Syntaxin 4蛋白在NK细胞中的表达及与SNAP-23蛋白的相互作用

目的　研究NK细胞中与囊泡分泌有关的膜蛋白syntaxin 4的表达和与其它蛋白的相互作用 ,为进一步研究NK细胞免疫效应的分泌调节分子机制提供新思路。方法　RT PCR和免疫印迹方法检测人类NK细胞syntaxin 4的表达 ,免疫荧光显微镜观察静息状态和经靶细胞激活后syntaxin4蛋白在NK92细胞中表达和分布的变化 ,免疫共沉淀检测syntaxin 4蛋白和SNAP 2 3蛋白的相互作用。结果　人类NK细胞中在mRNA水平和蛋白质水平均有syntaxin 4组成性表达 ,蛋白产物主要分布在细胞膜上。异种靶细胞刺激后 ,syntaxin 4蛋白有明显的细胞内定位变化和极化现象。syntaxin 4蛋白和SNAP 2 3蛋白有较强的相互作用。结论　syntaxin 4蛋白与NK细胞对靶细胞的识别过程有关 ,并与胞内膜交换相关分子SNAP 2 3蛋白相互作用 ,可作为研究干预移植排斥反应中杀伤性胞吐的新目标分子。

The expression of syntaxin 4 and co-interaction with SNAP-23 in human NK cells

Objective To study the expression of syntaxin 4 and interaction with other related proteins in human NK cells and to create a new idea to interfere the exocytosis in NK cytotoxin process. Method We examined the syntaxin 4 gene by RT PCR, the protein expression of syntaxin 4 in resting and activated NK cells by Western blot, the relocation of syntaxin 4 in resting and activated NK cells by indirect immunofluorescence and the interaction with SNAP 23 by coimmunoprecipitation. Results Syntaxin 4 is expressed both at mRNA and protein level. It is primarily located in cytomembrane dispersively and concentrated as a cap after stimulation by PEC. Coimmunoprecipitation assays indicated that syntaxin 4 interacts with SNAP 23 in vivo . Conclusion Syntaxin 4 is concerned with the recognition of target cell in transplantation rejection and interacts with the signal transmitter, SNAP 23. So, it may act as a target molecule in the regulation of exocytosis in NK cytotoxicity.