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Journal of Biomedicine and Biotechnology
Volume 2012 (2012), Article ID 758513, 17 pages
http://dx.doi.org/10.1155/2012/758513
Review Article

Plasminogen Binding Proteins and Plasmin Generation on the Surface of Leptospira spp.: The Contribution to the Bacteria-Host Interactions

1Centro de Biotecnologia, Instituto Butantan, Avenida Vital Brazil, 1500, 05503-900 São Paulo, SP, Brazil
2Interunidades em Biotecnologia, Instituto de Ciências Biomédicas, USP, Avenida Prof. Lineu Prestes, 1730, 05508-900 São Paulo SP, Brazil
3Laboratorio de Zoonoses Bacterianas do VPS, Faculdade de Medicina Veterinária e Zootecnia, USP, Avenida Prof. Dr. Orlando Marques de Paiva, 87, 05508-270 São Paulo, SP, Brazil

Received 13 February 2012; Revised 11 June 2012; Accepted 25 June 2012

Academic Editor: Edward F. Plow

Copyright © 2012 Monica L. Vieira et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Leptospirosis is considered a neglected infectious disease of human and veterinary concern. Although extensive investigations on host-pathogen interactions have been pursued by several research groups, mechanisms of infection, invasion and persistence of pathogenic Leptospira spp. remain to be elucidated. We have reported the ability of leptospires to bind human plasminogen (PLG) and to generate enzimatically active plasmin (PLA) on the bacteria surface. PLA-coated Leptospira can degrade immobilized ECM molecules, an activity with implications in host tissue penetration. Moreover, we have identified and characterized several proteins that may act as PLG-binding receptors, each of them competent to generate active plasmin. The PLA activity associated to the outer surface of Leptospira could hamper the host immune attack by conferring the bacteria some benefit during infection. The PLA-coated leptospires obstruct complement C3b and IgG depositions on the bacterial surface, most probably through degradation. The decrease of leptospiral opsonization might be an important aspect of the immune evasion strategy. We believe that the presence of PLA on the leptospiral surface may (i) facilitate host tissue penetration, (ii) help the bacteria to evade the immune system and, as a consequence, (iii) permit Leptospira to reach secondary sites of infection.