title: Characterization and partial purification of a specific interleukin 2 inhibitor.
abstract: To investigate the mechanisms that regulate the action of interleukin 2 (IL 2) and possibly limit its activity, we screened supernatants of mouse spleen cell cultures which had been stimulated with concanavalin A (Con A) for their ability to inhibit IL 2-mediated proliferation of a cloned IL 2-dependent line. Inhibitory activities with m.w. of 10,000 to 12,000 and 60,000 to 80,000 daltons could be identified in supernatants of both L3T4+ and Ly-2+ T cells, but not in supernatants of Con A or lipopolysaccharide-stimulated B cells. Maximal inhibitory activity was observed after 3 to 4 days of stimulation, and this inhibitory activity could be overcome by increasing the stimulatory concentration of IL 2. When the factor was further purified by reverse-phase high pressure liquid chromatography, it eluted as a single peak with an m.w. of 11,000 to 12,000 daltons which inhibited IL 2- but not IL 3-dependent proliferation. The mechanisms by which this new lymphokine might play in the control of the clonal expansion of T lymphocytes are discussed.
mesh_terms: D000818:Animals; D000950:Antigens, Ly / Q000032:analysis; D002460:Cell Line; D002478:Cells, Cultured; D003208:Concanavalin A / Q000494:pharmacology; D007376:Interleukin-2 / Q000037:antagonists & inhibitors*; D007377:Interleukin-3; D008222:Lymphokines / Q000276:immunology / Q000302:isolation & purification* / Q000494:pharmacology; D051379:Mice; D008970:Molecular Weight; D013154:Spleen / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D000950:Antigens, Ly; D007376:Interleukin-2; D007377:Interleukin-3; D008222:Lymphokines; C046147:interleukin 2 inhibitor; D003208:Concanavalin A