CD2AP is indispensable to multistep cytotoxic process by NK cells.
CD2AP is indispensable to multistep cytotoxic process by NK cells.
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DOI：
10.1016/j.molimm.2009.11.004
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发表时间：
2010-02
影响因子：
3.6
通讯作者：
Yuting Ma;H. Yang;Jing Qi;Dongfang Liu;P. Xiong;Yong Xu;Wei Feng;Guoying Zheng;Pan Li
中科院分区：
文献类型：
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作者：
Yuting Ma;H. Yang;Jing Qi;Dongfang Liu;P. Xiong;Yong Xu;Wei Feng;Guoying Zheng;Pan Li
CD2相关蛋白（CD2AP）是一种定位于细胞膜皱褶、脂筏和细胞前缘的胞浆蛋白。它与足细胞稳态、信号转导、动态肌动蛋白重塑以及胞吞和胞质分裂期间的膜运输有关。据报道，CD2AP在T细胞接触中协调受体模式和细胞骨架极性，并且还可以调节TCR信号传导。然而，它是否在NK细胞杀伤中发挥作用仍然未知。在本研究中，我们发现，干扰CD2AP的表达强烈地降低了人NK 92细胞系的细胞毒性，并且这种效果与靶细胞的FasL敏感性无关。在CD2AP敲低后，NK 92细胞中的结合物形成和脱粒受到阻碍。在遇到靶细胞时，NK92中的CD2AP在接触部位附近富集，并与携带FasL的颗粒共定位。与此相反，FasL轴承颗粒很少被发现极化后CD2AP敲除细胞接触部位。此外，通过NK 92细胞裂解物的免疫沉淀和在293T和Hela细胞中的瞬时表达研究，我们证明了CD2AP与FasL相关。因此，CD2AP通过促进缀合物形成和裂解颗粒的定向转运，在NK细胞杀伤中起重要作用。
CD2-associated protein (CD2AP) is a cytoplasmic protein which localizes to membrane ruffles, lipid rafts and the leading edges of cells. It is implicated in podocyte homeostasis, signal transduction, dynamic actin remodeling and also membrane trafficking during endocytosis and cytokinesis. CD2AP was reported to orchestrate receptor patterning and cytoskeletal polarity in T cell contacts and it could also modulate TCR signaling. However, whether it plays a role in NK cell killing remains unknown. In this study, we discovered that interfering with CD2AP expression strongly reduced cytotoxicity of human NK92 cell line and this effect was independent of FasL sensitivity of target cells. Conjugate formation and degranulation were impeded in NK92 cells after CD2AP knockdown. Upon encountering target cells, CD2AP in NK92 is enriched near contact site and colocalizes with FasL-bearing granules. In contrast, FasL-bearing granules were found rarely polarized toward cell contact site after CD2AP knockdown. Furthermore, by immunoprecipitation from NK92 cell lysates and transient expression studies in 293T and Hela cells, we demonstrated that CD2AP associates with FasL. Thus, CD2AP, through facilitating conjugate formation and directed transport of lytic granules, plays an important role in NK cells killing.