Construction and immunogenicity of a codon-optimized Entamoeba histolytica Gal-lectin-based DNA vaccine

Invasive amebiasis caused by Entamoeba histolytica is the third leading parasitic cause of mortality, and there are no vaccines available to help control the disease. The galactose-adherence lectin (Gal-lectin) is the parasite's major molecule allowing it to adhere to colonic mucin for colonization and to target cells for tissue destruction. It is immunodominant and is regarded as the most promising candidate molecule to be included in a subunit vaccine against amebiasis. In this study, we are reporting the construction of a codon-optimized DNA vaccine encoding a portion of the Gal-lectin heavy subunit that includes the carbohydrate recognition domain (CRD), and its in vivo testing in mice. The vaccine stimulated a Th1-type Gal-lectin-specific cellular immune response as well as the development of serum antibodies that recognized a recombinant portion of the heavy subunit, and that inhibited the adherence of trophozoites to target cells in vitro.