title: An NK1.1+ CD4+8- single-positive thymocyte subpopulation that expresses a highly skewed T-cell antigen receptor V beta family.
abstract: In the present report we describe a CD4+8- heat stable antigen-negative (HSA-) thymocyte subpopulation that expresses a distinguishably low density of alpha beta T-cell antigen receptors (TCRlo) from the majority of CD4+8- high-density TCR (TCRhi) mature-type thymocytes. This subpopulation appears relatively late in life. Analysis of MEL-14, Pgp-1 (CD44), ICAM-1 (CD54), and NK1.1 expression on this subpopulation revealed that the CD4+8- TCRlo population was a population having unique characteristics (MEL-14-, CD44+, ICAM-1+, and NK1.1+) compared to the CD4+8- TCRhi thymocytes, most of which are MEL-14+, CD44-, ICAM-1-, and NK1.1-. When TCR beta-chain variable region (V beta) usage was analyzed, this thymic population expressed predominantly products of V beta 7 and V beta 8.2 TCR gene families. Interestingly, cells with V beta 8.1 TCRs, which are reactive to Mls-1a antigens, were not eliminated from the CD4+8- HSA- TCRlo subpopulation but had been eliminated from the major CD4+8- HSA- TCRhi subpopulation in Mls-1a strains. A subset with a phenotype similar to the CD4+8- HSA- TCRlo thymocytes was also identified primarily in bone marrow, and this subset constituted approximately half of the CD4+ T cells in the bone marrow. The CD4+8- HSA- TCRlo cells showed extremely high proliferative responses to immobilized anti-TCR antibody but generated negligible responses to allogeneic H-2 antigens compared to the responses generated by the major CD4+8- HSA- CD3hi cells. However, the CD4+8- HSA- TCRlo cells in Mls-1b mice mounted vigorous proliferative responses to Mls-1a antigens but not in Mls-1a mice. The properties of this T-cell subset suggest that these cells belong to a lineage distinct from the major T-cell population.
authors.affiliation: Section of Pathology, Hokkaido University, Sapporo, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Arase
authors.forename: N
authors.initials: N
authors.lastname: Arase
authors.forename: K
authors.initials: K
authors.lastname: Ogasawara
authors.forename: R A
authors.initials: RA
authors.lastname: Good
authors.forename: K
authors.initials: K
authors.lastname: Onoé
mesh_terms: D000367:Age Factors; D000818:Animals; D015703:Antigens, CD / Q000032:analysis; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis; D017252:CD3 Complex; D015496:CD4-Positive T-Lymphocytes / Q000502:physiology; D019002:CD56 Antigen; D016827:CD8 Antigens / Q000378:metabolism; D015333:Gene Rearrangement, beta-Chain T-Cell Antigen Receptor; D008213:Lymphocyte Activation; D051379:Mice; D008815:Mice, Inbred Strains; D011948:Receptors, Antigen, T-Cell / Q000032:analysis; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000378:metabolism*; D016176:T-Lymphocyte Subsets / Q000502:physiology*; D013950:Thymus Gland / Q000166:cytology; D014018:Tissue Distribution
chemical_list: D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D017252:CD3 Complex; D019002:CD56 Antigen; D016827:CD8 Antigens; D011948:Receptors, Antigen, T-Cell; D016693:Receptors, Antigen, T-Cell, alpha-beta