Development of the antigenic recombinant tropomyosin of Echinococcus granulosus in a bacterial system as a vaccinal candidate against canine echinococcosis.

Motivation for the study. Cystic echinococcosis is a neglected disease associated with contact between dogs, humans and sheep. In countries such as Peru, control programs include vaccination of sheep; however, vaccination in dogs is a late control strategy to eliminate the adult parasite or to avoid infection with eggs in the environment. Main findings. We were able to clone and express a recombinant protein (tropomyosin) of the adult parasite in a bacterial system with immunogenic properties. Implications. Obtaining the tropomyosin recombinant protein from E. granulosus allows the development of vaccine candidates in dogs and the exploration of diagnostic tests in hosts. This study aimed to clone, express and produce the recombinant Echinococcus granulosus tropomyosin isoform A protein (EgTrpA) that maintains its antigenic and immunogenic properties as a potential vaccine candidate for dogs and sheep. The Echinococcus granulosus tropomyosin protein (EgTrp) gene was cloned into two vectors: Tropo/His-tag [pET28a (+)] and Tropo/GST-tag (pGEX6P-1). It was then expressed in E. coli BL21. Protein identity was determined by two-dimensional electrophoresis. Immunogenicity and antigenicity were verified by immunizing rabbits with each recombinant protein and assessed by western blot and ELISA. Two-dimensional electrophoresis identified the recombinant EgTrp protein as isoform A. The recombinant proteins showed recognition reactions on Western Blot and serum from immunized rabbits showed an increase in Tropo/His-tag IgG antibodies similar to Tropo/GST-tag. The recombinant EgTrpA protein showed antigenic and immunogenic characteristics in laboratory animals.