The relative contributions of B and T lymphocytes in the human peripheral blood mutagen test system as determined by cell survival, mitogenic stimulation, and induction of chromosome aberrations by radiation.
Ficoll-Hypaque-separated subpopulations of human peripheral blood T and B lymphocytes were exposed to 0, 0.5, 1.0, 2.5, or 5.0 Gy of gamma rays. Three parameters were examined: Survival, as measured by trypan blue dye exclusion in unstimulated cultures five days after irradiation; mitotic index, measured in phytohemagglutinin (PHA)-stimulated cultures 48 and 72 hours after irradiation; and chromosome aberration frequency, measured 48 or 60 hours after irradiation. Survival curves of T, B, and null cells are biphasic; the Do values for the radiosensitive populations of all three cell types are close to 0.6 Gy but are different for the radioresistant populations: 2.7 Gy for B cells, 4.77 Gy for T cells, and 6.03 Gy for null cells. B cells, as well as T cells, are stimulated to divide by PHA, and B cells comprise at least 10% of the mitotic figures seen in unirradiated cultures at 48 hours. The proportion of B lymphocytes in mitosis at any particular time after PHA stimulation decreases with increasing radiation dose, which reflects a higher mitotic radiosensitivity of B than of T cells. No significant difference, however, in chromosome aberration frequency was found between T and B cells.
D001402:B-Lymphocytes / Q000502:physiology / Q000528:radiation effects*; D002470:Cell Survival / Q000528:radiation effects; D002869:Chromosome Aberrations; D004307:Dose-Response Relationship, Radiation; D005720:Gamma Rays; D006801:Humans; D008213:Lymphocyte Activation / Q000528:radiation effects*; D008214:Lymphocytes / Q000502:physiology / Q000528:radiation effects; D013601:T-Lymphocytes / Q000502:physiology / Q000528:radiation effects*