The response of γ-H2AX in human lymphocytes and lymphocytes subsets measured in whole blood cultures
Purpose: To assess the use of phosphorylated histone H2AX protein (γ-H2AX) in human blood leukocytes as a rapid screening tool for radiation biodosimetry using a method that examines the characteristics of γ-H2AX phosphorylation in a variety of lymphocyte subsets following exposure to radiation. Materials and methods: Human peripheral blood exposed to 0-10Gy of 137Cs irradiation and cultured for 0-48h was analysed using a rapid whole blood flow cytometry assay to measure γ-H2AX phosphorylation in different lymphocyte subpopulations. Results: 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 1.5h and had essentially returned to baseline levels 24h post-exposure. Conclusions: Differences in the expression level of -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 24h of exposure. Even in this situation, the assay could only be used as an indicator of exposure and not a dosimeter.
|Keywords||γ-H2AX, Flow cytometry, Human lymphocytes, Radiation|
|Journal||International Journal of Radiation Biology|
Andrievski, A. (Andrei), & Wilkins, R.C. (2009). The response of γ-H2AX in human lymphocytes and lymphocytes subsets measured in whole blood cultures. International Journal of Radiation Biology, 85(4), 369–376. doi:10.1080/09553000902781147