Preliminary characterization of putative transporters from Echinococcus granulosus

CAMICIA, F.; CHALAR, C.; GUTIERREZ, A.M.; ROSENZVIT, M.C.

Mendoza, Argentina

Congreso; VII Congreso Argentino de Protozoología y Enfermedades Parasitarias; 2005

Sociedad Argentina de Protozoología

The cestode Echinococcus granulosus (Eg) is the causative agent of cystic hydatid disease, a major zoonosis that affects many areas around the world. The signal sequence trap technique allowed to isolate cDNAs coding for putative transporters proteins (PTP) from Eg. Since Eg lacks a digestive tract and all nutrients must enter through the tegument of the worm or the larvae, it is expected that some of these PTP are localized on the tegument of the worm or larvae. The aim of the present work was the preliminary characterization of PTP from Eg. Several of the cDNAs, EgP3G2 and EgP36G2, showed nucleotide and amino acid sequence similarity with neutral amino acid and glutamate transporters that belong to the dicarboxylate/amino acid:Cation (Na+ or H+) symporter (DAACS, TC 2.A.23) family. Additional analysis, also suggest that these cDNAs belong to the DACCS family. EgP20C2, showed sequence similarity with Krebs-cycle intermediates transporters belonging to the Divalent Anion:Na+ Symporter (DASS, TC 2.A.47) family. In situ hybridization showed that EgP3G2 is expressed in the tegument of protoscoleces (larvae) while EgP36G2 showed homogeneous localization with intense staining of isolated parenchymal cells of protoscoleces and localization in the wall of the brood capsules that give raise to protoscoleces. Some of these proteins have been expressed in E.coli and used for immunization. Immunolocalization experiments are underway. The characterization, including functional studies, of PTP would allow the identification of selective portals of entry for drugs, targets for new drugs and/or immunoprophylaxis. A number of genes coding for PTP from Eg have been isolated and preliminary characterized. Some of them are localized in the tegument and the walls of brood capsules, and would be in contact with host metabolites.