Abstract
BackgroundCathepsin cysteine proteases play multiple roles in the life cycle of parasites such as food uptake, immune invasion and pathogenesis, making them valuable targets for diagnostic assays, vaccines and drugs. The purpose of this study was to identify a cathepsin B of Clonorchis sinensis (CsCB) and to investigate its diagnostic value for human helminthiases.ResultsThe predicted amino acid sequence of the cathepsin B of C. sinensis shared 63%, 52%, 50% identity with that of Schistosoma japonicum, Homo sapiens and Fasciola hepatica, respectively. Sequence encoding proenzyme of CsCB was overexpressed in Escherichia coli. Reverse transcription PCR experiments revealed that CsCB transcribed in both adult worm and metacercaria of C. sinensis. CsCB was identified as a C. sinensis excretory/secretory product by immunoblot assay, which was consistent with immunohistochemical localization showing that CsCB was especially expressed in the intestine of C. sinensis adults. Both ELISA and western blotting analysis showed recombinant CsCB could react with human sera from clonorchiasis and other helminthiases.ConclusionsOur findings revealed that secreted CsCB may play an important role in the biology of C. sinensis and could be a diagnostic candidate for helminthiases.
Highlights
Cathepsin cysteine proteases play multiple roles in the life cycle of parasites such as food uptake, immune invasion and pathogenesis, making them valuable targets for diagnostic assays, vaccines and drugs
Kang et al [22] indicated that partially purified cysteine protease from excretory/secretory products (ESP) of C. sinensis adults exhibited significant cytotoxic effects against cultured cells
Little is known about cathepsin B (CB) in C. sinensis except five distinct sequences deposited in Genbank
Summary
Cathepsin cysteine proteases play multiple roles in the life cycle of parasites such as food uptake, immune invasion and pathogenesis, making them valuable targets for diagnostic assays, vaccines and drugs. The purpose of this study was to identify a cathepsin B of Clonorchis sinensis (CsCB) and to investigate its diagnostic value for human helminthiases. Clonorchiasis is endemic in Asian countries and over 35 million people globally are infected C. sinensis, including an estimated 15 million in People’s Republic of China [1]. Several genes encoding C. sinensis cysteine proteases have been identified and partially characterized [17,18,19]. Several genes encoding C. sinensis cysteine proteases have been identified and their value as diagnostic antigens for clonorchiasis was investigated [24,25]. Little is known about cathepsin B (CB) in C. sinensis except five distinct sequences deposited in Genbank
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
