Singh Srishti, Julia Estefania, Kalita Parismita, Mason Charlotte, Ming Qianqian, Lee-Sam Ansar, Gordon Sumai, Buitrago Maria Emilia, Leung Daisy W, Hwu Patrick, Luca Vincent C
Department of Immunology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL 33612, USA; Cancer Biology Ph.D. Program, University of South Florida, Tampa, FL 33612, USA.
Department of Clinical Science, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL 33612, USA.
Mol Ther. 2025 Apr 24. doi: 10.1016/j.ymthe.2025.04.032.
The immune checkpoint protein, CD112 receptor (CD112R, also known as PVRIG), suppresses T and natural killer (NK) cell activation upon binding to tumor-expressed CD112 (Nectin-2) ligands. Here, we determine the structure of the CD112-CD112R complex and use it to guide the engineering of multiple CD112-targeting immunotherapy candidates. The 2.2 Å-resolution crystal structure reveals an antiparallel, lock-and-key binding mode in which CD112R disrupts CD112 homodimerization. Structural analysis informed directed evolution campaigns focused on remodeling the CD112-CD112R interface, resulting in the isolation of CD112R mutants with greatly increased expression and CD112-binding affinity. The highest-affinity variant, CD112R, potently inhibits CD112-CD112R interactions when utilized as a soluble CD112 trap. Furthermore, incorporating CD112R variants into chimeric antigen receptors (CARs) and T cell engagers (TCEs) leads to more robust T cell activation and killing of CD112 triple-negative breast cancer (TNBC) cells compared with wild-type CD112R. This strategy demonstrates how structural insights can be leveraged to efficiently generate panels of "affinity-tuned" biologics for immunotherapy.
免疫检查点蛋白CD112受体（CD112R，也称为PVRIG）与肿瘤表达的CD112（NECTIN-2）配体结合后，可抑制T细胞和自然杀伤（NK）细胞的激活。在此，我们确定了CD112-CD112R复合物的结构，并利用该结构指导多种靶向CD112的免疫治疗候选物的工程设计。分辨率为2.2 Å的晶体结构揭示了一种反平行的锁钥结合模式，其中CD112R破坏了CD112的同二聚化。结构分析为旨在重塑CD112-CD112R界面的定向进化活动提供了信息，从而分离出表达量和CD112结合亲和力大大增加的CD112R突变体。亲和力最高的变体CD112R作为可溶性CD112陷阱时，能有效抑制CD112-CD112R的相互作用。此外，与野生型CD112R相比，将CD112R变体整合到嵌合抗原受体（CAR）和T细胞衔接器（TCE）中可导致更强劲的T细胞激活以及对CD112三阴性乳腺癌（TNBC）细胞的杀伤。该策略展示了如何利用结构见解来高效生成用于免疫治疗的“亲和力调整”生物制剂库。
