Lymphocyte subsets and their H2AX phosphorylation in response to in vivo irradiation in rats.
OBJECTIVE
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.


METHODS
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.


RESULTS
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.


CONCLUSIONS
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.
Department of Radiobiology, Faculty of Military Health Sciences, University of Defence, Hradec Králové, Czech Republic.
Lenka
L
Zárybnická
Jiřina
J
Vávrová
Radim
R
Havelek
Aleš
A
Tichý
Jaroslav
J
Pejchal
Zuzana
Z
Sinkorová
D000818:Animals; D016175:B-Lymphocyte Subsets / Q000276:immunology / Q000378:metabolism / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D005260:Female; D005720:Gamma Rays; D006657:Histones / Q000737:chemistry / Q000378:metabolism*; D016130:Immunophenotyping; D007694:Killer Cells, Natural / Q000276:immunology / Q000378:metabolism / Q000528:radiation effects; D017493:Leukocyte Common Antigens / Q000378:metabolism; D016131:Lymphocyte Subsets / Q000276:immunology / Q000378:metabolism* / Q000528:radiation effects*; D010750:Phosphoproteins / Q000737:chemistry / Q000378:metabolism*; D010766:Phosphorylation / Q000528:radiation effects; D011836:Radiation Tolerance; D051381:Rats; D017208:Rats, Wistar; D016176:T-Lymphocyte Subsets / Q000276:immunology / Q000378:metabolism / Q000528:radiation effects
D006657:Histones; D010750:Phosphoproteins; C577575:gamma-H2AX protein, rat; D017493:Leukocyte Common Antigens