Regulation mechanisms of pathogenicity of intestinal protozoa

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K08761
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Parasitology (including sanitary zoology)
• Research Institution: Nagasaki University
• Principal Investigator: KATO Kentaro 長崎大学, 熱帯医学研究所, 助教 (50508885)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 赤痢アメーバ / レクチン

Outline of Final Research Achievements

Entamoeba histolytica and non-virulent Entamoeba dispar lectins (Igls) have 2 isoforms, Igl1 and Igl2, and both isoforms showed hemolytic activities. The expression levels of Igl2 in Entamoeba histolytica and Entamoeba dispar are equivalent but those of Igl1 are higher in Entamoeba histolytica than in Entamoeba dispar. Therefore, we attenuated expression of Igl1 in Entamoeba histolytica utilizing a gene-silencing technique and evaluated the effect on hemolytic activity. The gene-silenced strain had less hemolytic activity compared with that of wild type indicating that the expression level of Igl1 affected the hemolytic activity of Entamoeba histolytica.
The hemolytic activity resided in 60 amino acids of Igl1 was confirmed from the hemolytic assay using recombinant fragment proteins of Igl1.

Free Research Field

寄生虫学、糖鎖生物学

Academic Significance and Societal Importance of the Research Achievements

赤痢アメーバ(Entamoeba histolytica)のIglのC末端側に溶血活性ならびに細胞障害性が存在することを明らかにしており、その発現量が溶血活性に影響を与えることを明らかにできた。このことより、EhIgl1のC末端側を抗体あるいは薬剤でブロックすればEntamoeba histolyticaの溶血活性を抑制でき、感染予防と発症を同時に行うことができる可能性がある。