CHANGES IN T CELL SUBSETS OF MICE AFTER ACUTE IRRADIATION INJURY / 解放军医学杂志

ABSTRACT

In order to evaluate the changes in T cell subsets after acute irradiation injury, and investigate the mechanism of deficiency of cellular immunity in acute irradiation syndrome, Balb/c mice were exposed to a single total body irradiation of 5Gy gamma rays from a 60 Co source. On days 10, 28 and 120, the amounts of CD4 + and CD8 + subsets in spleen cells were evaluated by flow cytometry (FCM), and expression of IL 4 gene in ConA stimulated spleen cells was evaluated by reverse transcription linked polymerase chain reaction, in which ?-actin gene was used as an internal control. It was found that after irradiation, the ratio of CD4 + /CD8 + became significantly higher than that of the controls, and then the ratio lowered gradually until day 120. However, it still did not return to the level of the controls. On day 10, expression of IL 4 gene at mRNA level increased significantly. The results indicated that CD8 + subset was more radiosensitive than CD4 + , and the pattern of cytokine seeretion shifted to that of Th2 soon after irradiation.