Remarkable progress has been made in developing intramuscular vaccines against severe acute respiratory syndrome coronavirus 2(SARS-CoV-2);however,they are limited with respect to eliciting local immunity in the respi...Remarkable progress has been made in developing intramuscular vaccines against severe acute respiratory syndrome coronavirus 2(SARS-CoV-2);however,they are limited with respect to eliciting local immunity in the respiratory tract,which is the primary infection site for SARS-CoV-2.To overcome the limitations of intramuscular vaccines,we constructed a nasal vaccine candidate based on an influenza vector by inserting a gene encoding the receptor-binding domain(RBD)of the spike protein of SARSCoV-2,named CA4-d NS1-n CoV-RBD(d NS1-RBD).A preclinical study showed that in hamsters challenged 1d after single-dose vaccination or 9 months after booster vaccination,d NS1-RBD largely mitigated lung pathology,with no loss of body weight.Moreover,such cellular immunity is relatively unimpaired for the most concerning SARS-Co V-2 variants,especially for the latest Omicron variant.In addition,this vaccine also provides cross-protection against H1N1 and H5N1 influenza viruses.The protective immune mechanism of d NS1-RBD could be attributed to the innate immune response in the nasal epithelium,local RBD-specific T cell response in the lung,and RBD-specific Ig A and Ig G response.Thus,this study demonstrates that the intranasally delivered d NS1-RBD vaccine candidate may offer an important addition to the fight against the ongoing coronavirus disease 2019 pandemic and influenza infection,compensating limitations of current intramuscular vaccines.展开更多
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
Currently,there is no effective antiviral medication for coronavirus disease 2019(COVID-19)and the knowledge on the potential therapeutic target is in great need.Guided by a time-course transmission electron microscop...Currently,there is no effective antiviral medication for coronavirus disease 2019(COVID-19)and the knowledge on the potential therapeutic target is in great need.Guided by a time-course transmission electron microscope(TEM)imaging,we analyzed early phosphorylation dynamics within the first 15 min during severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)viral entry.Based on alterations in the phosphorylation events,we found that kinase activities such as protein kinase C(PKC),interleukin-1 receptor-associated kinase 4(IRAK4),MAP/microtubule affinity-regulating kinase 3(MARK3),and TANK-binding kinase 1(TBK1)were affected within 15 min of infection.Application of the corresponding kinase inhibitors of PKC,IRAK4,and p38 showed significant inhibition of SARS-CoV-2 replication.Additionally,proinflammatory cytokine production was reduced by applying PKC and p38 inhibitors.By an acquisition of a combined image data using positiveand negative-sense RNA probes,as well as pseudovirus entry assay,we demonstrated that PKC contributed to viral entry into the host cell,and therefore,could be a potential COVID-19 therapeutic target.展开更多
SARS-CoV-2 continues to threaten human society by generating novel variants via mutation and recombination.The high number of mutations that appeared in emerging variants not only enhanced their immune-escaping abilit...SARS-CoV-2 continues to threaten human society by generating novel variants via mutation and recombination.The high number of mutations that appeared in emerging variants not only enhanced their immune-escaping ability but also made it difficult to predict the pathogenicity and virulence based on viral nucleotide sequences.Molecular markers for evaluating the pathogenicity of new variants are therefore needed.By comparing host responses to wild-type and variants with attenuated pathogenicity at proteome and metabolome levels,six key molecules on the polyamine biosynthesis pathway including putrescine,SAM,dc-SAM,ODC1,SAMS,and SAMDC were found to be differentially upregulated and associated with pathogenicity of variants.To validate our discovery,human airway organoids were subsequently used which recapitulates SARS-CoV-2 replication in the airway epithelial cells of COVID-19 patients.Using ODC1 as a proof-ofconcept,differential activation of polyamine biosynthesis was found to be modulated by the renin-angiotensin system(RAS)and positively associated with ACE2 activity.Further experiments demonstrated that ODC1 expression could be differentially activated upon a panel of SARS-CoV-2 variants of concern(VOCs)and was found to be correlated with each VOCs’pathogenic properties.Particularly,the presented study revealed the discriminative ability of key molecules on polyamine biosynthesis as a predictive marker for virulence evaluation and assessment of SARS-CoV-2 variants in cell or organoid models.Our work,therefore,presented a practical strategy that could be potentially applied as an evaluation tool for the pathogenicity of current and emerging SARS-CoV-2 variants.展开更多
基金supported by the National Program on Key Research Project of China(2020YFC0842600)the National Natural Science Foundation of China(82041038,81871651,and 81991491)+1 种基金the Major Science and Technology Program of Fujian Province(2020YZ014001)the Natural Science Foundation of Fujian Province(2021J02006)。
文摘Remarkable progress has been made in developing intramuscular vaccines against severe acute respiratory syndrome coronavirus 2(SARS-CoV-2);however,they are limited with respect to eliciting local immunity in the respiratory tract,which is the primary infection site for SARS-CoV-2.To overcome the limitations of intramuscular vaccines,we constructed a nasal vaccine candidate based on an influenza vector by inserting a gene encoding the receptor-binding domain(RBD)of the spike protein of SARSCoV-2,named CA4-d NS1-n CoV-RBD(d NS1-RBD).A preclinical study showed that in hamsters challenged 1d after single-dose vaccination or 9 months after booster vaccination,d NS1-RBD largely mitigated lung pathology,with no loss of body weight.Moreover,such cellular immunity is relatively unimpaired for the most concerning SARS-Co V-2 variants,especially for the latest Omicron variant.In addition,this vaccine also provides cross-protection against H1N1 and H5N1 influenza viruses.The protective immune mechanism of d NS1-RBD could be attributed to the innate immune response in the nasal epithelium,local RBD-specific T cell response in the lung,and RBD-specific Ig A and Ig G response.Thus,this study demonstrates that the intranasally delivered d NS1-RBD vaccine candidate may offer an important addition to the fight against the ongoing coronavirus disease 2019 pandemic and influenza infection,compensating limitations of current intramuscular vaccines.
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This research was made possible because of a generous grant from the National Key R&D Program,Ministry of Science and Technology,China(no.2017YFC1600500)the National Natural Science Foundation of China(no.21705137)+2 种基金the Theme-Based Research Scheme(no.T11/707/15)General Research Fund(no.17107019)the Research Grants Council,Hong Kong Special Administrative Region,and the Sanming-Project of Medicine in Shenzhen,China(nos.SZSM201911014 and SZSM201811070).
文摘Currently,there is no effective antiviral medication for coronavirus disease 2019(COVID-19)and the knowledge on the potential therapeutic target is in great need.Guided by a time-course transmission electron microscope(TEM)imaging,we analyzed early phosphorylation dynamics within the first 15 min during severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)viral entry.Based on alterations in the phosphorylation events,we found that kinase activities such as protein kinase C(PKC),interleukin-1 receptor-associated kinase 4(IRAK4),MAP/microtubule affinity-regulating kinase 3(MARK3),and TANK-binding kinase 1(TBK1)were affected within 15 min of infection.Application of the corresponding kinase inhibitors of PKC,IRAK4,and p38 showed significant inhibition of SARS-CoV-2 replication.Additionally,proinflammatory cytokine production was reduced by applying PKC and p38 inhibitors.By an acquisition of a combined image data using positiveand negative-sense RNA probes,as well as pseudovirus entry assay,we demonstrated that PKC contributed to viral entry into the host cell,and therefore,could be a potential COVID-19 therapeutic target.
基金This work was supported by the National Natural Science Foundation of China(21705137)the Theme-based Research Scheme(TRS,T11-709/21-N)+1 种基金the Collaborative Research Fund(CRF,C7042-21G)of the Research Grants Council of the HKSAR governmentthe Tier 1 Research Start-up Grants from Research Committee of Hong Kong Baptist University(162874).
文摘SARS-CoV-2 continues to threaten human society by generating novel variants via mutation and recombination.The high number of mutations that appeared in emerging variants not only enhanced their immune-escaping ability but also made it difficult to predict the pathogenicity and virulence based on viral nucleotide sequences.Molecular markers for evaluating the pathogenicity of new variants are therefore needed.By comparing host responses to wild-type and variants with attenuated pathogenicity at proteome and metabolome levels,six key molecules on the polyamine biosynthesis pathway including putrescine,SAM,dc-SAM,ODC1,SAMS,and SAMDC were found to be differentially upregulated and associated with pathogenicity of variants.To validate our discovery,human airway organoids were subsequently used which recapitulates SARS-CoV-2 replication in the airway epithelial cells of COVID-19 patients.Using ODC1 as a proof-ofconcept,differential activation of polyamine biosynthesis was found to be modulated by the renin-angiotensin system(RAS)and positively associated with ACE2 activity.Further experiments demonstrated that ODC1 expression could be differentially activated upon a panel of SARS-CoV-2 variants of concern(VOCs)and was found to be correlated with each VOCs’pathogenic properties.Particularly,the presented study revealed the discriminative ability of key molecules on polyamine biosynthesis as a predictive marker for virulence evaluation and assessment of SARS-CoV-2 variants in cell or organoid models.Our work,therefore,presented a practical strategy that could be potentially applied as an evaluation tool for the pathogenicity of current and emerging SARS-CoV-2 variants.
