Progress in the development of Fasciola hepatica vaccine using recombinant fatty acid binding protein with the adjuvant adaptation system ADAD

Fatty acid binding proteins (FABP) have been designed as a potential vaccine against fasciolosis. In this work, the immunoprophylaxis of the recombinant Fh15 FABP from E hepatica (Fh15) in adjuvant/immunomodulator ADAD system was evaluated using mice and sheep challenged with E hepatica. The ADAD system combines the Fh15 antigen with an immunomodulator (hydroalcoholic extract of Polypodium leucotomos; PAL) and/or an adjuvant (saponins of Quillaja saponaria; Qs) in a water/oil emulsion (30/70) with a non-mineral oil (Montanide). All the infected control mice died by 41-48 days postinfection. The mice vaccinated with ADAD only with PAL + Fh15 present a survival rate of 40-50% and those vaccinated with ADAD containing PAL + Qs + Fh15 had a survival rate of 50-62.5%. IgG1 antibodies were lower in surviving mice in comparison with non-surviving mice. The sheep vaccinated with ADAD PAL + Qs + Fh15 showed lower fluke recovery (43%), less hepatic lesions and higher post-infection daily weight gain than F hepatica infected control animals. Thus, the ADAD system using recombinant fatty acid binding proteins from F hepatica could be a good option to develop vaccines against E hepatica. (c) 2006 Elsevier B.V. All rights reserved.