title: T cell growth factor: parameters of production and a quantitative microassay for activity.
abstract: Several soluble factors have recently been associated with the proliferation and differentiation of thymus-derived lymphocytes. One of these factors present in medium conditioned by T cell mitogen-stimulated lymphocytes has the ability to promote the long-term culture of normal and antigen-specific cytotoxic T cells. We report a method to test for this proliferative stimulus in the form of a sensitive microassay based upon the tritiated-thymidine incorporation of continuous murine tumor-specific cytotoxic T cell lines (CTLL). The microassay requires microliter quantitites of sample fluid and is amenable to quantitative analysis. This highly reproducible,  quantitative assay for T cell growth factor (TCGF) has allowed investigation as to the kinetics of TCGF generation and has revealed that T lymphocytes are required for its production. Further investigation has supported the notion that this nonspecies-specific factor is actively removed from tissue culture medium by the proliferation of either T cell mitogen-activated lymphocytes or CTLL.
mesh_terms: D000818:Animals; D000941:Antigens; D002454:Cell Differentiation; D002460:Cell Line; D002478:Cells, Cultured; D006801:Humans; D007700:Kinetics; D008213:Lymphocyte Activation; D008722:Methods; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D008934:Mitogens / Q000494:pharmacology; D051381:Rats; D013154:Spleen / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D000941:Antigens; D008934:Mitogens