Andrievski Andrei, Wilkins Ruth C
Department of Physics, Carleton University, Ottawa, ON, Canada.
Int J Radiat Biol. 2009 Apr;85(4):369-76. doi: 10.1080/09553000902781147.
To assess the use of phosphorylated histone H2AX protein (gamma-H2AX) in human blood leukocytes as a rapid screening tool for radiation biodosimetry using a method that examines the characteristics of gamma-H2AX phosphorylation in a variety of lymphocyte subsets following exposure to radiation.
Human peripheral blood exposed to 0-10 Gy of (137)Cs irradiation and cultured for 0-48 h was analysed using a rapid whole blood flow cytometry assay to measure gamma-H2AX phosphorylation in different lymphocyte subpopulations.
Lymphocyte subsets displayed a similar linear dose response relationship, although cluster of differentiation 4(+) (CD4(+)) and CD8(+) lymphocytes were found to express H2AX phosphorylation on the order of 1.5 times higher than CD19(+) lymphocytes. Phosphorylation of all lymphocyte subsets reached a maximum at 1.5 h and had essentially returned to baseline levels 24 h post-exposure.
Differences in the expression level of gamma-H2AX between lymphocyte subsets were minimal. The usefulness of this assay for radiation biodosimetry is hampered by its relatively quick lifetime kinetics and large inter-individual variation. Therefore, it could only be useful if samples were obtained within 24 h of exposure. Even in this situation, the assay could only be used as an indicator of exposure and not a dosimeter.
通过一种检测辐射暴露后多种淋巴细胞亚群中γ-H2AX磷酸化特征的方法，评估人血白细胞中磷酸化组蛋白H2AX蛋白（γ-H2AX）作为辐射生物剂量测定快速筛选工具的应用。
采用快速全血流式细胞术分析方法，对暴露于0 - 10 Gy 137Cs辐射并培养0 - 48小时的人外周血进行分析，以测量不同淋巴细胞亚群中γ-H2AX的磷酸化情况。
淋巴细胞亚群呈现出相似的线性剂量反应关系，尽管发现分化簇4（+）（CD4（+））和CD8（+）淋巴细胞表达的H2AX磷酸化水平比CD19（+）淋巴细胞高约1.5倍。所有淋巴细胞亚群的磷酸化在1.5小时达到最大值，且在暴露后24小时基本恢复到基线水平。
淋巴细胞亚群之间γ-H2AX表达水平的差异极小。该检测方法在辐射生物剂量测定中的实用性受到其相对较快的寿命动力学和较大个体间差异的限制。因此，只有在暴露后24小时内获取样本时它才可能有用。即便如此，该检测方法也只能用作暴露指标，而非剂量计。
