Abstract: The present invention relates to a recombinant fusion protein and a polysaccharide conjugate vaccine. More specifically, the present invention relates to a fusion protein including a pentamer substrate protein and a peptide sequence capable of forming a trimer, an immunogenic composition including the fusion protein, the application of the fusion protein in immunology, a polynucleotide sequence encoding the fusion protein, an expression vector containing the polynucleotide sequence, and a host cell containing the expression vector.

Abstract: The present invention discloses a Acinetobacter baumannii immunogenic protein and its composition and application. This invention provides a protein, comprising 39 amino acids of the N-terminal ?-helix part of the Ata protein transport functional domain of Acinetobacter baumannii and an adjuvant protein; amino acid sequence of said 39 amino acids of the N-terminal ?-helix part of the Ata protein transport functional domain of Acinetobacter baumannii is shown as the 127th-165th amino acid residues of SEQ ID NO:2. In present invention the 39 amino acids of the N-terminal ?-helix part of surface protein Ata (Acinetobacter trimeric autotransporter) of Acinetobacter baumannii, was took to fuse with CTB, and express in BL21. The protein was purified by a nickel column, and used to intraperitoneally immunize mouses by 2.5 ?g/mouse. Its immunogenicity and immunoprotection was verified through the animal experiments, which proves it has a good effect of anti-infection of Acinetobacter baumannii.

Abstract: The invention provided a method for preparing a bacterial polysaccharide-modified recombinant fusion protein and use of the bacterial polysaccharide-modified recombinant fusion protein. The method comprises: co-expressing a recombinant fusion protein and the Neisseria meningitidis O-oligosaccharyltransferase PglL in an O-antigen ligase gene-defective bacterium, and linking a polysaccharides endogenous or exogenous for the bacterium to the recombinant fusion protein by the O-oligosaccharyltransferase PglL, to obtain the bacterial polysaccharide-modified recombinant fusion protein. The protein can be used for preparing antibodies against bacterial polysaccharides and vaccines.

Abstract: The present invention discloses a Salmonella paratyphi A with an O-antigen having an extended carbohydrate chain and uses thereof. The method comprises the following steps: inactivating an cld gene encoding an enzyme controlling chain length of O-antigen of a Salmonella paratyphi A strain to obtain a Salmonella paratyphi A with deletion of cld gene; allowing overexpression of cldLT2 gene encoding an enzyme controlling chain length of O-antigen of Salmonella typhimurium in Salmonella paratyphi A deficient in the cld gene encoding an enzyme controlling chain length of O-antigen, so as to extend carbohydrate chain length of O-antigen. Both of the Salmonella paratyphi A O-polysaccharide-recombinant fusion protein conjugate vaccines rCTB45733-OPSSpty50973 and rEPA4573-OPSSpty50973 as prepared by using Salmonella paratyphi A with an O-antigen having an extended carbohydrate chain can induce mice to generate specific antibodies against Salmonella paratyphi A, and their antibody titers are significantly improved.

Abstract: The present invention discloses a Salmonella paratyphi A with an O-antigen having an extended carbohydrate chain and uses thereof. The method comprises the following steps: inactivating an cld gene encoding an enzyme controlling chain length of O-antigen of a Salmonella paratyphi A strain to obtain a Salmonella paratyphi A with deletion of cld gene; allowing overexpression of cldLT2 gene encoding an enzyme controlling chain length of O-antigen of Salmonella typhimurium in Salmonella paratyphi A deficient in the cld gene encoding an enzyme controlling chain length of O-antigen, so as to extend carbohydrate chain length of O-antigen. Both of the Salmonella paratyphi A O-polysaccharide-recombinant fusion protein conjugate vaccines rCTB45733-OPSSpty50973 and rEPA4573-OPSSpty50973 as prepared by using Salmonella paratyphi A with an O-antigen having an extended carbohydrate chain can induce mice to generate specific antibodies against Salmonella paratyphi A, and their antibody titers are significantly improved.

Abstract: The invention provided a method for preparing a bacterial polysaccharide-modified recombinant fusion protein and use of the bacterial polysaccharide-modified recombinant fusion protein. The method comprises: co-expressing a recombinant fusion protein and the Neisseria meningitidis O-oligosaccharyltransferase PglL in an O-antigen ligase gene-defective bacterium, and linking a polysaccharides endogenous or exogenous for the bacterium to the recombinant fusion protein by the O-oligosaccharyltransferase PglL, to obtain the bacterial polysaccharide-modified recombinant fusion protein. The protein can be used for preparing antibodies against bacterial polysaccharides and vaccines.

Abstract: The present invention discloses a Salmonella Paratyphi A with an O-antigen having an extended carbohydrate chain and uses thereof. The method comprises the following steps: inactivating an cld gene encoding an enzyme controlling chain length of O-antigen of a Salmonella paratyphi A strain to obtain a Salmonella paratyphi A with deletion of cld gene; allowing overexpression of cldLT2 gene encoding an enzyme controlling chain length of O-antigen of Salmonella typhimurium in Salmonella paratyphi A deficient in the cld gene encoding an enzyme controlling chain length of O-antigen, so as to extend carbohydrate chain length of O-antigen. Both of the Salmonella paratyphi A O-polysaccharide-recombinant fusion protein conjugate vaccines rCTB45733-OPSSpty50973 and rEPA4573-OPSSpty50973 as prepared by using Salmonella Paratyphi A with an O-antigen having an extended carbohydrate chain can induce mice to generate specific antibodies against Salmonella paratyphi A, and their antibody titers are significantly improved.