title: Different inducing activities for cytotoxic T cells by heterogeneous thymocyte-activating factors from SV40-transformed human embryo fibroblasts.
abstract: Thymocyte-activating factors are produced by human embryo fibroblasts and their production is enhanced by SV40-induced transformation (Okai, Gotoh and Yamashita, Immununol. Lett. (1985), 9, 153-159). The activities for thymocyte DNA synthesis in the culture medium from SV40-transformed cells are separated into the two fractions by a DEAE Sephadex A-25 column chromatography eluting at 150 and 500 mM NaCl. Each fraction contains the heterogeneous molecular weight activities as judged by a Sephadex G-100 column chromatography. In the fraction eluted at 150 mM NaCl, the inducing activities for cytotoxic T cells by the factors are dependent upon their molecular weights; the larger factors exhibit much higher cytotoxic activity than that of the smaller factors. In contrast, the heterogeneous molecular weight factors eluted at 500 mM NaCl do not show the remarkable difference of their biological activities. In addition, the inducing activities by thymocyte-activating factors are also dependent upon their charge properties. These different inducing activities for cytotoxic T cells by thymocyte-activating factors is discussed from the aspect of the immunological regulation.
mesh_terms: D000818:Animals; D001688:Biological Products / Q000096:biosynthesis / Q000276:immunology* / Q000302:isolation & purification; D002472:Cell Transformation, Viral; D002478:Cells, Cultured; D002848:Chromatography, DEAE-Cellulose; D002850:Chromatography, Gel; D016207:Cytokines; D004622:Embryo, Mammalian; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism*; D006801:Humans; D008213:Lymphocyte Activation / Q000187:drug effects; D051379:Mice; D008815:Mice, Inbred Strains; D008970:Molecular Weight; D013539:Simian virus 40; D013602:T-Lymphocytes, Cytotoxic / Q000187:drug effects* / Q000276:immunology
chemical_list: D001688:Biological Products; D016207:Cytokines; C051922:thymocyte-activating factor, fibroblasts