Keigo Kurata

The University of Tokyo, Tokyo, Tokyo-to, Japan

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Publications (26)37.62 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: To detect allergen-specific IgE in dogs with allergic diseases, we developed a recombinant canine high affinity IgE receptor α chain (FcεRIα)-based IgE detection system. Using the recombinant protein of canine FcεRIα expressed by an Escherichia coli expression system, we could detect house dust mite (Dermatophagoides farinae) allergen-specific IgE in sera from dogs naturally and experimentally sensitized to this allergen with ELISA and western blotting. The IgE binding activity of recombinant canine FcεRIα on ELISA was impaired by heat treatment of these sera. The specificity of this recombinant canine FcεRIα-based IgE detection system was confirmed by inhibition assays with canine IgE. The recombinant canine FcεRIα-based IgE detection system established in this study offers an alternative tool to measure allergen-specific IgE in dogs.
    Journal of Veterinary Medical Science 02/2012; 74(7):851-6. · 0.88 Impact Factor
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    ABSTRACT: Three cats were diagnosed as having food hypersensitivity by food elimination and oral food provocation tests. Twelve allergenic food ingredients were identified by oral food provocation test in the 3 cats. Of the 12 food ingredients, 9 offending food antigens were shown to be positive in a lymphocyte stimulation test; however, none of them were positive in antigen-specific IgE testing, and only four food antigens were positive in intradermal testing. The stimulation indices in the lymphocyte stimulation tests for the 9 food ingredients were found to be decreased after the cats were fed elimination diets. The present study demonstrates that the lymphocyte stimulation test reflects an immunologic reaction involved in food hypersensitivity and can help identify allergenic food ingredients in feline food hypersensitivity.
    Journal of Veterinary Medical Science 01/2012; 74(6):821-5. · 0.88 Impact Factor
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    ABSTRACT: We determined whether a major Japanese cedar pollen allergen (Cry j 1) conjugated with CpG oligodeoxynucleotide would enhance allergen-specific Th1 responses in mice. Cry j 1 conjugated with CpG (Cry j 1-CpG) induced IL-12 in the spleen cells of naïve mice. Cry j 1-CpG immunization of BALB/c mice suppressed anti-Cry j 1 IgE response and enhanced anti-Cry j 1 IgG(2a) to subsequent Cry j 1 and alum adjuvant injection. CD4(+)T cells isolated from the spleens in mice immunized with Cry j 1-CpG produced higher IFN-γ levels than did CD4(+)T cells obtained from mice as negative controls. Our results suggested that Cry j 1-CpG immunization can induce Cry j 1-specific Th1 immune responses, thereby inhibiting IgE response to the pollen allergen.
    Comparative immunology, microbiology and infectious diseases 03/2011; 34(2):157-61. · 2.99 Impact Factor
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    ABSTRACT: CpG oligodeoxynucleotides (CpG-ODNs) are ligands for toll-like receptor 9 (TLR9), signaling of which plays a role in innate immunity by inducing T helper 1 (TH1)-cell responses and pro-inflammatory cytokine production. The activation of TLR9 signaling is considered to be effective for the therapy of cancer, infectious diseases, and allergies and preclinical studies using CpG-ODNs have been performed in dogs and humans. In order to investigate the precise mechanisms responsible for the effect of CpG-ODNs in dogs, we examined their role in cell proliferation and cytokine gene expression in canine B cells. Canine B cells were collected by a magnetic cell isolation method using anti-CD21 antibody. Flow cytometric analysis for the intracellular CD79α revealed the purity of canine B cells to be as high as 90.2 ± 2.1%. Transcription of TLR2, TLR4, and TLR9 mRNA on canine CD21(+) cells was confirmed by reverse-transcript polymerase chain reaction (RT-PCR). CpG-ODNs induced dose-dependent proliferation of canine CD21(+) cells (P<0.05 compared with control-ODNs) detected by BrdU incorporation. Quantification of IL-6, IL-10, and IL-12p40 mRNA transcription on canine CD21(+) cells revealed that CpG-ODNs enhanced IL-6 mRNA transcription but not IL-10 and IL-12p40 mRNA transcription (P<0.05 compared with control-ODNs). These responses to CpG-ODNs in the canine B cells indicated that CpG-ODNs would be useful as an immunological adjuvant for vaccine in dogs.
    Journal of Veterinary Medical Science 09/2010; 73(2):177-84. · 0.88 Impact Factor
  • Journal of Allergy and Clinical Immunology - J ALLERG CLIN IMMUNOL. 01/2008; 121(2).
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    ABSTRACT: Aminoprotect Care (APC) is a novel diet composed of aminoacids, potato proteins and corn starch. The objectives of this study were to determine whether Maltese-Beagle atopic (MBA) dogs hypersensitive to corn exhibited clinical signs and changes in immunological markers after being fed APC. The study was designed as a blinded randomized controlled crossover experiment. Ten MBA dogs with signs of allergy within five days of ingesting corn were selected. Dogs were randomized to be fed either their maintenance diet with corn or APC for five days. After a washout of two weeks, diets were switched. Before and daily during each intervention, skin lesions were graded by an investigator while pruritus was assessed by another. Before and at the end of each intervention, the percentage of circulating CD4+CCR4+, corn-activated CD4+ T-lymphocytes and serum corn-specific IgE levels were measured and ratios of post:pre values calculated. During this trial, pruritus and skin lesions increased significantly in MBA dogs when ingesting corn while no such increase occurred when fed APC. Total, median and maximal pruritus values were significantly higher in MBA dogs ingesting corn compared to APC. There were no significant differences between interventions in the immunological parameters assessed. In summary, even though APC contains corn starch to which corn-sensitive MBA dogs often react, the ingestion of APC did not lead to significant increases in skin lesions or pruritus. Aminoprotect Care might prove valuable for management of food allergies. These experimental observations must be validated in large field studies.
    Journal of Veterinary Medical Science 11/2007; 69(10):1025-31. · 0.88 Impact Factor
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    ABSTRACT: Japanese cedar (Cryptomeria japonica) pollinosis is the most prevalent allergy in Japan. Recently, the Japanese cedar pollen allergen Cry j 3 was cloned as a homologue of Jun a 3, which is a major allergen from mountain cedar (Juniperus ashei) pollen. However, native Cry j 3 has not been isolated and there are no reports on its allergenic activity. The aims of this study were to isolate native Cry j 3 and assess its immunoglobulin E (IgE)-binding capacity in patients with Japanese cedar pollinosis. Native Cry j 3 was purified from Japanese cedar pollen by multidimensional chromatography. We assessed the IgE-binding capacity using sera from patients allergic to Japanese cedar pollen by immunoblot analysis and ELISA. Moreover, we assayed the capacity of Cry j 3 to induce histamine release from the patients' leukocytes. We cloned cDNA corresponding to purified Cry j 3 from a cDNA library of Japanese cedar pollen. We isolated native Cry j 3 as a 27-kDa protein. The IgE-binding frequency of Cry j 3 from the sera of patients allergic to Japanese cedar pollen was estimated as 27% (27/100) by ELISA. Cry j 3 induced the release of histamine from leukocytes. We cloned the cDNA and named it Cry j 3.8. Cry j 3.8 cDNA encoded 225 amino acids and had significant homology with thaumatin-like proteins. Cry j 3 is a causative allergen in Japanese cedar pollinosis and may play crucial roles in the cross-reactivity with oral allergy syndrome.
    Allergy 06/2007; 62(5):547-53. · 5.88 Impact Factor
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    ABSTRACT: Allergic reactions after vaccination are considered as an important practical problem in dogs; however, their immunological mechanism has not been well understood. The present study was designed to investigate the relationship between IgE reactivity to the vaccines and immediate-type allergic reactions after vaccination in dogs. Sera from 10 dogs that developed immediate-type allergic reactions such as circulatory collapse, cyanosis, dyspnea, facial edema, and vomiting within 1h after vaccination with non-rabies monovalent or combined vaccines and sera from 50 dogs that did not develop allergic reactions after vaccination were collected. Serum IgE reactivity to the injected vaccines was measured by fluorometric ELISA using a mouse monoclonal anti-dog IgE antibody. Then, IgE reactivity to fetal calf serum (FCS) and stabilizer proteins (gelatin, casein, and peptone) included in the vaccines was measured in sera that had high levels of IgE to the vaccines. Levels of serum specific IgE to the vaccines in dogs with immediate-type allergic reactions (59-4173 fluorescence units [FU], mean +/- S.D.: 992.5 +/- 1181.9 FU) were significantly higher than those in control dogs (38-192 FU, 92.4 +/- 43.3 FU) (P < 0.001). Of the eight dogs that developed immediate-type allergic reactions and had high levels of serum specific IgE to the vaccines, seven had specific IgE directed to FCS. The IgE reactivity to the vaccines in sera from these dogs was almost completely inhibited by FCS. The other one dog had serum IgE directed to gelatin and casein included in the vaccine as stabilizers. The results obtained in this study suggest that immediate-type allergic reactions after vaccination in dogs were induced by type I hypersensitivity mediated by IgE directed to vaccine components. In addition, FCS, gelatin, and casein included in vaccines could be the causative allergens that induced immediate-type allergic reactions after vaccination in dogs.
    Veterinary Immunology and Immunopathology 05/2005; 104(3-4):249-56. · 1.88 Impact Factor
  • Journal of Allergy and Clinical Immunology - J ALLERG CLIN IMMUNOL. 01/2005; 115(2).
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    ABSTRACT: Oligodeoxynucleotides containing the cytosine-phosphate-guanine (CpG) motif (CpG-ODNs) have been shown to induce T(H)1 immune responses in animals. Since the sequences of CpG-ODNs that induce T(H)1 responses are considered to vary among animal species, it is necessary to identify effective CpG-ODNs in each animal. In order to identify the sequences of CpG-ODNs that induce T(H)1 responses in dogs, mRNA expression and protein production of IFN-gamma were examined in peripheral blood mononuclear cells (PBMCs) from healthy dogs treated with 11 kinds of synthetic CpG-ODNs. One of the 11 CpG-ODNs (No. 2 CpG-ODN, 5'-GGTGCATCGATGCAGGGGGG-3') was shown to significantly increase mRNA expression and protein production of IFN-gamma in canine PBMCs in a manner dependent on the sequence of the CpG motif. This CpG-ODN also enhanced the expression of IL-12 p40 mRNA in canine PBMCs, whereas expression of IL-12 p35, IL-18, and IL-4 mRNAs was not induced by this CpG-ODN. These results indicate that this CpG-ODN was able to produce IFN-gamma by induction of T(H)1-skewed immune response in dogs. CpG-ODNs may be useful for inducing prophylactic and therapeutic immunity against allergic diseases, viral infection, and tumors in dogs.
    Veterinary Immunology and Immunopathology 01/2005; 102(4):441-50. · 1.88 Impact Factor
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    ABSTRACT: Japanese cedar (Cryptomeria japonica, CJ) pollen has been known to cause atopic dermatitis in dogs in Japan. However, since the mechanism of the CJ antigen recognition is not well understood in dogs, it is difficult to develop effective immunotherapy for atopic dermatitis caused by sensitization to CJ pollen. In order to aim at development of a peptide immunotherapy, we tried to identify T-cell epitopes of a major allergen of CJ pollen, Cry j 1, in dogs sensitive to CJ pollen allergen. Peripheral blood mononuclear cells (PBMCs) obtained from 22 dogs experimentally sensitized to CJ pollen allergen and 5 atopic dogs sensitive to CJ pollen allergen were used for mapping of T-cell epitopes of Cry j 1 using 35 kinds of synthesized overlapping peptides of Cry j 1. Reactive peptides were identified based on the results of blastogenic responses of PBMCs against the peptides when the stimulation indices were beyond 2.0. Three reactive peptides were identical in a relatively high population of experimental dogs, which were Nos. 8 (p71-90) (41%), 10 (p91-110) (50%), and 11 (p101-120) (41%). It was considered that these synthesized peptides should contain T-cell epitopes of Cry j 1 in the dogs. However, there were no reactive peptides identical among the five atopic dogs spontaneously sensitive to CJ pollen. The population of dogs experimentally sensitized to CJ pollen antigen will be used in order to investigate effects of a peptide immunotherapy using the reactive peptides. The results in atopic dogs sensitive to CJ pollen antigen will also provide useful information on necessity to develop a tailor-made immunotherapy using reactive peptides in each dog.
    Veterinary Immunology and Immunopathology 12/2004; 102(1-2):45-52. · 1.88 Impact Factor
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    ABSTRACT: Since dogs frequently develop allergic diseases, similar to those in humans, dogs represent a possible animal model for allergy in humans. In human atopic dermatitis (AD), CC chemokine receptor 4 (CCR4) has been shown to play an important role in the development of allergic inflammation of AD; however, the association between allergic reaction and CCR4 is not well understood in dogs. To examine CCR4 expression in peripheral blood CD4+ cells in dogs that had AD and were experimentally sensitized with Japanese cedar pollen. Peripheral blood mononuclear cells (PBMCs) were isolated from 17 dogs with AD. The proportion of CCR4+ cells in peripheral blood CD4+ cells (CCR4/CD4) was evaluated by flow cytometry and compared with that in 10 healthy dogs. Similarly, in dogs that were experimentally sensitized to Japanese cedar pollen antigen, the proportion of CCR4/CD4 was examined pre- and post-sensitization. The proportion of CCR4/CD4 in dogs with AD was 40.3+/-3.3%, which was significantly higher than that in normal dogs (23.6+/-4.3%) (P<0.01). In the experimentally sensitized dogs, the proportion of CCR4/CD4 was 25.4+/-2.6% at pre-sensitization and it was significantly increased (29.8+/-2.9%) at post-sensitization (P<0.01). The proportion of CCR4+ cells in peripheral blood CD4+ cells was measured in dogs with allergic conditions. The present findings indicate that CCR4+ cells may be involved in the pathogenesis of allergy in dogs as in humans.
    Clinical & Experimental Allergy 09/2004; 34(9):1467-73. · 4.79 Impact Factor
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    ABSTRACT: DNA immunization induces systemic humoral and cellular immune responses to the antigen encoded by cDNA in a plasmid DNA. In the present study, a plasmid DNA encoding cDNA of beta-galactosidase (beta-gal), pCAGGS-lacZ, was inoculated intramuscularly to a healthy dog in order to evaluate location and duration of the gene expression. On day 7, the plasmid DNA was found by PCR in the muscle where the plasmid was injected. Furthermore, beta-gal expression was detected in the same muscle sample by beta-gal staining. However, the plasmid DNA was not detected in any samples collected on days 14, 21 and 28. The present results suggest that duration of the gene expression of beta-gal by the plasmid DNA is limited in the muscle in dogs and an efficacy for a gene expression should be evaluated depending on the gene inserted in the plasmid DNA for immunotherapy.
    Journal of Veterinary Medical Science 04/2004; 66(3):337-9. · 0.88 Impact Factor
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    ABSTRACT: Three dogs clinically diagnosed with allergic rhinitis (AR) were examined for their immunological findings. House dust mites (HDM) such as Dermatophagoides farinae (DF) and D. pteronyssinus (DP) were identified as positive allergens in the 3 dogs with both intradermal skin test and serum antigen-specific IgE test. Lymphocyte blastogenic response of peripheral blood mononuclear cells (PBMCs) under stimulation with DF antigen in dogs with AR was higher than that in 4 healthy control dogs. Expression level of IL-4 mRNA in PBMCs obtained from the 3 AR dogs was higher than that in PBMCs obtained from 4 healthy control dogs before and after stimulation with DF antigen. Expression level of IFN-gamma mRNA in PBMCs was not different between the AR and control dogs before and after stimulation with DF antigen. These results suggested that allergic reaction to HDM antigen and T(H)2-type immune response were associated with the development of AR in 3 dogs examined in this study.
    Journal of Veterinary Medical Science 02/2004; 66(1):25-9. · 0.88 Impact Factor
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    ABSTRACT: Lymphocyte blastogenic responses against food allergens in dogs with food hypersensitivity were evaluated in this study. Eleven dogs with food hypersensitivity, based on food elimination and oral food provocation tests and allergic responses to food allergens, were examined by various tests such as intradermal testing, antigen-specific IgE testing, and lymphocyte blastogenic responses. The number and kinds of food allergens identified as positive by these tests were compared with the offending food allergens that were found in an oral food provocation test. In 9 (82%) of the 11 dogs with food hypersensitivity, there was close agreement for positive allergens between the results of lymphocyte blastogenic responses and oral food provocation test; however, there was little agreement for intradermal and IgE testing of the positive allergens with those of the oral food provocation test (11% and 31%, respectively). In the 9 dogs, the stimulation indices of lymphocyte blastogenic responses increased to 2.0-10.1 upon food provocation but decreased significantly to 0.7-1.4 upon feeding the elimination diet until clinical signs disappeared. These results indicate that lymphocyte blastogenic responses may fluctuate because of exposure to offending food allergens in dogs with food hypersensitivity. Lymphocytes reactive to food allergens may play an important role in the pathogenesis of food hypersensitivity in dogs.
    Journal of Veterinary Internal Medicine 01/2004; 18(1):25-30. · 2.06 Impact Factor
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    ABSTRACT: An in vitro evidence of IgE-mediated hypersensitivity to food allergens was detected by positive results of antigen-specific histamine release in dogs with food hypersensitivity. Eight dogs were diagnosed to have food hypersensitivity based on identification of offending food allergens with food elimination followed by oral food provocation. The percentages of histamine release against the stimulation of offending food allergens in the cases ranged from 2.1% to 70.9%. Six of the 8 cases showed histamine release higher than those of healthy control dogs. Four dogs showed relatively high histamine release at the percentage beyond 10% that was compatible with a positive value of histamine release in humans with food hypersensitivity. These findings would suggest that IgE-mediated hypersensitivity against food allergens could be involved in canine food hypersensitivity.
    Journal of Veterinary Medical Science 04/2003; 65(3):435-8. · 0.88 Impact Factor
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    ABSTRACT: In this study, we investigated the mRNA expression of a chemokine, thymus and activation-regulated chemokine (TARC), and cytokines including IL-1beta, IL-4, IFN-gamma and TNF-alpha in skin samples obtained from both dogs with atopic dermatitis (AD) and healthy dogs. TARC mRNA was found to be selectively expressed in lesional skin of the dogs with AD, but not in non-lesional skin of the dogs with AD or the normal skin of the healthy dogs. The expression levels of IL-1beta, IFN-gamma and TNF-alpha in the lesional skin were also significantly higher than those in the non-lesional skin of the dogs with AD. However, IL-4 mRNA was not detected in any of the skin samples in this study. The present results suggest that TARC and inflammatory cytokines such as IL-1beta, IFN-gamma and TNF-alpha may play roles in the pathogenesis of canine AD as well as that of human AD.
    Veterinary Immunology and Immunopathology 10/2002; 88(1-2):79-87. · 1.88 Impact Factor
  • Journal of Allergy and Clinical Immunology - J ALLERG CLIN IMMUNOL. 01/2002; 109(1).
  • Journal of Allergy and Clinical Immunology - J ALLERG CLIN IMMUNOL. 01/2002; 109(1).
  • Journal of Allergy and Clinical Immunology - J ALLERG CLIN IMMUNOL. 01/2002; 109(1).

Publication Stats

247 Citations
37.62 Total Impact Points

Institutions

  • 2000–2012
    • The University of Tokyo
      • • Faculty and Graduate School of Agriculture and Life Sceince
      • • Department of Animal Resource Sciences
      Tokyo, Tokyo-to, Japan
  • 2007
    • Chiba University
      • Graduate School of Medicine
      Chiba-shi, Chiba-ken, Japan
  • 2004–2005
    • RIKEN
      Вако, Saitama, Japan
    • National Institute of Infectious Diseases, Tokyo
      Edo, Tōkyō, Japan