title: Role of interleukin 1 in early T cell development: Lyt-2-L3T4- thymocytes bind and respond in vitro to recombinant IL 1.
abstract: Thymocytes that bear neither Lyt-2 nor L3T4 differentiation antigens (2-4- thymocytes) contain the precursors for mature L3T4+Lyt-2- and Lyt-2-L3T4+ T cells. In the present study we determined the capacity of 2-4- cells to respond to recombinant interleukin 1 (rIL 1) in vitro. The presence of rIL 1 enhanced IL 2-dependent proliferation to the lectins Con A and PHA by threefold to eightfold. In a second assay, rIL 1 enhanced proliferation and IL 2 production by 2-4- cells in response to phorbol myristate acetate (PMA) and the calcium ionophore, ionomycin. Using a direct IL 1 binding assay, we were able to detect both high-affinity (Kd approximately 5 pM) and low-affinity (Kd approximately 200 pM) classes of IL 1 receptors on freshly isolated 2-4- cells. Bound IL 1 was rapidly internalized, suggesting that such receptors were functional. These results are compatible with a role for interleukin 1 during thymocyte maturation.
mesh_terms: D000818:Animals; D000945:Antigens, Differentiation, T-Lymphocyte; D000950:Antigens, Ly / Q000032:analysis; D000954:Antigens, Surface / Q000032:analysis; D002454:Cell Differentiation; D003208:Concanavalin A / Q000494:pharmacology; D004357:Drug Synergism; D004705:Endocytosis; D004987:Ethers / Q000494:pharmacology; D007375:Interleukin-1 / Q000502:physiology*; D007376:Interleukin-2 / Q000096:biosynthesis; D015759:Ionomycin; D008213:Lymphocyte Activation / Q000187:drug effects; D051379:Mice; D010835:Phytohemagglutinins / Q000494:pharmacology; D011971:Receptors, Immunologic / Q000502:physiology; D017472:Receptors, Interleukin-1; D013601:T-Lymphocytes / Q000166:cytology / Q000502:physiology*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
chemical_list: D000945:Antigens, Differentiation, T-Lymphocyte; D000950:Antigens, Ly; D000954:Antigens, Surface; D004987:Ethers; D007375:Interleukin-1; D007376:Interleukin-2; D010835:Phytohemagglutinins; D011971:Receptors, Immunologic; D017472:Receptors, Interleukin-1; D003208:Concanavalin A; D015759:Ionomycin; D013755:Tetradecanoylphorbol Acetate