与非经典的MHC T2222复合体中的 gamma delta T 细胞受体的结构
Erin J Adams1, Yueh-Hsiu Chien, K Christopher Garcia
1Department of Microbiology and Immunology, Stanford University School of Medicine, Fairchild D319, 299 Campus Drive, Stanford, CA 94035-5124, USA.
概括
揭示了与MHC Ib类结合的 gamma delta T 细胞受体 (TCR) 的结构. 这一发现澄清了gamma delta TCR的识别,与alphabeta TCR有很大的不同.
科学领域:
- 免疫学 免疫学 免疫学
- 结构生物学 结构生物学
- 分子生物学分子生物学
背景情况:
- T细胞受体 (TCRs),包括gamma delta TCRs和alphabeta TCRs,以及抗体,是关键的体质重组抗原受体.
- 虽然对alphabeta TCRs和抗体的连接体识别的结构基础已经确立,但对于gammadelta TCRs,它仍然在很大程度上没有定义.
研究的目的:
- 阐明了对 gamma delta T 细胞受体 (TCR) 的连接体识别的结构基础.
- 呈现一个特定的小鼠马三角体TCR (G8) 与其同类的MHC Ib类联结体 (T22) 复合的原子结构.
主要方法:
- 采用X射线晶体学来确定与T22合体结合的小鼠马三角形TCR G8的3.4 Å分辨率结构.
- 结构分析的重点是互动接口,特别是 gamma delta TCR 的互补性决定区域3 (CDR3) 循环.
主要成果:
- 这项研究介绍了小鼠马三角体TCR G8的3.4 Å结构与其MHC Ib类联结体T22.22的复合.
- 泛三角形TCR G8在它的三角形链CDR3循环中主要使用生殖系编码的残留物来结合T22.
- 观察到的结合方向与通常在alphabeta TCR/peptide-MHC相互作用中看到的基本不同.
结论:
- 结构数据显示,与alphabeta TCR相比,gammadelta TCRs的连接体识别模式与alphabeta TCRs不同.
- 主要使用生殖系编码的残留物表明,在Gamma Delta T细胞中,先天性和适应性免疫识别策略的潜在融合.
- 这项工作提供了关键的洞察力,了解基底的分子机制, gamma delta T 细胞的功能.
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