胞浆APE1结合STING抑制IRF3磷酸化介导肺癌免疫抑制作用的研究

胞质dsDNA激活的cGAS/STING/IRF3通路在肺癌免疫中具有重要作用。APE1具有独特的DNA损伤修复和氧化还原双功能，理论上APE1可通过降低dsDNA抑制cGAS/STING/IRF3通路。我们在预实验中确实发现抑制APE1可促进IRF3磷酸化和I型IFN的产生，但却发现STING的磷酸化被显著抑制；同时Co-IP也发现胞浆APE1可与STING结合。由此，我们提出假说：胞浆APE1可与STING结合形成复合体，一方面促进TBK1对STING的磷酸化，另一方面却抑制了STING尾端结构对IRF3募集，进而阻遏TBK1对IRF3磷酸化和I型IFN的合成。本项目应用现代分子生物学技术，通过体外和体内实验探讨胞浆APE1对I型IFN的抑制作用，以及APE1对STING/TBK1/IRF3通路磷酸化的调控机制，为揭示肺癌免疫抑制微环境的机理，提高免疫治疗疗效和个体化提供实验基础。

Cytoplasmic dsDNA-activated cGAS/STING/IRF3 pathway plays an important role in lung cancer immunity. APE1 has unique dual functions of DNA damage repair and redox. In theory, APE1 can inhibit the cGAS/STING/IRF3 pathway by reducing dsDNA. In the preliminary experiment, we did find that inhibiting APE1 can promote IRF3 phosphorylation and type I IFN production, but found that STING phosphorylation was significantly inhibited; at the same time, Co-IP also found that cytosolic APE1 can bind to STING. Therefore, we hypothesize that cytosolic APE1 can combine with STING to form a complex, on the one hand, it promotes the phosphorylation of STING by TBK1, on the other hand, it inhibits the recruitment of IRF3 by the tail structure of STING, and thus inhibits the phosphorylation of IRF3 and Type I IFN synthesis. This project uses modern molecular biology techniques to explore the inhibitory effect of cytoplasmic APE1 on type I IFN and the regulatory mechanism of APE1 on the phosphorylation of STING/TBK1/RF3 pathway through in vitro and in vivo experiments, in order to reveal the mechanism of lung cancer immune suppression microenvironment. To improve the efficacy of immunotherapy and provide an experimental basis for individualization.