Phospholipase PlaB is a new virulence factor of Legionella pneumophila.

Abstract

We previously identified Legionella pneumophila PlaB as the major cell-associated phospholipase A/lysophospholipase A with contact-dependent hemolytic activity. In this study, we further characterized this protein and found it to be involved in the virulence of L. pneumophila. PlaB was mainly expressed and active during exponential growth. Active PlaB was outer membrane-associated and at least in parts surface-exposed. Transport to the outer membrane was not dependent on the type I (T1SS), II (T2SS), IVB (T4BSS) or Tat secretion pathways. Furthermore, PlaB activity was not dependent on the presence of the macrophage infectivity potentiator (Mip) or the major secreted zinc metalloproteinase A (MspA). Despite the fact that PlaB is not essential for replication in protozoa or macrophage cell lines, we found that plaB mutants were impaired for replication in the lungs and dissemination to the spleen in the guinea pig infection model. Histological sections monitored less inflammation and destruction of the lung tissue after infection with the plaB mutants compared to L. pneumophila wild type. Taken together, PlaB is the first phospholipase A/lysophospholipase A with a confirmed role in the establishment of Legionnaires' disease.

• Authors: Eva Schunder, Patrick Adam, Futoshi Higa, Katharina A Remer, Udo Lorenz, Jennifer Bender, Tino Schulz, Antje Flieger, Michael Steinert, Klaus Heuner
• Journal: International journal of medical microbiology : IJMM (Int J Med Microbiol) Vol. 300 Issue 5 Pg. 313-23 (Jun 2010) ISSN: 1618-0607 [Electronic] Germany
• PMID: 20153694 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright 2010 Elsevier GmbH. All rights reserved.

Chemical References

• Bacterial Outer Membrane Proteins
• Virulence Factors
• Phospholipases

Topics

• Animals
• Bacterial Outer Membrane Proteins (genetics, physiology)
• Disease Models, Animal
• Gene Expression Profiling
• Gene Knockout Techniques
• Guinea Pigs
• Histocytochemistry
• Legionella pneumophila (enzymology, growth & development, pathogenicity)
• Legionnaires' Disease (microbiology)
• Lung (microbiology, pathology)
• Male
• Phospholipases (genetics, physiology)
• Spleen (microbiology)
• Virulence
• Virulence Factors (physiology)