The crystal structure of a TL/CD8alphaalpha complex at 2.1 A resolution: implications for modulation of T cell activation and memory.
The crystal structure of a TL/CD8alphaalpha complex at 2.1 A resolution: implications for modulation of T cell activation and memory.
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发表时间：
2003
期刊：
影响因子：
32.4
通讯作者：
Yi‐we Liu;Y. Xiong;O. Naidenko;Jin‐huan Liu;Rong-guang Zhang;A. Joachimiak;M. Kronenberg;H. Cheroutre;E. Reinherz;Jia-huai Wang
中科院分区：
文献类型：
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作者：
Yi‐we Liu;Y. Xiong;O. Naidenko;Jin‐huan Liu;Rong-guang Zhang;A. Joachimiak;M. Kronenberg;H. Cheroutre;E. Reinherz;Jia-huai Wang
TL是一种非经典的MHC I类分子，通过与CD8αα相对高亲和力的相互作用来调节T细胞的激活。为了研究TL/CD8α相互作用如何影响TCR信号转导，我们用X射线结晶学表征了TL/CD8α复合体的结构。与抗原呈递分子不同，TL抗原结合沟被特定的构象变化所堵塞。这一特征消除了抗原提呈，严重阻碍了直接的TCR识别，并阻止了TL参与TCR激活复合体。同时，通过TLα3结构域的微妙结构变化，TL/CD8αα相互作用得到加强。因此，TL起到隔离和重定向CD8AlphaAlpha远离TCR的作用，从而修改Lck依赖的信号转导。
TL is a nonclassical MHC class I molecule that modulates T cell activation through relatively high-affinity interaction with CD8alphaalpha. To investigate how the TL/CD8alphaalpha interaction influences TCR signaling, we characterized the structure of the TL/CD8alphaalpha complex using X-ray crystallography. Unlike antigen-presenting molecules, the TL antigen-binding groove is occluded by specific conformational changes. This feature eliminates antigen presentation, severely hampers direct TCR recognition, and prevents TL from participating in the TCR activation complex. At the same time, the TL/CD8alphaalpha interaction is strengthened through subtle structure changes in the TL alpha3 domain. Thus, TL functions to sequester and redirect CD8alphaalpha away from the TCR, modifying lck-dependent signaling.