Are carbohydrates of hosts involved with parasites' host specificity?

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K06238
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 40040:Aquatic life science-related
• Research Institution: Kagoshima University
• Principal Investigator: Satoshi TASUMI 鹿児島大学, 農水産獣医学域水産学系, 准教授 (90359646)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 宿主認識 / 寄生虫 / 糖鎖 / 魚類

Outline of Final Research Achievements

In order to elucidate host-recognition mechanisms of fish parasite, we selected the combination of multiple species of genus Takifugu and monogenean parasite Heterobothrium okamotoi, which specifically parasitize gills of T. rubripes. It was shown that the parasites attached to the gills of species with more amount of L-fucose in the tissue tend to be detached earlier than the ones attached to the gills with less amount of L-fucose. To prove directly the involvement of L-fucose in host-recognition, several families being lost the function of fucosyltransferase, which transfers L-fucose to oligosaccharide were prepared by using CRISPR-Cas9. Those families and additional ones under preparation are going to be used for experimental in vivo challenge test in the near future, to examine our hypothesis that L-fucose is involved with host-recognition of H. okamotoi.

Free Research Field

魚介類免疫学

Academic Significance and Societal Importance of the Research Achievements

魚類寄生虫の宿主認識の分子機構はこれまでほとんど解明されていない。本研究では、宿主特異性の極めて高い寄生虫とその宿主および近縁種を用いた比較研究を行うことによって、L-フコースが重要な役割を果たしている可能性が高いことを示した。さらに、遺伝子編集技術を用い、フコシルトランスフェラーゼ遺伝子の機能を欠失しうる個体の作出も行った。交配に要する時間的制約により、直接的証明には至らなかったが、今後これらの家系を用いて我々の仮説を証明してゆく予定である。宿主認識に関与する分子が特定できれば、学術的に重要な知見が得られるだけでなく、予防薬や予防方法の開発につながり、社会的にも貢献できることが期待される。