OBJECTIVETo study the effect of Chinese drugs for invigorating qi and tonifying Shen (IQTS) on expression of CD4+CD25+ regulatory T cells in spleen and maternal-fetal interface of abortion-prone mice during pregnancy.

METHODSCBA female mice were mated with DBA/2 male mice to establish abortion-prone models, which were randomly divided into 4 groups, the negative control group (fed with normal saline), the positive control group (treated with CsA), the Chinese medicine group (treated with IQTS), and the Chinese and Western medicine group (treated with IQTS+CsA). Mice were sacrificed in batches on the 9th and the 14th day of gestation, their splenic and decidual tissues were taken out to analyse CD4+CD25+ regulatory T-cell expression by flow cytometry.

RESULTSCompared with the negative control group, the expression of splenic CD4+CD25+ regulatory T all significantly increased on the 9th day of gestation (P < 0.01 or P < 0.05). There was no statistical difference in intergroup comparison of the three treatment groups (P > 0.05). Compared with the negative control group, the expression of splenic CD4+CD25+ regulatory T all significantly increased on the 14th day of gestation (P < 0.01 or P < 0.05). Of them, its expression was the highest in the Chinese and Western medicine group, showing significant difference from that in the Chinese medicine group and the positive group (P < 0.01). The difference between the Chinese medicine group and the positive group was insignificant (P > 0.05). On day 9 of gestation, compared with the negative control group, the expressions of CD4+CD25+ regulatory T in maternal-fetal interface increased in the three treated groups, showing no statistical significance (P > 0.05). Its expression was ordered from high to low in sequence as the Chinese and Western medicine group, the positive control group, the Chinese medicine group, and the negative control group. On day 14 its expression was obviously enhanced in the Chinese and Western medicine group, showing statistical difference from that in the negative control group (P < 0.05). But its expression was obviously enhanced in the Chinese medicine group and the positive group, showing insignificant difference from that in the negative group. The same sequence was found in the percentage of CD4+CD25+ T cells in CD4+ T cells.

CONCLUSIONSChinese drugs for IQTS could up-regulate the expression of CD4+CD25+ regulatory T in spleen of abortion-prone mice in the early and late pregnancy stages. When combined with CsA, it also could up-regulate its expression in maternal-fetal interface in the mid and late pregnancy stages, suggesting that Chinese drugs for IQTS are facilitate to maintain the immune tolerance state in mice during pregnancy.