title: Preparation and immunogenicity-evaluation of typhoid O-specific polysaccharides bio-conjugate vaccines.
abstract: Typhoid fever caused by Salmonella Typhi is still a major public health problem in developing countries. In this study, we constructed a genetically modified Salmonella Typhi strain expressing O-specific polysaccharides (OPS) antigen conjugated to a carrier, recombinant Pseudomonas aeruginosa exotoxin A(rEPA N29). The conjugates (OPS-rEPA N29) were further purified and evaluated for their immunogenicity. The results of ELISA showed that the conjugates evoked higher titers of IgG than OPS, suggesting that rEPAN29 increased immunogenicity of OPS significantly as a carrier. Moreover, three injections with 3-week interval evoked slightly higher titers of IgG than three injections with 2-week interval. However, injection of excess conjugates could not evoke higher titers of IgG against lipid polysaccharide (LPS). In summary, our study provides a new strategy for preparing polysaccharides-protein conjugate vaccines as well as similar bio-conjugate vaccines of other Gram-negative pathogens.
authors.affiliation: 1. College of Biology and Environmental Sciences, Jishou University, Jishou 416000, China; 2. State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Biotechnology, Beijing 100071, China;
authors.forename: Zhe-hui
authors.initials: ZH
authors.lastname: Peng
authors.affiliation: State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Biotechnology, Beijing 100071, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Pan
authors.affiliation: State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Biotechnology, Beijing 100071, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Sun
authors.affiliation: State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Biotechnology, Beijing 100071, China.
authors.forename: Er-ling
authors.initials: EL
authors.lastname: Feng
authors.affiliation: State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Biotechnology, Beijing 100071, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Biotechnology, Beijing 100071, China.
authors.forename: Li
authors.initials: L
authors.lastname: Zhu
authors.affiliation: College of Biology and Environmental Sciences, Jishou University, Jishou 416000, China.
authors.forename: Qing-zhong
authors.initials: QZ
authors.lastname: Peng
authors.affiliation: State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Biotechnology, Beijing 100071, China.
authors.forename: Heng-liang
authors.initials: HL
authors.lastname: Wang
mesh_terms: D036002:ADP Ribose Transferases / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology; D000818:Animals; D000907:Antibodies, Bacterial / Q000276:immunology; D001427:Bacterial Toxins / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology; D005098:Exotoxins / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology; D005260:Female; D006801:Humans; D008807:Mice, Inbred BALB C; D019081:O Antigens / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D012485:Salmonella typhi / Q000235:genetics / Q000276:immunology*; D014435:Typhoid Fever / Q000276:immunology* / Q000382:microbiology / Q000517:prevention & control; D014436:Typhoid-Paratyphoid Vaccines / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D018074:Vaccines, Conjugate / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D037521:Virulence Factors / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology; D000097668:Pseudomonas aeruginosa Exotoxin A
chemical_list: D036002:ADP Ribose Transferases; D000907:Antibodies, Bacterial; D001427:Bacterial Toxins; D005098:Exotoxins; D019081:O Antigens; D014436:Typhoid-Paratyphoid Vaccines; D018074:Vaccines, Conjugate; D037521:Virulence Factors; D000097668:Pseudomonas aeruginosa Exotoxin A