SARS-CoV-2B.1.1.7核衣壳蛋白突变与宿主天然免疫应答及C0VID-19临床状态的相关性

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中图分类号：R373.1 文献标志码：A DOI：10.11958/20251997

The correlation between SARS-CoV-2 B.1.1.7 nucleocapsid protein mutation with host innate immuneresponseandclinical manifestationof COViD-19

HE Xianzhen1，FU Ya'nan，YOU Wanling， GENG Aohua，SUN Xiaoguang³，ZENG Feng³，LIU Long1，3△

2tionofYuxi City;3DepartmentofPathogeniciologyholof Basic Medical Sciences， Hubei University of Medicine Corresponding Author E-mail： liulong2015@outlook.com

Abstract：ObjectiveTo elucidate thecorrelation between specific nucleocapsid （N） protein mutant of the SARSCoV-2B.1.1.7variantand clinical stratification inCOVID-19 patients，revealing their impactonNprotein liquid-liquid phase separation （LLPS）and host innate immune response.MethodsBased on whole-genome sequencing data of theSARS-CoV-2 B.1.1.7lineage from the GISAID database，non-synonymous mutation sites significantly asociated with mild/ severe clinical phenotypes were screened.For high-frequency N protein mutant， IFN- β promoter transcriptional activity was quantitatively measured usinga dual-luciferase reporter system.qPCR was used to detect the mRNA expresion levels of interferon （IFN）- β ，interleukin （IL）-6 and tumor necrosis factor （TNF）- α .LLPS characteristics were observed by confocal microscopy.Theubiquitination status ofhost MAVS was detectedby Western blotassy.ResultsA totalof17640 nonsynonymous mutationsites were identified，among which 65 wereasociatedwith mildcases and 2Owererelatedto severe cases，with a mutation frequency >1% .TheN protein mutation sites associated with severe cases were D3L，M234I and R203K-G204R-T205I. N protein and the mutants N M2341 ，NR203K-G204Rsinibtedtepromoterativityof IN β P<0.05 ） Compared to the wild type Nprotein，NR2o3K-G204R-T205I mutation significantly reduced the mRNA levels of IFN- β ， IL-6 and TNF- α （ P<0.05 ），and altered the phase separation state by dispersing the formation of LLPS condensates.However，N mutant did notafecttheubiquitination modificationof host MAVS.ConclusionN protein mutants of the SARS-CoV-2 B.1.1.7variantcaninfluencetheclinical prognosisofCOVID-19patients byalteringLLPSstatusandsuppessngtheinnate immune responses.Thesefinding provides atheoretical basis for the designof antiviral drugs targeting theNprotein.

KeyWords： SARS-CoV-2;coronavirus nucleocapsid proteins;interferonbeta;clinical manifestations; B.1.1.7lineage; liquid liquid phasese separation

2020年11月，新型冠状病毒（SARS-CoV-2）B.1.1.7谱系（亦称V0C-202012/01变异株）在英国东南部被首次发现，其刺突蛋白多突变特征引发全球关注[。（剩余13349字）