T细胞激活第一信号（TCR-CD3+MHC1/2+CD8/CD4）结构示意图. 大量实验证实，如果缺乏共刺激分子提供的协同刺激信号，T细胞便不能激活，而处于无能（anergy）状态，甚至发生凋亡。T细胞通过TCR识别MHC/抗原肽后，出现一系列和激活有关的事件。

CD3复合物 和ξ蛋白可以非共价的形式和TCRαβ异二聚体结合，形成TCR复合物，TCR识别多肽-MHC后，CD3复合物和ξ蛋白随后负责传导信号，激活T细胞； CD3蛋白是一个复合物，其家族有三个亚型为γ、δ和ε。 每个CD3的亚型都包含一个类似Ig的结构，其跨膜结构中有一个负电的氨基酸残基——天冬氨酸，用于和上述TCRαβ的胞内结构域中的正电氨基酸残基结合。 三个CD3亚型的胞内结构域的长度大约为44-81个氨基酸，其中每一个胞内结构域包含一 …

CD3 (cluster of differentiation 3) is a protein complex and T cell co-receptor that is involved in activating both the cytotoxic T cell (CD8+ naive T cells) and T helper cells (CD4+ naive T cells). [1] It is composed of four distinct chains. In mammals, the complex contains a CD3γ chain, a CD3δ chain, and two CD3ε chains.

2025年3月12日 · Explore the structure and signaling of the TCR CD3 complex, its role in T-cell function, and how variations influence immune responses and development. T cells play a crucial role in adaptive immunity, recognizing and responding to pathogens through the T …

2019年8月28日 · Here we report a cryo-electron microscopy structure of human TCRαβ in complex with the CD3 hexamer at 3.7 Å resolution. The structure contains the complete extracellular domains and all the...

2021年12月13日 · Signals from both the TCR-CD3 complex and co-stimulatory receptors, such as CD28, CD2, and the CD150/SLAM (signaling lymphocyte activation molecule) family, are required for full activation of T...

2020年4月19日 · TCR-CD3 complex: The TCR complex is pictured as four dimers; αβ or Ƴ𝛿 of TCR and Ƴε, 𝛿ε and ζζ or ζη of CD3; The αβ or Ƴ𝛿 TCR heterodimer determines the ligand binding site with specificity; The CD3 dimers ((Ƴε, 𝛿ε and ζζ or ζη) are required for membrane expression of the T cell receptor and for signal transduction.

We review evidence from single-molecule and structural studies for force-induced conformational changes in the TCR–CD3 complex, for dynamically-driven TCR allostery, and for pMHC-induced structural changes in the transmembrane and cytoplasmic regions of CD3 subunits.

The T cell receptor for antigen (TCR) consists of two glycoproteins containing variable regions (TCR-alpha/beta or TCR-gamma/delta) which are expressed on the cell surface in association with at least four invariant proteins (CD3-gamma, -delta, ...

2024年4月24日 · Here we report the structures of two prototypical human Vγ9Vδ2 and Vγ5Vδ1 TCR–CD3 complexes 5, 6, revealing two distinct assembly mechanisms that depend on Vγ usage. The Vγ9Vδ2 TCR–CD3 complex...