title: Protection of gerbils from amebic liver abscess by vaccination with a 25-mer peptide derived from the cysteine-rich region of Entamoeba histolytica galactose-specific adherence lectin.
abstract: The protozoan parasite Entamoeba histolytica causes extensive morbidity and mortality through intestinal infection and amebic liver abscess. Here we show that immunization of gerbils with a single keyhole limpet hemocyanin-coupled 25-mer peptide derived from the 170-kDa subunit of the E. histolytica galactose-binding adhesin is sufficient to confer substantial protection against experimentally induced amebic liver abscesses. Vaccination provided total protection in 5 of 15 immunized gerbils, and abscesses were significantly smaller (P < 0.01) in the remaining vaccinated animals. The degree of protection correlated with the titer of antibodies to the peptide, and results of passive transfer experiments performed with SCID mice were consistent with a role for antibodies in protection. In addition, parenteral or oral vaccination of gerbils with 13-amino-acid subfragments of the peptide N-terminally fused to the B subunit of cholera toxin also significantly inhibited liver abscess formation (P < 0.05). These data indicate that small peptides derived from the galactose-binding adhesin administered by the parenteral or oral route can provide protection against amebic liver abscess and should be considered as components of a subunit vaccine against invasive amoebiasis.
authors.affiliation: Department of Molecular Parasitology, Bernhard Nocht Institute for Tropical Medicine, 20359 Hamburg, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Lotter
authors.forename: F
authors.initials: F
authors.lastname: Khajawa
authors.forename: S L
authors.initials: SL
authors.lastname: Stanley
authors.forename: E
authors.initials: E
authors.lastname: Tannich
mesh_terms: D000276:Adjuvants, Immunologic; D000284:Administration, Oral; D000818:Animals; D002772:Cholera Toxin / Q000235:genetics / Q000276:immunology; D003545:Cysteine; D005260:Female; D005849:Gerbillinae; D006433:Hemocyanins; D007116:Immunization, Passive; D037102:Lectins / Q000235:genetics / Q000276:immunology / Q000627:therapeutic use*; D008101:Liver Abscess, Amebic / Q000517:prevention & control*; D008562:Membrane Glycoproteins / Q000235:genetics / Q000276:immunology / Q000627:therapeutic use*; D051379:Mice; D016513:Mice, SCID; D010446:Peptide Fragments / Q000235:genetics / Q000276:immunology / Q000627:therapeutic use*; D015800:Protozoan Proteins / Q000235:genetics / Q000276:immunology / Q000627:therapeutic use*; D016052:Protozoan Vaccines / Q000235:genetics / Q000276:immunology / Q000627:therapeutic use*; D011993:Recombinant Fusion Proteins / Q000276:immunology / Q000627:therapeutic use; D014611:Vaccination
chemical_list: D000276:Adjuvants, Immunologic; D037102:Lectins; D008562:Membrane Glycoproteins; D010446:Peptide Fragments; D015800:Protozoan Proteins; D016052:Protozoan Vaccines; D011993:Recombinant Fusion Proteins; C052452:galactose inhibitable adherence protein, Entamoeba histolytica; D002772:Cholera Toxin; D006433:Hemocyanins; C032808:keyhole-limpet hemocyanin; D003545:Cysteine