title: Characteristics of immunosuppressive macrophages induced in spleen cells by Mycobacterium avium complex infections in mice.
abstract: The profile of generation and characteristics of splenic macrophages (M phi s) which suppress the concanavalin A (Con A) mitogenic response of splenic T cells (designated as 'immunosuppressive M phi s') in host CBA/JN mice during the course of Mycobacterium avium complex (MAC) infection were investigated. In MAC-infected mice, reductions in some cellular functions of host splenic T cells, such as the Con A mitogenic response and mixed leucocyte reaction, were seen around 2 weeks after challenge of organisms, and this was accompanied by appearance of immunosuppressive M phi s in spleen cells. In this case, increase in immunosuppressive M phi activity was seen in terms of both activity per spleen and activity per individual M phi. In this phase of the infection, MAC-induced splenic M phi s showed a markedly increased ability to produce reactive oxygen radicals in response to phorbol myristate acetate. Thus, the expression of suppressor activity of MAC-induced M phi s seems to be closely linked to their activated state. A large proportion of the immunosuppressive M phi s exhibited suppressor activity dependent on prostaglandins and membrane functions related to microfilaments. It was also found that the generation of IL-2-reactive T cell populations in response to Con A was markedly inhibited by MAC-induced splenic M phi s, whereas they caused no significant reduction in the IL-2-producing ability of normal spleen cells.
authors.affiliation: Department of Microbiology and Immunology, Shimane Medical University, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Tomioka
authors.forename: H
authors.initials: H
authors.lastname: Saito
authors.forename: Y
authors.initials: Y
authors.lastname: Yamada
mesh_terms: D000818:Animals; D003208:Concanavalin A / Q000494:pharmacology; D007108:Immune Tolerance; D007111:Immunity, Cellular; D007376:Interleukin-2 / Q000096:biosynthesis; D007700:Kinetics; D008213:Lymphocyte Activation; D008264:Macrophages / Q000276:immunology*; D008297:Male; D051379:Mice; D008808:Mice, Inbred CBA; D009162:Mycobacterium avium; D013154:Spleen / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology; D014376:Tuberculosis / Q000276:immunology*
chemical_list: D007376:Interleukin-2; D003208:Concanavalin A