Jiro Hirota
National Agriculture and Food Research Organization
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Publication
Featured researches published by Jiro Hirota.
The Laboratory Mouse (Second Edition) | 2012
Jiro Hirota; Shinya Shimizu
Here we describe techniques for the administration of substances to mice. A knowledge of available methods and techniques of administration as well as knowledge of the deposition and fate of the administered substance will help scientists/investigators to select the most appropriate route for their purposes. The administration of test substances, such as chemical elements, compounds, drugs, antibodies, cells, or other agents to mice is one of the major methods for evaluating their biological activity. The route of administration is important and largely dependent on the property of the test substance and the objective of the experiment. All routes have both advantages and disadvantages, such as the absorption, bioavailability and metabolism of the substance. Consideration should be given to the pH, viscosity, concentration, sterility, pyrogenicity, irritancy and toxicity, as well as the existence of hazardous substances.
Clinical and Vaccine Immunology | 2012
Jiro Hirota; Yoshihiro Shimoji; Shinya Shimizu
ABSTRACT An anti-West Nile virus (anti-WNV) monoclonal antibody, SHW-7A11, was developed for competitive enzyme-linked immunosorbent assays (c-ELISAs). SHW-7A11 reacted with nonstructural protein 1 in Western blot analysis. SHW-7A11 was relatively specific for the WNV strain NY99 and recognized Kunjin and Eg101 strains in indirect ELISAs. Two c-ELISAs were developed for sera diluted 10 and 100 times and named c-ELISA10 and c-ELISA100, respectively. Both c-ELISAs detected antibodies against WNV NY99 and Kunjin strains. Little cross-reactivity was observed for antibodies against Japanese encephalitis virus and St. Louis encephalitis virus in these assays. Using the cutoff point for the St. Louis encephalitis virus, all WNV-infected chickens were found to be positive on day 21 after infection in both c-ELISAs. On the other hand, all infected chickens were found to be positive on day 35 after infection in a virus neutralization test. Our newly developed SHW-7A11-based c-ELISA can detect WNV infection with sera diluted 10 to 100 times. Therefore, this c-ELISA can be used for WNV serosurveillance of chickens and wild birds.
Infection and Immunity | 2013
Fang Shi; Yohsuke Ogawa; Akiyuki Sano; Tomoyuki Harada; Jiro Hirota; Masahiro Eguchi; Eiji Oishi; Yoshihiro Shimoji
ABSTRACT Erysipelothrix rhusiopathiae, the causative agent of swine erysipelas, is a facultative intracellular Gram-positive bacterium. It has been shown that animals immunized with a filtrate from E. rhusiopathiae cultures are protected against lethal challenge. In this study, we identified and characterized the extracellular proteins of E. rhusiopathiae to search for novel vaccine antigens. A concentrated culture supernatant from the E. rhusiopathiae Fujisawa strain, which has been found to induce protection in mice, was analyzed using two-dimensional electrophoresis. From more than 40 confirmed protein spots, 16 major protein spots were selected and subjected to N-terminal amino acid sequence determination, and 14 protein spots were successfully identified. The identified proteins included housekeeping proteins and other metabolic enzymes. We searched for surface-localized proteins by analyzing the genomes of two E. rhusiopathiae strains: Fujisawa and ATCC 19414. Genome analysis revealed that the ATCC 19414 strain has three putative surface-exposed choline-binding proteins (CBPs): CbpA, CbpB, and CbpC. Each CBP contains a putative choline-binding domain. The CbpC gene is mutated in Fujisawa, becoming a nonfunctional pseudogene. Immunogold electron microscopy confirmed that CbpA and CbpB, as well as the majority of the metabolic enzymes examined, are associated with the cell surface of E. rhusiopathiae Fujisawa. Immunization with recombinant CbpB, but not with other recombinant CBPs or metabolic enzymes, protected mice against lethal challenge. A phagocytosis assay revealed that antiserum against CbpB promoted opsonin-mediated phagocytosis by murine macrophages in vitro. The protective capabilities of CbpB were confirmed in pigs, suggesting that CbpB could be used as a vaccine antigen.
Journal of Microbiological Methods | 2015
Swarmistha Devi Aribam; Yohsuke Ogawa; Hidenori Matsui; Jiro Hirota; Masashi Okamura; Masato Akiba; Yoshihiro Shimoji; Masahiro Eguchi
Serotyping is an important element for surveillance of Salmonella. In this study, an anti-O:4 Salmonella monoclonal antibody-based competitive enzyme-linked immunosorbent assay that could identify Salmonella infection in cow, pig, horse, and chicken was developed. This detection system can therefore be useful for a wide range of animals and for humans.
Journal of Virological Methods | 2013
Jiro Hirota; Shinya Shimizu
Precursor membrane protein (prM) is found in the envelope of immature West Nile virus (WNV) particles. Anti-prM antibodies are found in flavivirus-infected animal sera, and they are known as relatively virus species specific antibodies. However, there are no known reports of WNV-specific epitope blocking or competitive enzyme-linked immunosorbent assay (c-ELISA) that detect anti-prM antibodies. Two anti-WNV-prM monoclonal antibodies (SHW-29C2 and SHW-31B2) were generated, and c-ELISAs were developed using these monoclonal antibodies. The c-ELISAs were evaluated using WNV-infected chicken sera. Both c-ELISAs detected anti-prM antibodies in WNV-infected chicken sera and showed little cross-reactivity to antisera against Japanese encephalitis virus, St. Louis encephalitis virus, and Murray valley encephalitis virus. The average inhibition of chicken sera at 3 weeks post WNV infection was 61.6% in SHW-29C2-based c-ELISA and 71.8% in SHW-31B2-based c-ELISA. High correlation was seen between percent inhibition in the c-ELISAs and optical density values of an IgG indirect ELISA. Additionally, SHW-31B2-based c-ELISA detected antibodies against a wide variety of WNV strains. Detecting anti-PrM antibodies using c-ELISA could be useful for WNV serodiagnosis.
Veterinary Medicine International | 2012
Atsushi Watanabe; Jiro Hirota; Shinya Shimizu; Shigeki Inumaru; Kazuhiro Kimura
A single intramammary infusion of recombinant bovine interleukin-8 (IL-8) at 50 μg/quarter/head, but not 10 μg/quarter/head, induced clinical mastitis in three of four cows during the dry-off period, resulting in an elevated rectal temperature, redness and swelling of the mammary gland, extensive polymorphonuclear leukocyte (PMNL) infiltration, and milk clot formation from 1 to 28 days post infusion (PI). In the mammary secretions of the mastitic glands, high levels of IL-8 were sustained from 8 hours to 28 days PI, peaking at 1–3 days PI. The levels of leukocyte-derived elastase and inflammatory 22 and 23 kDa lactoferrin derived peptides (LDP) were also increased in the mammary secretions from the mastitic glands. In addition to the experimentally induced mastitis, the mammary secretions from the glands of cattle with spontaneous Staphylococcus aureus dry-period mastitis displayed milk clot formations and significant increases in their levels of PMNL counts, elastase, LDP, and IL-8, compared with those of the mammary secretions from the uninfected glands. These results suggest that after an intramammary infusion of IL-8 has elicited inflammatory responses, it induces the prolonged secretion of elastase, inflammatory LDP, and IL-8, and that long-lasting IL-8-induced inflammatory reactions are involved in the pathogenesis of S. aureus dry-period mastitis.
Clinical and Vaccine Immunology | 2012
Jiro Hirota; Shinya Shimizu; Tomoyuki Shibahara; Takashi Isobe; Manabu Yamada; Nobuhiko Tanimura
ABSTRACT West Nile virus (WNV) is endemic throughout Africa, Eurasia, America, and Australia and has important implications for avian, horse, and human health. In these regions, dead birds are monitored for the presence of WNV through immunohistochemistry (IHC) and PCR. However, a number of the tools for IHC are inadequate owing to their cross-reactivity to other Japanese encephalitis serogroup viruses. Here we have established eight monoclonal antibodies (MAbs) to WNV. Four of them bound to the envelope protein, three of them bound to nonstructural protein 1 (NS1), and one bound to precursor membrane protein (prM), as shown by Western blot analysis. The anti-NS1 MAbs and the anti-prM MAb did not cross-react with Japanese encephalitis virus (JEV), Murray valley encephalitis virus, or St. Louis encephalitis virus in an indirect enzyme-linked immunosorbent assay. One NS1-specific MAb, SHW-32B1, and the previously reported NS1-specific MAb, SHW-7A11, were shown by IHC to specifically detect the cytoplasm of degenerated cells in the heart and brain of a WNV-infected goose. Neither of these MAbs were shown by IHC to cross-react with degenerated cells in the brain of a JEV-infected pig. These MAbs are the first reported anti-NS1 MAbs that can be used for WNV-specific IHC using formalin-fixed, paraffin-embedded sections. They may be useful for WNV research and surveillance.
Fems Microbiology Letters | 2015
Swarmistha Devi Aribam; Marta Elsheimer-Matulova; Hidenori Matsui; Jiro Hirota; Kazumasa Shiraiwa; Yohsuke Ogawa; Hirokazu Hikono; Yoshihiro Shimoji; Masahiro Eguchi
Serotyping is widely used for typing Salmonella during surveillance, and depends on determining the lipopolysaccharide (LPS) O-antigen and the flagellar protein (H-antigens) components. As the O-antigen is highly variable, and structurally unique to each serotype, we investigated the binding affinities of LPS from Salmonella serotypes of O4 serogroup with specific anti-antigen serum via immunoblot and enzyme-linked immunosorbent assays. Since the serotypes from O4 serogroup also express the O-antigen factor 12, O12 antiserum was also used for the analysis. LPS from the different serotypes showed different binding affinities with the antisera. Therefore, based on the antigen-antibody affinity, a modified agglutination assay was carried out by using O4 and O12 antisera. Although serotypes from O4 serogroup have the common O-antigen factors 4 and 12, the analysis showed that the degree of agglutination reaction is different for each of the serotypes. We suggest that Salmonella serogroup O4 serotypes exhibit different binding affinities with specific antisera despite the presence of common O-antigen factors 4 and 12.
Journal of Microbiological Methods | 2014
Swarmistha Devi Aribam; Jiro Hirota; Masahiro Kusumoto; Tomoyuki Harada; Kazumasa Shiraiwa; Yohsuke Ogawa; Yoshihiro Shimoji; Masahiro Eguchi
Enteroinvasive Escherichia coli (EIEC) comprise 21 major serotypes defined by the presence of O and H antigens, and diagnosis depends on determining its invasive potential. Using HEp-2 cells infected with an EIEC strain, we developed a simple growth-dependent assay that differentiated EIEC strain from non-invasive strains 6 h after infection.
Expert Review of Anti-infective Therapy | 2013
Jiro Hirota; Shinya Shimizu; Tomoyuki Shibahara
West Nile virus (WNV) is an enveloped RNA virus in the family Flaviviridae and belongs to Japanese encephalitis virus serocomplex group. The WNV has a wide geographic distribution that includes Africa, Europe, Asia, America and Australia. Recently, it has re-emerged as an important pathogenic organism, illustrated by the series of WNV outbreaks in North America and in Europe. Several hundred people are sacrificed by WNV infection every year. WNV can infect many mammals, birds, reptiles and amphibians. A variety of diagnoses for WNV infection have been developed, such as virus isolation, nucleotide amplification, antigen detection and serology. Flaviviruses, including WNV, share common nucleotide sequences and antigenic epitopes. Understanding these properties that can influence cross-reactivity is important for accurate diagnosis, especially because areas with multiple flaviviruses are currently expanding. Herein, the authors outline the different diagnostic methods for detecting WNV infection as well as important considerations in using these methods.