title: The role of tumour necrosis factor-alpha in combination with interferon-gamma or interleukin-1 in the induction of immunosuppressive macrophages because of Mycobacterium avium complex infection.
abstract: The role of some cytokines including tumour necrosis factor-alpha (TNF-alpha), interleukin-1 alpha (IL-1 alpha), interferon-gamma (IFN-gamma), transforming growth factor-beta (TGF-beta) and interleukin-6 (IL-6) in the generation of immunosuppressive macrophages (M phi s) in host spleen cells of Mycobacterium avium complex (MAC)-infected mice was studied. M phi populations with potent suppressor activity against concanavalin A (Con A)-induced mitogenesis of splenocytes (SPCs) were elicited not only in euthymic but also in athymic nude mice during MAC infection. The suppressor M phi s are, therefore, inducible not only through a T-cell-dependent mechanism but also through T-cell-independent mechanism. However, MAC-induced M phi s of athymic mice displayed about four times lower suppressor activity than those of euthymic mice, indicating that mature T cells are important for M phi activation to the highly immunosuppressive state. Anti-TNF, anti-IFN-gamma, and anti-TGF-beta antibodies (Abs) but not anti-IL-6 Ab inhibited in vivo generation of MAC-induced immunosuppressive M phi s, and the neutralizing efficacy was in the order of anti-IFN-gamma Ab > anti-TNF Ab > anti-TGF-beta Ab. The effects of TNF-alpha, IL-1 alpha, IL-6, and IFN-gamma alone or combinations of them upon the acquisition of the suppressor activity by cultured splenic M phi s were studied. When normal splenic M phi s were treated with each cytokine for 3 days, TNF-alpha, IFN-gamma, and IL-1 alpha alone caused a slight elevation of their suppressive activity. Treatment of the normal M phi s with the combination of either TNF-alpha+IL-1 alpha or TNF-alpha+IFN-gamma yielded a marked increase in the suppressor activity, followed by IL-1 alpha+IFN-gamma. These findings indicate the important roles of TNF-alpha, IFN-gamma, and IL-1 alpha in the generation of MAC-induced suppressor M phi s.
authors.affiliation: Department of Microbiology and Immunology, Shimane Medical University, Izumo, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Tomioka
authors.forename: W W
authors.initials: WW
authors.lastname: Maw
authors.forename: K
authors.initials: K
authors.lastname: Sato
authors.forename: H
authors.initials: H
authors.lastname: Saito
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D002478:Cells, Cultured; D016207:Cytokines / Q000276:immunology / Q000502:physiology*; D005260:Female; D006801:Humans; D007108:Immune Tolerance; D007111:Immunity, Cellular; D007371:Interferon-gamma / Q000276:immunology / Q000502:physiology; D007375:Interleukin-1 / Q000276:immunology / Q000502:physiology; D008264:Macrophages / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D015270:Mycobacterium avium-intracellulare Infection / Q000276:immunology*; D013154:Spleen / Q000276:immunology*; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology / Q000502:physiology
chemical_list: D000911:Antibodies, Monoclonal; D016207:Cytokines; D007375:Interleukin-1; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma