title: Identification of a novel human thymocyte subset with a phenotype of CD3- CD4+ CD8 alpha + beta-1. Possible progeny of the CD3- CD4- CD8- subset.
abstract: We investigated responsiveness to cytokines and differentiating potential of early human T cell precursors in vitro. Human CD3- CD4- CD8- (triple negative) thymocytes were highly purified by using magnetic bead columns and cell sorting. These cells proliferated for the first 3 to 4 days and then remained viable for up to 14 days in the presence of IL-7, IL-2 or IL-4 had only limited growth-promoting activity on these cells and could not maintain the cell viability. We followed the phenotypic change of triple negative thymocytes during culture with IL-7. After 7 to 14 days of culture with IL-7, a considerable proportion became CD4+ CD8+ (double positive). These cells were found to be CD3- CD4+ CD8 alpha+ beta- in contrast to common double positive thymocytes, which express low levels of CD3 and both alpha- and beta-chains of CD8. By using four-color immunofluorescence and multi-parameter cytofluorometric analysis, we could identify this novel subset in fresh thymocytes. These results suggest that the CD3- CD4+ CD8 alpha+ beta- subset exists physiologically in the human thymus and may represent an intermediate stage between triple negative and common double positive thymocytes.
authors.affiliation: Department of Human Immunology, DNAX Research Institute of Molecular and Cellular Biology, Palo Alto, CA 94304-1104.
authors.forename: T
authors.initials: T
authors.lastname: Hori
authors.forename: J
authors.initials: J
authors.lastname: Cupp
authors.forename: N
authors.initials: N
authors.lastname: Wrighton
authors.forename: F
authors.initials: F
authors.lastname: Lee
authors.forename: H
authors.initials: H
authors.lastname: Spits
mesh_terms: D015703:Antigens, CD / Q000032:analysis*; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis*; D017252:CD3 Complex; D015704:CD4 Antigens / Q000032:analysis*; D016827:CD8 Antigens; D002478:Cells, Cultured; D006412:Hematopoietic Stem Cells / Q000276:immunology*; D006801:Humans; D007376:Interleukin-2 / Q000494:pharmacology; D015847:Interleukin-4 / Q000494:pharmacology; D015851:Interleukin-7 / Q000494:pharmacology; D008213:Lymphocyte Activation / Q000187:drug effects; D010641:Phenotype; D011948:Receptors, Antigen, T-Cell / Q000032:analysis*; D016176:T-Lymphocyte Subsets / Q000276:immunology*
chemical_list: D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D017252:CD3 Complex; D015704:CD4 Antigens; D016827:CD8 Antigens; D007376:Interleukin-2; D015851:Interleukin-7; D011948:Receptors, Antigen, T-Cell; D015847:Interleukin-4