融合蛋白mTSLPR-Ig体外抑制TSLP对树突状细胞的活化

Fusion protein of thymic stromal lymphopoietin-immunoglobulin inhibits the in vitro activation on dendritic cells by TSLP

胸腺基质淋巴细胞生成素(thymic stromal lymphopoietin,TSLP)通过结合树突状细胞(dendritic cell,DC)表面TSLP受体(TSLPR)活化DC,在导致哮喘Th1/Th2失衡中发挥重要作用。本研究探讨TSLPR可溶性受体mTSLPR-Ig(小鼠TSLPR胞外段与小鼠Ig Fc段的融合蛋白)体外抑制TSLP活化DC的可行性。实验包括分离培养及鉴定小鼠髓系DC;在TSLP作用DC(TSLP-DC)培养体系中加入mTSLPR-Ig,通过FCM检测mTSLPR-Ig对TSLP-DC表面共刺激分子CD80、CD86、CD40表达的影响;将TSLP、抗原OVA脉冲处理的DC以及DO11.10小鼠脾脏CD4+T细胞在体外共培养,MTT法检测体系中加入mTSLPR-Ig对CD4+T细胞增殖能力的影响,同时ELISA法检测上清中细胞因子IL-4、IL-5、IFN-γ以及IL-10表达水平的变化。结果表明,融合蛋白mTSLPR-Ig显著抑制TSLP-DC表面共刺激分子CD80、CD86、CD40的表达;mTSLPR-Ig体外显著抑制TSLP-DC对抗原特异性T细胞的增殖效应,促进上清中IL-10、IFN-γ表达水平,同时抑制IL-4、IL-5表达水平。mTSLPR-Ig通过抑制TSLP-DC活化及所致的Th2偏移,该融合蛋白有望在哮喘或变应性皮炎等TSLP相关性疾病的治疗中发挥重要作用。

Thymic stromal lymphopoietin（TSLP） can activate dendritic cells（DC） through the combination with TSLP receptor（TSLPR） on DC surface,resulting in Th1/Th2 imbalance in asthma.The aim of this study is to find out the feasibility of the soluble TSLPR receptor（mTSLPR-Ig）,constituted by the fusion protein of the extracellular segment of mouse TSLPR and Fc segment of mouse immunoglobulin,to inhibit the activation of DC by TSLP in vitro.The murine myeloid DCs were isolated and identified,and then mTSLPR-IG was added to the culture system,in which DCs were effected byTSLP（TSLP-DCs）.The influence of mTSLP-Ig on the expression of surface co-stimulatory molecules CD80,CD86 and CD40 was analyzed by FCM.In addition.the impact of the added mTSLPR-Ig fusion protein on the proliferative activity of CD4＋ cells was analyzed by FCM and the changes of cytokine,such as IL-4,IL-5,IFN-γ and IL-10,in the cultural supernatants were detected by ELISA.It was demonstrated that expressions of surface co-stimulatory molecules CD80,CD86 and CD40 were significantly inhibited by fusion protein mTSLPR-Ig and mTSLPR-Ig also could inhibit significantly the proliferative activity of the antigen-specific T cells induced by this fusion protein,and promote the secretion of IL-10 and IFN-γ in the cultural supernatants,but inhibit the expression levels of IL-4 and IL-5.From these observation,it is evident that fusion protein mTSLPR-Ig can inhibit the activation of the TSLP-DCs,resulting Th2 biasis,and it is expected that this protein may play some role in the treatment of the TSLP-related disorders,such as asthma or allergic dermatitis.