title: Modified lymphocyte response to mitogens after intraperitoneal injection of glycopeptidolipid antigens from Mycobacterium avium complex.
abstract: Intraperitoneal injection of glycopeptidolipid (GPL) antigens from Mycobacterium avium complex serovar 4 resulted in the decreased ability of murine splenic lymphocytes to respond to nonspecific-mitogen-induced blastogenesis when exposed to concanavalin A, phytohemagglutinin, and lipopolysaccharide. Adherent cell depletion and cell mixing experiments with T lymphocytes indicated that macrophages were not a major contributor to the immunosuppression observed in this study. Enumeration of splenic lymphocytes by means of flow-cytometry with fluorescein isothiocyanate-conjugated monoclonal antibodies demonstrated that intraperitoneal injection of GPL antigens resulted in a significant decrease in Thy-1+ and Lyt-1+ cells but no change in the numbers of Lyt-2+ cells. Treatment with GPL antigens in vitro affected the ability of splenic mononuclear cells to respond optimally for concanavalin A-induced blastogenesis at 40 micrograms of GPL per 4 X 10(5) cells per 0.2 ml and lipopolysaccharide-induced blastogenesis at concentrations ranging from 5 to 40 micrograms of GPL per 4 X 10(5) cells per 0.2 ml. However, in vitro treatment with GPL antigens did not affect phytohemagglutinin-induced blastogenesis at concentrations ranging from 5 to 40 micrograms of GPL per 4 X 10(5) cells per 0.2 ml. These findings suggest that GPL antigens or their metabolites affect lymphocyte function and may be important cofactors in the overall pathogenesis of M. avium complex infections.
authors.affiliation: Department of Microbiology and Immunology, Texas College of Osteopathic Medicine, Fort Worth 76107.
authors.forename: P E
authors.initials: PE
authors.lastname: Brownback
authors.forename: W W
authors.initials: WW
authors.lastname: Barrow
mesh_terms: D000818:Animals; D000942:Antigens, Bacterial / Q000276:immunology*; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis; D004306:Dose-Response Relationship, Immunologic; D005434:Flow Cytometry; D006017:Glycolipids / Q000276:immunology*; D006020:Glycopeptides / Q000276:immunology*; D066298:In Vitro Techniques; D007274:Injections, Intraperitoneal; D008213:Lymphocyte Activation; D051379:Mice; D009162:Mycobacterium avium / Q000276:immunology*; D013154:Spleen / Q000166:cytology
chemical_list: D000942:Antigens, Bacterial; D000945:Antigens, Differentiation, T-Lymphocyte; D006017:Glycolipids; D006020:Glycopeptides