Gedamu, LashitewMurtatha, Asel2016-09-092016-09-0920162016Murtatha, A. (2016). The Effect of Leishmania Donovani Cathepsin B on Transforming Growth Factor Beta-1 Activation and Regulation of Inducible Nitric Oxide Synthase and Arginase Activity Inside the Macrophages (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/28083http://hdl.handle.net/11023/3284Leishmania parasites contain high level of cathepsin B and cathepsin L like cysteine proteases. The anti-inflammatory immune response depends mainly on the interleukin-10 (IL-10) and transforming growth factor beta-1 (TGF-β1) production. This study elucidated the role of L.donovani cathepsin B on L donovani parasites survival and multiplication. Our data suggest that cathepsin B could play a role in activating latent TGF-β1 in vitro and inside the macrophages. Our data also suggest that L.donovani cathepsin B could facilitate the parasite survival inside the macrophages via inhibiting iNOS and enhancing arginase expression. Exosomes, which are secreted vesicles, are important in cell to cell communication. We found that cathepsin B could be exported through L.donovani exosomes and could also activate TGF-β1 in vitro and inside the macrophages. Moreover, we found that L.donovani exosomes could deactivate macrophages and enhance the parasites survival inside macrophages.engUniversity of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.BiologyBiology--CellMicrobiologyBiology--MolecularParasitologyHostPathogenInteractionLeishmaniaParasitemaster thesis10.11575/PRISM/28083