Abstract
To evaluate the peptidoglycan-associated lipoprotein (PAL) antigen of Legionella pneumophila as a vaccine candidate, mice were immunized intramuscularly with pcDNA3-PAL and intraperitoneally with recombinant PAL (t-rPAL), which were compared for their ability to induce PAL-specific immune responses. The t-rPAL protein induced PAL-specific IgG antibody production significantly more than did pcDNA3-PAL. The IgG2a and IgG1 production was predominant after pcDNA3-PAL and t-rPAL administration, respectively. In particular, pcDNA3-PAL induced much higher PAL-specific cytotoxic T-lymphocyte responses than did t-rPAL. Furthermore, in vivo, CD19+ B-cell populations were dramatically increased by t-rPAL vaccination, suggesting a B-cell immunomodulatory activity of the lipoprotein. The PAL antigen was also conserved among Legionella species, as determined by PCR and immunoblot analyses. These results support a potential use of the t-rPAL protein and in particular DNA vaccines against Legionella infections.
Publication types
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Comparative Study
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Evaluation Study
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Research Support, Non-U.S. Gov't
MeSH terms
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Animals
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Antibodies, Bacterial / biosynthesis*
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Antigens, Bacterial / administration & dosage
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Antigens, Bacterial / genetics
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Antigens, Bacterial / immunology*
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Bacterial Outer Membrane Proteins*
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Bacterial Proteins / genetics
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Bacterial Proteins / immunology*
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Bacterial Vaccines / immunology*
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Cytokines / metabolism
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Escherichia coli Proteins
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Female
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Immunity, Cellular
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Immunization
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Immunization, Secondary
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Immunoglobulin G / biosynthesis
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Injections, Intramuscular
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Injections, Intraperitoneal
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Legionella / classification
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Legionella / immunology*
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Legionella pneumophila / immunology
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Lipoproteins / genetics
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Lipoproteins / immunology*
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Mice
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Mice, Inbred BALB C
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Peptidoglycan / genetics
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Peptidoglycan / immunology*
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Proteoglycans*
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Rabbits
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Serotyping
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Species Specificity
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Specific Pathogen-Free Organisms
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T-Lymphocytes, Cytotoxic / immunology*
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Th1 Cells / immunology
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Th1 Cells / metabolism
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Vaccines, DNA / immunology*
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Vaccines, Synthetic / immunology
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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Bacterial Proteins
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Bacterial Vaccines
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Cytokines
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Escherichia coli Proteins
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ExcC protein, E coli
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Immunoglobulin G
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Lipoproteins
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Peptidoglycan
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Proteoglycans
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Vaccines, DNA
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Vaccines, Synthetic
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PplA protein, Legionella pneumophila