Lp95, a novel leptospiral protein that binds extracellular matrix components and activates e-selectin on endothelial cells

• Published in: The Journal of infection 2009-10, Vol.59 (4), p.264-276
• Main Authors: Atzingen, Marina V, Gómez, Ricardo M, Schattner, Mirta, Pretre, Gabriela, Gonçales, Amane P, de Morais, Zenaide M, Vasconcellos, Silvio A, Nascimento, Ana L.T.O
• Format: Article
• Language: English
• Subjects: Bacterial Outer Membrane Proteins - genetics; Bacterial Outer Membrane Proteins - isolation & purification; Bacterial Outer Membrane Proteins - metabolism; Biological and medical sciences; Cell Adhesion; DNA Fingerprinting; E-Selectin - metabolism; Endothelial Cells - metabolism; Escherichia coli; Extracellular Matrix - metabolism; Gene Expression; General aspects; Infectious Disease; Intercellular Adhesion Molecule-1 - metabolism; Leptospira; Leptospira - classification; Leptospira - metabolism; Leptospira interrogans; Leptospirosis; Medical sciences; Pathogenesis; Recombinant protein
• ISSN: 0163-4453; 1532-2742
• DOI: 10.1016/j.jinf.2009.07.010

Summary Objectives The study of a predicted outer membrane leptospiral protein encoded by the gene LIC12690 in mediating the adhesion process. Methods The gene was cloned and expressed in Escherichia coli BL21 (SI) strain by using the expression vector pAE. The recombinant protein tagged with N-terminal hexahistidine was purified by metal-charged chromatography and used to assess its ability to activate human umbilical vein endothelial cells (HUVECs). Results The recombinant leptospiral protein of 95 kDa, named Lp95, activated E-selectin in a dose-dependent fashion but not the intercellular adhesion molecule 1 (ICAM-1). In addition, we show that pathogenic and non-pathogenic Leptospira are both capable to stimulate endothelium E-selectin and ICAM-1, but the pathogenic L. interrogans serovar Copenhageni strain promotes a statistically significant higher activation than the non-pathogenic L. biflexa serovar Patoc ( P < 0.01). The Lp95 was identified in vivo in the renal tubules of animal during experimental infection with L. interrogans . The whole Lp95 as well as its fragments, the C-terminal containing the domain of unknown function (DUF), the N-terminal and the central overlap regions bind laminin and fibronectin ECM molecules, being the binding stronger with the DUF containing fragment. Conclusion This is the first leptospiral protein capable to mediate the adhesion to ECM components and the activation of HUVECS, thus suggesting its participation in the pathogenesis of Leptospira.