High-affinity, peptide-specific T cell receptors can be generated by mutations in CDR1, CDR2 or CDR3
High-affinity, peptide-specific T cell receptors can be generated by mutations in CDR1, CDR2 or CDR3
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DOI：
10.1016/j.jmb.2004.11.057
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发表时间：
2005-02-11
影响因子：
5.6
通讯作者：
Kranz, DM
中科院分区：
文献类型：
--
作者：
Chlewicki, LK;Holler, PD;Kranz, DM
抗体和T细胞受体(TCR)的第三互补决定区(CDR3)已被证明在抗原结合和特异性中起主要作用。与这一概念一致，我们先前证明，在体外，2C TCR的CDR3α区域的突变可以产生高亲和力的多肽特异性TCR。相反，有人认为CDR1和CDR2在MHC限制过程中比CDR3参与得更多，因为它们参与了MHC螺旋。基于这一前提，我们启动了本研究，以探索通过这些CDR或其他区域的突变产生的更高亲和力的TCR是否会导致多肽特异性的显著降低(即通过与主要组织相容性复合体(MHC)螺旋的相互作用获得更大的结合能)。利用酵母展示技术和流式分选技术从CDR突变体或随机突变体文库中筛选高亲和力的TCR。分离到具有Valpha、CDR1、CDR2或CDR3第一个残基突变的高亲和力TCR。出乎意料的是，每个TCR突变体，包括CDR1和CDR2中的突变体，都保留了显著的肽特异性。对各种突变体的分子模拟表明，这种精致的特异性可能是由于：(1)关键多肽或MHC残基的静电相互作用增强；或(2)CDRs在特定构象中的稳定。结果表明，TCR的定位使得几乎每个CDR都可以促进T细胞的抗原特异性。因此，TCRs的保守对角对接可以引导每个CDR环直接或间接地通过多肽对MHC的诱导作用来感觉多肽。(C)2004爱思唯尔有限公司。保留所有权利。
The third complementarity-determining regions (CDR3s) of antibodies and T cell receptors (TCRs) have been shown to play a major role in antigen binding and specificity Consistent with this notion, we demonstrated previously that high-affinity, peptide-specific TCRs could be generated in vitro by mutations in the CDR3alpha region of the 2C TCR. In contrast, it has been argued that CDR1 and CDR2 are involved to a greater extent than CDR3s in the process of MHC restriction, due to their engagement of MHC helices. Based on this premise, we initiated the present study to explore whether higher affinity TCRs generated through mutations in these CDRs or other regions would lead to significant reductions in peptide specificity (i.e. the result of greater binding energy gained through interactions with major histocompatibility complex (MHC) helices). Yeast-display technology and flow sorting were used to select high-affinity TCRs from libraries of CDR mutants or random mutants. High-affinity TCRs with mutations in the first residue of the Valpha, CDR1, CDR2, or CDR3 were isolated. Unexpectedly, every TCR mutant, including those in CDR1 and CDR2, retained remarkable peptide specificity. Molecular modeling of various mutants suggested that such exquisite specificity may be due to: (1) enhanced electrostatic interactions with key peptide or MHC residues; or (2) stabilization of CDRs in specific conformations. The results indicate that the TCR is positioned so that virtually every CDR can contribute to the antigen-specificity of a T cell. The conserved diagonal docking of TCRs could thus orient each CDR loop to sense the peptide directly or indirectly through peptide-induced effects on the MHC. (C) 2004 Elsevier Ltd. All rights reserved.