Departments of Molecular and Cellular Physiology and Structural Biology, Stanford University School of Medicine, Stanford, CA, USA.
Department of Biology and Center of Cellular Nanoanalytics, University of Osnabrück, Osnabrück, Germany.
Nat Biotechnol. 2023 Jul;41(7):932-943. doi: 10.1038/s41587-022-01567-w. Epub 2023 Jan 2.
Monoclonal antibodies (Abs) that recognize major histocompatability complex (MHC)-presented tumor antigens in a manner similar to T cell receptors (TCRs) have great potential as cancer immunotherapeutics. However, isolation of 'TCR-mimic' (TCRm) Abs is laborious because Abs have not evolved the structurally nuanced peptide-MHC restriction of αβ-TCRs. Here, we present a strategy for rapid isolation of highly peptide-specific and 'MHC-restricted' Abs by re-engineering preselected Abs that engage peptide-MHC in a manner structurally similar to that of conventional αβ-TCRs. We created structure-based libraries focused on the peptide-interacting residues of TCRm Ab complementarity-determining region (CDR) loops, and rapidly generated MHC-restricted Abs to both mouse and human tumor antigens that specifically killed target cells when formatted as IgG, bispecific T cell engager (BiTE) and chimeric antigen receptor-T (CAR-T). Crystallographic analysis of one selected pMHC-restricted Ab revealed highly peptide-specific recognition, validating the engineering strategy. This approach can yield tumor antigen-specific antibodies in several weeks, potentially enabling rapid clinical translation.
单克隆抗体 (Abs) 以类似于 T 细胞受体 (TCRs) 的方式识别主要组织相容性复合体 (MHC) 呈递的肿瘤抗原，具有作为癌症免疫疗法的巨大潜力。然而，由于 Abs 尚未进化出与 αβ-TCR 结构细微的肽-MHC 限制相匹配的结构，因此分离“TCR 模拟物”(TCRm) Abs 非常费力。在这里，我们提出了一种通过重新设计以类似于传统 αβ-TCR 方式与肽-MHC 结合的预先选择的 Abs 来快速分离高度肽特异性和“MHC 限制”Abs 的策略。我们创建了基于结构的文库，重点关注 TCRm Ab 互补决定区 (CDR) 环的肽相互作用残基，并且快速生成了针对小鼠和人类肿瘤抗原的 MHC 限制 Abs，当作为 IgG、双特异性 T 细胞衔接器 (BiTE) 和嵌合抗原受体-T (CAR-T) 构建时，这些 Abs 能够特异性杀伤靶细胞。对一种选定的 pMHC 限制 Ab 的晶体学分析显示出高度的肽特异性识别，验证了该工程策略。这种方法可以在数周内产生肿瘤抗原特异性抗体，有可能实现快速的临床转化。
