基于特异激活NK-ADCC免疫效应的靶向抗肝癌生物新药2GL-mFc融合肽体的研究

肝癌内NK细胞数量急剧减少和功能耗竭特征显著，表明基于NK细胞的肝癌免疫治疗值得期待。课题组以“NK-ADCC效应靶向抗肿瘤”为切入点，率先探索融合肽体类新药，针对传统ADCC存在Fc段NK细胞FcγRIII分子亲和力较弱及Fab段分子量大、实体肿瘤靶向性欠佳”等缺陷，通过制备突变mFc替代“IgG1分子Fc”以增加与NK细胞FcγRIII高亲和性，通过差异筛选优化与肝癌细胞ANXA2高亲和肽2GL替代“IgG1分子Fab”，构建2GL-mFc融合肽体作为新型IgG1替代物，攻克融合肽体新药研制技术瓶颈，建立单细胞克隆制备工艺及质控体系，探究2GL-mFc靶向抗肝癌NK-ADCC效应，考察免疫脱靶等安全性。本项目旨在明确2GL-mFc 逆转NK细胞免疫耐受+逆转肝癌细胞免疫逃逸双重效应与机制，探索介导肿瘤免疫耐受的瓶颈问题，为推进高效安全的靶向抗肝癌原创免疫生物新药从0到1的研发奠定基础。

The immunotherapy of hepatoma based on NK cells is expected due to the lack of and the significant functional exhaustion NK cells in hepatoma. The project based on “ NK-ADCC targeted anti-tumor effect ” as the breakthrough point, took the lead in exploring the engineering fusion peptibody drugs. Traditional ADCC effect existed defects, such as the low affinity between Fc segment and NK cells FcγRIII, the high molecular weight of Fab segment, and poor solid tumor targeting. Preparing mutated mFc to replace IgG1 Fc segment increased the high affinity with NK cells FcγRIII. Differentially screening optimized the high affinity peptide of ANXA2, 2GL, in liver cancer cells to replace IgG1 Fab segment to construct the fusion peptidibody 2GL-mFc as a novel IgG molecule replacement. The project overcame bottleneck of the production of novel fusion peptibody. The preparation process and quality control system of single cell cloning were established. The project explored the NK-ADCC effect targeting hepatoma and the safety such as immune off-target toxicity of 2GL-mFc. This project aimed to clarify the dual effect and the mechanism of 2GL-mFc to reverse NK cell immune tolerance and immune escape of liver cancer cells and to solve the bottleneck of NK autoimmune tolerance and NK immune escape of liver cancer cells, and explore the bottleneck of immune tolerance, which provided basis for promoting the effectively and safely original anti-hepatoma immunobiological drugs to realize the breakthrough from 0 to 1.