Binding of human plasminogen by the lipoprotein LipL46 of Leptospira interrogans

Author(s)

Santos, Jadson V. ; Pereira, Priscila R. M. ; Fernandes, Luis G. V. ; Siqueira, Gabriela Hase ; de Souza, Gisele O. ; Souza Filho, Antonio ; Vasconcellos, Silvio A. ; Heinemann, Marcos B. ; Chapola, Erica G. B. ; Nascimento, Ana L. T. O.

• Document type: Journal article
• Source: MOLECULAR AND CELLULAR PROBES; v. 37, p. 10-pg., 2018-02-01.

Abstract

Leptospirosis is a widespread zoonosis caused by pathogenic Leptospira. Bacteria disseminate via the bloodstream and colonize the renal tubules of reservoir hosts. Leptospiral surface-exposed proteins are important targets, because due to their location they can elicit immune response and mediate adhesion and invasion processes. LipL46 has been previously reported to be located at the leptospiral outer membrane and recognized by antibodies present in serum of infected hamsters. In this study, we have confirmed the cellular location of this protein by immunofluorescence and FACS. We have cloned and expressed the recombinant protein LipL46 in its soluble form. LipL46 was recognized by confirmed leptospirosis human serum, suggesting its expression during infection. Binding screening of LipL46 with extracellular matrix (ECM) and plasma components showed that this protein interacts with plasminogen. The binding is dose-dependent on protein concentration, but saturation was not reached with the range of protein concentration used. Kringle domains of plasminogen and lysine residues of the recombinant protein are involved in the binding because the lysine analog, amino caproic acid (ACA) almost totally inhibited the reaction. The interaction of LipL46 with plasminogen generates plasmin in the presence of plasminogen activator uPA. Because plasmin generated at the leptospiral surface can degrade ECM molecules and decrease opsonophagocytosis, we tentatively infer that Lip46 has a role in helping the invasion process of pathogenic Leptospira. (AU)

• FAPESP's process: 15/02590-5 - Immunological and functional characterization of two predict lipoproteins of Leptospira interrogans expressed in the host Escherichia coli
• Grantee: Priscila Romero Mazzini Pereira
• Support Opportunities: Scholarships in Brazil - Master
• FAPESP's process: 14/50981-0 - Search for surface proteins among the genome sequences of Leptospira interrogans: functional and immunological characterization to understanding mechanisms involved in the bacterial pathogenesis
• Grantee: Ana Lucia Tabet Oller do Nascimento
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 12/24164-0 - Characterization of the interaction of Leptospira interrogans with prothrombin/thrombin system and possible implications in virulence
• Grantee: Luis Guilherme Virgílio Fernandes
• Support Opportunities: Scholarships in Brazil - Doctorate