SARS-CoV-2 S protein disrupts the formation of ISGF3 complex through conserved S2 subunit to antagonize type I interferon response

作者：Zeng Cai, Wenjia Ni, Wenkang Li, Zhixuan Wu, Xiaoqian Yao, Yucheng Zheng, Yongliang Zhao, Weifeng Yuan, Simeng Liang, Qi Wang, Mingliang Tang, Yu Chen, Ke Lan, Li Zhou, Ke Xu · 发表于：Journal of Virology · 年份：2024 · DOI：10.1128/jvi.01516-24 · 被引用次数：15 · 研究领域：interferon and immune responses、SARS-CoV-2 and COVID-19 Research、Animal Virus Infections Studies

Viral immunosuppression substantially affects the host immune response of infected patients and the protective efficacy of vaccines. Here, we found that the spike (S) protein, the major vaccine antigen of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), strongly suppresses host innate immunity by inhibiting interferon-stimulated gene (ISG) expression through both S1 and S2 subunits. Mechanistically, the S protein inhibited the formation of the classic interferon-stimulated gene factor 3 (ISGF3) complex composed of STAT1, STAT2, and IRF9 by competing with STAT2 for binding to IRF9, thereby impeding the transcription of ISGs. A strong interaction between S and the STAT1/STAT2 proteins further traps the ISGF3 complex in the endoplasmic reticulum and hinders the nuclear translocation of ISGF3. Notably, the interferon-inhibitory mechanism of the S protein was universal among SARS-CoV-2 variants and other human coronaviruses, including SARS-CoV, Middle East respiratory syndrome coronavirus (MERS-CoV), human coronavirus 229E (HCoV-229E), human coronavirus NL63 (HCoV-NL63), and human coronavirus HKU1 (HCoV-HKU1), through the most evolutionarily conserved region of S2 subunit. Taken together, the findings of this study reveal a new mechanism by which the coronavirus S protein attenuates the host antiviral immune response and provides new insights into the proper design of coronavirus S-based vaccines to prevent immunosuppressive effects. IMPORTANCE: This study unveils a n...