title: A rapid extremely sensitive, quantitative microassay for cytotoxic cytokines.
abstract: Pretreatment of the murine mammary adenocarcinoma cell line, EMT-6, with low levels (0.8-1.2 micrograms/ml) of actinomycin D, prior to incubation with a spectrum of cytotoxic cytokines, converted this target from marked resistance to extreme sensitivity. The drug-treated EMT-6 was from 5-50 fold more sensitive to cytokine attack than the widely used actinomycin D-treated murine L-929 target. Drug-induced growth inhibition allowed evaluation solely of the cytolytic effects of these cytokines. Lysis was evaluated after a 16-24 hr incubation by the uptake by viable cells of neutral red or by their reduction of [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide]. This microcytotoxicity assay should facilitate purification and characterization of cytotoxic cytokines, the purification of their mRNAs in translation systems and the detection of the expression of their encoding genes.
mesh_terms: D000230:Adenocarcinoma / Q000276:immunology; D000818:Animals; D002452:Cell Count; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D003601:Cytotoxicity Tests, Immunologic / Q000379:methods*; D003602:Cytotoxicity, Immunologic / Q000187:drug effects; D003609:Dactinomycin / Q000494:pharmacology; D006801:Humans; D007739:L Cells / Q000276:immunology; D008233:Lymphotoxin-alpha / Q000494:pharmacology; D008264:Macrophages / Q000276:immunology; D008325:Mammary Neoplasms, Experimental / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D009000:Monocytes / Q000276:immunology
chemical_list: D008233:Lymphotoxin-alpha; D003609:Dactinomycin