title: Evidence for in vivo clonal proliferation of unique population of blood CD4-/CD8- T cells bearing T-cell receptor alpha and beta chains in two normal men.
abstract: Rare T lymphocytes bearing CD3 surface antigen and T-cell receptor (TCR) alpha and beta chains, but lacking both CD4 and CD8 antigens, viz, TCR alpha beta+CD4-8- cells, appear at a frequency of 0.1% to 2% in peripheral blood TCR alpha beta+ cells of normal donors. Here we report two unusual cases, found among 100 healthy individuals studied, who showed an abnormally elevated frequency of these T cells, ie, 5% to 10% and 14% to 19%. Southern blot analyses of the TCR alpha beta+CD4-8- clones all showed the identical rearrangement patterns for each individual, demonstrating that these are derivatives of a single T cell. The same rearrangement patterns were also observed for the freshly isolated lymphocytes of TCR alpha beta+CD4-CD8- fraction, which excludes the possible bias in the processes of in vitro cloning. These TCR alpha beta+CD4-8- T cells were found to express other mature T-cell markers such as CD2, CD3, and CD5 antigens, as well as natural killer (NK) cell markers (CD11b, CD16, CD56, and CD57 antigens) for both individuals. Further, although lectin-dependent or redirected antibody-dependent cell-mediated cytotoxicities were observed for both freshly sorted lymphocytes of TCR alpha beta+CD4-8- fraction and in vitro established clones, NK-like activity was not detected.
authors.affiliation: Department of Radiobiology, Radiation Effects Research Foundation, Hiroshima, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Kusunoki
authors.forename: Y
authors.initials: Y
authors.lastname: Hirai
authors.forename: S
authors.initials: S
authors.lastname: Kyoizumi
authors.forename: M
authors.initials: M
authors.lastname: Akiyama
mesh_terms: D015703:Antigens, CD / Q000032:analysis; D015139:Blotting, Southern; D015704:CD4 Antigens / Q000032:analysis; D016827:CD8 Antigens / Q000032:analysis; D002455:Cell Division; D002469:Cell Separation; D002999:Clone Cells / Q000166:cytology; D005434:Flow Cytometry; D015329:Gene Rearrangement, T-Lymphocyte; D006801:Humans; D016130:Immunophenotyping; D007694:Killer Cells, Natural / Q000276:immunology; D007958:Leukocyte Count; D008297:Male; D011948:Receptors, Antigen, T-Cell / Q000032:analysis*; D013601:T-Lymphocytes / Q000166:cytology* / Q000276:immunology
chemical_list: D015703:Antigens, CD; D015704:CD4 Antigens; D016827:CD8 Antigens; D011948:Receptors, Antigen, T-Cell