Study of the protective capacity of the chimeric protein Fh3Tq against infection in experimental model of Fasciola hepatica

Resumen

Fasciolosis is a zoonosis caused by trematodes of the genus Fasciola, that mainlyaffects grazing ruminants. The drug of choice is triclabendazole, but the emergenceof resistance in recent decades leads to the search for new control strategies. Thedevelopment of a vaccine provides a profitable and sustainable alternative for thecontrol of fasciolosis. In previous studies, a battery of peptides with B and T epitopesdesigned by bioinformatic methods were evaluated. Three of them, T14, T15 andT16, showed a high protective capacity formulated in the adjuvant adaptationADAD vaccination system. It was proposed to bind these three peptides in a singlemolecule, giving rise to a recombinant chimeric protein that was called Fh3Tq.BALB/c mice were immunized with Fh3Tq or T14+T15+T16, using the ADADvaccination system, and infected with metacercariae of F. hepatica. The magnitudeof the hepatic injuries and the reduction in the number of flukes were evaluated,and the immunoglobulins were quantified to study the existence of an immunemodulation. The group immunized with the peptide subunits T14, T15 and T16showed the greatest reduction in liver score and number of flukes, followed by thegroup immunized with the chimeric protein Fh3Tq. Immunization in the two groupscaused high levels of IgGTotal and generated a mixed Th1/Th2 response. However,the group immunized with Fh3Tq didn’t achieve a higher survival rate than the groupimmunized with the peptides mixture T, that got the best protection results.