Open AccessA 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
Author(s) -
Liu WenTssann,
Hsu HuiLing,
Liang ChungChih,
Chuang ChuanChang,
Lin HuangChi,
Liu YuTien
Publication year - 2007
Publication title -
fems immunology & medical microbiology
Language(s) - English
Resource type - Journals
eISSN - 1574-695X
pISSN - 0928-8244
DOI - 10.1111/j.1574-695x.2007.00280.x
Subject(s) - immunogenicity , yersinia pestis , plague (disease) , nasal administration , immunization , microbiology and biotechnology , biology , virology , salmonella , serotype , immunity , salmonella enterica , immunology , antigen , immune system , virulence , medicine , bacteria , pathology , biochemistry , genetics , gene
We investigated the relative immunogenicity and protective efficacy of recombinant X85MF1 and X85V strains of ΔcyaΔcrpΔasd‐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. × 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. × 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. × 3 and/or oral‐i.n. × 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.