Expression and function of interleukin-2 receptors on immature thymocytes.
T-cell differentiation represents a unique system for studying mechanisms of lymphoid development because it occurs in a segregated site, the thymus, in which distinct subpopulations of thymocytes at various stages of differentiation can be defined on the basis of the differential expression of T-cell surface antigens as well as topography. There is particular interest in thymocyte differentiation because the genotype of radioresistant thymus cells influences the specificity repertoire of the pool of T cells that mature therein: that is, the major histocompatibility complex (MHC) antigens expressed by thymus cells bias the pool of maturing T cells towards recognition of antigens in the 'context' of the products of that MHC haplotype ('thymus education'; refs 1-3). Immature T cells with affinity for thymus MHC antigens are generally thought to undergo a stage of positive selection in the thymus. Here we report that 30% of cells in the least mature adult thymocyte subpopulation yet defined, as well as 50% of immature fetal thymocytes, express receptors for interleukin-2 (IL-2, the T-cell growth factor) without in vitro induction, and will proliferate vigorously in an IL-2-dependent fashion if provided with co-stimulating mitogen.
D000818:Animals; D000911:Antibodies, Monoclonal; D000950:Antigens, Ly / Q000032:analysis; D000954:Antigens, Surface / Q000032:analysis; D002454:Cell Differentiation; D003208:Concanavalin A / Q000494:pharmacology; D007376:Interleukin-2 / Q000276:immunology; D008198:Lymph Nodes / Q000166:cytology / Q000276:immunology; D008213:Lymphocyte Activation; D051379:Mice; D008807:Mice, Inbred BALB C; D011971:Receptors, Immunologic / Q000276:immunology*; D015375:Receptors, Interleukin-2; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology*; D013950:Thymus Gland / Q000166:cytology* / Q000196:embryology / Q000276:immunology
D000911:Antibodies, Monoclonal; D000950:Antigens, Ly; D000954:Antigens, Surface; D007376:Interleukin-2; D011971:Receptors, Immunologic; D015375:Receptors, Interleukin-2; D003208:Concanavalin A