1996 Fiscal Year Final Research Report Summary
Studies on the pathogenesis of Loffler's syndrome induced by nematode infection
| Project/Area Number |
07457067
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
寄生虫学(含医用動物学)
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| Research Institution | Kyoto Prefectural University of Medicine |
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Principal Investigator |
ARIZONO Naoki Kyoto Prefectural University of Medicine, Dept. Medical Zoology, Professor, 医学部, 教授 (10079725)
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| Co-Investigator(Kenkyū-buntansha) |
TEGOSHI Tatsuya Kyoto Pref. Univ. of Medicine, Dept. Medical Zoology, Research Associate, 医学部, 助手 (40254370)
UCHIKAWA Ryuichi Kyoto Pref. Univ. of Medicine, Dept. Medical Zoology, Research Associate, 医学部, 助手 (80145466)
MATSUDA Shinji Kyoto Pref. Univ. of Medicine, Dept. Medical Zoology, Research Associate, 医学部, 助手 (70199800)
YAMADA Minoru Kyoto Pref. Univ. of Medicine, Dept. Medical Zoology, Lecturer, 医学部, 講師 (70106392)
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| Project Period (FY) |
1995 – 1996
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| Keywords | nematode / Ws / Ws rat / lung / mast cell / IgE / vascular peameability / leukotriene / cytokine |
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| Research Abstract |
Infection with the intestinal nematode Nippostrongylus brasiliensis induces Loffler's syndrome-like pneumonitis. To elucidate the role of type I hypersensitivity in the pathogenesis of nematode-induced lung lesions, we studied lung inflammation, IgE responses, mediator releases, vascular permeability, and cytokine mRNA expressions in the lungs and/or trachea of normal +/+ and genetically mast cell-deficient Ws/Ws rats. After infection, +/+ and Ws/Ws rats showed similar levels of IgE antibody response in the blood and pulmonary hilar lymph nodes. Nematode-induced pneumonitis was significantly less severe in Ws/Ws rat lungs, and levels of eosinophil infiltration in BALF was significantly lower in Ws/Ws than in +/+ animals. Intravenous challenge with nematode antigen together with Evans blue dye to nematode-sensitized +/+ and Ws/+ rats induced significantly high levels of the dye leakage in the trachea, whereas Ws/Ws rats did not show any increases of dye leakage. Stimulation of lung tissues obtained from nematode-sensitized +/+ animals with nematode antigens in vitro showed significantly higher levels of histamine release and leukotriene C4 production than those from Ws/Ws rat lungs. RT-PCR studies showed that mRNA expressions of IL-2, IL-3, IL-4, IL-5, IL-6 and IL-13 were increased in the lung tissues of both Ws/Ws and +/+ rats after infection. These results indicate that mast cells are indispensable for the initiation of immediate-type increase of vascular permeability and mediator releases in the trachea and lungs, and that the activation of IgE-mast-cell axis seems to be relevant to the occurrence of nematode-induced pneumonitis. The role of cytokines for the modulation of pneumonitis still to be elucidated.
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