title: Immunosuppressive properties of the Mycoplasma arthritidis T-cell mitogen in vivo: inhibition of proliferative responses to T-cell mitogens.
abstract: We have previously shown that Mycoplasma arthritidis produces a soluble T-cell mitogen (MAM) which is active for most mouse strains that express the alpha chain of the I-E molecule (E alpha) encoded within the murine major histocompatibility complex. The lymphocytes from mice injected intravenously with the MAM exhibited a marked decrease in their ability to respond in vitro to MAM, to phytohemagglutinin, or to concanavalin A T-cell mitogens. Suppression could only be induced in MAM-responsive mouse strains and was most marked 1 to 4 days postinjection. Splenic and node cells and, to a lesser extent, thymic cells from MAM-injected mice could inhibit the ability of lymphocytes from normal mice to respond to MAM and lectin mitogens. A minimum of 2.5 x 10(4) viable cells was required for significant transfer of suppression, and no major histocompatibility complex restrictions were seen. Unlike concanavalin A-induced suppressor cells, which consist of a CD4-, CD8+ T-cell subset, suppressor cells induced by MAM were due to a CD4+ CD8- subset. We hypothesize that MAM may play a role in M. arthritidis-mediated disease by both its inflammatory and immunosuppressive properties.
authors.affiliation: Department of Internal Medicine, College of Medicine, University of Utah, Salt Lake City 84132.
authors.forename: B C
authors.initials: BC
authors.lastname: Cole
authors.forename: D J
authors.initials: DJ
authors.lastname: Wells
mesh_terms: D000818:Animals; D000941:Antigens; D000942:Antigens, Bacterial; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D007108:Immune Tolerance; D007116:Immunization, Passive; D066298:In Vitro Techniques; D008213:Lymphocyte Activation; D051379:Mice; D008934:Mitogens / Q000276:immunology* / Q000494:pharmacology; D009174:Mycoplasma / Q000276:immunology*; D009175:Mycoplasma Infections / Q000276:immunology*; D011506:Proteins; D018089:Superantigens; D013601:T-Lymphocytes / Q000276:immunology*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology; D013997:Time Factors
chemical_list: D000941:Antigens; D000942:Antigens, Bacterial; D008934:Mitogens; C052996:Mycoplasma arthritidis mitogen; D011506:Proteins; D018089:Superantigens