PDF(Pubmed)
Abstract：
Bispecific T cell engagers are a promising class of therapeutic proteins for cancer therapy. Their potency and small size often come with systemic toxicity and short half-life, making intravenous administration cumbersome. These limitations can be overcome by tumor-specific in situ expression, allowing high local accumulation while reducing systemic concentrations. However, encoding T cell engagers in viral or non-viral vectors and expressing them in situ ablates all forms of quality control performed during recombinant protein production. It is therefore vital to design constructs that feature minimal domain mispairing, and increased homogeneity of the therapeutic product. Here, we report a T cell engager architecture specifically designed for vector-mediated immunotherapy. It is based on a fusion of a designed ankyrin repeat protein (DARPin) to a CD3-targeting single-chain antibody fragment, termed DATE (DARPin-fused T cell Engager). The DATE induces potent T cell-mediated killing of HER2+ cancer cells, both as recombinantly produced therapeutic protein and as in situ expressed payload from a HER2+-retargeted high-capacity adenoviral vector (HC-AdV). We report remarkable tumor remission, DATE accumulation, and T cell infiltration through in situ expression mediated by a HER2+-retargeted HC-AdV in vivo. Our results support further investigations and developments of DATEs as payloads for vector-mediated immunotherapy.
摘要：
双特异性T细胞衔接剂是一类有前途的用于癌症治疗的治疗性蛋白质。它们的效力和小尺寸通常伴随着全身毒性和短半衰期，使静脉给药变得繁琐。这些限制可以通过肿瘤特异性原位表达来克服，允许高局部积累，同时降低全身浓度。然而,编码病毒或非病毒载体中的T细胞衔接者并原位表达它们消除了在重组蛋白生产期间进行的所有形式的质量控制。因此，设计具有最小域错误配对的构造至关重要，和增加的同质性的治疗产品。这里,我们报道了一种专门为载体介导的免疫治疗而设计的T细胞接合器结构.它基于设计的锚蛋白重复蛋白（DARPin）与CD3靶向单链抗体片段的融合，称为DATE(DARPin融合T细胞接合器)。DATE诱导强效T细胞介导的HER2+癌细胞杀伤，作为重组产生的治疗性蛋白和作为来自HER2+重靶向的高容量腺病毒载体(HC-AdV)的原位表达的有效载荷。我们报告了显著的肿瘤缓解，日期累积,和T细胞浸润通过在体内由HER2+重新靶向的HC-AdV介导的原位表达。我们的结果支持DATEs作为载体介导的免疫治疗的有效载荷的进一步研究和发展。
