IN VIVO BIODOSIMETRY OF PORCINE T-LYMPHOCYTE SUBSETS AND NK CELLS

The aim of the present study was to evaluate the biodosimetric potential of peripheral blood lymphocytes, particularly of T-cell subsets (null and T helper) and natural killer cells (NK), upon exposure to gamma irradiation (Co-60) in vivo. For this purpose, the change in relative numbers of NK cells and T-lymphocyte subsets, as well as in the H2AX phosphorylation rate, were evaluated as potential early markers of the lymphocytic response to irradiation in vivo. These experiments were performed on a Large White Pig model. As a result, significant but not dose-dependent changes in the proportion of lymphocyte subpopulations (NK cells, null and T helper cells) were found after exposure to ionising radiation in vivo. On the other hand, circulating NK cells showed relatively higher radioresistance capacity when compared to the T-lymphocyte subsets; however, gamma-H2AX expression showed no significant difference between the evaluated lymphocyte subsets.