Live attenuated vaccines might elicit mucosal and sterilizing immunity against SARS-CoV-2 that the existing mRNA,adenoviral vector and inactivated vaccines fail to induce.Here,we describe a candidate live attenuated v...Live attenuated vaccines might elicit mucosal and sterilizing immunity against SARS-CoV-2 that the existing mRNA,adenoviral vector and inactivated vaccines fail to induce.Here,we describe a candidate live attenuated vaccine strain of SARS-CoV-2 in which the NSP16 gene,which encodes 2′-O-methyltransferase,is catalytically disrupted by a point mutation.This virus,designated d16,was severely attenuated in hamsters and transgenic mice,causing only asymptomatic and nonpathogenic infection.A single dose of d16 administered intranasally resulted in sterilizing immunity in both the upper and lower respiratory tracts of hamsters,thus preventing viral spread in a contact-based transmission model.It also robustly stimulated humoral and cell-mediated immune responses,thus conferring full protection against lethal challenge with SARS-CoV-2 in a transgenic mouse model.The neutralizing antibodies elicited by d16 effectively cross-reacted with several SARS-CoV-2 variants.Secretory immunoglobulin A was detected in the blood and nasal wash of vaccinated mice.Our work provides proof-of-principle evidence for harnessing NSP16-deficient SARS-CoV-2 for the development of live attenuated vaccines and paves the way for further preclinical studies of d16 as a prototypic vaccine strain,to which new features might be introduced to improve safety,transmissibility,immunogenicity and efficacy.展开更多
The emergence of SARS-CoV-2 variants of concern and repeated outbreaks of coronavirus epidemics in the past two decades emphasize the need for next-generation pan-coronaviral therapeutics.Drugging the multi-functional...The emergence of SARS-CoV-2 variants of concern and repeated outbreaks of coronavirus epidemics in the past two decades emphasize the need for next-generation pan-coronaviral therapeutics.Drugging the multi-functional papain-like protease(PLpro)domain of the viral nsp3 holds promise.However,none of the known coronavirus PLpro inhibitors has been shown to be in vivo active.Herein,we screened a structurally diverse library of 50,080 compounds for potential coronavirus PLpro inhibitors and identified a noncovalent lead inhibitor F0213 that has broad-spectrum anti-coronaviral activity,including against the Sarbecoviruses(SARSCoV-1 and SARS-CoV-2),Merbecovirus(MERS-CoV),as well as the Alphacoronavirus(hCoV-229E and hCoVOC43).Importantly,F0213 confers protection in both SARS-CoV-2-infected hamsters and MERS-CoV-infected human DPP4-knockin mice.F0213 possesses a dual therapeutic functionality that suppresses coronavirus replication via blocking viral polyprotein cleavage,as well as promoting antiviral immunity by antagonizing the PLpro deubiquitinase activity.Despite the significant difference of substrate recognition,mode of inhibition studies suggest that F0213 is a competitive inhibitor against SARS2-PLpro via binding with the 157K amino acid residue,whereas an allosteric inhibitor of MERSPLpro interacting with its 271E position.Our proof-ofconcept findings demonstrated that PLpro is a valid target for the development of broad-spectrum anticoronavirus agents.The orally administered F0213 may serve as a promising lead compound for combating the ongoing COVID-19 pandemic and future coronavirus outbreaks.展开更多
基金supported by the Hong Kong Health and Medical Research Fund grants COVID190121 to JF-WC and COVID190114 to D-YJthe Hong Kong Research Grants Council grants C7142-20GF and T11-709/21-N to D-YJ.
文摘Live attenuated vaccines might elicit mucosal and sterilizing immunity against SARS-CoV-2 that the existing mRNA,adenoviral vector and inactivated vaccines fail to induce.Here,we describe a candidate live attenuated vaccine strain of SARS-CoV-2 in which the NSP16 gene,which encodes 2′-O-methyltransferase,is catalytically disrupted by a point mutation.This virus,designated d16,was severely attenuated in hamsters and transgenic mice,causing only asymptomatic and nonpathogenic infection.A single dose of d16 administered intranasally resulted in sterilizing immunity in both the upper and lower respiratory tracts of hamsters,thus preventing viral spread in a contact-based transmission model.It also robustly stimulated humoral and cell-mediated immune responses,thus conferring full protection against lethal challenge with SARS-CoV-2 in a transgenic mouse model.The neutralizing antibodies elicited by d16 effectively cross-reacted with several SARS-CoV-2 variants.Secretory immunoglobulin A was detected in the blood and nasal wash of vaccinated mice.Our work provides proof-of-principle evidence for harnessing NSP16-deficient SARS-CoV-2 for the development of live attenuated vaccines and paves the way for further preclinical studies of d16 as a prototypic vaccine strain,to which new features might be introduced to improve safety,transmissibility,immunogenicity and efficacy.
基金partly supported by funding from Health@InnoHK,Innovation and Technology Commission,the Government of the Hong Kong Special Administrative RegionTheme-Based Research Scheme of the Research Grants Council(T11-709/21-N)+7 种基金the National Program on Key Research Project of China(2020YFA0707500 and 2020YFA0707504)Guangdong Natural Science Foundation(2022A1515010099)the University of Hong Kong Outstanding Young Researcher Awardthe University of Hong Kong Li Ka Shing Faculty of Medicine Research Output Prizethe High Level-Hospital Program,Health Commission of Guangdong Province,Chinathe research project of Hainan Academician Innovation Platform(YSPTZX202004)Emergency Key Program of Guangzhou Laboratory(EKPG22-01)the Swiss National Science Foundation,the National Research Programme Covid-19(No.4078P0_198290/1)。
文摘The emergence of SARS-CoV-2 variants of concern and repeated outbreaks of coronavirus epidemics in the past two decades emphasize the need for next-generation pan-coronaviral therapeutics.Drugging the multi-functional papain-like protease(PLpro)domain of the viral nsp3 holds promise.However,none of the known coronavirus PLpro inhibitors has been shown to be in vivo active.Herein,we screened a structurally diverse library of 50,080 compounds for potential coronavirus PLpro inhibitors and identified a noncovalent lead inhibitor F0213 that has broad-spectrum anti-coronaviral activity,including against the Sarbecoviruses(SARSCoV-1 and SARS-CoV-2),Merbecovirus(MERS-CoV),as well as the Alphacoronavirus(hCoV-229E and hCoVOC43).Importantly,F0213 confers protection in both SARS-CoV-2-infected hamsters and MERS-CoV-infected human DPP4-knockin mice.F0213 possesses a dual therapeutic functionality that suppresses coronavirus replication via blocking viral polyprotein cleavage,as well as promoting antiviral immunity by antagonizing the PLpro deubiquitinase activity.Despite the significant difference of substrate recognition,mode of inhibition studies suggest that F0213 is a competitive inhibitor against SARS2-PLpro via binding with the 157K amino acid residue,whereas an allosteric inhibitor of MERSPLpro interacting with its 271E position.Our proof-ofconcept findings demonstrated that PLpro is a valid target for the development of broad-spectrum anticoronavirus agents.The orally administered F0213 may serve as a promising lead compound for combating the ongoing COVID-19 pandemic and future coronavirus outbreaks.
