부산대학교 도서관

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.molbiopara.2005.06.007 Byline: Jason M. Correnti (a), Paul J. Brindley (b), Edward J. Pearce (a) Keywords: Parasite; Helminth; RNAi; Cysteine protease Abbreviations: SmCB1, Schistosoma mansoni cathepsin; L, luciferase; dsRNA, double strand RNA; RNAi, RNA interference Abstract: Schistosoma mansoni is an important flatworm parasite of man that has remained intractable to experimental analyses of gene function. We have developed an approach for using dsRNA to target schistosome transcripts for RNA interference, and used it to address the role of cathepsin B (SmCB1), a cysteine protease that has been proposed to play a central role in hemoglobin digestion in the schistosome gut. Electroporation of 3h old larval schistosomes with SmCB1-specific dsRNA (SmCB1-dsRNA) resulted in a greater than 10-fold reduction in SmCB1 transcript levels that persisted for >20 days. RNAi mediated reductions in transcript levels led to associated reductions in SmCB1 enzyme activity. Schistosomes treated with SmCB1-dsRNA were viable and developed intestinal heme pigmentation indicative of hemoglobin digestion, but showed significant growth retardation when compared to control parasites, indicating that SmCB1 function is not essential for hemoglobin digestion but is necessary for normal parasite growth. This effect on growth was apparent when parasites were maintained in culture or introduced into mammalian hosts. The report sheds new light on the role of SmCB1 and provides a template for using RNAi to examine gene function in the mammal-parasitic stages of schistosomes during early development in vitro and in vivo. Author Affiliation: (a) Department of Pathobiology, University of Pennsylvania, School of Veterinary Medicine, Philadelphia, PA 19104-6008, USA (b) Department of Tropical Medicine, School of Public Health and Tropical Medicine, Tulane University Health Sciences Center, New Orleans, LA 70112, USA Article History: Received 17 March 2005; Revised 22 June 2005; Accepted 22 June 2005