The mechanisms by which a T cell detects antigen using its T cell antigen receptor (TCR) are crucial to our understanding of immunity and the harnessing of T cells therapeutically. A hallmark of the T cell response is the ability of T cells to quantitatively respond to antigenic ligands derived from pathogens while remaining inert to similar ligands derived from host tissues. Recent studies have revealed exciting properties of the TCR and the behaviors of its signaling effectors that are used to detect and discriminate between antigens. Here we highlight these recent findings, focusing on the proximal TCR signaling molecules Zap70, Lck, and LAT, to provide mechanistic models and insights into the exquisite sensitivity and specificity of the TCR.

T 细胞使用其 T 细胞抗原受体 (TCR) 检测抗原的机制对于我们理解免疫和治疗性 T 细胞的利用至关重要。T 细胞反应的一个标志是 T 细胞能够对源自病原体的抗原配体进行定量反应，同时对源自宿主组织的类似配体保持惰性。最近的研究揭示了 TCR 的令人兴奋的特性及其用于检测和区分抗原的信号效应器的行为。在这里，我们重点介绍这些最近的发现，重点关注近端 TCR 信号分子 Zap70、Lck 和 LAT，以提供机制模型和对 TCR 精细敏感性和特异性的见解。