靶向膀胱癌细胞内突变p53的跨膜重组抗体研究

肿瘤细胞内有大量特异度高、免疫原性强的突变蛋白，但以其为靶点设计的传统抗体药物治疗效果有限，因为跨膜效率低。我们前期已建立了提高抗体入胞效率的技术平台（通过在其Fc末端融合穿膜肽），并且制备了在肿瘤中广泛存在的突变p53（mut-p53）广谱特异性单抗，但融合有穿膜肽的重组抗体降解mut-p53的效果和机制还有待研究。本项目拟:1）构建融合有穿膜肽的可以高效跨膜的mut-p53重组抗体；2）在膀胱癌细胞模型中，研究重组蛋白降解mut-p53的能力，以及是否激活胞内Fc受体（TRIM21）介导的胞内免疫；3）在已构建的小鼠原位膀胱癌模型中，评估该重组抗体是否可以激发体内抗肿瘤免疫。该项目的实施有望阐明重组抗体降解mut-p53的效果及分子机制，为肿瘤胞内靶标的开发提供新思路。

Traditional antibody therapy did not achieve treatment effects against intracellular mutant proteins, which are abundant、specific and high immunogenic in cancer, duo to low interlazation rate. Our previous study has established a new technology platform to improve antibody endocytosis efficiency (by fusing cell-penetrating peptides to its Fc terminal), and selected Anti-mut-p53 broad specific monoclonal antibodies. However, whether the recombined Anti-mut-p53 could degrade inner mut-p53 is not clear. The present study includude : 1)optimizing strategies to improve recombined Anti-mut-p53 antibodies internalization rate; 2) evaluating the possibility of if recombined antibodies could bind to the inner mut-p53 and degradate it by stimulating TRIM21 dependent intracellular immune; 3) testing wether recombined antibody therapy could stimulate in vivo antitumor immunity in the constructed murine orthotopic bladder cancer model. This study will shed light on the mechanism of mut-p53 degradation through recombined antibody therapy, providing new strategy for intracellular tumor targets design.