title: Responsiveness of fetal and adult CD4-, CD8- thymocytes to T cell activation.
abstract: Day-14 fetal CD4-, CD8- thymocytes showed a greater proliferative response to PMA + IL-4 than did adult double-negative thymocytes. In contrast, adult double-negative thymocytes were more responsive to PMA + IL-1 + IL-2 or to IL-1 + IL-2 alone. The adult double-negative thymocytes showed significantly greater proliferation than fetal thymocytes after stimulation via anti-CD3 or anti-Thy-1 in the presence or absence of interleukins (IL-1 + IL-2 or IL-4). Adult CD4-, CD8- thymocytes also exhibited greater calcium mobilization following anti-CD3 stimulation IL-2-dependent activation with anti-Thy-1 or IL-1 + IL-2 in the absence of PMA resulted in marked expansion of CD 3+, F23.1+, CD4-, CD8- thymocytes, a population absent in fetal thymocytes but constituting 4% of pre-cultured CD4-, CD8- adult thymocytes. IL-4 + PMA failed to expand this CD 3+ population. It is hypothesized that before expression of functional TCR, T cell development may be more dependent on activation pathways not using IL-2; after TCR expression, IL-2-dependent pathways, including Thy-1-mediated stimulation, become functional.
authors.affiliation: Cellular Immunology Section, National Institute of Arthritis and Musculoskeletal and Skin Diseases, Bethesda, MD 20892.
authors.forename: T
authors.initials: T
authors.lastname: Takashi
authors.forename: A D
authors.initials: AD
authors.lastname: Steinberg
authors.forename: C H
authors.initials: CH
authors.lastname: June
authors.forename: W C
authors.initials: WC
authors.lastname: Gause
mesh_terms: D000818:Animals; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis* / Q000276:immunology; D000954:Antigens, Surface / Q000276:immunology; D017252:CD3 Complex; D016827:CD8 Antigens; D002118:Calcium / Q000378:metabolism; D005260:Female; D005333:Fetus / Q000276:immunology*; D007375:Interleukin-1 / Q000494:pharmacology; D007376:Interleukin-2 / Q000494:pharmacology; D015847:Interleukin-4; D007378:Interleukins / Q000494:pharmacology; D008213:Lymphocyte Activation; D051379:Mice; D008810:Mice, Inbred C57BL; D011948:Receptors, Antigen, T-Cell / Q000032:analysis / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D018800:Thy-1 Antigens
chemical_list: D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface; D017252:CD3 Complex; D016827:CD8 Antigens; D007375:Interleukin-1; D007376:Interleukin-2; D007378:Interleukins; D011948:Receptors, Antigen, T-Cell; D018800:Thy-1 Antigens; D015847:Interleukin-4; D013755:Tetradecanoylphorbol Acetate; D002118:Calcium