title: Contribution of immune interferon (IFN-gamma) in lymphokine-induced anti-toxoplasma activity: studies with recombinant murine IFN-gamma.
abstract: Recombinant E. coli-derived murine interferon gamma (cDNA IFN-gamma) per se induced resident mouse peritoneal macrophages (MPM) and mouse embryo cells to exert marked antitoxoplasma activity. This capacity of cDNA IFN-gamma was abrogated by a specific antiserum to cDNA IFN-gamma which could only neutralize the antiviral activity mediated by this product, whereas a rabbit antiserum directed against murine IFN-alpha/beta proved ineffective in neutralizing these functions. It has been found that rabbit antiserum to cDNA IFN-gamma could also neutralize IFN-gamma-mediated antiviral activity present in crude lymphokine-enriched supernatants of antigen-stimulated toxoplasma-sensitized spleen cells (Toxo-LK) but proved ineffective in abolishing the capacity of Toxo-LK to trigger macrophage anti-toxoplasma activity. The data obtained suggest that macrophage anti-toxoplasma activity induced by Toxo-LK may be an interplay of multiple factor(s) and that Toxo-LK preparations contain soluble factor(s) other than IFN-gamma, which can induce macrophages to kill intracellular Toxoplasma. Experiments in which crude Toxo-LK preparations were incubated with lectin concanavalin A (Con A) showed that this treatment resulted in a block of anti-toxoplasma arming factor(s) activity, as well as a significant reduction of IFN-gamma-mediated antiviral activity present in Toxo-LK. By contrast, no significant difference was observed in the macrophage anti-toxoplasma activity mediated by Con A or untreated cDNA-IFN-gamma.
mesh_terms: D000818:Animals; D000918:Antibody Specificity; D002478:Cells, Cultured; D003208:Concanavalin A / Q000494:pharmacology; D004247:DNA / Q000235:genetics; D004622:Embryo, Mammalian / Q000276:immunology; D004625:Embryo, Nonmammalian; D005260:Female; D066298:In Vitro Techniques; D007371:Interferon-gamma / Q000235:genetics / Q000276:immunology*; D008222:Lymphokines / Q000276:immunology*; D008264:Macrophages / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D013045:Species Specificity; D013154:Spleen / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology; D014122:Toxoplasma / Q000276:immunology*
chemical_list: D008222:Lymphokines; D003208:Concanavalin A; D007371:Interferon-gamma; D004247:DNA