Pseudomonas aeruginosa elastase degrades surfactant proteins A and D.

Published

Journal Article

Both in vitro and in vivo studies provide evidence that surfactant protein (SP)-A and SP-D have an important role in the innate immune response to Pseudomonas aeruginosa. In preliminary experiments characterizing the binding of SP-A to this bacteria, we observed the appearance of apparent degradation products of SP-A, and therefore we hypothesized that P. aeruginosa produces an enzyme that degrades SP-A. Incubation of SP-A with P. aeruginosa organisms from several clinical isolates resulted in concentration- and temperature-dependent degradation of SP-A that was inhibited by a metalloproteinase inhibitor, phosphoramidon. The degradative enzyme was purified by anion exchange chromatography and identified by ion trap mass spectroscopy as Pseudomonas elastase, which was shown to directly degrade SP-A and SP-D. Incubation of P. aeruginosa or purified elastase with cell-free bronchoalveolar lavage (BAL) resulted in degradation of SP-A. Furthermore, SP-A degradation fragments were detectable in BAL from lung transplant patients with cystic fibrosis. We speculate that degradation of SP-A and SP-D is a virulence mechanism in the pathogenesis of chronic P. aeruginosa infection.

Full Text

Duke Authors

Cited Authors

  • Mariencheck, WI; Alcorn, JF; Palmer, SM; Wright, JR

Published Date

  • April 2003

Published In

Volume / Issue

  • 28 / 4

Start / End Page

  • 528 - 537

PubMed ID

  • 12654643

Pubmed Central ID

  • 12654643

International Standard Serial Number (ISSN)

  • 1044-1549

Digital Object Identifier (DOI)

  • 10.1165/rcmb.2002-0141OC

Language

  • eng

Conference Location

  • United States