title: Activation of CD 4-, CD 8- thymocytes with IL 4 vs IL 1 + IL 2.
abstract: Thymocytes from C57BL/6 mice were highly purified to obtain the CD 4-, CD 8- subpopulation which constitutes only 5% of all thymocytes. Substantial proliferation was induced in vitro with either IL-1 + IL-2 or with IL-4 in the presence of PMA. IL-1 and IL-2 synergized in inducing proliferation of these purified CD 4-, CD 8- thymocytes whereas neither synergized with IL-4. In order to determine whether stimulation with IL-1 + IL-2 acted via IL-4 or vice versa, cultures were treated reciprocally with affinity-purified anti-IL-2 or anti-IL-4 antibodies. Cultures with IL-4 were inhibited by anti-IL-4 but were unaffected by anti-IL-2. The CD 4-, CD 8- thymocytes cultured with IL-1 + IL-2 + anti-IL-2 were inhibited to baseline IL-1 stimulation. At low concentrations of IL-1 (1 U/ml) and IL-2 (100 U/ml), anti-IL-4 had no effect, whereas at higher levels of IL-1 (2 U/ml IL-1), and 100 or 200 U/ml IL-2, anti-IL-4 significantly reduced DNA synthesis. This result suggests that at higher concentrations the combination of IL-1 + IL-2 can induce cells to produce IL-4 which then contributes to overall proliferation. When CD 4-, CD 8- thymocytes were cultured with the low doses of IL-1 + IL-2 for 72 h, 62% expressed cell surface T3 complex (vs 11% at initiation) and 27% were F23.1+ (vs 5% at initiation). In contrast, culture with IL-4 led to no increase in numbers of T3+ cells and none were F23.1+; however, there was coexpression of Thy1 and 6B2 on 20% of cells at the end of culture (vs 4% at initiation). Thus, IL-1 + IL-2 causes expansion of a CD 4-, CD 8- thymocyte population expressing the alpha, beta-T cell receptor, whereas IL-4 induces cells to express a phenotype present in small numbers in the periphery of normal mice and in larger numbers in mice bearing the lpr gene.
authors.affiliation: Cellular Immunology Section, National Institute of Arthritis and Musculoskeletal and Skin Diseases, Bethesda, MD 20892.
authors.forename: W C
authors.initials: WC
authors.lastname: Gause
authors.forename: T
authors.initials: T
authors.lastname: Takashi
authors.forename: J D
authors.initials: JD
authors.lastname: Mountz
authors.forename: F D
authors.initials: FD
authors.lastname: Finkelman
authors.forename: A D
authors.initials: AD
authors.lastname: Steinberg
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte; D004338:Drug Combinations; D004357:Drug Synergism; D005260:Female; D007375:Interleukin-1 / Q000494:pharmacology; D007376:Interleukin-2 / Q000276:immunology / Q000494:pharmacology; D015847:Interleukin-4; D007378:Interleukins / Q000276:immunology / Q000494:pharmacology*; D008213:Lymphocyte Activation / Q000187:drug effects*; D051379:Mice; D008810:Mice, Inbred C57BL; D010641:Phenotype; D013601:T-Lymphocytes / Q000145:classification* / Q000276:immunology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
chemical_list: D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte; D004338:Drug Combinations; D007375:Interleukin-1; D007376:Interleukin-2; D007378:Interleukins; D015847:Interleukin-4; D013755:Tetradecanoylphorbol Acetate