Department of Hematology, Leiden University Medical Center, The Netherlands.
Department of Hematopoiesis, Sanquin Research and Landsteiner Laboratory for Blood Cell Research, Amsterdam, The Netherlands.
Eur J Immunol. 2022 Nov;52(11):1819-1828. doi: 10.1002/eji.202249975. Epub 2022 Oct 19.
Anti-viral T-cell responses are usually directed against a limited set of antigens, but often contain many T cells expressing different T-cell receptors (TCRs). Identical TCRs found within virus-specific T-cell populations in different individuals are known as public TCRs, but also TCRs highly-similar to these public TCRs, with only minor variations in amino acids on specific positions in the Complementary Determining Regions (CDRs), are frequently found. However, the degree of freedom at these positions was not clear. In this study, we used the HLA-A*02:01-restricted EBV-LMP2 -specific public TCR as model and modified the highly-variable position 5 of the CDR3β sequence with all 20 amino acids. Our results demonstrate that amino acids at this particular position in the CDR3β region of this TCR are completely inter-changeable, without loss of TCR function. We show that the inability to find certain variants in individuals is explained by their lower recombination probability rather than by steric hindrance.
抗病毒 T 细胞反应通常针对一组有限的抗原,但通常包含许多表达不同 T 细胞受体 (TCR) 的 T 细胞。在不同个体的病毒特异性 T 细胞群体中发现的相同 TCR 称为公共 TCR,但也发现了与这些公共 TCR 高度相似的 TCR,仅在互补决定区 (CDR) 的特定位置上的氨基酸有微小变化。然而,这些位置的自由度尚不清楚。在这项研究中,我们使用 HLA-A*02:01 限制的 EBV-LMP2 特异性公共 TCR 作为模型,并修饰了 CDR3β 序列的高度可变位置 5,使用了所有 20 种氨基酸。我们的结果表明,该 TCR 的 CDR3β 区域中该特定位置的氨基酸是完全可互换的,不会丧失 TCR 功能。我们表明,个体中无法找到某些变体是由于它们的重组概率较低而不是由于空间位阻。