Effect of thymosin alpha 1 on C57BL/6 model mice with sarcoidosis granuloma

Objective：To investigate the effect of thymosin alpha 1 (Tα1) on the sarcoidosis granuloma. Methods：Twenty-five C57BL/6 mice were randomly divided into 2 groups: 15 in model group and 10 in blank control group. Mice in the model group were treated with superoxide dismutase A, whereas mice in the blank control group were treated with PBS of the same volume. Twenty-two days after the establishing of the model, 5 mice in each group were randomly selected and sacrificed. Twenty-two to 35 days after the establishing of the model, the remaining 10 mice in the model group were further randomly divided into two groups, 5 in the model group and 5 in the administration group, mice in the drug group was given an intraperitoneal injection of 10 μg Tα1 every day, and mice in the model group and the blank control group were given a intraperitoneal injection of 0.5 mL PBS every day. On the 36th day: mice were sacrificed, the histologic changes of the lung and lymph node were evaluated; CD4+T cells and macrophages in granuloma were detected by immunohistochemistry; the levels of Th1, Th2, Th17, Treg, and CD4/CD8 in peripheral blood were detected by flow cytometry; and the cytokines IL-17A and IL-10 in lung homogenate and plasma were analyzed by ELISA. Results：Mice in the model group showed granulomatous changes, and the macrophage specific antigen macrophage and CD4+T were positive in the granuloma. The histopathological changes improved in the administration group.The levels of Th1 and Th17 in peripheral blood of both treatment group and model group were higher than the control group (P<0.05). There was no significant difference in the levels of Treg, Th2, or CD4/CD8 ratio in peripheral blood among all groups. The plasma IL-10 level of the mice in the model group was lower than that in the control group (P<0.05); plasm IL-17A level of the mice in the model groups was higher than that in the control group (P<0.05). There was no significant difference in the lung-tissue IL-10 level among all groups; the lung-tissue IL-17A level of the mice in the model group was higher than that in the control group (P<0.05). 〖JP〗Conclusions：Tα1 has a therapeutic effect on sarcoidosis mice, which might be related to the downregulation of the Th17 level, while the results need to be approved.