Chimeric antigen receptor T (CAR-T) therapy faces at least two major obstacles in solid tumors, including to find specific antigen among the heterogeneous tumor mass and to overcome the inhibitory microenvironment. Developing novel strategies to overcome these difficulties has been the burning issue in immunotherapy. Here we came up with the concept of tagging cancer cells by tumor-targeting adenoviruses (Ad). We constructed recombinant Ads expressing CD19 tag driven by tumor-specific promoters, which could label antigenically different tumors for single anti-CD19 CAR-T recognition. One Ad, namely AdC68-TMC-tCD19 could mediate universal tag expression and functional immunological synapse formation between CAR-T and cancer cells. In premixed mice model, all tagged mice survived after CAR-T infusion and tumor volume were inhibited by 91.78%. Furthermore, we combined the tumor tagging ability with oncolysis and generated the replicative AdC68-Sur-E1A-TMC-tCD19. Oncolytic tagging system could diminish established tumors in vivo and prolong mice survival significantly. Therefore, we suggest the universal oncolytic Ad-tagging system in combination with single target CAR-T cells could be a powerful complement in immunotherapy against antigenically mismatched solid tumors.

嵌合抗原受体T（CAR-T）治疗在实体瘤中面临至少两个主要障碍，包括在异质肿瘤块中找到特定抗原并克服抑制性微环境。开发克服这些困难的新策略一直是免疫治疗中的紧迫问题。在这里，我们提出了通过靶向肿瘤的腺病毒（Ad）标记癌细胞的概念。我们构建了表达由肿瘤特异性启动子驱动的CD19标签的重组Ads，它可以标记单个抗原CD19 CAR-T识别的抗原性不同的肿瘤。一种Ad，即AdC68-TMC-tCD19，可以介导CAR-T与癌细胞之间的通用标签表达和功能性免疫突触形成。在预混小鼠模型中，所有标记的小鼠在CAR-T输注后均存活，肿瘤体积被抑制了91.78％。此外，我们结合了肿瘤标记能力和溶瘤作用，并生成了复制型AdC68-Sur-E1A-TMC-tCD19。溶瘤标记系统可以减少已建立的肿瘤体内和延长小鼠的存活率显着。因此，我们建议与单个目标CAR-T细胞结合的通用溶瘤性Ad-tag系统可以作为针对抗原错配实体瘤的免疫疗法的有力补充。