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Ibrahim R B Aly, Eman E L-Ahwany, Enas Nweir, Shreif Edris and Suher Zad
Accepted Abstracts: J Clin Cell Immunol
Schistosomes utilize proteinases to accomplish several activities such as tissue penetration, tissue digestion and evasion of host immune responses. Cathepsin L which indicates that this enzyme contributes to the proteolysis of ingested hemoglobin is a cysteine proteinase of the papain superfamily detected in their gut lumen. Due to the roles played in the schistosome biology, proteolytic enzymes are considered potential targets for developing and guiding antischistosomal therapies. In the present work, the cathepsin L cDNA coding of Schistosoma mansoni was cloned providing high-level expression of heterologous proteins in Escherichia coli to produce recombinant schistosome cathepsin L with 597 bp. Our product had 99% similarity to a Schistosoma mansoni Puerto Rican preprocathepsin L (SmCL1) mRNA. The recombinant fusion protein was then analyzed by SDS-PAGE and Western blotting resulting in a molecular weight of approximately 31 kDa. The recombinant protein was expressed as inclusion bodies, purified under denaturing conditions. This recombinant protein could be recognized specifically by rabbit antiserum against Schistosoma adult worm antigen preparation (SWAP), showing that the expressed product possessed good antigenicity. The specificity and sensitivity of the purified recombinant cathepsin L against S. mansoni infected patients was assessed using ELISA. Sera from 97 S. mansoni infected patients, 30 patients infected with other helminthic infection and 30 healthy controls were collected. Anti-Cathepsin-L S. mansoni antibodies were detected with the sensitivity reached to 99% and specificity was 99.3 %. These results suggest that our product of S. mansoni cathepsin L might be considered as a suitable candidate for diagnosis of human schistosomiasis.
Hongyan Qin has completed her PhD from Fourth Military Medical University and Postdoctoral studies from Department of Immunology and Genomic Medicine in Graduate School of Medicine of Kyoto University. She is the Vice-Director of Department of Medical Genetics and Developmental Biology of Fourth Military Medical University. Until now she has published more than 20 papers in reputed international journals.