Mapping of B-Cell Epitopes on a Novel 11.5-Kilodalton Fasciola hepatica-Schistosoma mansoni Cross-Reactive Antigen Belonging to a Member of the F. hepatica Saposin-Like Protein Family

FhSAP-2 is a novel member of the Fasciola hepatica saposin-like protein family that induces protection in rabbits against a challenge infection. We investigated the presence of lineal B-cell epitopes within this protein using a set of overlapping synthetic peptides. Peptides were tested in enzyme-linked immunosorbent assays against sera from rabbits infected with F. hepatica. Two dominant epitopes were identified, which were also highly reactive with sera from mice infected with Schistosoma mansoni. These peptides may be suitable to incorporate into a polyepitope-based vaccine formulation against F. hepatica.