|Eshghi, Azad - University Of Victoria|
|Cullen, Paul - Monash University|
|Cowen, Laura - University Of Victoria|
|Cameron, Caroline - University Of Victoria|
Submitted to: Journal of Proteome Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/10/2009
Publication Date: 8/10/2009
Citation: Eshghi, A.A., Cullen, P., Cowen, L., Zuerner, R.L., Cameron, C.E. 2009. Global Proteome Analysis of Leptospira interrogans. Journal of Proteome Research. 8(10):4564-4578.
Interpretive Summary: Leptospirosis is a widespread zoonotic disease caused by various pathogenic serovars of the spirochete bacterium Leptospira. A greater understanding of the Leptospira infection process is required. As such, research focusing on the molecular components utilized by Leptospira to establish infection will permit the identification of novel virulence factors that may facilitate vaccine design and the development of novel diagnostics. In the present study, we have performed both non-gel-based and gel-based proteomic analyses on L. interrogans. These studies provide the first comprehensive, comparative and quantitative analysis of Leptospira total proteome alterations in response to environmental conditions that mimic those found within the host.
Technical Abstract: Comparative global proteome analyses were performed on Leptospira interrogans serovar Copenhageni grown under conventional in vitro conditions and those mimicking in vivo conditions (iron limitation and serum presence). Proteomic analyses were conducted using iTRAQ and LC-ESI-tandem mass spectrometry complemented with two-dimensional gel electrophoresis and MALDI-TOF mass spectrometry. A total of 558 proteins were identified in this study. Altered expression of 65 proteins, including upregulation of the Leptospira virulence factor Loa22 and 5 novel proteins with homology to virulence factors found in other pathogens, was observed between the comparative conditions. Immunoblot analyses confirmed upregulation of putative virulence factors in Leptospira exposed to the in vivo-like environmental conditions. Further, ELISA analyses using serum from patients with leptospirosis and immunofluorescence studies performed on liver and kidney sections derived from Leptospira-infected hamsters verified expression of several of the identified proteins during infection. These studies, which represent the first documented total proteome analysis of Leptospira, demonstrated proteome alterations under conditions that mimic in vivo infection and allowed for the identification of novel putative Leptospira virulence factors.