由pMHC结合的完全组装的瘤特异性T细胞受体的结构
Lukas Sušac1, Mai T Vuong2, Christoph Thomas1
1Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt am Main, Germany.
Cell
|August 19, 2022
概括
结合癌症特异性-MHC的T细胞受体 (TCR) 结构揭示了T细胞如何识别抗原. 这种结构洞察力表明TCR可以在没有重大前结合变化的情况下被激活,从而影响免疫反应的理解.
科学领域:
- 免疫学
- 结构生物学
- 生物化学
背景情况:
- T细胞受体 (TCR) 对于适应性免疫至关重要,它们对病原体和瘤进行调解反应.
- 了解TCR-pMHC相互作用是解读免疫激活的关键.
- 关于与pMHC结合的TCR/ CD3复合物的先前结构数据有限.
研究的目的:
- 阐明T细胞受体 (TCR) 信号启动的结构基础,该信号启动时与载主要基因相容性复合体 (pMHC) 分子结合.
- 确定与特定的pMHC结合的瘤反应性TCR复合物的高分辨率结构.
- 研究TCR激活的分子机制.
主要方法:
- 使用冷电子显微镜 (cryo-EM) 来确定与人类I类pMHC结合的TCRαβ/ CD3复合物的结构.
- 进行分子动力学模拟以分析受体动力学和形状变化.
- 生物化学测定和结构比较用于评估连接和不连接的状态.
主要成果:
- 在3. 08 Å分辨率下确定了与黑色素瘤特异性pMHC结合的11个子单元TCRαβ/ CD3复合体的结构.
- 跨三层的多价相互作用稳定了该复合体,集群的囊参与了CD3异构体稳定.
- 在跨膜区域内发现了固醇脂,这表明它在TCR组合和稳定性中起作用.
- 几何表示精确的膜定位是有效的pMHC的TCR扫描所必需的.
- 通过比较和模拟,TCR可以在没有显著的自发结构重组的情况下触发.
结论:
- 高分辨率结构为参与pMHC的TCR/CD3复合物的分子结构提供了前所未有的洞察力.
- 这些发现揭示了TCR组合的新方面,包括脂质的参与和膜接近的重要性.
- 该研究提出了一种不依赖于先前存在的大型形状变化的TCR激活模型,为免疫突触形成和T细胞激活值提供了新的视角.
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