Purification and characterization of cytostatic lymphokines produced by activated human T lymphocytes. Synergistic antiproliferative activity of transforming growth factor beta 1, interferon-gamma, and oncostatin M for human melanoma cells.
Supernatants from activated human T lymphocytes were highly growth inhibitory for A375 human melanoma cells. Three growth inhibiting polypeptides, transforming growth factor beta 1 (TGF-beta 1), interferon-gamma (IFN-gamma), and oncostatin M, were isolated from the acid-soluble fraction of serum-free T cell-conditioned medium and purified by gel permeation chromatography and reverse-phase high performance liquid chromatography in volatile solvents at acid pH. The purification was monitored in a growth inhibition assay. The release of TGF-beta 1 biologic activity by and the purification of IFN-gamma from the medium of activated human peripheral blood T lymphocytes have been reported. We now describe the isolation of oncostatin M from the conditioned medium of activated human T cells. The concentration of oncostatin M required for half-maximal inhibition of A375 melanoma cells was approximately 4 pM when assayed in the presence of 10% fetal bovine serum. The purified oncostatin M had an apparent m.w. 28,000 and an amino-terminal sequence that was identical with the sequence of oncostatin M isolated from supernatants of macrophage-like cells. Suboptimal concentrations of TGF-beta 1 in combination with suboptimal concentrations of IFN-gamma or oncostatin M resulted in synergistic antiproliferative responses for A375 cells (1.9 and 3.1 times the expected additive responses, respectively). Combinations of oncostatin M and IFN-gamma added simultaneously to A375 cells caused an additive growth inhibitory response. These results demonstrate that oncostatin M is a novel lymphokine, and its interaction with other cytostatic polypeptide growth inhibitors may play a role in the immune regulation of tumor cell growth.
D002455:Cell Division / Q000187:drug effects; D004357:Drug Synergism; D006131:Growth Inhibitors / Q000302:isolation & purification*; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology*; D008222:Lymphokines / Q000302:isolation & purification* / Q000494:pharmacology; D008546:Melanoma, Experimental / Q000473:pathology*; D053683:Oncostatin M; D010455:Peptides / Q000494:pharmacology*; D013601:T-Lymphocytes / Q000032:analysis* / Q000502:physiology; D015291:Transforming Growth Factors
D006131:Growth Inhibitors; D008222:Lymphokines; C508351:OSM protein, human; D010455:Peptides; D053683:Oncostatin M; D015291:Transforming Growth Factors; D007371:Interferon-gamma