URSA中维生素D3诱导CTLA-4表达抑制Th17细胞炎性作用及Treg-Th17细胞转分化

Unexplained recurrent spontaneous abortion (URSA) is a common disease with women of childbearing age, seriously affect women's reproductive health. It is reported that Vitamin D (VD) deficiency would influence B cell proliferation, increase NK cells cytotoxicity and Th1/Th2 cell imbalance in URSA patients; both of our previous study and some articles were think about that Th17/Treg imbalance should be one of the reason of URSA occurrence; VD can suppress autoimmunity diseases based on it could induce CTLA-4 expression and inhibit Th17 cells inflammatory; Treg-Th17 cells transdifferentiation play an important promote role in autoimmunity diseases ; Based on our previous study and related articles, we proposed a hypothesis for "VD induced expression of CTLA-4 in URSA patients, inhibit Th17 inflammatory effect and Treg-Th17 cell transdifferentiation", by analyze the correlation of VDR and CTLA-4; we use in vitro cells culture and in vivo abortion mouse model, after VD or VD+CTLA-4Ig treatment,by analyze the change of Th17/Treg/Intermediate cells proportion, related cytokines, mRNA and protein in peripheral blood and maternal-fetal interface. It is illustrated that pathway of VD function, and provide a theoretical basis for clinical treatment and strategies for new treatment.

不明原因性复发性流产(URSA)是育龄妇女常见病，严重影响女性生殖健康。文献中维生素D3 (VD) 缺乏通过B细胞增殖，NK细胞杀伤毒性增加和Th1/Th2细胞平衡失调导致URSA发生；我们前期研究及文献中Th17/Treg细胞失衡将导致URSA发生；VD诱导CTLA-4表达抑制Th17细胞炎性作用抑制自身免疫性疾病，Treg-Th17细胞转分化促进自身免疫性疾病发生。综合文献及申请者前期基础，提出“VD诱导CTLA-4抑制Th17细胞炎性作用及Treg-Th17细胞转分化抑制URSA发生”假说，分析URSA中VDR与CTLA-4相关性，通过体外细胞培养及流产小鼠模型中分析VD或 CTLA-4Ig+VD治疗后，分析外周血及母胎界面中Th17/Treg/转分化状态细胞数量、相关细胞因子、mRNA及蛋白的变化，阐释VD可能作用途径，为VD临床治疗提供理论依据及新的治疗策略。

不明原因性复发性流产(URSA)是育龄妇女常见病，严重影响女性生殖健康。URSA患者中半数以上VD缺乏，有研究发现VD缺乏通过B细胞增殖，NK细胞杀伤毒性增加和Th1/Th2细胞平衡失调导致URSA发生。而本项目探究VD是否通过调节Th17/Treg细胞平衡诱导流产的作用机制。通过流式细胞技术分析患者及对照外周血中Th17/Treg细胞的比例；通过Realtime PCR技术分析母胎界面Th17/Treg细胞相关分子及核转录因子的表达。应用正常孕鼠及流产小鼠模型，给予不同饲料喂养，形成不同维生素D状态，探究脾脏血中及母胎界面蜕膜组织中的维生素D对T淋巴细胞分化的调节作用。我们的研究结果显示URSA患者且VD缺乏时，无论外周血和母胎界面，均发现Th17细胞相关炎性细胞因子分泌增加，Treg细胞相关分子CTLA-4及核转录因子分泌降低，与流产发生密切相关。通过观察不同组孕鼠胚胎吸收率，VD缺乏孕鼠胚胎吸收率明显增高，由此认为VD缺乏不利于妊娠维持；在流产小鼠中发现，在给予充足的维生素D饲料的饲养时，脾脏血中Th17细胞和Treg细胞处于相对平衡的状态，而缺乏维生素D饲料的饲养后，Th17炎性细胞显著增加，而Treg细胞却显著降低，同时Treg细胞相关分子及核转录因子均显著降低，与流产的加重密切相关；在流产小鼠母胎界面，维生素D缺乏状态下Th17炎性细胞相关因子显著增加，而Treg细胞相关的分子CTLA-4显著降低，核转录因子也显著降低。通过本项目阐释维生素D3抑制URSA发生的可能作用途径，通过诱导CTLA-4表达抑制Th17炎性作用，抑制流产的发生，为维生素D3的在URSA中的广泛应用提供理论依据和新的治疗靶点。