Using C. elegans to determine the functions of lipid binding proteins of parasitic nematodes

JOSE LOMBARDO; GISELA R. FRANCHINI; COLLETTE BRITTON; BETINA CÓRSICO

Congreso; Latin American Worm Meeting 2020; 2020

Parasitic nematodes are a global problem and cause prolonged and potentially lethal infections. Blood feeding intestinal hookworm of humans, Necator. americanus and Ancylostoma duodenale, are a significant problem in the north of Argentina and South America. Nematodes, both free-living and parasitic, synthesise unusual lipid-binding proteins that are not found in other phyla. Among them Fatty Acid and Retinol Binding Proteins (FARs) have drawn attention because they are secreted by parasitic species and their encoding transcripts are relatively abundant. They have also proven useful for serodiagnosis and have shown promise in experimental vaccines. FARs have been proposed to facilitate infection by manipulating host lipid-mediated defenses, but their specific functions are still unknown. At least six FAR proteins have been recognized in the genome of N. americanus. In previous work we have determined the 3D structure of the first N. americanus FAR protein (Na-FAR-1) by NMR and X-ray crystallography. We have also analyzed the protein binding preferences and determined its stage and tissue distribution. Since gene knockout technology is not currently available for parasitic species, we propose using C. elegans to study the functions of nematode FAR proteins. Eight FAR genes are present in Caenorhabditis elegans, most of them have a close phylogenetic relationship with FAR proteins found in parasitic nematodes. Employing this model system, we will be able to gain insight into the biological functions of these proteins in free living and parasitic nematodes and analyze their potential use as therapeutic and diagnostic targets in parasitic infections. We are employing RNA interference (RNAi) gene silencing and genetic mutants to determine the effects on its development, viability and metabolism. Up to now we have detected an apparently premature internal hatching and defects in male reproductive capacity in one of the FAR knock downs. Further analysis of the rest of the mutants is currently underway.