Outer membrane protein OlpA contributes to Moraxella catarrhalis serum resistance via interaction with factor H and the alternative pathway.
Factor H is an important complement regulator of the alternative pathway commonly recruited by pathogens to achieve increased rates of survival in the human host. The respiratory pathogen Moraxella catarrhalis, which resides in the mucosa, is highly resistant to the bactericidal activity of serum and causes otitis media in children and respiratory tract infections in individuals with underlying diseases. In this study, we show that M. catarrhalis binds factor H via the outer membrane protein OlpA. M. catarrhalis serum resistance was dramatically decreased in the absence of either OlpA or factor H, demonstrating that this inhibition of the alternative pathway significantly contributes to the virulence of M. catarrhalis.
Medical Microbiology, Department of Laboratory Medicine Malmö, Lund University, Sweden.
Sara
S
Bernhard
Medical Microbiology, Department of Laboratory Medicine Malmö, Lund University, Sweden.
Christophe
C
Fleury
Medical Microbiology, Department of Laboratory Medicine Malmö, Lund University, Sweden.
Yu-Ching
YC
Su
Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany.
Peter F
PF
Zipfel
Medical Microbiology, Department of Laboratory Medicine Malmö, Lund University, Sweden.
Iris
I
Koske
Medical Microbiology, Department of Laboratory Medicine Malmö, Lund University, Sweden.
Therése
T
Nordström
Medical Microbiology, Department of Laboratory Medicine Malmö, Lund University, Sweden.
Kristian
K
Riesbeck
D001422:Bacterial Adhesion; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D017242:Complement Factor H / Q000378:metabolism*; D003170:Complement Pathway, Alternative / Q000502:physiology*; D006801:Humans; D001936:Moraxella catarrhalis / Q000378:metabolism*; D011485:Protein Binding; D058248:Serum Bactericidal Antibody Assay
D001425:Bacterial Outer Membrane Proteins; D017242:Complement Factor H
Moraxella catarrhalis; factor H; serum resistance