Comparative proteomic profiling of Leishmania tropica: investigation of a case infected with simultaneous cutaneous and viscerotropic leishmaniasis by 2-dimentional electrophoresis and mass spectrometry

Background: Viscerotropic leishmaniasis caused by Leishmania tropica poses a significant prob­lem in the diagnosis and treatment management. Since differential gene expression is more im­portant in outcome of the infection, we employed proteomic approach to identify potential pro­teins involved in visceralization of L. tropica. Methods: The proteomes profiling of L. tropica isolated from cutaneous and visceral tissues of one host were compared by 2-DE/MS proteomics study. Moreover, the transcript level of some identified proteins was confirmed using real-time RT-PCR. Results: Of the 700 protein spots that were detected reproducibly on each gel, 135 were found to be differentially expressed (P≤ 0.05). Most of responsive proteins in visceral isolate changed in less abundant compared to cutaneous isolate. Among differentially expressed proteins, 56 proteins were confidently identified and classified according to the biological process. The larg­est groups consist of proteins involved in carbohydrate metabolism and protein synthesis. Most of the identified proteins, which implicated in energy metabolism, cell signaling and virulence were down-regulated, whereas some proteins that have a role in protein folding, antioxidant defense and proteolysis were up-regulated in visceral form. Moreover, the transcript level of some identified proteins such as co-chaperon was confirmed using real-time RT-PCR. Conclusion: L. tropica probably uses different mechanisms for survival and multiplication in viscera to establish viscerotropic leishmaniasis. The current study provides some clues into the mechanisms underlying the dissemination of L. tropica