Abstract: 　Objective To search for a candidate DNA vaccine of Fasciola hepatica. Methods Using RT-PCR and digestion with Hind III and BamHI, Fasciola hepatica secreted cathepsin L1(FheCL1) cDNA was cloned into the expression vector pcDNA3.1. Results The cloning was successful, the cDNA sequence and its deduced amino acid sequence were analyzed. There was much difference between the cloned FheCL1 and the published one. But the first 20 residues of their amino acid sequences were the same. Conclusion The recombinant plasmid pcDNA3.1-FheCL1 may be a new type of candidate DNA vaccine candidate for Fasciola hepatica. It is possible that Fasciola hepatica presents different sub-species but their amino acid residues (1 to 20) encoded by FheCL1 might build up membrane spanning helix.

Key words: Fasciola hepatica, cathepsin L1, DNA vaccine, cloning