title: Characterization of a novel murine T cell-activating factor.
abstract: Purified resting peripheral lymph node T cells can be activated to produce interleukin 2 (IL 2) and to proliferate in the presence of Concanavalin A (Con A) and an apparently novel lymphokine that we call T cell activating factor (TAF). TAF is biochemically distinct from IL 1, IL 2, IL 3, and other colony stimulating factors, IL 4 (BSF-1) and interferons. Furthermore, of the recombinant and natural cytokines tested, only IL 2 and TAF are active in the TAF assay. In the presence of Con A, TAF stimulates an increase in the steady-state level of IL 2 mRNA in T cells, the secretion of active IL 2 into the culture medium, and the proliferation of the T cells. We propose that TAF is a previously undescribed molecule the function of which is to stimulate IL 2 production by T cells that have encountered antigen, and we propose that TAF has an important role in primary T cell immune responses.
mesh_terms: D000818:Animals; D001688:Biological Products / Q000494:pharmacology; D002455:Cell Division / Q000187:drug effects; D002850:Chromatography, Gel; D003208:Concanavalin A / Q000494:pharmacology; D016207:Cytokines; D007376:Interleukin-2 / Q000096:biosynthesis; D008213:Lymphocyte Activation / Q000187:drug effects*; D008222:Lymphokines / Q000302:isolation & purification* / Q000494:pharmacology; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D012333:RNA, Messenger / Q000096:biosynthesis; D011994:Recombinant Proteins / Q000494:pharmacology; D013154:Spleen / Q000032:analysis; D013601:T-Lymphocytes / Q000032:analysis*
chemical_list: D001688:Biological Products; D016207:Cytokines; D007376:Interleukin-2; D008222:Lymphokines; D012333:RNA, Messenger; D011994:Recombinant Proteins; C051344:t cell-activating lymphokine; D003208:Concanavalin A