Abstract: Objective To study the difference of radiosensitivity of lymphocyte subsets in human peripheral venous blood to different irradiation times under the same irradiation dose, and provide a new idea for the treatment of immune diseases. Methods The peripheral blood of volunteers was collected, the peripheral blood lymphocytes were isolated and extracted, and irradiated 6 times (50 mGy/time), 3 times (100 mGy/time), and 2 times (150 mGy/time) with a total dose of 300 mGy. The intervals between each irradiation were 24 h, and apoptosis, proliferation, cycle, and cytokines were detected 24 h after the last irradiation of each dose. Results Compared with the control, the apoptosis rate of lymphocytes after irradiation was significantly increased. CD3^-CD56⁺NK>CD3⁺T>CD3^-CD19⁺B cells in the 50 mGy/time group; CD3^-CD56⁺NK>CD3^-CD19⁺B>CD3⁺T cells in 100 mGy and 150 mGy/times groups. After 50 mGy, 100 mGy and 150 mGy/time X-ray irradiation, the proliferation activity of lymphocytes was inhibited; Lymphocytes were blocked in G0/G1 phase. Conclusion The same dose and different low-dose irradiation induced apoptosis treatment mode showed different radiosensitivity to human peripheral blood lymphocyte subsets, which could inhibit the proliferation activity and cytokine secretion function of some lymphocytes, and block lymphocytes in G0/G1 phase.

Key words: Low dose irradiation, Human peripheral blood lymphocytes, Radiosensitivity