000276:immunology / Q000378:metabolism*; D003922:Diabetes Mellitus, Type 1 / Q000276:immunology* / Q000517:prevention & control / Q000628:therapy*; D007166:Immunosuppressive Agents / Q000737:chemistry* / Q000494:pharmacology*; D007371:Interferon-gamma / Q000037:antagonists & inhibitors; D007519:Isoantigens / Q000276:immunology; D007959:Lymphocyte Culture Test, Mixed; D051379:Mice; D016688:Mice, Inbred NOD
chemical_list: D007166:Immunosuppressive Agents; D007519:Isoantigens; D007371:Interferon-gamma