Intermediate Subunit as a Vaccine Candidate against Amebic Liver Abscess

Background Entamoeba histolytica is an intestinal protozoan parasite that causes amoebiasis, including amebic dysentery and liver abscesses. E. histolytica invades host tissues by adhering onto cells and phagocytosing them depending on the adaptation and expression of pathogenic factors, including Gal/GalNAc lectin. We have previously reported that E. histolytica pos-sesses multiple CXXC sequence motifs, with the intermediate subunit of Gal/GalNAc lectin (i.e., Igl) as a key factor affecting the amoeba's pathogenicity. The present work showed the effect of immunization with recombinant Igl on amebic liver abscess formation and the cor-responding immunological properties. Methodology/Principal Findings A prokaryotic expression system was used to prepare the full-length Igl and the N-terminal, middle, and C-terminal fragments (C-Igl) of Igl. Vaccine efficacy was assessed by challeng-ing hamsters with an intrahepatic injection of E. histolytica trophozoites. Hamsters intramus-cularly immunized with full-length Igl and C-Igl were found to be 92 % and 96 % immune t