Objective: To investigate the characteristic functional changes of the decidual natural killer (NK) cells and γδ T cells, two immunocytes in the decidua, at the maternal-fetal interface in in vitro fertilization-embryo transfer (IVF-ET) pregnancy.
Methods: Decidual samples were collected from 12 women of natural pregnancy (NP) and 32 women of IVF-ET pregnancy, who were enrolled in the NP group and the IVF-ET group, respectively. Then part of the decidual samples were paraffin-embedded for HE staining and immunofluorescence staining, while the rest of the samples were digested and Percoll was used for isolating decidual immunocytes (DICs) by gradient centrifugation. Flow cytometry was used to determine the cell counts of decidual NK cells and γδ T cells and the expression levels of their surface activation markers, CD69 and NKG2D in the NP and the IVF-ET groups. In addition, the expression levels of IFN-γ, TNF-α, IL-17A, and IL-10, the intracellular cytokines, and granzyme B, perforin, and granulysin, the cytolytic granules, were measured. The characteristic changes in the relevant immunological indicators were compared and analyzed.
Results: HE staining of the tissue specimens showed that the typical structure of decidua was observed, and that lymphocytes were enriched in the decidua. Immunofluorescence staining showed that the percentage of decidual NK (dNK) cells in nucleated cells of the IVF-ET group was significantly lower than that of the NP group ( P<0.05). Flow cytometry analysis of DICs showed that, compared with those of the NP group, the percentage of dNK cells of the IVF-ET group was decreased ( P<0.05) and the expression levels of IL-10 and perforin were significantly decreased in the IVF-ET group ( P<0.05). However, there was no significant difference in the decidual γδ T (dγδT) cell count between the two groups. The expression of IL-10, IL-17A, and perforin was downregulated in the IVF-ET group ( P<0.05). There was no significant difference in the expression of IFN-γ, TNF-α, granzyme B, and granulysin, the cellular function indicators ( P>0.05).
Conclusion: The dNK cell count and the secretion of some intracellular cytokines of dNK and dγδT cells of women of IVF-ET pregnancy decreased to some degree, which suggests that certain changes may have taken place in the immunological microenvironment at the maternal-fetal interface. The specific effect of these changes on pregnancy outcomes needs further investigation.
目的: 探究体外受精-胚胎移植 (in vitro fertilization-embryo transfer, IVF-ET)妊娠母胎界面蜕膜免疫细胞中自然杀伤（natural killer, NK）细胞与γδT细胞的功能变化特征。
方法: 收取32例接受IVF-ET及12例自然受孕产妇的蜕膜组织，分别纳入IVF-ET组与NP（natural pregnancy, NP）组，取部分组织经石蜡包埋用于HE染色及免疫荧光染色检测；其余组织经消化、Percoll梯度离心分离出蜕膜免疫细胞（decidual immunocytes, DICs）；流式细胞术检测NP组和IVF-ET组中蜕膜NK细胞与γδT细胞的数量及其细胞表面活化标志CD69和NKG2D水平，同时检测功能性细胞因子IFN-γ、TNF-α、IL-17A、IL-10以及毒性颗粒granzyme B、perforin、granulysin的表达水平，比较和分析其相关免疫学指标的变化特点。
结果: 组织切片经HE染色后可见蜕膜组织的典型结构，并显示有较多淋巴细胞富集；免疫荧光染色结果显示：IVF-ET组中蜕膜NK（decidual NK, dNK）细胞占有核细胞总数比例低于NP组（ P<0.05）；DICs经流式细胞术分析后显示：与NP组相比，IVF-ET组dNK细胞占淋巴细胞总数百分比降低（P<0.05）；IVF-ET组dNK细胞的IL-10与perforin表达水平下调（P<0.05）；而两组蜕膜γδT（decidual γδT，dγδT）细胞的数量差异无统计学意义，IVF-ET组的IL-10、IL-17A以及perforin表达下调（P<0.05）；相关细胞功能指标IFN-γ、TNF-α、granzyme B及granulysin的表达差异无统计学意义（P>0.05）。
结论: IVF-ET产妇的dNK细胞数量以及dNK、dγδT细胞的部分功能性细胞因子分泌有所下降，提示其母胎界面免疫微环境发生了一定变化，这些改变对妊娠结局的确切影响还有待进一步研究证实。
Keywords: Immunological microenvironment; Maternal-fetal interface; Natural killer cells; in vitro fertilization-embryo transfer; γδ T cells.
Copyright© by Editorial Board of Journal of Sichuan University (Medical Sciences).