T cell receptor (TCR) β-selection (herein referred to as β-selection) is a pivotal checkpoint in mammalian T cell development when immature CD4^–CD8^– T-cells (thymocytes) express pre-TCR following successful Tcrb gene rearrangement. At this stage, αβ T cell lineage commitment and allelic exclusion to restrict one β-chain per cell take place and thymocytes undergo a proliferative burst. β-selection is known to be crucially dependent upon synchronized Notch and pre-TCR signaling; however, other necessary inputs have been identified over the past decade, expanding our knowledge and understanding of the β-selection process. In this review, we discuss recent mechanistic findings that have enabled a more detailed decoding of the molecular dynamics of the β-selection checkpoint and have helped to elucidate its role in early T cell development.

T 细胞受体 (TCR) β-选择（此处称为 β-选择）是哺乳动物 T 细胞发育的关键检查点，当Tcrb成功后未成熟的 CD4 ^- CD8 ^- T 细胞（胸腺细胞）表达前 TCR 时基因重排。在这个阶段，发生 αβ T 细胞谱系定型和等位基因排斥以限制每个细胞一个 β 链，并且胸腺细胞经历增殖爆发。众所周知，β-选择关键取决于同步的 Notch 和 pre-TCR 信号；然而，在过去十年中已经确定了其他必要的输入，扩展了我们对 β 选择过程的知识和理解。在这篇综述中，我们讨论了最近的机制发现，这些发现能够更详细地解码 β 选择检查点的分子动力学，并有助于阐明其在早期 T 细胞发育中的作用。