title: Soluble factors from murine and human tumors induce suppressor cells.
abstract: A tumor-derived suppressor factor ( TDSF ) has been isolated from 3 M KCl extracts of a chemically induced fibrosarcoma of C3H/HeJ mice by preparative isoelectric focusing. Incubation of TDSF with normal spleen cells induces suppressor cells that enhance tumor growth and inhibit DTH to the chemical sensitizer 2,4-dinitro-1-chlorobenzene (DNCB). Similar suppressogenic activity has been detected in extracts of the 10T1/2 fibroblast line, an ultraviolet-induced fibrosarcoma of C3H/HeN mice, the C57B1/6J Lewis lung carcinoma, and four human colonic adenocarcinoma. TDSF activity was not found in extracts of syngeneic muscle or spleen cells. Chemical characterization of TDSF from the murine fibrosarcoma MCA-F revealed sensitivity to treatment with heat and RNase, partial sensitivity to treatment with trypsin, but resistance to treatment with DNase, pronase, and neuraminidase. TDSF has an apparent molecular weight of greater than 300 kDa by high-performance gel permeation chromatography. Acidic soluble factors isolated from murine and human tumors induce suppressor cells to inhibit cell-mediated immunity in an intact host.
mesh_terms: D000230:Adenocarcinoma / Q000276:immunology*; D000818:Animals; D002460:Cell Line; D003110:Colonic Neoplasms / Q000276:immunology*; D004137:Dinitrochlorobenzene; D005260:Female; D005354:Fibrosarcoma / Q000139:chemically induced / Q000276:immunology*; D006801:Humans; D006968:Hypersensitivity, Delayed / Q000276:immunology; D007525:Isoelectric Focusing; D008175:Lung Neoplasms / Q000139:chemically induced / Q000276:immunology*; D008222:Lymphokines / Q000276:immunology* / Q000302:isolation & purification; D008748:Methylcholanthrene; D051379:Mice; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D009381:Neoplasms, Radiation-Induced / Q000276:immunology*; D012995:Solubility; D013154:Spleen / Q000187:drug effects / Q000276:immunology; D013491:Suppressor Factors, Immunologic; D014466:Ultraviolet Rays
chemical_list: D004137:Dinitrochlorobenzene; D008222:Lymphokines; D013491:Suppressor Factors, Immunologic; D008748:Methylcholanthrene