[Genomic cloning of Fasciola hepatica secretory antigens in Escherichia coli].

This paper reported the immunoscreening of three recombinants expressing secretory antigens from the genomic DNA library of F. hepatica and the primary study of expression of the three recombinants. To construct the genomic DNA library, DNA from the adult F. hepatica was cut with Sau3AI to an average length of about 2.0 kb and inserted into the BamHI site of the expression vector pUC18, the size of the genomic DNA library of F. hepatica being 1.5 x 10(5) recombinants. Three recombinants expressing antigenic determinants of F. hepatica pFH16, pFH23, pFH48 were detected through primary screening and rescreening with F. hepatica infected rabbit serum (1:50) preabsorbed to remove antibodies to E. coli and SPA-HRP (1:40). The test of the ability of expressing fusion proteins showed pFH16 > pFH48 > pFH23. These studies provide the possibility of further research on the expression of recombinant antigenic genes, the immunity of their expressed products and the protection of animals.