The gut pathogen Enterocloster bolteae(E.bolteae)has been associated with autism spectrum disorder(ASD).The development of an E.bolteae vaccine to prevent gastrointestinal diseases,might be beneficial for understandin...The gut pathogen Enterocloster bolteae(E.bolteae)has been associated with autism spectrum disorder(ASD).The development of an E.bolteae vaccine to prevent gastrointestinal diseases,might be beneficial for understanding and treating ASD.Capsular polysaccharide(CPS)is a major virulence factor for E.bolteae.Based on an antigenicity evaluation of oligosaccharides associated with E.bolteae CPS and a structural revision of this carbohydrate antigen,two series of glycans including the D-Manp-D-Rhap type oligosaccharides 13-18 and the D-Ribp-D-Rhap type disaccharides 19-23 related to E.bolteae WAL-16351 CPS were prepared.The hydrogen-bond mediated glycosylation and conformational locking strategy facilitated the constructions of two 1,2-cis-β-glycosidic linkages.Glycan microarray analysis revealed that oligosaccharides 4,5,and 19 are recognized by antibodies in the anti-E.bolteae sera.The sera IgG antibodies induced by glycoconjugate 19-CRM197 recognize the CPS and bacteria specifically,whereas the IgG antibodies induced respectively by glycoconjugates 4-CRM197 and 5-CRM197 showed almost no binding to the CPS and bacteria.These results indicated that disaccharide 19 is a potential candidate for the development of E.bolteae vaccines.展开更多
[Objective] The effect of different culture conditions on type 5 capsular polysaccharide production of Staphylococcus aureus from diary cattle was studied to provide simple way for CP production and preparation and la...[Objective] The effect of different culture conditions on type 5 capsular polysaccharide production of Staphylococcus aureus from diary cattle was studied to provide simple way for CP production and preparation and laid foundation for carrying out new polysaccharide vaccine research. [Method] Staph-ylococcus aureus was isolated from milk sample of sick dairy cattle and capsular polysaccharide serotypes were identified. Type 5 capsular polysaccharide was cultured on BHI,solid columbia and mod110 culture media. Glucose and lactose were taken as carbon sources for every culture media in solid and liquid state. Therefore 9 different culture conditions were taken to study the effect of culture conditions on capsular polysaccharide production. [Result] Different culture conditions indicated that compared with columbia culture media, BHI culture media could decline capsular polysaccharide production and mod110 culture media could increase capsular polysaccharide production. While for same culture media, solid culture media was better for capsular polysaccharide production,meanwhile,taken lactose as carbon source could increase capsular polysaccharide production.展开更多
The ribose and phosphorus contents in Haemophilus influenzae type b(Hib)capsular polysaccharide(CPS)are two important chemical indexes for the development and quality control of Hib conjugate vaccine.A quantitative ^(...The ribose and phosphorus contents in Haemophilus influenzae type b(Hib)capsular polysaccharide(CPS)are two important chemical indexes for the development and quality control of Hib conjugate vaccine.A quantitative ^(1)H-and ^(31)P-NMR method using a single internal standard was developed for simultaneous determination of ribose and phosphorus contents in Hib CPS.Hexamethylphosphoramide(HMPA)was successfully utilized as an internal standard in quantitative ^(1)H-NMR method for ribose content determination.The ribose and phosphorus contents were found to be affected by the concentration of polysaccharide solution.Thus,15–20 mg·L^(−1) was the optimal concentration range of Hib CPS in D_(2)O solution for determination of ribose and phosphorus contents by this method.The ribose and phosphorus contents obtained by the quantitative NMR were consistent with those obtained by traditional chemical methods.In conclusion,this quantitative ^(1)H-and ^(31)P-NMR method using a single internal standard shows good specificity,accuracy and precision,providing a valuable approach for the quality control of Hib glycoconjugate vaccines.展开更多
Objective To determine the distribution of two important virulence factors[lipooligosaccharide(LOS)and capsular polysaccharide(CPS)]in Campylobacter jejuni(C.jejuni)isolated from different sources in China and to deve...Objective To determine the distribution of two important virulence factors[lipooligosaccharide(LOS)and capsular polysaccharide(CPS)]in Campylobacter jejuni(C.jejuni)isolated from different sources in China and to develop a rapid screening method for Guillain–Barrésyndrome(GBS)-associated strains.Methods Whole-genome sequencing was carried out for 494 C.jejuni strains.The Ortho MCL software was used to define the LOS/CPS gene clusters.CPS genotyping was performed with serotype-specific sequence alignment using the BLAST software.Real-time Polymerase chain reaction(PCR)was developed with the unique sequences of specific CPS types.Results Nine novel and 29 previously confirmed LOS classes were identified.LOS classes A,B,and C were the most common(48.2%,238/494)among the 494 strains.Twenty-six capsular types were identified in 448 strains.HS2,HS4c,HS5/31,HS19,and HS8/17 were the most frequent CPS genotypes(58.7%,263/448).Strains of 17 CPS genotypes(strain number>5)had one or two prevalent LOS classes(P<0.05).Multiplex real-time PCR for rapid identification of HS2,HS19,and HS41 was developed and validated with strains of known serotypes.Conclusion Our results describe the genetic characteristics of the important virulence factors in C.jejuni strains in China.The multiplex real-time PCR developed in this study will facilitate enhanced surveillance of GBS-associated strains in China.展开更多
The first assembly of a conjugation-ready hexasaccharide from the capsular glycan of C.jejuni.strain BH0142 has been accomplished.The synthesis features the efficient preparation of 6-deoxy-D-idoheptopyranosyl fluorid...The first assembly of a conjugation-ready hexasaccharide from the capsular glycan of C.jejuni.strain BH0142 has been accomplished.The synthesis features the efficient preparation of 6-deoxy-D-idoheptopyranosyl fluoride donors proceeding from allylα-D-C-glucopyranoside by a C1-to-C5 switch strategy with radical dehydroxymethylative fluorination as a key step,stereocontrolled construction of 1,2-trans-α-D-ido-heptopyranosidic bonds and of 1,2-cis-α-D-galactopyranosidic linkages.The obtained target oligosaccharide sets a solid foundation for making structurally-defined multivalent glycoconjugate vaccine candidates against C.jejuni.infections.展开更多
Acinetobacter baumannii infections pose a great threat to public health owing to upsurging antibiotic resistance.Capsular polysaccharides(CPS)are major virulence determinants of pathogenic bacteria and have attracted ...Acinetobacter baumannii infections pose a great threat to public health owing to upsurging antibiotic resistance.Capsular polysaccharides(CPS)are major virulence determinants of pathogenic bacteria and have attracted much attention as potential targets for vaccine development.However,the obtainability of structurally well-defined CPS-related oligosaccharides remains challenging.Herein,we report an efficient chemoenzymatic strategy for the first total synthesis of common CPS pentasaccharide repeating unit of Acinetobacter baumannii K27 and K44,containing a difficult-to-constructα-linked 5,7-di-N-acetyllegionaminic acid(Leg5,7Ac_(2))residue.The chemical synthesis of a branched tetrasaccharide precursor was accomplished by flexible orthogonal protecting-group manipulations and stereocontrolled glycosylations.Furthermore,the enzyme-catalyzed stereoselective installment of legionaminic acid residue into the tetrasaccharide,using one-pot multienzyme(OPME)synthesis system to produce sugar nucleotide CMP-Leg5,7diN_(3) and subsequentα2,6-sialyltransferase-catalyzed glycosylation,was achieved to synthesize the pentasaccharide.展开更多
The biochemical property and functional identification of three recombinant glycosyltransferases,includingβ-1,4-rhamnosyltransferase(Cps8R),β-1,4-galactosyltransferase(Cps8) and α-2,3-sialyltransferase(Cps8K)involv...The biochemical property and functional identification of three recombinant glycosyltransferases,includingβ-1,4-rhamnosyltransferase(Cps8R),β-1,4-galactosyltransferase(Cps8) and α-2,3-sialyltransferase(Cps8K)involved in the biosynthesis of the tetrasaccharide repeating unit of serotypeⅧcapsular polysaccharide(CPS)of Group B Streptococci(GBS),were systematically investigated.Subsequently,these recombinant enzymes were employed for one-pot three-enzyme efficient synthesis of the tetrasaccharide repeating unit of GBS serotypeⅧCPS using the chemically synthesized Glca-PP-(CH2)ir-OPh as the starting substrate in a satisfying yieldof 87%.展开更多
Studies have determined the immunomodulatory activities of cell-surface polysaccharides of lactic acid bacteria(LAB)and Bacteroides;however,the mechanisms,synthesis,regulation,structure,and functional links have not b...Studies have determined the immunomodulatory activities of cell-surface polysaccharides of lactic acid bacteria(LAB)and Bacteroides;however,the mechanisms,synthesis,regulation,structure,and functional links have not been systematically discussed.We first introduce the structure of the capsular poly saccharides(CPS s)of commonly studied probiotics and Bacteroides.Wzx-Wzy dependent and ATP-binding cassette(ABC)transporter-dependent pathways are the two main biosynthesis and secretion of CPS pathways.The genes known to be associated with these two pathways are mainly those associated with priming glycosyltransferase(pGT);a variable number of genes encoding for different glycosyl transferases(GTs);Wzx/Wzy-encoding enzymes related to flippases and polymerases;and ABC-transporter genes.In addition,the effects of CPSs on host immunity as well as their related underlying mechanisms are described.Surface polysaccharides on probiotics can serve as a mask to aid in their escape from attacks from the host’s immune system.In turn,they also exhibit immunomodulatory activities,such as strengthening the functions of macrophages,promoting the maturation of antigen-presenting cells,and inducing regulatory T cells.All of these effects of cell-surface polysaccharides exhibit their significant protective properties in immunocompromised diseases,such as colitis,arthritis,and dermatitis.Finally,we focused on their structure and functional links.展开更多
Nosocomial pathogen carbapenem-resistant Klebsiella pneumoniae(CRKP)poses a heightened risk to public health through carbapenem resistance and virulence convergence,particularly in China’s dominant sequence type 11(S...Nosocomial pathogen carbapenem-resistant Klebsiella pneumoniae(CRKP)poses a heightened risk to public health through carbapenem resistance and virulence convergence,particularly in China’s dominant sequence type 11(ST11)clone[1,2].Monoclonal K.pneumoniae exhibits within-host diversity during prolonged infections[3–5],with certain variants surviving through adaptation[4,6].CRKP strains from the blood of a single patient are heterogeneous in terms of antibiotic susceptibility,capsular polysaccharide production,and mucoviscosity[3].Intra-host evolution drives novel resistance via cumulative mutations(e.g.,the transcriptional regulator gene ramR mutations and the outer membrane porin gene OmpK35 loss)[4].展开更多
基金the National Natural Science Foundation of China(Nos.22325803,22277042,22177041,22207042,22107037)the Max Planck Society International Partner Group Program,the China Scholarship Council(CSC)the Fundamental Research Funds for the Central Universities for funding。
文摘The gut pathogen Enterocloster bolteae(E.bolteae)has been associated with autism spectrum disorder(ASD).The development of an E.bolteae vaccine to prevent gastrointestinal diseases,might be beneficial for understanding and treating ASD.Capsular polysaccharide(CPS)is a major virulence factor for E.bolteae.Based on an antigenicity evaluation of oligosaccharides associated with E.bolteae CPS and a structural revision of this carbohydrate antigen,two series of glycans including the D-Manp-D-Rhap type oligosaccharides 13-18 and the D-Ribp-D-Rhap type disaccharides 19-23 related to E.bolteae WAL-16351 CPS were prepared.The hydrogen-bond mediated glycosylation and conformational locking strategy facilitated the constructions of two 1,2-cis-β-glycosidic linkages.Glycan microarray analysis revealed that oligosaccharides 4,5,and 19 are recognized by antibodies in the anti-E.bolteae sera.The sera IgG antibodies induced by glycoconjugate 19-CRM197 recognize the CPS and bacteria specifically,whereas the IgG antibodies induced respectively by glycoconjugates 4-CRM197 and 5-CRM197 showed almost no binding to the CPS and bacteria.These results indicated that disaccharide 19 is a potential candidate for the development of E.bolteae vaccines.
基金Supported by the National Natural Science Foundation of China(30771596)~~
文摘[Objective] The effect of different culture conditions on type 5 capsular polysaccharide production of Staphylococcus aureus from diary cattle was studied to provide simple way for CP production and preparation and laid foundation for carrying out new polysaccharide vaccine research. [Method] Staph-ylococcus aureus was isolated from milk sample of sick dairy cattle and capsular polysaccharide serotypes were identified. Type 5 capsular polysaccharide was cultured on BHI,solid columbia and mod110 culture media. Glucose and lactose were taken as carbon sources for every culture media in solid and liquid state. Therefore 9 different culture conditions were taken to study the effect of culture conditions on capsular polysaccharide production. [Result] Different culture conditions indicated that compared with columbia culture media, BHI culture media could decline capsular polysaccharide production and mod110 culture media could increase capsular polysaccharide production. While for same culture media, solid culture media was better for capsular polysaccharide production,meanwhile,taken lactose as carbon source could increase capsular polysaccharide production.
基金supported by the National Natural Science Foundation of China(Nos.22077052,21877052,21907039 and 22107037)the China Postdoctoral Science Foundation(Nos.2020M681487 and 2021M691279)+4 种基金the National Key R&D Program of China(No.2020YFA0908304)the Natural Science Foundation of Jiangsu Province(Nos.BK20180030 and BK20190575)the National First-class Discipline Program of Light Industry Technology and Engineering(No.LITE2018-14)the 111 Project(No.111-2-06)the Open Project of Key Laboratory of Carbohydrate Chemistry and Biotechnology(Jiangnan University),Ministry of Education(No.KLCCB-KF202005)。
文摘The ribose and phosphorus contents in Haemophilus influenzae type b(Hib)capsular polysaccharide(CPS)are two important chemical indexes for the development and quality control of Hib conjugate vaccine.A quantitative ^(1)H-and ^(31)P-NMR method using a single internal standard was developed for simultaneous determination of ribose and phosphorus contents in Hib CPS.Hexamethylphosphoramide(HMPA)was successfully utilized as an internal standard in quantitative ^(1)H-NMR method for ribose content determination.The ribose and phosphorus contents were found to be affected by the concentration of polysaccharide solution.Thus,15–20 mg·L^(−1) was the optimal concentration range of Hib CPS in D_(2)O solution for determination of ribose and phosphorus contents by this method.The ribose and phosphorus contents obtained by the quantitative NMR were consistent with those obtained by traditional chemical methods.In conclusion,this quantitative ^(1)H-and ^(31)P-NMR method using a single internal standard shows good specificity,accuracy and precision,providing a valuable approach for the quality control of Hib glycoconjugate vaccines.
基金supported by the National Key Research and Development Program of China[2021YFC2301000]the Sanming Project of Medicine in Shenzhen[SZSM201803081]。
文摘Objective To determine the distribution of two important virulence factors[lipooligosaccharide(LOS)and capsular polysaccharide(CPS)]in Campylobacter jejuni(C.jejuni)isolated from different sources in China and to develop a rapid screening method for Guillain–Barrésyndrome(GBS)-associated strains.Methods Whole-genome sequencing was carried out for 494 C.jejuni strains.The Ortho MCL software was used to define the LOS/CPS gene clusters.CPS genotyping was performed with serotype-specific sequence alignment using the BLAST software.Real-time Polymerase chain reaction(PCR)was developed with the unique sequences of specific CPS types.Results Nine novel and 29 previously confirmed LOS classes were identified.LOS classes A,B,and C were the most common(48.2%,238/494)among the 494 strains.Twenty-six capsular types were identified in 448 strains.HS2,HS4c,HS5/31,HS19,and HS8/17 were the most frequent CPS genotypes(58.7%,263/448).Strains of 17 CPS genotypes(strain number>5)had one or two prevalent LOS classes(P<0.05).Multiplex real-time PCR for rapid identification of HS2,HS19,and HS41 was developed and validated with strains of known serotypes.Conclusion Our results describe the genetic characteristics of the important virulence factors in C.jejuni strains in China.The multiplex real-time PCR developed in this study will facilitate enhanced surveillance of GBS-associated strains in China.
基金financial support from the Marine S&T Fund of Shandong Province for Pilot National Laboratory for Marine Science and Technology(Qingdao)(No.2022QNLM030003-2)the National Natural Science Foundation of China(Nos.21977088 and 21672194)the National Natural Science Foundation of China-Shandong Joint Foundation(No.U1906213)。
文摘The first assembly of a conjugation-ready hexasaccharide from the capsular glycan of C.jejuni.strain BH0142 has been accomplished.The synthesis features the efficient preparation of 6-deoxy-D-idoheptopyranosyl fluoride donors proceeding from allylα-D-C-glucopyranoside by a C1-to-C5 switch strategy with radical dehydroxymethylative fluorination as a key step,stereocontrolled construction of 1,2-trans-α-D-ido-heptopyranosidic bonds and of 1,2-cis-α-D-galactopyranosidic linkages.The obtained target oligosaccharide sets a solid foundation for making structurally-defined multivalent glycoconjugate vaccine candidates against C.jejuni.infections.
基金financially supported by the National Natural Science Foundation of China(22077130 and 22377134)Shanghai Municipal Science and Technology Major Project.
文摘Acinetobacter baumannii infections pose a great threat to public health owing to upsurging antibiotic resistance.Capsular polysaccharides(CPS)are major virulence determinants of pathogenic bacteria and have attracted much attention as potential targets for vaccine development.However,the obtainability of structurally well-defined CPS-related oligosaccharides remains challenging.Herein,we report an efficient chemoenzymatic strategy for the first total synthesis of common CPS pentasaccharide repeating unit of Acinetobacter baumannii K27 and K44,containing a difficult-to-constructα-linked 5,7-di-N-acetyllegionaminic acid(Leg5,7Ac_(2))residue.The chemical synthesis of a branched tetrasaccharide precursor was accomplished by flexible orthogonal protecting-group manipulations and stereocontrolled glycosylations.Furthermore,the enzyme-catalyzed stereoselective installment of legionaminic acid residue into the tetrasaccharide,using one-pot multienzyme(OPME)synthesis system to produce sugar nucleotide CMP-Leg5,7diN_(3) and subsequentα2,6-sialyltransferase-catalyzed glycosylation,was achieved to synthesize the pentasaccharide.
基金This work was supported by grants from the National Natural Science Foundation of China(Grant numbers 21877074 and 21672129).
文摘The biochemical property and functional identification of three recombinant glycosyltransferases,includingβ-1,4-rhamnosyltransferase(Cps8R),β-1,4-galactosyltransferase(Cps8) and α-2,3-sialyltransferase(Cps8K)involved in the biosynthesis of the tetrasaccharide repeating unit of serotypeⅧcapsular polysaccharide(CPS)of Group B Streptococci(GBS),were systematically investigated.Subsequently,these recombinant enzymes were employed for one-pot three-enzyme efficient synthesis of the tetrasaccharide repeating unit of GBS serotypeⅧCPS using the chemically synthesized Glca-PP-(CH2)ir-OPh as the starting substrate in a satisfying yieldof 87%.
基金supported by the National Natural Science Foundation of China Program[31871773 and 31820103010]the Key Scientific and Technological Research Projects in the Key Areas of the Xinjiang Production and Construction Corps[2018AB010]+2 种基金National First-Class Discipline Program of Food Science and Technology[JUFSTR20180102]the BBSRC Newton Fund Joint Centre AwardCollaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province。
文摘Studies have determined the immunomodulatory activities of cell-surface polysaccharides of lactic acid bacteria(LAB)and Bacteroides;however,the mechanisms,synthesis,regulation,structure,and functional links have not been systematically discussed.We first introduce the structure of the capsular poly saccharides(CPS s)of commonly studied probiotics and Bacteroides.Wzx-Wzy dependent and ATP-binding cassette(ABC)transporter-dependent pathways are the two main biosynthesis and secretion of CPS pathways.The genes known to be associated with these two pathways are mainly those associated with priming glycosyltransferase(pGT);a variable number of genes encoding for different glycosyl transferases(GTs);Wzx/Wzy-encoding enzymes related to flippases and polymerases;and ABC-transporter genes.In addition,the effects of CPSs on host immunity as well as their related underlying mechanisms are described.Surface polysaccharides on probiotics can serve as a mask to aid in their escape from attacks from the host’s immune system.In turn,they also exhibit immunomodulatory activities,such as strengthening the functions of macrophages,promoting the maturation of antigen-presenting cells,and inducing regulatory T cells.All of these effects of cell-surface polysaccharides exhibit their significant protective properties in immunocompromised diseases,such as colitis,arthritis,and dermatitis.Finally,we focused on their structure and functional links.
基金Guangdong Basic and Applied Basic Research Foundation(grant number 2024A1515010319 to J.Q.)Science and Technology Program of Shenzhen(grant numbers KCXFZ20230731100901003 to J.Q.and L.L.,KJZD20230923115116032 to J.Q.,JCYJ20190809144005609 to J.Q.)+1 种基金Shenzhen Key Laboratory of Biochip(grant number ZDSYS201504301534057 to J.Q.)Shenzhen High-level Hospital Construction Fund(to J.Q.).
文摘Nosocomial pathogen carbapenem-resistant Klebsiella pneumoniae(CRKP)poses a heightened risk to public health through carbapenem resistance and virulence convergence,particularly in China’s dominant sequence type 11(ST11)clone[1,2].Monoclonal K.pneumoniae exhibits within-host diversity during prolonged infections[3–5],with certain variants surviving through adaptation[4,6].CRKP strains from the blood of a single patient are heterogeneous in terms of antibiotic susceptibility,capsular polysaccharide production,and mucoviscosity[3].Intra-host evolution drives novel resistance via cumulative mutations(e.g.,the transcriptional regulator gene ramR mutations and the outer membrane porin gene OmpK35 loss)[4].
