Nonstructural Protein NSs Activates Inflammasome and Pyroptosis through Interaction with NLRP3 in Human Microglial Cells Infected with Severe Fever with Thrombocytopenia Syndrome Bandavirus
Chengfeng Gao, Yufeng Yu, Chunxia Wen, Zhifeng Li, Haida Ding, Xian Qi, Carol J. Cardona, Zheng Xing
Abstract
Encephalitis or encephalopathy during severe fever with thrombocytopenia syndrome (SFTS) is considered a critical risk factor leading to high mortality, but there have been no studies to date on the pathogenesis of encephalitis or encephalopathy caused by SFTS virus. Here, we report that SFTSV infection can active the NLRP3 inflammasome and induce IL-1β secretion in the brains of infected newborn mice. In infected human HMC3 microglia, SFTSV activated the NLRP3 inflammasome via the viral nonstructural protein NSs through interaction with its N-terminal fragment. Notably, our findings suggest that the activation of the NLRP3 inflammasome may promote SFTSV replication in infected microglial cells. This study may reveal a novel mechanism by SFTSV to dysregulate host responses through its nonstructural protein, which could help us understand viral neuropathogenesis in SFTS patients.