Identification of proteins in promastigote and amastigote-like stages of Leishmania tropica by a quantitative proteomic approach

Abstract

Background Leishmania parasites differentiate into the infective metacyclic form in the sand-fly and following is transformed to the amastigote in the host cells. The aims of this study were to identified differentially regulated proteins in the metacyclic and amastigote-like stages of L. tropica, and investigate their potential role in differentiation and pathogenesis molecular mechanisms.Methods The samples were cultured and identified by using PCR-RFLP technique. We employed We employed Sequential window acquisition of all theoretical fragment ion spectra mass spectrometry (SWATH-MS) to identify differentially regulated proteins between the metacyclic and amastigote-like stages of L. tropica.Results A total 176 and 155 distinct proteins were identified in metacyclic and axenic amastigote, respectively. Of these, 65 proteins were altered at least 2 folds. Proteins that were up- or down-regulated included energy production, lipid and amino acid metabolism, heat shock proteins, mRNA processing proteins, glycolytic and translational activity proteins. Several enriched GO terms were identified via biological process analyses, which “metabolic process” (GO: 0044281, P-Value: 6.52e-5), and “translation” (GO: 0006412, p-value: 5.01e-14) were disclosed as top category in up and down-regulated proteins, respectively. Also, the KEGG analysis indicated “metabolic pathways” and “ribosome” term as the top pathways in up and down-regulated proteins, respectively.Conclusions This study provides the first quantitative analysis of protein expression during differentiation from metacyclic to amastigote-like of L. tropica. In conclusion, anabolic pathways were down-regulated, whereas catabolic pathways were up-regulated during L. tropica differentiation in order to parasite survival in host macrophages, in which these changes can be used as novel potential targets for the infection management.