| Project/Area Number |
15590398
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Bacteriology (including Mycology)
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| Research Institution | Kitasato University |
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Principal Investigator |
MATSUI Hidenori Kitasato University, Kitasato Institute for Life Sciences, Assistant Professor, 北里生命科学研究所, 講師 (30219373)
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| Co-Investigator(Kenkyū-buntansha) |
SEKIYA Kachiko Kitasato University, School of Pharmaceutical Sciences, Assistant Professor, 薬学部, 講師 (30050579)
EGUCHI Masahiro Kitasato University, Kitasato Institute for Life Sciences, Research Associate, 北里生命科学研究所, 助手 (00312215)
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| Project Period (FY) |
2003 – 2004
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| Project Status |
Completed (Fiscal Year 2004)
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| Budget Amount *help |
¥3,000,000 (Direct Cost: ¥3,000,000)
Fiscal Year 2004: ¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 2003: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Keywords | Salmonella / vaccine / stress response |
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| Research Abstract |
The Lon protease-deficient Salmonella enterica serovar Typhimurium (CS2022) is immunogenic when given via the oral infection route in mice. In the present study, CS2022 continuously resided in the spleen of BALB/c mice with less than 10^2 CFU for up to 6 weeks after a single oral inoculation with 10^7 CFU of salmonellae. A significant increase in the serovar Typhimurium lipopolysaccharide (LPS)-specific IgG2a was detected in the serum at weeks 4, 6, and 13 after inoculation. In contrast, the LPS-specific IgG1 was detectable at weeks 6 and 13 after inoculation. The expression of IFN-γ mRNA in the spleens of these mice was significantly increased at weeks 4 and 6 after inoculation. In contrast, the expression of IL-4 mRNA was increased at week 6 after inoculation. As a result, oral inoculation with CS2022 protected mice against subsequent subcutaneous challenge with the virulent serovar Typhimurium. In addition, the inoculation was able to reduce the colonization of Listeria monocytogenes in the livers for at least 6 weeks after inoculation when it was administered via the subcutaneous infection route. Furthermore, peritoneal macrophages isolated from immunized mice at weeks 2, 4, and 6 after inoculation led to an increase in the intracellular killing activity against L.monocytogenes as well as against serovar Typhimurium. These findings suggest that oral immunization with CS2022 promoted the protective innate immunity associated with macrophages, and this rapid protective immunity might also be sufficient to eliminate the colonization of certain intracellular pathogens other than Salmonella for at least 6 weeks after immunization of mice.
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