title: Radiosensitivity of CD4 or CD8 positive human T-lymphocytes by an in vitro colony formation assay.
abstract: The recent development of an in vitro lymphocyte colony assay makes it possible to examine variations in the radiosensitivity of humans using peripheral blood lymphocytes (PBL) instead of the skin fibroblast assay. Our recent study (M. Hakoda et al., Mutat. Res. 197, 161-169, 1988) showed that most of the colonies consisted of lymphocytes bearing CD4 or CD8 antigens. Since the fraction of CD4+ and CD8+ cells in PBL differs among individuals, we suspected that individual radiosensitivity might be biased by the different subset frequencies if the dose-survival curves of the CD4+ and CD8+ cells were different from each other. In the present study, CD4+ (helper/inducer T) and CD8+ (suppressor/cytotoxic T) lymphocytes were isolated from PBL and their dose-survival curves were determined. The results showed that the D10 (dose required to reduce the surviving fraction to 10%) was similar for these two types of cells [3.13 +/- 0.10 Gy (mean +/- SD) for CD4+, 3.34 +/- 0.50 Gy for CD8+ and 3.14 +/- 0.17 Gy for the unsorted cells], supporting the use of the whole PBL population for the screening of individuals with altered radiosensitivity.
authors.affiliation: Department of Radiobiology, Radiation Effects Research Foundation, Hiroshima, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Nakamura
authors.forename: Y
authors.initials: Y
authors.lastname: Kusunoki
authors.forename: M
authors.initials: M
authors.lastname: Akiyama
mesh_terms: D000328:Adult; D000945:Antigens, Differentiation, T-Lymphocyte; D015704:CD4 Antigens; D016827:CD8 Antigens; D002470:Cell Survival / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D006801:Humans; D008297:Male; D011836:Radiation Tolerance; D013601:T-Lymphocytes / Q000276:immunology / Q000528:radiation effects*
chemical_list: D000945:Antigens, Differentiation, T-Lymphocyte; D015704:CD4 Antigens; D016827:CD8 Antigens