Interaction with human plasminogen system turns on proteolytic activity in Streptococcus agalactiae and enhances its virulence in a mouse model

• Type: Article in International Scientific Journal
• Date: 2007

Authors

Vanessa Magalhaes (Author) Other; Isabel Veiga Malta (Author) Other; Maria Rosario Almeida (Author) ICBAS; Marina Baptista (Author) Other; Adilia Ribeiro (Author) ICBAS; Patrick Trieu Cuot (Author) Other; Paula Ferreira (Author) ICBAS

Journal

Title: Microbes and Infection

Vol. 9

Pages: 1276-1284

ISSN: 1286-4579

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 31 Citations

Scopus - 33 Citations

Scientific classification

FOS: Medical and Health sciences > Basic medicine

Other information

Authenticus ID: P-004-7ZT

DOI: 10.1016/j.micinf.2007.06.001

Abstract (EN): Interactions of several microbial pathogens with the plasminogen system increase their invasive potential. In this study, we show that Streptococcus agalactiae binds human plasminogen which can be subsequently activated to plasmin, thus generating a proteolytic bacterium. S. agalactiae binds plasminogen via the direct pathway, using plasminogen receptors, and via the indirect pathway through fibrinogen receptors. The glyceraldehyde-3-phosphate dehydrogenase is one If the S. agalactiae proteins that bind plasminogen. Presence of exogenous activators such as uPA and tPA are required to activate bound plasminogen. Results from competitive inhibition assays indicate that binding is partially mediated through the lysine binding sites of plasminogen. Following plasminogen binding and activation, S. agalactiae is able to degrade in vitro fibronectin, one of the host extracellular matrix proteins. Moreover, incubation of S. agalactiae with either plasminogen alone, or plasminogen plus fibrinogen, in the presence of tPA enhanced its virulence in C57BL/6 mice, suggesting that acquisition of plasmin-like activity by the bacteria increase their invasiveness.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 9