2020 Fiscal Year Final Research Report
Elucidation of onset factors and mechanisms in fulminant anisakiasis and establishment of risk management
| Project/Area Number |
18K08009
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Review Section |
Basic Section 53010:Gastroenterology-related
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| Research Institution | Oita University |
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Principal Investigator |
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| Co-Investigator(Kenkyū-buntansha) |
杉山 広 国立感染症研究所, 寄生動物部, 主任研究官 (00145822)
村上 和成 大分大学, 医学部, 教授 (00239485)
飛彈野 真也 大分大学, 医学部, 助教 (80516386)
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| Project Period (FY) |
2018-04-01 – 2021-03-31
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| Keywords | アニサキス症 / アナフィラキシー / 無症候型アニサキス症 |
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| Outline of Final Research Achievements |
Anisakiasis is a fish-borne parasitic disease caused by the accidental ingestion of Anisakis larvae. The larvae penetrate the gastric mucosa resulting in acute epigastralgia, while some cases of asymptomatic anisakiasis have been reported. We assumed that the fulminant form of anisakiasis is caused by acute allergic reactions to Anisakis larvae due to repeated infections of the larvae. Although mice orally and repeatedly administrated with larval homogenate showed no allergic reactions, mice orally and repeatedly infected with Anisakis larvae exhibited increased levels of IgE in the serum as well as an increase in number of eosinophils in the gastric mucosa, suggesting that repeated penetrations of the larvae in the gastric mucosa are required to induce the reactions. In addition, repeated infection with Anisakis larvae increased the number of innate immune cells associated with allergy such as ILC2 in the gastric mucosa accompanied by the elevation of cytokines such as IL-4 and IL-5.
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| Free Research Field |
消化器内科
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| Academic Significance and Societal Importance of the Research Achievements |
アニサキス症は、魚を生でたべる日本人特有の寄生虫症で、年間約7000例も発症するとされている。本研究により、アニサキス症の劇症化は知らない間に何度かアニサキス幼虫に噛みつかれて、ある時を契機にアレルギーが起こり激しい腹痛になるという可能性が示された。また、それには生きたアニサキスの感染が重要で、加熱処理や冷凍処理によって死滅したアニサキス幼虫ではアレルギー反応は起きないことが予想されたことは安心材料となる。今回、アニサキス感染により胃の組織内にアレルギーに関連する免疫細胞やサイトカインが誘導されていることが初めて示されたのは、今後のアニサキス症の劇症化を解明する上で重要な知見となる。
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