Ex Vivo Irradiation Protocol in Murine Lymph Node Cells.

The aim was to test the protocol for obtaining lymphoid tissue from mouse lymph nodes and characterize the level of DNA damage with analysis of the repair and apoptosis protein markers in ex vivo model of cell irradiation. The lymph node cell suspension was exposed to X-ray irradiation at a dose of 2 Gy and compared with a sham-irradiated (0 Gy) control. Ex vivo irradiation at a dose of 2 Gy after 3 h caused a 7-fold increase in DNA damage level determined in DNA comet assay. A significant increase in the level of repair proteins γH2AX (by 3.7 times), Rad51 (by 2.2 times), and XPA (by 28 times), cell cycle arrest proteins Cdc25A (by 2.6 times), p21 (by 10 times), and p16 (by 5 times), and pro-apoptotic protein Bax (by 3.8 times) was noted, without significant changes in Bcl-2 level. The proposed technique allows quick obtaining lymphoid tissue samples suitable for analysis of the radiosensitivity of lymphoid cells in mice of various strains, changes in their sensitivity after or in combination with the primary damaging exposure.