State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China.
Central Laboratory, The Second Affiliated Hospital of Guilin Medical University, Guilin, China.
Immunology. 2020 Dec;161(4):354-363. doi: 10.1111/imm.13256. Epub 2020 Oct 7.
T cells must display diversity regarding both the cell state and T-cell receptor (TCR) repertoire to provide effective immunity against pathogens; however, the generation and evolution of cellular T-cell heterogeneity in the adaptive immune system remains unclear. In the present study, a combination of multiplex PCR and immune repertoire sequencing (IR-seq) was used for a standardized analysis of the TCR β-chain repertoire of CD4 naive, CD4 memory, CD8 naive and CD8 memory T cells. We showed that the T-cell subsets could be distinguished from each another with regard to the TCR β-chain (TCR-β) diversity, CDR3 length distribution and TRBV usage, which could be observed both in the preselection and in the post-selection repertoire. Moreover, the Dβ-Jβ and Vβ-Dβ combination patterns at the initial recombination step, template-independent insertion of nucleotides and inter-subset overlap were consistent between the pre- and post-selection repertoires, with a remarkably positive correlation. Taken together, these results support differentiation of the CD4 and CD8 T-cell subsets prior to thymic selection, and these differences survived both positive and negative selection. In conclusion, these findings provide deeper insight into the generation and evolution of TCR repertoire generation.
T 细胞必须在细胞状态和 T 细胞受体 (TCR) 库方面表现出多样性，才能提供针对病原体的有效免疫；然而，适应性免疫系统中细胞 T 细胞异质性的产生和进化仍不清楚。在本研究中，采用多重 PCR 和免疫受体库测序 (IR-seq) 的组合方法，对 CD4 幼稚、CD4 记忆、CD8 幼稚和 CD8 记忆 T 细胞的 TCR β 链库进行了标准化分析。我们表明，T 细胞亚群可以通过 TCR β 链 (TCR-β) 多样性、CDR3 长度分布和 TRBV 利用来区分彼此，这种区分既可以在预选库中观察到，也可以在选择后库中观察到。此外，在初始重组步骤中 Dβ-Jβ 和 Vβ-Dβ 的组合模式、模板非依赖性核苷酸插入和亚群间重叠在预选库和选后库之间是一致的，且具有显著的正相关性。综上所述，这些结果支持 CD4 和 CD8 T 细胞亚群在胸腺选择之前发生分化，并且这些差异在阳性和阴性选择后都得以保留。总之，这些发现为 TCR 库生成的产生和进化提供了更深入的了解。
