Department of Radiobiology, Faculty of Military Health Sciences, University of Defence, Hradec Králové, Czech Republic.
Int J Radiat Biol. 2013 Feb;89(2):110-7. doi: 10.3109/09553002.2012.721050.
The objective of the study was to investigate differences in the radiosensitivity of rat peripheral blood lymphocyte subsets identified by expression of surface clusters of differentiation markers (CD3, CD4, CD8, CD45RA, CD161) after whole-body in vivo gamma-ray irradiation and to assess their individual histone H2AX phosphorylation as an early cell response to irradiation.
The relative representations of CD45RA B-lymphocytes, CD161 natural killer cells (NK cells), CD3CD4 T-lymphocyte subset and CD3CD8 T-lymphocyte subset in the rat peripheral blood were studied 24-72 hours after irradiation in a dose range of 0-5 Gy. Their intracellular H2AX phosphorylation (γ-H2AX) after 4 Gy and 9 Gy whole-body in vivo irradiation was assessed by multicolour flow cytometry.
We determined the linear dose response of radioresistant CD161 NK cells (24 h), both radiosensitive T-lymphocyte subsets (24 h) and CD45RA B-lymphocytes (72 h) after in vivo irradiation. CD45RA B-lymphocytes showed the highest radiosensitivity and we observed pronounced H2AX phosphorylation which remained expressed in these cells for over 4 h after irradiation.
The combination of the surface immunophenotyping together with intracellular detection of γ-H2AX offers the possibility to assess the absorbed dose of ionizing irradiation with high sensitivity post irradiation and could be successfully applied to biodosimetry.
本研究旨在探讨大鼠外周血淋巴细胞亚群在全身 γ 射线照射后，根据表面分化标记物（CD3、CD4、CD8、CD45RA、CD161）的表达差异的放射敏感性，并评估其组蛋白 H2AX 磷酸化作为对照射的早期细胞反应。
在 0-5 Gy 的剂量范围内，研究了照射后 24-72 小时大鼠外周血中 CD45RA B 淋巴细胞、CD161 自然杀伤细胞（NK 细胞）、CD3CD4 T 淋巴细胞亚群和 CD3CD8 T 淋巴细胞亚群的相对表达。通过多色流式细胞术评估了它们在 4 Gy 和 9 Gy 全身体内照射后细胞内 H2AX 磷酸化（γ-H2AX）的情况。
我们确定了体内照射后具有放射抗性的 CD161 NK 细胞（24 小时）、两种敏感性 T 淋巴细胞亚群（24 小时）和 CD45RA B 淋巴细胞（72 小时）的线性剂量反应。CD45RA B 淋巴细胞表现出最高的放射敏感性，我们观察到明显的 H2AX 磷酸化，在照射后超过 4 小时，这些细胞仍表达这种磷酸化。
将表面免疫表型与细胞内γ-H2AX 的检测相结合，提供了一种在照射后高灵敏度地评估离子照射吸收剂量的可能性，并可成功应用于生物剂量测定。
