Abstract
In this study, a novel recombinant attenuated Yersinia pseudotuberculosis PB1+ strain (χ10069) engineered with ΔyopK ΔyopJ Δasd triple mutations was used to deliver a Y. pestis fusion protein, YopE amino acid 1 to 138-LcrV (YopENt138-LcrV), to Swiss Webster mice as a protective antigen against infections by yersiniae. χ10069 bacteria harboring the pYA5199 plasmid constitutively synthesized the YopENt138-LcrV fusion protein and secreted it via the type 3 secretion system (T3SS) at 37°C under calcium-deprived conditions. The attenuated strain χ10069(pYA5199) was manifested by the establishment of controlled infection in different tissues without developing conspicuous signs of disease in histopathological analysis of microtome sections. A single-dose oral immunization of χ10069(pYA5199) induced strong serum antibody titers (log10 mean value, 4.2), secretory IgA in bronchoalveolar lavage (BAL) fluid from immunized mice, and Yersinia-specific CD4+ and CD8+ T cells producing high levels of tumor necrosis factor alpha (TNF-α), gamma interferon (IFN-γ), and interleukin 2 (IL-2), as well as IL-17, in both lungs and spleens of immunized mice, conferring comprehensive Th1- and Th2-mediated immune responses and protection against bubonic and pneumonic plague challenges, with 80% and 90% survival, respectively. Mice immunized with χ10069(pYA5199) also exhibited complete protection against lethal oral infections by Yersinia enterocolitica WA and Y. pseudotuberculosis PB1+. These findings indicated that χ10069(pYA5199) as an oral vaccine induces protective immunity to prevent bubonic and pneumonic plague, as well as yersiniosis, in mice and would be a promising oral vaccine candidate for protection against plague and yersiniosis for human and veterinary applications.
Keywords:
Y. pseudotuberculosis; mucosal immunity; oral immunization; plague; systemic immunity; yersiniosis.
Copyright © 2019 American Society for Microbiology.
Publication types
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Research Support, N.I.H., Extramural
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Research Support, Non-U.S. Gov't
MeSH terms
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Administration, Oral
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Animals
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Antibodies, Bacterial / biosynthesis*
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Antigens, Bacterial / genetics
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Antigens, Bacterial / immunology
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Bacterial Outer Membrane Proteins / genetics
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Bacterial Outer Membrane Proteins / immunology
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CD4-Positive T-Lymphocytes / drug effects
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CD4-Positive T-Lymphocytes / immunology
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CD4-Positive T-Lymphocytes / microbiology
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CD8-Positive T-Lymphocytes / drug effects
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CD8-Positive T-Lymphocytes / immunology
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CD8-Positive T-Lymphocytes / microbiology
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Cross Protection
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Female
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Gene Expression
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Humans
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Immunization
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Immunoglobulin A / biosynthesis*
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Interferon-gamma / genetics
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Interferon-gamma / immunology
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Interleukin-2 / genetics
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Interleukin-2 / immunology
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Lung / drug effects
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Lung / immunology
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Lung / microbiology
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Male
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Mice
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Plague / immunology
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Plague / microbiology
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Plague / mortality
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Plague / prevention & control*
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Plague Vaccine / administration & dosage*
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Plague Vaccine / biosynthesis
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Plague Vaccine / genetics
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Plague Vaccine / immunology
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Plasmids / chemistry
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Plasmids / metabolism
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Pore Forming Cytotoxic Proteins / genetics
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Pore Forming Cytotoxic Proteins / immunology
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Recombinant Fusion Proteins / administration & dosage*
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Recombinant Fusion Proteins / genetics
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Recombinant Fusion Proteins / immunology
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Survival Analysis
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Tumor Necrosis Factor-alpha / genetics
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Tumor Necrosis Factor-alpha / immunology
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Vaccines, Synthetic
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Yersinia pestis / drug effects*
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Yersinia pestis / immunology
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Yersinia pestis / pathogenicity
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Yersinia pseudotuberculosis / drug effects*
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Yersinia pseudotuberculosis / immunology
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Yersinia pseudotuberculosis / pathogenicity
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Yersinia pseudotuberculosis Infections / immunology
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Yersinia pseudotuberculosis Infections / microbiology
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Yersinia pseudotuberculosis Infections / mortality
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Yersinia pseudotuberculosis Infections / prevention & control*
Substances
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Antibodies, Bacterial
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Antigens, Bacterial
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Bacterial Outer Membrane Proteins
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Immunoglobulin A
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Interleukin-2
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LcrV protein, Yersinia
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Plague Vaccine
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Pore Forming Cytotoxic Proteins
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Recombinant Fusion Proteins
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Tumor Necrosis Factor-alpha
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Vaccines, Synthetic
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yopE protein, Yersinia
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Interferon-gamma