Results 1 - 1 of 1
Results 1 - 1 of 1. Search took: 0.015 seconds
[en] Complete text of publication follows. Objective: Our purpose was to characterize the most responsive lymphocyte subpopulation to low dose exposure of ionizing radiation. Methods: Using the microarray technology, we examine gene expression variations in two types of T lymphocyte subpopulations. Blood samples from 6 healthy donors were independently exposed to 0 (sham irradiation), 0.05 and 0.5 Gray of ionizing radiations. Three and 24 hours after exposure, CD4+ and CD8+ cells were negatively isolated with magnetic beads sort system and total RNA was extracted from each sample. After linear amplification, RNA from each condition was competitively hybridized on 26k oligonucleotide microarray against a common reference RNA. Microarray data were analyzed with R software using marray and multtest Bioconductor packages. Results: Three kinds of gene expression modulations were observed: a time dependent one, a dose dependent one and a cell specific one. Indeed a large number of gene expression downregulation was measured specifically in CD4+ cells 3 hours post-exposure. This modulation was early, independent of the received dose and specific of this lymphocyte subpopulation. Twenty four hours after exposure, inductions of known IR-responsive genes were measured only for 0.5 Gy dose in both of the tested lymphocytes subtypes. This more late modulation was independent of the T lymphocyte subpopulation but specific of the highest tested dose. In fact, no more gene expression variation was measured for 0.05 Gy exposed cells at 24 hours post-exposition. Conclusion: CD4+ lymphocyte cells appear to be highly and early sensitive to doses as low as 0.05 Gy of ionizing radiations. It means that biological mechanisms could be sensitive enough to such stress. These cells could be of interest in the detection of low dose of ionizing radiation exposure.