title: A novel population of T-cell receptor alpha beta-bearing thymocytes which predominantly expresses a single V beta gene family.
abstract: Recent studies have demonstrated that CD3 is expressed on a subset of thymocytes with a CD4-CD8- (double negative) phenotype. At least some of these cells bear the CD3-associated gamma delta T-cell receptor (TCR gamma delta). Here we describe a second subset of double negative thymocytes which expresses CD3-associated alpha beta receptors (TCR alpha beta). Surprisingly, these cells express predominantly the products of a single V beta gene family (V beta 8). These CD4-CD8-, TCR alpha beta+ cells appear relatively late in ontogeny (between birth and day 5 of life) and thus are unlikely to be the precursors to the TCR alpha beta-bearing cells (CD4+CD8- and CD4-CD8+) already present at birth. They can be selectively expanded in vitro by stimulation with a monoclonal antibody to V beta 8 (F23.1) in the presence of interleukin I (IL-1). We propose that this cell type is a unique T-cell population distinguishable from typical TCR alpha beta+ T cells by its CD4-CD8- phenotype and a restricted TCR V beta repertoire. Analysis of the unique phenotype of these cells suggests that they may represent the normal counterpart of the defective CD4-CD8- T cells found in the lpr autoimmune mouse.
mesh_terms: D000818:Animals; D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface / Q000235:genetics*; D005796:Genes; D007163:Immunosorbent Techniques; D007375:Interleukin-1 / Q000502:physiology; D008213:Lymphocyte Activation; D046911:Macromolecular Substances; D051379:Mice; D008807:Mice, Inbred BALB C; D010641:Phenotype; D051381:Rats; D011948:Receptors, Antigen, T-Cell / Q000235:genetics*; D013601:T-Lymphocytes / Q000276:immunology*; D013950:Thymus Gland / Q000196:embryology / Q000254:growth & development / Q000276:immunology
chemical_list: D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface; D007375:Interleukin-1; D046911:Macromolecular Substances; D011948:Receptors, Antigen, T-Cell