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Immuno-fluorescence Assay of Leptospiral Surface-exposed Proteins
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Immuno-fluorescence Assay of Leptospiral Surface-exposed Proteins

Published on: July 1, 2011

Leptospiral endostatin-like protein A is a bacterial cell surface receptor for human plasminogen

Ashutosh Verma1, Catherine A Brissette, Amy A Bowman

  • 1Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky College of Medicine, MN 469 Chandler Medical Center, Lexington, KY 40536-0298, USA. ashutosh.verma@uky.edu

Infection and Immunity
|February 18, 2010
PubMed

Insights

Leptospira interrogans uses its LenA protein to bind human plasminogen, a key step in pathogen invasion. This interaction may facilitate bacterial spread by enabling plasminogen activation and subsequent tissue degradation.

Area of Science:

  • Microbiology
  • Infectious Diseases
  • Biochemistry

Background:

  • Leptospira interrogans is a significant global pathogen.
  • L. interrogans can bind host plasminogen, which can be activated to plasmin.
  • Plasmin aids pathogen invasion and dissemination.

Purpose of the Study:

  • To investigate the interaction between Leptospira interrogans endostatin-like protein A (LenA) and human plasminogen.
  • To determine the role of LenA in acquiring host plasminogen and its potential contribution to bacterial pathogenesis.

Main Methods:

  • Dose-dependent binding assays for LenA and plasminogen.
  • Inhibition studies using xi-aminocaproic acid to probe lysine-binding sites.
  • Competition assays with factor H and laminin to assess binding site overlap.
  • Functional assays to determine plasminogen activation and fibrinogen degradation.

Main Results:

  • LenA binds human plasminogen in a dose-dependent manner.
  • Lysine-binding sites on plasminogen are involved in LenA binding.
  • LenA exhibits overlapping binding sites for plasminogen, factor H, and laminin.
  • LenA-bound plasminogen can be converted to plasmin, which degrades fibrinogen.

Conclusions:

  • LenA facilitates the acquisition of host plasminogen by L. interrogans.
  • The interaction between LenA and plasminogen may enhance bacterial dissemination through host tissues.
  • LenA represents a potential therapeutic target for leptospirosis.

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