Neutralizing monoclonal antibody epitopes of the Entamoeba histolytica galactose adhesin map to the cysteine-rich extracellular domain of the 170-kilodalton subunit.
AUTOR(ES)
Mann, B J
RESUMO
Entamoeba histolytica adheres to human colonic mucins and colonic epithelial cells via a galactose-binding adhesin. The adhesin is a heterodimeric glycoprotein composed of 170- and 35-kDa subunits. Fragments of the hgl1 gene encoding the 170-kDa subunit were expressed as recombinant fusion proteins in Escherichia coli and reacted with anti-adhesin monoclonal antibodies (MAbs) or pooled human immune sera. The MAbs tested recognize seven distinct epitopes on the 170-kDa subunit and have distinct effects on the adherence and complement-inhibitory activities of the adhesin. All seven MAbs reacted with a fusion protein containing the cysteine-rich domain of the protein. Pooled human immune sera reacted with the same cysteine-rich domain as the MAbs and also with a construct containing the first 596 amino acids. Reactivity of three MAbs with the surface of intact trophozoites confirmed that the cysteine-rich domain was located extracellularly. The location of individual epitopes was fine mapped by constructing carboxy-terminal deletions in the cysteine-rich region of the fusion protein. The locations of adherence-enhancing and -inhibiting epitopes were partially distinguished, and the epitopes where complement-inhibitory MAbs bound were demonstrated to be near the adhesin's area of sequence identity with the human complement inhibitor CD59.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=280764Documentos Relacionados
- Sequence of a cysteine-rich galactose-specific lectin of Entamoeba histolytica.
- The Cysteine-Rich Region of the Entamoeba histolytica Adherence Lectin (170-Kilodalton Subunit) Is Sufficient for High-Affinity Gal/GalNAc-Specific Binding In Vitro
- cDNA sequence analysis of a 29-kDa cysteine-rich surface antigen of pathogenic Entamoeba histolytica.
- Protection of gerbils from amebic liver abscess by immunization with a recombinant protein derived from the 170-kilodalton surface adhesin of Entamoeba histolytica.
- 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