Molecular characterization of IgG and IgE antigens of Entamoeba histolytica

Several surface IgG antigens of E. histolytica have been characterized. We isolated two novel cDNAs by screening a library of pathogenic E. histolytica with rabbit antiserum against a membrane preparation of pathogenic amebas. cDNA K15 encodes a large protein > 220 kDa with sequence homology to myosins and K18 encodes a protein of around 40 kDa. Serum IgG from patients suffering from amebiasis binds to both antigens. Some IgE antibodies are able to recognize homologous proteins in all eukaryotes investigated. We demonstrate that IgE antibodies from pollen allergic patients bind to plant, human, as well as E. histolytica profilins.