外周CD4~+CD25~+T细胞降调节及CD28~+T细胞升调节参与人类自然流产

目的:探讨CD4+CD25+调节性T细胞及CD28、CTLA-4协同刺激分子在人孕早期母胎免疫耐受中的作用机制。方法:以15例黄体期育龄妇女外周血为对照,应用流式细胞术对15例早孕期正常妊娠者、15例早孕期自然流产患者外周血淋巴细胞中CD4+CD25+T细胞亚群及CD28、CTLA-4分子的表达进行分析。结果:早孕期正常妊娠者外周CD4+CD25+T细胞比例显著高于早孕期自然流产患者及黄体期育龄妇女(P<0.05);早孕期自然流产患者外周CD28分子的表达水平显著高于早孕期正常妊娠者及黄体期育龄妇女(P<0.05);各组淋巴细胞基本不表达表面CTLA-4(CTLA-4s)分子,而均表达细胞内CTLA-4(CTLA-4i)分子,各组间CTLA-4i分子表达水平比较无显著性差异。结论:人早孕期外周CD4+CD25+调节性T细胞比例下降及CD28分子表达水平上升可能与早期妊娠失败有关。

The Down-regulation of CD4+CD25+ T Cell Subpopulation and the Up-regulation of CD28+ T Cell Population in Peripheral Blood are Involved in Human Spontaneous Abortion

Objective: To explore roles of the CD4+CD25+ regulatory T cells and CD28, CTLA-4 costimulatory molecule expressions in materno-fetal immuno-tolerance of human early pregnancy. Methods: The peripheral blood of 15 normal early pregnancy women and 15 spontaneous abortive early pregnancy were got and analyzed by direct immunofluorescence flow cytometry for CD4+CD25+ T cell population and CD28, CTLA-4 expression, with the peripheral blood of 15 healthy fertile women of luteal phase as control. Results: The ratio of CD4+CD25+ T cells increased significantly in peripheral blood of normal early pregnancy women compared with that of spontaneous abortive early pregnancy and the healthy fertile women of luteal phase (P<0.05). The expression of CD28 increased significantly in peripheral blood of spontaneous abortive early pregnancy compared with that of normal early pregnancy women and the healthy fertile women of luteal phase (P<0.05). The lymphocytes of each group hardly expressed surface CTLA-4 (CTLA-4s), but expressed intracellular CTLA-4 (CTLA-4i), and showed no significant difference among each group. Conclusion: The down-regulation of CD4+CD25+ regulatory T cells population and the up-regulation of CD28+ population in human early pregnancy leads to the early abortion.