Pseudomonas aeruginosa (P. aeruginosa) is a common opportunistic human pathogen that can lead to severe diseases in immunocompromised patients. The insulin-cleaving membrane protease (ICMP) of P. aeruginosa plays a vi...Pseudomonas aeruginosa (P. aeruginosa) is a common opportunistic human pathogen that can lead to severe diseases in immunocompromised patients. The insulin-cleaving membrane protease (ICMP) of P. aeruginosa plays a vital role in the pathogenesis of the bacterium and is therefore characterized as an important bacterial virulence factor. In addition, ICMP also serves as a founding member of the M75 peptidase family and represents a prototype of the imelysin/imelysin-like proteins. Despite of its functional importance in the pathogenesis of P. aeruginosa and of a root position as the prototypic imelysin/imelysin-like member, the structural features of the protein remain uninvestigated. Since preparation of homogeneous and crystallizable protein species is the prerequisite for structural studies by crystallography, we reported the successful expression, purification, and crystallization of P. aeruginosa ICMP in this study. The protein was over-expressed in Escherichia coli as a GST-fusion protein, cleaved to remove the fusion tag, and then purified to homogeneity. Diffractable crystals were obtained using the sitting-drop vapour-diffusion method. The crystals diffracted to 2.5 Å?resolution and belonged to space group P212121, with unit-cell parameters a = 54.47, b = 158.98, c = 162.84 Å, α = β = γ = 90°. Preliminary analysis of the diffraction data revealed high-quality crystallographic statistics with a Matthews coefficient of about 2.61 Å3.Da-1 and a solvent content of about 52.58%, indicating the presence of three ICMP molecules in the asymmetric unit. The current work therefore paved the way for future studies aiming to delineate the characteristics of ICMP at the atomic level.展开更多
The outbreak of coronavirus disease 2019(COVID-19)has posed great threats to global health and economy.Several effective vaccines are available now,but additional booster immunization is required to retain or increase...The outbreak of coronavirus disease 2019(COVID-19)has posed great threats to global health and economy.Several effective vaccines are available now,but additional booster immunization is required to retain or increase the immune responses owing to waning immunity and the emergency of new variant strains.The deficiency of intramuscularly delivered vaccines to induce mucosal immunity urged the development of mucosal vaccines.Here,we developed an adjuvanted intranasal RBD vaccine and monitored its long-term immunogenicity against both wild-type and mutant strains of severe acute respiratory syndrome coronavirus-2(SARSCoV-2),including Omicron variants,in mice.Three-dose intranasal immunization with this vaccine induced and maintained high levels of neutralizing IgG antibodies in the sera for at least 1 year.Strong mucosal immunity was also provoked,including mucosal secretory IgA and lung-resident memory T cells(TRM).We also demonstrated that the long-term persistence of lung TRM cells is a consequence of local T-cell proliferation,rather than T-cell migration from lymph nodes.Our data suggested that the adjuvanted intranasal RBD vaccine is a promising vaccine candidate to establish robust,long-lasting,and broad protective immunity against SARS-CoV-2 both systemically and locally.展开更多
Bacterial cell division is strictly regulated in the formation of equal daughter cells. This process is governed by a series of spatial and temporal regulators, and several new factors of interest to the field have re...Bacterial cell division is strictly regulated in the formation of equal daughter cells. This process is governed by a series of spatial and temporal regulators, and several new factors of interest to the field have recently been identified. Here, we report the requirement of gluconate 5-dehydrogenase （Ga5DH） in cell division of the zoonotic pathogen Strepto- coccus suis. GaSDH catalyzes the reversible reduction of 5-ketogluconate to D-gluconate and was localized to the site of cell division. The deletion of Ga5DH in S. suis resulted in a plump morphology with aberrant septa joining the progeny. A significant increase was also observed in cell length. These defects were determined to be the conse- quence of Ga5DH deprivation in S. suis causing FtsZ delo- calization. In addition, the interaction of FtsZ with Ga5DH in vitro was confirmed by protein interaction assays. These results indicate that GaSDH may function to prevent the formation of ectopic Z rings during S. suis cell division.展开更多
The emergence of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)variants has decreased the efficacy of SARs-CoV-2 vaccines in containing coronavirus disease 2019(CoVID-19)over time,and booster vaccination ...The emergence of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)variants has decreased the efficacy of SARs-CoV-2 vaccines in containing coronavirus disease 2019(CoVID-19)over time,and booster vaccination strategies are urgently necessitated to achieve sufficient protection.Intranasal immunization can improvemucosal immunity,offer-ing protection against the infection and sustaining the spread of SARS-CoV-2.In this study,an intranasal booster of the RBD-HR vaccine after two doses of the mRNA vaccine significantly increased the levels of specific binding antibodies in serum,nasal lavage fluid,and bronchoal-veolar lavage fluid compared with only two doses of mRNA vaccine.After intranasal boosting with the RBD-HR vaccine,the levels of serum neutralizing antibodies against prototype and variant strains of SARS-Cov-2 pseudoviruses weremarkedly higher than those in mice receiving mRNA vaccine alone,and intranasal boosting with the RBD-HR vaccine also inhibited the bind-ing of RBD to hACE2 receptors.Furthermore,the heterologous intranasal immunization regimen promoted extensive memory T cell responses and activated CD103+dendritic cells in the respiratory mucosa,and potently enhanced the formation of T follicular helper cells and germinal center B cells in vital immune organs,including mediastinal lymph nodes,inguinal lymph nodes,and spleen.Collectively,these data infer that heterologous intranasal boosting with the RBD-HR vaccine elicited broad protective immunity against SARS-CoV-2 both locallyandsystemically.展开更多
On September 23rd,the United Kingdom Health Protection Agency(HPA)reported the diagnostic confirmation of a human infection case by a new type of coronavirus(http://www.hpa.org.uk/NewsCentre/NationalPressReleases/2012...On September 23rd,the United Kingdom Health Protection Agency(HPA)reported the diagnostic confirmation of a human infection case by a new type of coronavirus(http://www.hpa.org.uk/NewsCentre/NationalPressReleases/2012PressReleases/120923acuterespiratoryillnessidentified/).The patient is a 49-year-old Qatari who suffered from an acute,serious respiratory illness.展开更多
Enolase is a conserved cytoplasmic metalloenzyme existing universally in both eukaryotic and prokaryotic cells.The enzyme can also locate on the cell surface and bind to plasminogen,via which contributing to the mucos...Enolase is a conserved cytoplasmic metalloenzyme existing universally in both eukaryotic and prokaryotic cells.The enzyme can also locate on the cell surface and bind to plasminogen,via which contributing to the mucosal surface localization of the bacterial pathogens and assisting the invasion into the host cells.The functions of the eukaryotic enzymes on the cell surface expression(including T cells,B cells,neutrophils,monocytoes,neuronal cells and epithelial cells)are not known.Streptococcus suis serotype 2(S.suis 2,SS2)is an important zoonotic pathogen which has recently caused two large-scale outbreaks in southern China with severe streptococcal toxic shock syndrome(STSS)never seen before in human sufferers.We recently identified the SS2 enolase as an important protective antigen which could protect mice from fatal S.suis 2 infection.In this study,a 2.4-angstrom structure of the SS2 enolase is solved,revealing an octameric arrangement in the crystal.We further demonstrated that the enzyme exists exclusively as an octamer in solution via a sedimentation assay.These results indicate that the octamer is the biological unit of SS2 enolase at least in vitro and most likely in vivo as well.This is,to our knowledge,the first comprehensive characterization of the SS2 enolase octamer both structurally and biophysically,and the second octamer enolase structure in addition to that of Streptococcus pneumoniae.We also investigated the plasminogen binding property of the SS2 enzyme.展开更多
Dear Editor,The unexpected outbreak of a novel human coronavirus infection has imposed great threat to public health.Thus far,this newly-identified virus has spread to 215 countries and territories,infected more than ...Dear Editor,The unexpected outbreak of a novel human coronavirus infection has imposed great threat to public health.Thus far,this newly-identified virus has spread to 215 countries and territories,infected more than 3.5 million people,and caused over 240,000 deaths worldwide.1 Although intensified countermeasures have been implemented globally to control the virus infection,the pandemic is still surging with a daily increase in infection case of over 65,000 ever since April 1st 2020.1 No prophylactic vaccines or clinical drugs are currently available to prevent or treat the disease,namely coronavirus disease 2019(COVID-19).展开更多
The COVID-19 response strategies in Chinese mainland were recently adjusted due to the reduced pathogenicity and enhanced infectivity of Omicron subvariants.In Chengdu,China,an infection wave was predominantly induced...The COVID-19 response strategies in Chinese mainland were recently adjusted due to the reduced pathogenicity and enhanced infectivity of Omicron subvariants.In Chengdu,China,an infection wave was predominantly induced by the BA.5 subvariant.It is crucial to determine whether the hybrid anti-SARS-CoV-2 immunity following BA.5 infection.展开更多
There are currently approximately 4000 mutations in the SARS-CoV-2 S protein gene and emerging SARS-CoV-2 variants continue to spread rapidly worldwide.Universal vaccines with high efficacy and safety urgently need to...There are currently approximately 4000 mutations in the SARS-CoV-2 S protein gene and emerging SARS-CoV-2 variants continue to spread rapidly worldwide.Universal vaccines with high efficacy and safety urgently need to be developed to prevent SARS-CoV-2 variants pandemic.Here,we described a novel self-assembling universal mRNA vaccine containing a heterologous receptorbinding domain(HRBD)-based dodecamer(HRBD^(dodecamer))against SARS-CoV-2 variants,including Alpha(B.1.1.7),Beta(B.1.351),Gamma(B.1.1.28.1),Delta(B.1.617.2)and Omicron(B.1.1.529).HRBD containing four heterologous RBD(Delta,Beta,Gamma,and Wild-type)can form a stable dodecameric conformation under T4 trimerization tag(Flodon,FD).The HRBD^(dodecamer)-encoding mRNA was then encapsulated into the newly-constructed LNPs consisting of a novel ionizable lipid(4N4T).The obtained universal mRNA vaccine(4N4T-HRBD^(dodecamer))presented higher efficiency in mRNA transfection and expression than the approved ALC-0315 LNPs,initiating potent immune protection against the immune escape of SARS-CoV-2 caused by evolutionary mutation.These findings demonstrated the first evidence that structure-based antigen design and mRNA delivery carrier optimization may facilitate the development of effective universal mRNA vaccines to tackle SARS-CoV-2 variants pandemic.展开更多
The Streptococcus suis serotype 2（S. suis 2） isolates 05ZYH33 and 98HAH33 have caused severe human infections in China. Using a strand-specific RNA-seq analysis, we compared the in vitro transcriptomes of these two ...The Streptococcus suis serotype 2（S. suis 2） isolates 05ZYH33 and 98HAH33 have caused severe human infections in China. Using a strand-specific RNA-seq analysis, we compared the in vitro transcriptomes of these two Chinese isolates with that of a reference strain（P1/7）. In the89 K genomic island that is specific to these Chinese isolates, a toxin–antitoxin system showed relatively high levels of transcription among the S. suis. The known virulence factors with high transcriptional activity in these two highly-pathogenic strains are mainly involved in adhesion, biofilm formation, hemolysis and the synthesis and transport of the outer membrane protein. Furthermore,our analysis of novel transcripts identified over 50 protein-coding genes with one of them encoding a toxin protein. We also predicted over 30 small RNAs（s RNAs） in each strain, and most of them are involved in riboswitches. We found that six s RNA candidates that are related to bacterial virulence, including csp A and rli38, are specific to Chinese isolates. These results provide insight into the factors responsible for the difference in virulence among the different S. suis 2 isolates.展开更多
Neutrophil extracellular traps(NETs)can capture and kill viruses,such as influenza viruses,human immunodeficiency virus(HIV),and respiratory syncytial virus(RSV),thus contributing to host defense.Contrary to our expec...Neutrophil extracellular traps(NETs)can capture and kill viruses,such as influenza viruses,human immunodeficiency virus(HIV),and respiratory syncytial virus(RSV),thus contributing to host defense.Contrary to our expectation,we show here that the histones released by NETosis enhance the infectivity of SARS-CoV-2,as found by using live SARS-CoV-2 and two pseudovirus systems as well as a mouse model.The histone H3 or H4 selectively binds to subunit 2 of the spike(S)protein,as shown by a biochemical binding assay,surface plasmon resonance and binding energy calculation as well as the construction of a mutant S protein by replacing four acidic amino acids.Sialic acid on the host cell surface is the key molecule to which histones bridge subunit 2 of the S protein.Moreover,histones enhance cell-cell fusion.Finally,treatment with an inhibitor of NETosis,histone H3 or H4,or sialic acid notably affected the levels of sgRNA copies and the number of apoptotic cells in a mouse model.These findings suggest that SARS-CoV-2 could hijack histones from neutrophil NETosis to promote its host cell attachment and entry process and may be important in exploring pathogenesis and possible strategies to develop new effective therapies for COVID-19.展开更多
NDM-1(New Delhi metallo-beta-lactamase)gene encodes a metallo-beta-lactamase(MBL)with high carbapenemase activity,which makes the host bacterial strain easily dispatch the last-resort antibiotics known as carbapenems ...NDM-1(New Delhi metallo-beta-lactamase)gene encodes a metallo-beta-lactamase(MBL)with high carbapenemase activity,which makes the host bacterial strain easily dispatch the last-resort antibiotics known as carbapenems and cause global concern.Here we present the bioinformatics data showing an unexpected similarity between NDM-1 and beta-lactamase II from Erythrobacter litoralis,a marine microbial isolate.We have further expressed these two mature proteins in E.coli cells,both of which present as a monomer with a molecular mass of 25 kDa.Antimicrobial susceptibility assay reveals that they share similar substrate specificities and are sensitive to aztreonam and tigecycline.The conformational change accompanied with the zinc binding visualized by nuclear magnetic resonance,Zn2+-bound NDM-1,adopts at least some stable tertiary structure in contrast to the metal-free protein.Our work implies a close evolutionary relationship between antibiotic resistance genes in environmental reservoir and in the clinic,challenging the antimicrobial resistance monitoring.展开更多
Cancers and chronic diseases have always been global health problems. The occurrence and development of such diseases are closely related to the abnormalities of proteins, nucleic acids, ions or small molecules in the...Cancers and chronic diseases have always been global health problems. The occurrence and development of such diseases are closely related to the abnormalities of proteins, nucleic acids, ions or small molecules in the body. Nowadays, nanopores/nanochannels have emerged as a powerful platform for detecting these biomolecules based on the electrical signal variation caused by biomolecules passing. However, detection relied on the electrical signal easily suffered from the clogging defects, low throughput, and strong background signals. Fortunately, the emergence of designing nanopores/nanochannels based on electrical and optical dual signal response has brought innovative impetus to biological detection, which can also identify the chemical compositions and conformations of the biomolecules. In this review, we summarize the reasonable preparation of nanopores/nanochannels with electrical and optical dual signal response and their application in biological detection. According to different biomolecules, we divide the targets into four types, including nucleic acids, small molecules, ions and proteins. In each section, the design of representative examples and the principle of dual signal generation are introduced and discussed. Finally, the prospects and challenges of nanopores/nanochannels based on electrical and optical dual signal response are also discussed.展开更多
Human NUDT16(hNUDT16)is a decapping enzyme initially identified as the human homolog to the Xenopus laevis X29.As a metalloenzyme,hNUDT16 relies on divalent cations for its cap-hydrolysis activity to remove m7 GDP and...Human NUDT16(hNUDT16)is a decapping enzyme initially identified as the human homolog to the Xenopus laevis X29.As a metalloenzyme,hNUDT16 relies on divalent cations for its cap-hydrolysis activity to remove m7 GDP and m227GDP from RNAs.Metal also determines substrate specificity of the enzyme.So far,only U8 small nucleolar RNA(snoRNA)has been identified as the substrate of hNUDT16 in the presence of Mg2+.Here we demonstrate that besides U8,hNUDT16 can also actively cleave the m7 GDP cap from mRNAs in the presence of Mg2+or Mn2+.We further show that hNUDT16 does not preferentially recognize U8 or mRNA substrates by our cross-inhibition and quantitative decapping assays.In addition,our mutagenesis analysis identifies several key residues involved in hydrolysis and confirms the key role of the REXXEE motif in catalysis.Finally an investigation into the subcellular localization of hNUDT16 revealed its abundance in both cytoplasm and nucleus.These findings extend the substrate spectrum of hNUDT16 beyond snoRNAs to also include mRNA,demonstrating the pleiotropic decapping activity of hNUDT16.展开更多
Dear Editor,The recent-emerging Omicron variant(B.1.1.529 lineage)of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)has raised serious public concern because of its rapid regional-and global-transmission.A...Dear Editor,The recent-emerging Omicron variant(B.1.1.529 lineage)of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)has raised serious public concern because of its rapid regional-and global-transmission.As of 11th January 2022,the Omicron variant has spread to 140 countries,territories or areas through infected air travelers,and the number is continuously increasing.展开更多
SARS-CoV-2 recognizes,via its spike receptor-binding domain(S-RBD),human angiotensin-converting enzyme 2(ACE2)to initiate infection.Ecto-domain protein of ACE2 can therefore function as a decoy.Here we show that mutat...SARS-CoV-2 recognizes,via its spike receptor-binding domain(S-RBD),human angiotensin-converting enzyme 2(ACE2)to initiate infection.Ecto-domain protein of ACE2 can therefore function as a decoy.Here we show that mutations of S19W,T27W,and N330Y in ACE2 could individually enhance SARS-CoV-2 S-RBD binding.Y330 could be synergistically combined with either W19 or W27,whereas W19 and W27 are mutually unbeneficial.The structures of SARS-CoV-2S-RBD bound to the ACE2 mutants reveal that the enhan ced binding is mainly con tributed by the van der Waals interactio ns mediated by the aromatic side-chai ns from W19,W27,and Y330.While Y330 and W19/W27 are distantly located and devoid of any steric interference,W19 and W27 are shown to orient their side-chains toward each other and to cause steric conflicts,explai ning their in compatibility.Finally,using pseudotyped SARS-CoV-2 viruses,we dem on strate that these residue substitutions are associated with dramatically improved entry-inhibition efficacy toward both wild-type and antibody-resistant viruses.Taken together,our biochemical and structural data have delineated the basis for the elevated S-RBD binding associated with S19W,T27W,and N330Y mutations in ACE2,paving the way for potential application of these mutants in dinical treatment of COVID-19.展开更多
Dear Editor,The worldwide outbreak of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection has urged the investigation of preventive vaccines.Recently,our team has developed a recombinant protein vacci...Dear Editor,The worldwide outbreak of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection has urged the investigation of preventive vaccines.Recently,our team has developed a recombinant protein vaccine,targeting receptor binding domain(RBD)of the spike protein(S-RBD)of SARS-CoV-2,which could induce a potent antibody response and protect non-human primates from SARS-CoV-2 challenge.1 The recombinant RBD protein is proved as a potent antigen and a novel adjuvant is in demand for the effective stimulation of adaptive immunity.Therefore,to improve the efficacy of the vaccine and seek a novel adjuvant that can stimulate both humoral and cellular immunity,we investigated the potential of series of cationic nanocarriers as adjuvants of the recombinant S-RBD vaccine for SARS-CoV-2.As the surface charge of a nanocarrier might dramatically affect the immunogenicity of a vaccine and enhance and/or shape antigen-specific immune responses,we also used anionic nanocarriers and neutral nanocarriers as controls(Supplementary Table S1).S-RBD vaccines with adjuvant candidates were administered intranasally or intramuscularly in the present study.展开更多
The ongoing global pandemic of coronavirus disease 2019(COVID-19),caused by severe acute respiratory syndrome coronavirus 2(SARS‐CoV‐2),has caused devastating impacts on the public health and the global economy.Rapi...The ongoing global pandemic of coronavirus disease 2019(COVID-19),caused by severe acute respiratory syndrome coronavirus 2(SARS‐CoV‐2),has caused devastating impacts on the public health and the global economy.Rapid viral antigenic evolution has led to the continual generation of new variants.Of special note is the recently expanding Omicron subvariants that are capable of immune evasion from most of the existing neutralizing antibodies(nAbs).This has posed new challenges for the prevention and treatment of COVID-19.Therefore,exploring broad-spectrum antiviral agents to combat the emerging variants is imperative.In sharp contrast to the massive accumulation of mutations within the SARS-CoV-2 receptor-binding domain(RBD),the S2 fusion subunit has remained highly conserved among variants.Hence,S2-based therapeutics may provide effective cross-protection against new SARS-CoV-2 variants.Here,we summarize the most recently developed broad-spectrum fusion inhibitors(e.g.,nAbs,peptides,proteins,and small-molecule compounds)and candidate vaccines targeting the conserved elements in SARS-CoV-2 S2 subunit.The main focus includes all the targetable S2 elements,namely,the fusion peptide,stem helix,and heptad repeats 1 and 2(HR1-HR2)bundle.Moreover,we provide a detailed summary of the characteristics and action-mechanisms for each class of cross-reactive fusion inhibitors,which should guide and promote future design of S2-based inhibitors and vaccines against new coronaviruses.展开更多
Dear Editor,The severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)variant Omicron(B.1.1.529)has attracted great concerns since its identification in South Africa.Omicron is the fifth variant of concern(VOC)af...Dear Editor,The severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)variant Omicron(B.1.1.529)has attracted great concerns since its identification in South Africa.Omicron is the fifth variant of concern(VOC)after Alpha(B.1.1.7),Beta(B.1.351),Gamma(P.1)and Delta(B.1.617.2),and set a record with the shortest duration from variants of interest(VOI)to VOC so far.Within 2 months after its first report,over 80%of global sequenced samples are verified as Omicron according to GISAID(https://cov-spectrum.org/explore/World/AllSamples/from=2021-12-15&to=2022-01-15/variants?pangoLineage=B.1.1.529*).展开更多
Dear Editor,The worldwide outbreak of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection has urged the investigation of preventive vaccines.Recently,our team has developed a recombinant protein vacci...Dear Editor,The worldwide outbreak of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection has urged the investigation of preventive vaccines.Recently,our team has developed a recombinant protein vaccine,targeting receptor binding domain(RBD)of the spike protein(S-RBD)of SARS-CoV-2,which could induce a potent antibody response and protect non-human primates from SARS-CoV-2 challenge.1 The recombinant RBD protein is proved as a potent antigen and a novel adjuvant is in demand for the effective stimulation of adaptive immunity.展开更多
文摘Pseudomonas aeruginosa (P. aeruginosa) is a common opportunistic human pathogen that can lead to severe diseases in immunocompromised patients. The insulin-cleaving membrane protease (ICMP) of P. aeruginosa plays a vital role in the pathogenesis of the bacterium and is therefore characterized as an important bacterial virulence factor. In addition, ICMP also serves as a founding member of the M75 peptidase family and represents a prototype of the imelysin/imelysin-like proteins. Despite of its functional importance in the pathogenesis of P. aeruginosa and of a root position as the prototypic imelysin/imelysin-like member, the structural features of the protein remain uninvestigated. Since preparation of homogeneous and crystallizable protein species is the prerequisite for structural studies by crystallography, we reported the successful expression, purification, and crystallization of P. aeruginosa ICMP in this study. The protein was over-expressed in Escherichia coli as a GST-fusion protein, cleaved to remove the fusion tag, and then purified to homogeneity. Diffractable crystals were obtained using the sitting-drop vapour-diffusion method. The crystals diffracted to 2.5 Å?resolution and belonged to space group P212121, with unit-cell parameters a = 54.47, b = 158.98, c = 162.84 Å, α = β = γ = 90°. Preliminary analysis of the diffraction data revealed high-quality crystallographic statistics with a Matthews coefficient of about 2.61 Å3.Da-1 and a solvent content of about 52.58%, indicating the presence of three ICMP molecules in the asymmetric unit. The current work therefore paved the way for future studies aiming to delineate the characteristics of ICMP at the atomic level.
基金supported by the National Natural Science Foundation Regional Innovation and Development(No.U19A2003)the National Science Fund for Excellent Young Scholars National Science Fund for Excellent Young Scholars(No.32122052).
文摘The outbreak of coronavirus disease 2019(COVID-19)has posed great threats to global health and economy.Several effective vaccines are available now,but additional booster immunization is required to retain or increase the immune responses owing to waning immunity and the emergency of new variant strains.The deficiency of intramuscularly delivered vaccines to induce mucosal immunity urged the development of mucosal vaccines.Here,we developed an adjuvanted intranasal RBD vaccine and monitored its long-term immunogenicity against both wild-type and mutant strains of severe acute respiratory syndrome coronavirus-2(SARSCoV-2),including Omicron variants,in mice.Three-dose intranasal immunization with this vaccine induced and maintained high levels of neutralizing IgG antibodies in the sera for at least 1 year.Strong mucosal immunity was also provoked,including mucosal secretory IgA and lung-resident memory T cells(TRM).We also demonstrated that the long-term persistence of lung TRM cells is a consequence of local T-cell proliferation,rather than T-cell migration from lymph nodes.Our data suggested that the adjuvanted intranasal RBD vaccine is a promising vaccine candidate to establish robust,long-lasting,and broad protective immunity against SARS-CoV-2 both systemically and locally.
文摘Bacterial cell division is strictly regulated in the formation of equal daughter cells. This process is governed by a series of spatial and temporal regulators, and several new factors of interest to the field have recently been identified. Here, we report the requirement of gluconate 5-dehydrogenase （Ga5DH） in cell division of the zoonotic pathogen Strepto- coccus suis. GaSDH catalyzes the reversible reduction of 5-ketogluconate to D-gluconate and was localized to the site of cell division. The deletion of Ga5DH in S. suis resulted in a plump morphology with aberrant septa joining the progeny. A significant increase was also observed in cell length. These defects were determined to be the conse- quence of Ga5DH deprivation in S. suis causing FtsZ delo- calization. In addition, the interaction of FtsZ with Ga5DH in vitro was confirmed by protein interaction assays. These results indicate that GaSDH may function to prevent the formation of ectopic Z rings during S. suis cell division.
基金funded by the National Science Foundation for Excellent Young Scholars of China(No.32122052)the National Natural Science Foundation Regional Innovation and Development of China(No.U19A2003).
文摘The emergence of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)variants has decreased the efficacy of SARs-CoV-2 vaccines in containing coronavirus disease 2019(CoVID-19)over time,and booster vaccination strategies are urgently necessitated to achieve sufficient protection.Intranasal immunization can improvemucosal immunity,offer-ing protection against the infection and sustaining the spread of SARS-CoV-2.In this study,an intranasal booster of the RBD-HR vaccine after two doses of the mRNA vaccine significantly increased the levels of specific binding antibodies in serum,nasal lavage fluid,and bronchoal-veolar lavage fluid compared with only two doses of mRNA vaccine.After intranasal boosting with the RBD-HR vaccine,the levels of serum neutralizing antibodies against prototype and variant strains of SARS-Cov-2 pseudoviruses weremarkedly higher than those in mice receiving mRNA vaccine alone,and intranasal boosting with the RBD-HR vaccine also inhibited the bind-ing of RBD to hACE2 receptors.Furthermore,the heterologous intranasal immunization regimen promoted extensive memory T cell responses and activated CD103+dendritic cells in the respiratory mucosa,and potently enhanced the formation of T follicular helper cells and germinal center B cells in vital immune organs,including mediastinal lymph nodes,inguinal lymph nodes,and spleen.Collectively,these data infer that heterologous intranasal boosting with the RBD-HR vaccine elicited broad protective immunity against SARS-CoV-2 both locallyandsystemically.
文摘On September 23rd,the United Kingdom Health Protection Agency(HPA)reported the diagnostic confirmation of a human infection case by a new type of coronavirus(http://www.hpa.org.uk/NewsCentre/NationalPressReleases/2012PressReleases/120923acuterespiratoryillnessidentified/).The patient is a 49-year-old Qatari who suffered from an acute,serious respiratory illness.
基金supported by National Natural Science Foundation of China(NSFC)a leading principal investigator of the NSFC Innovative Research Group(Grant No.81021003).
文摘Enolase is a conserved cytoplasmic metalloenzyme existing universally in both eukaryotic and prokaryotic cells.The enzyme can also locate on the cell surface and bind to plasminogen,via which contributing to the mucosal surface localization of the bacterial pathogens and assisting the invasion into the host cells.The functions of the eukaryotic enzymes on the cell surface expression(including T cells,B cells,neutrophils,monocytoes,neuronal cells and epithelial cells)are not known.Streptococcus suis serotype 2(S.suis 2,SS2)is an important zoonotic pathogen which has recently caused two large-scale outbreaks in southern China with severe streptococcal toxic shock syndrome(STSS)never seen before in human sufferers.We recently identified the SS2 enolase as an important protective antigen which could protect mice from fatal S.suis 2 infection.In this study,a 2.4-angstrom structure of the SS2 enolase is solved,revealing an octameric arrangement in the crystal.We further demonstrated that the enzyme exists exclusively as an octamer in solution via a sedimentation assay.These results indicate that the octamer is the biological unit of SS2 enolase at least in vitro and most likely in vivo as well.This is,to our knowledge,the first comprehensive characterization of the SS2 enolase octamer both structurally and biophysically,and the second octamer enolase structure in addition to that of Streptococcus pneumoniae.We also investigated the plasminogen binding property of the SS2 enzyme.
基金supported by the special research fund on COVID-19 of Sichuan Province(grant No.2020YFS0010)the special research fund on COVID-19 of West China Hospital Sichuan University(grant No.HX-2019-nCoV-004).
文摘Dear Editor,The unexpected outbreak of a novel human coronavirus infection has imposed great threat to public health.Thus far,this newly-identified virus has spread to 215 countries and territories,infected more than 3.5 million people,and caused over 240,000 deaths worldwide.1 Although intensified countermeasures have been implemented globally to control the virus infection,the pandemic is still surging with a daily increase in infection case of over 65,000 ever since April 1st 2020.1 No prophylactic vaccines or clinical drugs are currently available to prevent or treat the disease,namely coronavirus disease 2019(COVID-19).
基金This work was supported by the National Science Foundation for Excellent Young Scholars(32122052)National Natural Science Foundation Regional Innovation and Development(No.U19A2003)National Natural Science Foundation of China(82200018).Figure 1a was created by BioRender.
文摘The COVID-19 response strategies in Chinese mainland were recently adjusted due to the reduced pathogenicity and enhanced infectivity of Omicron subvariants.In Chengdu,China,an infection wave was predominantly induced by the BA.5 subvariant.It is crucial to determine whether the hybrid anti-SARS-CoV-2 immunity following BA.5 infection.
基金financially supported by the Postdoctoral Research Foundation of China(2022TQ0225)Sichuan Province Science and Technology Support Program(2021YFH0003,2021YFSY008,2020YFH0065,2020YJ0238,China)the Chengdu Key S&T Innovation Projects(2019-YF08-00139-GX,China)。
文摘There are currently approximately 4000 mutations in the SARS-CoV-2 S protein gene and emerging SARS-CoV-2 variants continue to spread rapidly worldwide.Universal vaccines with high efficacy and safety urgently need to be developed to prevent SARS-CoV-2 variants pandemic.Here,we described a novel self-assembling universal mRNA vaccine containing a heterologous receptorbinding domain(HRBD)-based dodecamer(HRBD^(dodecamer))against SARS-CoV-2 variants,including Alpha(B.1.1.7),Beta(B.1.351),Gamma(B.1.1.28.1),Delta(B.1.617.2)and Omicron(B.1.1.529).HRBD containing four heterologous RBD(Delta,Beta,Gamma,and Wild-type)can form a stable dodecameric conformation under T4 trimerization tag(Flodon,FD).The HRBD^(dodecamer)-encoding mRNA was then encapsulated into the newly-constructed LNPs consisting of a novel ionizable lipid(4N4T).The obtained universal mRNA vaccine(4N4T-HRBD^(dodecamer))presented higher efficiency in mRNA transfection and expression than the approved ALC-0315 LNPs,initiating potent immune protection against the immune escape of SARS-CoV-2 caused by evolutionary mutation.These findings demonstrated the first evidence that structure-based antigen design and mRNA delivery carrier optimization may facilitate the development of effective universal mRNA vaccines to tackle SARS-CoV-2 variants pandemic.
基金supported by the CAS Key Laboratory of Pathogenic Microbiology and Immunology of China (Grant No. 2009CASPMI-007) to DZthe National Natural Science Foundation of China (Grant No. 81201700) to DZ
文摘The Streptococcus suis serotype 2（S. suis 2） isolates 05ZYH33 and 98HAH33 have caused severe human infections in China. Using a strand-specific RNA-seq analysis, we compared the in vitro transcriptomes of these two Chinese isolates with that of a reference strain（P1/7）. In the89 K genomic island that is specific to these Chinese isolates, a toxin–antitoxin system showed relatively high levels of transcription among the S. suis. The known virulence factors with high transcriptional activity in these two highly-pathogenic strains are mainly involved in adhesion, biofilm formation, hemolysis and the synthesis and transport of the outer membrane protein. Furthermore,our analysis of novel transcripts identified over 50 protein-coding genes with one of them encoding a toxin protein. We also predicted over 30 small RNAs（s RNAs） in each strain, and most of them are involved in riboswitches. We found that six s RNA candidates that are related to bacterial virulence, including csp A and rli38, are specific to Chinese isolates. These results provide insight into the factors responsible for the difference in virulence among the different S. suis 2 isolates.
基金supported by the National Science Foundation for Excellent Young Scholars (32122052)National Natural Science Foundation Regional Innovation and Development (No.U19A2003).
文摘Neutrophil extracellular traps(NETs)can capture and kill viruses,such as influenza viruses,human immunodeficiency virus(HIV),and respiratory syncytial virus(RSV),thus contributing to host defense.Contrary to our expectation,we show here that the histones released by NETosis enhance the infectivity of SARS-CoV-2,as found by using live SARS-CoV-2 and two pseudovirus systems as well as a mouse model.The histone H3 or H4 selectively binds to subunit 2 of the spike(S)protein,as shown by a biochemical binding assay,surface plasmon resonance and binding energy calculation as well as the construction of a mutant S protein by replacing four acidic amino acids.Sialic acid on the host cell surface is the key molecule to which histones bridge subunit 2 of the S protein.Moreover,histones enhance cell-cell fusion.Finally,treatment with an inhibitor of NETosis,histone H3 or H4,or sialic acid notably affected the levels of sgRNA copies and the number of apoptotic cells in a mouse model.These findings suggest that SARS-CoV-2 could hijack histones from neutrophil NETosis to promote its host cell attachment and entry process and may be important in exploring pathogenesis and possible strategies to develop new effective therapies for COVID-19.
基金the Innovative Research Group of the National Natural Science Foundation of China(Grant No.81021003)Work in GFG's laboratory is supported,in part,by the National Basic Research Program(973 Project)from China Ministry of Science and Technology(Grant No.2011CB504703)。
文摘NDM-1(New Delhi metallo-beta-lactamase)gene encodes a metallo-beta-lactamase(MBL)with high carbapenemase activity,which makes the host bacterial strain easily dispatch the last-resort antibiotics known as carbapenems and cause global concern.Here we present the bioinformatics data showing an unexpected similarity between NDM-1 and beta-lactamase II from Erythrobacter litoralis,a marine microbial isolate.We have further expressed these two mature proteins in E.coli cells,both of which present as a monomer with a molecular mass of 25 kDa.Antimicrobial susceptibility assay reveals that they share similar substrate specificities and are sensitive to aztreonam and tigecycline.The conformational change accompanied with the zinc binding visualized by nuclear magnetic resonance,Zn2+-bound NDM-1,adopts at least some stable tertiary structure in contrast to the metal-free protein.Our work implies a close evolutionary relationship between antibiotic resistance genes in environmental reservoir and in the clinic,challenging the antimicrobial resistance monitoring.
基金financial support by the National Key R&D Program of China(2021YFA1200403,2020YFA0211200)the National Natural Science Foundation of China(22090050,21974128,21874121,52003257,22104040)+2 种基金the Joint NSFC-ISF Research Grant Program(Grant No:22161142020)the Hubei Provincial Natural Science Foundation of China(2020CFA037)the Zhejiang Provincial Natural Science Foundation of China under Grant No.LD21B050001.
文摘Cancers and chronic diseases have always been global health problems. The occurrence and development of such diseases are closely related to the abnormalities of proteins, nucleic acids, ions or small molecules in the body. Nowadays, nanopores/nanochannels have emerged as a powerful platform for detecting these biomolecules based on the electrical signal variation caused by biomolecules passing. However, detection relied on the electrical signal easily suffered from the clogging defects, low throughput, and strong background signals. Fortunately, the emergence of designing nanopores/nanochannels based on electrical and optical dual signal response has brought innovative impetus to biological detection, which can also identify the chemical compositions and conformations of the biomolecules. In this review, we summarize the reasonable preparation of nanopores/nanochannels with electrical and optical dual signal response and their application in biological detection. According to different biomolecules, we divide the targets into four types, including nucleic acids, small molecules, ions and proteins. In each section, the design of representative examples and the principle of dual signal generation are introduced and discussed. Finally, the prospects and challenges of nanopores/nanochannels based on electrical and optical dual signal response are also discussed.
基金the Natural Science Foundation of China(No.30870118)。
文摘Human NUDT16(hNUDT16)is a decapping enzyme initially identified as the human homolog to the Xenopus laevis X29.As a metalloenzyme,hNUDT16 relies on divalent cations for its cap-hydrolysis activity to remove m7 GDP and m227GDP from RNAs.Metal also determines substrate specificity of the enzyme.So far,only U8 small nucleolar RNA(snoRNA)has been identified as the substrate of hNUDT16 in the presence of Mg2+.Here we demonstrate that besides U8,hNUDT16 can also actively cleave the m7 GDP cap from mRNAs in the presence of Mg2+or Mn2+.We further show that hNUDT16 does not preferentially recognize U8 or mRNA substrates by our cross-inhibition and quantitative decapping assays.In addition,our mutagenesis analysis identifies several key residues involved in hydrolysis and confirms the key role of the REXXEE motif in catalysis.Finally an investigation into the subcellular localization of hNUDT16 revealed its abundance in both cytoplasm and nucleus.These findings extend the substrate spectrum of hNUDT16 beyond snoRNAs to also include mRNA,demonstrating the pleiotropic decapping activity of hNUDT16.
基金This work was supported by the National Key Research and Development Program of China(Grant no.2021YFC2301400)the National Natural Science Foundation of China(Grant no.82041042)+1 种基金the special research fund on COVID-19 of West China Hospital,Sichuan University(Grant no.HX-2019-nCoV-004)the 1.3.5 project for disciplines of excellence,West China Hospital,Sichuan University(Grant no.ZYYC20008).
文摘Dear Editor,The recent-emerging Omicron variant(B.1.1.529 lineage)of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)has raised serious public concern because of its rapid regional-and global-transmission.As of 11th January 2022,the Omicron variant has spread to 140 countries,territories or areas through infected air travelers,and the number is continuously increasing.
基金supported by the special research fund on COVID-19 of Sichuan Province(Grant no.2020YFS0010)the special research fund on COVID-19 of West China Hospital Sichuan University(Grant no.HX-2019-nCoV-004)the 1.3.5 project for disciplines of excellence,West China Hospital,Sichuan University(Grant no.ZYYC20008).
文摘SARS-CoV-2 recognizes,via its spike receptor-binding domain(S-RBD),human angiotensin-converting enzyme 2(ACE2)to initiate infection.Ecto-domain protein of ACE2 can therefore function as a decoy.Here we show that mutations of S19W,T27W,and N330Y in ACE2 could individually enhance SARS-CoV-2 S-RBD binding.Y330 could be synergistically combined with either W19 or W27,whereas W19 and W27 are mutually unbeneficial.The structures of SARS-CoV-2S-RBD bound to the ACE2 mutants reveal that the enhan ced binding is mainly con tributed by the van der Waals interactio ns mediated by the aromatic side-chai ns from W19,W27,and Y330.While Y330 and W19/W27 are distantly located and devoid of any steric interference,W19 and W27 are shown to orient their side-chains toward each other and to cause steric conflicts,explai ning their in compatibility.Finally,using pseudotyped SARS-CoV-2 viruses,we dem on strate that these residue substitutions are associated with dramatically improved entry-inhibition efficacy toward both wild-type and antibody-resistant viruses.Taken together,our biochemical and structural data have delineated the basis for the elevated S-RBD binding associated with S19W,T27W,and N330Y mutations in ACE2,paving the way for potential application of these mutants in dinical treatment of COVID-19.
基金supported by the National Key Research and Development Program of China(No.2016YFA0201402)National Natural Science Foundation Regional Innovation and Development(U19A2003)The National Major Scientific and Technological Special Project for“Significant New Drugs Development”(No.2018ZX09733001).
文摘Dear Editor,The worldwide outbreak of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection has urged the investigation of preventive vaccines.Recently,our team has developed a recombinant protein vaccine,targeting receptor binding domain(RBD)of the spike protein(S-RBD)of SARS-CoV-2,which could induce a potent antibody response and protect non-human primates from SARS-CoV-2 challenge.1 The recombinant RBD protein is proved as a potent antigen and a novel adjuvant is in demand for the effective stimulation of adaptive immunity.Therefore,to improve the efficacy of the vaccine and seek a novel adjuvant that can stimulate both humoral and cellular immunity,we investigated the potential of series of cationic nanocarriers as adjuvants of the recombinant S-RBD vaccine for SARS-CoV-2.As the surface charge of a nanocarrier might dramatically affect the immunogenicity of a vaccine and enhance and/or shape antigen-specific immune responses,we also used anionic nanocarriers and neutral nanocarriers as controls(Supplementary Table S1).S-RBD vaccines with adjuvant candidates were administered intranasally or intramuscularly in the present study.
基金supported by the National Key Research and Development Program of China(Grant no.2022YFC2303702)the National Natural Science Foundation of China(Grant no.81971925)the 1.3.5 project for disciplines of excellence,West China Hospital,Sichuan University(Grant no.ZYYC20008).
文摘The ongoing global pandemic of coronavirus disease 2019(COVID-19),caused by severe acute respiratory syndrome coronavirus 2(SARS‐CoV‐2),has caused devastating impacts on the public health and the global economy.Rapid viral antigenic evolution has led to the continual generation of new variants.Of special note is the recently expanding Omicron subvariants that are capable of immune evasion from most of the existing neutralizing antibodies(nAbs).This has posed new challenges for the prevention and treatment of COVID-19.Therefore,exploring broad-spectrum antiviral agents to combat the emerging variants is imperative.In sharp contrast to the massive accumulation of mutations within the SARS-CoV-2 receptor-binding domain(RBD),the S2 fusion subunit has remained highly conserved among variants.Hence,S2-based therapeutics may provide effective cross-protection against new SARS-CoV-2 variants.Here,we summarize the most recently developed broad-spectrum fusion inhibitors(e.g.,nAbs,peptides,proteins,and small-molecule compounds)and candidate vaccines targeting the conserved elements in SARS-CoV-2 S2 subunit.The main focus includes all the targetable S2 elements,namely,the fusion peptide,stem helix,and heptad repeats 1 and 2(HR1-HR2)bundle.Moreover,we provide a detailed summary of the characteristics and action-mechanisms for each class of cross-reactive fusion inhibitors,which should guide and promote future design of S2-based inhibitors and vaccines against new coronaviruses.
基金This work was supported by the National Science Foundation for Excellent Young Scholars(32122052)National Natural Science Foundation Regional Innovation and Development(No.U19A2003)+1 种基金National Natural Science Foundation of China(No.81800421)National Natural Science Foundation of China(No.82041042)。
文摘Dear Editor,The severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)variant Omicron(B.1.1.529)has attracted great concerns since its identification in South Africa.Omicron is the fifth variant of concern(VOC)after Alpha(B.1.1.7),Beta(B.1.351),Gamma(P.1)and Delta(B.1.617.2),and set a record with the shortest duration from variants of interest(VOI)to VOC so far.Within 2 months after its first report,over 80%of global sequenced samples are verified as Omicron according to GISAID(https://cov-spectrum.org/explore/World/AllSamples/from=2021-12-15&to=2022-01-15/variants?pangoLineage=B.1.1.529*).
基金This work was supported by the National Key Research and Development Program of China(No.2016YFA0201402)National Natural Science Foundation Regional Innovation and Development(U19A2003)The National Major Scientific and Technological Special Project for“Significant New Drugs Development”(No.2018ZX09733001).
文摘Dear Editor,The worldwide outbreak of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection has urged the investigation of preventive vaccines.Recently,our team has developed a recombinant protein vaccine,targeting receptor binding domain(RBD)of the spike protein(S-RBD)of SARS-CoV-2,which could induce a potent antibody response and protect non-human primates from SARS-CoV-2 challenge.1 The recombinant RBD protein is proved as a potent antigen and a novel adjuvant is in demand for the effective stimulation of adaptive immunity.
