Biologic effect of heavy ion radiation on human peripheral blood derived T lympho-cytes / 军事医学

ABSTRACT

Objective To study the effect of heavy ion radiation on proliferation and apoptosis of human peripheral blood derived T lymphocytes and the mechanism .Methods T lymphocytes were isolated from heparinized whole blood samples by density gradient centrifugation using Ficoll before being irradiated with heavy ion beams 12 C.The accumulated absorbed dose (dose-rate values=0.5 Gy/min, and meanLET=29 keV/μm).12 h and 24 h post-infection, total RNA of T lymphocytes was isolated , and the apoptosis related gene expression , including Bcl-2, Bax, Caspase3, Caspase8 and Caspase9, was detected by RT-RT-PCR.24 h and 48 h after irradiation, the proliferation was analyzed by CCK 8 kit.The cell apoptosis was detected by flow cytometry after being labeled with AnnexinV-PE/7-AAD or AnnexinV-FITC/PE.The expression of Bcl-2, Bax and Caspase3 was also assayed by RT-PCR.Results Data showed that heavy ion radiation could inhibit the proliferation of T lymphocytes obviously , and the inhibition ratio in cells that received 2 Gy dose was much high-er than in cells that received 1 Gy dose.Furthermore, heavy ion radiation promoted the apoptosis of T lymphocytes signifi-cantly.The results of RT-PCR showed that the mRNA expression of Bcl-2 was down-regulated in heavy ion radiation T lym-phocytes while the expression of Bax and Caspase 3 was up-regulated.Conclusion Heavy ion radiation can inhibit the pro-liferation and promote the apoptosis of human peripheral blood derived T lymphocytes .