Inhibition of cGAS-Mediated Interferon Response Facilitates Transgene Expression

Yajuan Fu; Yijun Fang; Zhang Lin; Lei Yang; Liqun Zheng; Hao Hu; Tingting Yu; Baoting Huang; Suxing Chen; Hanze Wang; Shan Xu; Wei Bao; Qi Chen; Lijun Sun

doi:10.1016/j.isci.2020.101026

Inhibition of cGAS-Mediated Interferon Response Facilitates Transgene Expression

iScience. 2020 Apr 24;23(4):101026. doi: 10.1016/j.isci.2020.101026. Epub 2020 Mar 31.

Authors

Yajuan Fu¹, Yijun Fang¹, Zhang Lin¹, Lei Yang¹, Liqun Zheng¹, Hao Hu¹, Tingting Yu¹, Baoting Huang¹, Suxing Chen¹, Hanze Wang¹, Shan Xu¹, Wei Bao², Qi Chen³, Lijun Sun⁴

Affiliations

¹ Fujian Key Laboratory of Innate Immune Biology, Biomedical Research Center of South China, College of Life Science, Fujian Normal University Qishan Campus, College Town, Fuzhou, Fujian Province 350117, China.
² Fujian Normal University Hospital, Fujian Normal University Qishan Campus, College Town, Fuzhou, Fujian Province 350117, China.
³ Fujian Key Laboratory of Innate Immune Biology, Biomedical Research Center of South China, College of Life Science, Fujian Normal University Qishan Campus, College Town, Fuzhou, Fujian Province 350117, China. Electronic address: nfsw@fjnu.edu.cn.
⁴ Fujian Key Laboratory of Innate Immune Biology, Biomedical Research Center of South China, College of Life Science, Fujian Normal University Qishan Campus, College Town, Fuzhou, Fujian Province 350117, China. Electronic address: sunlijun@fjnu.edu.cn.

Abstract

DNA transfection is often the bottleneck of research and gene therapy practices. To explore the mechanism regulating transgene expression, we investigated the role of the cGAS-STING signaling pathway, which induces type-I interferons in response to DNA. We confirmed that deletion of cGAS enhances transgene expression at the protein level by ~2- to 3-fold. This enhancement is inversely correlated with the expression of interferons and interferon stimulated genes (ISGs), which suppress expression of transfected genes at the mRNA level. Mechanistically, DNA transfection activates the cGAS-STING pathway and induces the expression of the OAS family proteins, leading to the activation of RNaseL and degradation of mRNA derived from transgenes. Administration of chemical inhibitors that block cGAS-mediated signaling cascades improves the expression of transgenes by ~1.5- to 3-fold in multiple cell lines and primary cells, including T cells. These data suggest that targeting the cGAS-STING pathway can improve transgene expression, and this strategy may be applied to gene therapy.

Keywords: Biological Sciences; Molecular Biology; Molecular Mechanism of Gene Regulation.