美国华盛顿大学David Baker课题组发现，设计的内吞诱导蛋白能够降解靶标并放大信号。该项研究成果于2024年9月25日在线发表在《自然》杂志上。

研究人员表示，内吞和溶酶体转运细胞表面受体可以由内源性配体触发。治疗性方法如靶向溶酶体的嵌合体（LYTAC）和靶向细胞因子受体的嵌合体（KineTAC）利用这一机制通过将修饰过的天然配体与靶向结合蛋白融合，针对特定蛋白进行降解。尽管这些方法强大，但可能受到与天然配体竞争的限制，并且对化学修饰的要求可能限制遗传编码能力并复杂化制造。更一般来说，可能没有天然配体通过给定受体刺激内吞。

研究人员描述了用于内吞触发结合蛋白（EndoTag）的计算设计方法来克服这些挑战。研究人员展示了针对胰岛素样生长因子2受体（IGF2R）、肝素结合蛋白受体（ASGPR）、sortilin和转铁蛋白受体的EndoTag，并显示将这些标签与可溶或跨膜靶蛋白结合物融合会导致溶酶体转运和靶标降解。由于这些受体在不同组织中的分布不同，不同的EndoTag可能使得靶向降解不同组织成为可能。

相比于单独的抗体，EndoTag与PD-L1抗体的融合在小鼠肿瘤模型中显著提高了疗效。EndoTag的模块化和遗传编码能力使得AND门控制更高特异性靶向降解，以及从工程细胞局部分泌降解剂。通过促进内吞，EndoTag融合可以使通过工程配体-受体系统的信号传导增加近100倍。EndoTag作为靶向降解诱导剂、内吞依赖路径的信号激活剂和靶向抗体-药物与抗体-RNA 结合物的细胞摄取诱导剂，具有巨大的治疗潜力。

附：英文原文

Title: Designed endocytosis-inducing proteins degrade targets and amplify signals

Author: Huang, Buwei, Abedi, Mohamad, Ahn, Green, Coventry, Brian, Sappington, Isaac, Tang, Cong, Wang, Rong, Schlichthaerle, Thomas, Zhang, Jason Z., Wang, Yujia, Goreshnik, Inna, Chiu, Ching Wen, Chazin-Gray, Adam, Chan, Sidney, Gerben, Stacey, Murray, Analisa, Wang, Shunzhi, ONeill, Jason, Yi, Li, Yeh, Ronald, Misquith, Ayesha, Wolf, Anitra, Tomasovic, Luke M., Piraner, Dan I., Duran Gonzalez, Maria J., Bennett, Nathaniel R., Venkatesh, Preetham, Ahlrichs, Maggie, Dobbins, Craig, Yang, Wei, Wang, Xinru, Sahtoe, Danny D., Vafeados, Dionne, Mout, Rubul, Shivaei, Shirin, Cao, Longxing, Carter, Lauren, Stewart, Lance, Spangler, Jamie B., Roybal, Kole T., Greisen, Per Jr, Li, Xiaochun, Bernardes, Gonalo J. L., Bertozzi, Carolyn R., Baker, David

Issue&Volume: 2024-09-25

Abstract: Endocytosis and lysosomal trafficking of cell surface receptors can be triggered by endogenous ligands. Therapeutic approaches such as lysosome-targeting chimaeras1,2 (LYTACs) and cytokine receptor-targeting chimeras3 (KineTACs) have used this to target specific proteins for degradation by fusing modified native ligands to target binding proteins. Although powerful, these approaches can be limited by competition with native ligands and requirements for chemical modification that limit genetic encodability and can complicate manufacturing, and, more generally, there may be no native ligands that stimulate endocytosis through a given receptor. Here we describe computational design approaches for endocytosis-triggering binding proteins (EndoTags) that overcome these challenges. We present EndoTags for insulin-like growth factor 2 receptor (IGF2R) and asialoglycoprotein receptor (ASGPR), sortilin and transferrin receptors, and show that fusing these tags to soluble or transmembrane target protein binders leads to lysosomal trafficking and target degradation. As these receptors have different tissue distributions, the different EndoTags could enable targeting of degradation to different tissues. EndoTag fusion to a PD-L1 antibody considerably increases efficacy in a mouse tumour model compared to antibody alone. The modularity and genetic encodability of EndoTags enables AND gate control for higher-specificity targeted degradation, and the localized secretion of degraders from engineered cells. By promoting endocytosis, EndoTag fusion increases signalling through an engineered ligand–receptor system by nearly 100-fold. EndoTags have considerable therapeutic potential as targeted degradation inducers, signalling activators for endocytosis-dependent pathways, and cellular uptake inducers for targeted antibody–drug and antibody–RNA conjugates.

DOI: 10.1038/s41586-024-07948-2

Source: https://www.nature.com/articles/s41586-024-07948-2