T cells play an important role in adaptive immunity. An enormous clonal diversity of T cells with a different specificity, encoded by the T cell receptor (TCR), protect the body against infection. Most TCRβ chains are generated from a V, D, and J segment during recombination in the thymus. Although complete absence of the D segment is not easily detectable from sequencing data, we find convincing evidence for a substantial proportion of TCRβ rearrangements lacking a D segment. Additionally, sequences without a D segment are more likely to be abundant within individuals and/or shared between individuals. Our analysis indicates that such sequences are preferentially generated during fetal development and persist within the elderly. Summarizing, TCRβ rearrangements without a D segment are not uncommon, and tend to allow for TCRβ chains with a high abundance in the naive repertoire.

T细胞在适应性免疫中起重要作用。由 T 细胞受体 (TCR) 编码的具有不同特异性的大量 T 细胞克隆多样性保护身体免受感染。大多数 TCRβ 链是在胸腺重组过程中由 V、D 和 J 片段产生的。尽管很难从测序数据中检测到 D 段的完全缺失，但我们发现了大量缺乏 D 段的 TCRβ 重排的令人信服的证据。此外，没有 D 段的序列更有可能在个体中丰富和/或在个体之间共享。我们的分析表明，此类序列优先在胎儿发育期间产生，并在老年人中持续存在。总之，没有 D 段的 TCRβ 重排并不少见，