title: A comparison of immunogenicity and protective immunity against experimental plague by intranasal and/or combined with oral immunization of mice with attenuated Salmonella serovar Typhimurium expressing secreted Yersinia pestis F1 and V antigen.
abstract: We investigated the relative immunogenicity and protective efficacy of recombinant X85MF1 and X85V strains of DeltacyaDeltacrpDeltaasd-attenuated Salmonella Typhimurium expressing, respectively, secreted Yersinia pestis F1 and V antigens, following intranasal (i.n.) or i.n. combined with oral immunization for a mouse model. A single i.n. dose of 10(8) CFU of X85MF1 or X85V induced appreciable serum F1- or V-specific IgG titres, although oral immunization did not. Mice i.n. immunized three times (i.n. x 3) with Salmonella achieved the most substantial F1/V-specific IgG titres, as compared with corresponding titres for an oral-primed, i.n.-boosted (twice; oral-i.n. x 2) immunization regimen. The level of V-specific IgG was significantly greater than that of F1-specific IgG (P<0.001). Analysis of the IgG antibodies subclasses revealed comparable levels of V-specific Th-2-type IgG1 and Th-1-type IgG2a, and a predominance of F1-specific Th-1-type IgG2a antibodies. In mice immunized intranasally, X85V stimulated a greater IL-10-secreting-cell response in the lungs than did X85MF1, but impaired the induction of gamma-interferon-secreting cells. A program of i.n. x 3 and/or oral-i.n. x 2 immunization with X85V provided levels of protection against a subsequent lethal challenge with Y. pestis, of, respectively, 60% and 20%, whereas 80% protection was provided following the same immunization but with X85MF1.
authors.affiliation: Institute of Preventive Medicine, National Defence Medical Center, Taipei, Taiwan. jeffwtliu@yahoo.com.tw
authors.forename: Wen-Tssann
authors.initials: WT
authors.lastname: Liu
authors.forename: Hui-Ling
authors.initials: HL
authors.lastname: Hsu
authors.forename: Chung-Chih
authors.initials: CC
authors.lastname: Liang
authors.forename: Chuan-Chang
authors.initials: CC
authors.lastname: Chuang
authors.forename: Huang-Chi
authors.initials: HC
authors.lastname: Lin
authors.forename: Yu-Tien
authors.initials: YT
authors.lastname: Liu
mesh_terms: D000281:Administration, Intranasal; D000284:Administration, Oral; D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D000942:Antigens, Bacterial / Q000235:genetics / Q000276:immunology*; D001426:Bacterial Proteins / Q000235:genetics / Q000276:immunology*; D005260:Female; D007114:Immunization; D007074:Immunoglobulin G / Q000097:blood; D051379:Mice; D008807:Mice, Inbred BALB C; D010930:Plague / Q000517:prevention & control*; D010931:Plague Vaccine / Q000276:immunology*; D052899:Pore Forming Cytotoxic Proteins / Q000235:genetics / Q000276:immunology*; D011993:Recombinant Fusion Proteins / Q000276:immunology; D012486:Salmonella typhimurium / Q000235:genetics*; D014614:Vaccines, Synthetic / Q000276:immunology*; D015010:Yersinia pestis
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D007074:Immunoglobulin G; C043908:LcrV protein, Yersinia; D010931:Plague Vaccine; D052899:Pore Forming Cytotoxic Proteins; D011993:Recombinant Fusion Proteins; D014614:Vaccines, Synthetic; C086725:caf1 protein, Yersinia pestis