Laboratory of Parasite Immunology, Departments of Pathology and Biology, University of Puerto Rico, Department of Pathology, Molteno Laboratories of Parasitology, University of Cambridge, San Juan, Puerto Rico 00936-5067, England
Total RNA containing messenger RNA has been isolated from adult Fasciola hepatica and translated in vitro using the rabbit reticulocyte lysate system. L-[35S]-methionine labeled translation products have been immunoprecipitated with sera collected from rabbits infected with F. hepatica, rabbits immunized with adult worm homogenate, and a rabbit and 5 calves immunized with a Fasciola/Schistosoma cross-reactive, cross-protective antigen, denoted FhSmIII(M). Precipitated antigens were analyzed by SDS-polyacrylamide gel electrophoresis. The major antigens recognized by hyperimmune sera had apparent molecular weights of 12,500, 13,500, 14,000, 26,500, and 27,000. The rabbit anti-FhSmIII(M) serum precipitated a 13,500 Mr antigen. Sera collected from calves immunized with FhSmIII(M) also precipitated a 13,500 Mr antigen together with a 26,500 Mr molecule. Antibody with specificity for F. hepatica mRNA translation products could be detected in rabbit serum 2 weeks after infection.