Moraxella catarrhalis Evades Host Innate Immunity via Targeting Cartilage Oligomeric Matrix Protein.
Guanghui LiuHenrik GradstedtDavid ErmertEmelie EnglundBirendra SinghYu-Ching SuMartin E JohanssonAnders AspbergVaibhav AgarwalKristian RiesbeckAnna M BlomPublished in: Journal of immunology (Baltimore, Md. : 1950) (2015)
Moraxella catarrhalis is a respiratory tract pathogen commonly causing otitis media in children and acute exacerbations in patients suffering from chronic obstructive pulmonary disease. Cartilage oligomeric matrix protein (COMP) functions as a structural component in cartilage, as well as a regulator of complement activity. Importantly, COMP is detected in resident macrophages and monocytes, alveolar fluid, and the endothelium of blood vessels in lung tissue. We show that the majority of clinical isolates of M. catarrhalis (n = 49), but not other tested bacterial pathogens, bind large amounts of COMP. COMP interacts directly with the ubiquitous surface protein A2 of M. catarrhalis. Binding of COMP correlates with survival of M. catarrhalis in human serum by inhibiting bactericidal activity of the complement membrane attack complex. Moreover, COMP inhibits phagocytic killing of M. catarrhalis by human neutrophils. We further observed that COMP reduces bacterial adhesion and uptake by human lung epithelial cells, thus protecting M. catarrhalis from intracellular killing by epithelial cells. Taken together, our findings uncover a novel mechanism that M. catarrhalis uses to evade host innate immunity.
Keyphrases
- chronic obstructive pulmonary disease
- respiratory tract
- binding protein
- end stage renal disease
- nitric oxide
- newly diagnosed
- chronic kidney disease
- ejection fraction
- endothelial cells
- protein protein
- amino acid
- extracellular matrix
- young adults
- liver failure
- intensive care unit
- escherichia coli
- transcription factor
- drug induced
- biofilm formation
- patient safety
- pseudomonas aeruginosa
- patient reported
- hepatitis b virus
- extracorporeal membrane oxygenation
- patient reported outcomes
- acute respiratory distress syndrome
- pluripotent stem cells