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Extracellular DNA: A Major Proinflammatory Component of Pseudomonas aeruginosa Biofilms
- Source :
- The Journal of Immunology. 184:6386-6395
- Publication Year :
- 2010
- Publisher :
- The American Association of Immunologists, 2010.
-
Abstract
- We previously demonstrated that extracellular bacterial DNA activates neutrophils through a CpG- and TLR9-independent mechanism. Biofilms are microbial communities enclosed in a polymeric matrix that play a critical role in the pathogenesis of many infectious diseases. Because extracellular DNA is a key component of biofilms of different bacterial species, the aim of this study was to determine whether it plays a role in the ability of biofilms to induce human neutrophil activation. We found that degradation of matrix extracellular DNA with DNase I markedly reduced the capacity of Pseudomonas aeruginosa biofilms to induce the release of the neutrophil proinflammatory cytokines IL-8 and IL-1β (>75%); reduced the upregulation of neutrophil activation markers CD18, CD11b, and CD66b (p < 0.001); reduced the number of bacteria phagocytosed per neutrophil contacting the biofilm; and reduced the production of neutrophil extracellular traps. Consistent with these findings, we found that biofilms formed by the lasI rhlI P. aeruginosa mutant strain, exhibiting a very low content of matrix extracellular DNA, displayed a lower capacity to stimulate the release of proinflammatory cytokines by neutrophils, which was not decreased further by DNase I treatment. Together, our findings support that matrix extracellular DNA is a major proinflammatory component of P. aeruginosa biofilms.
- Subjects :
- DNA, Bacterial
Neutrophils
Immunology
Matrix (biology)
medicine.disease_cause
Neutrophil Activation
Proinflammatory cytokine
Microbiology
chemistry.chemical_compound
medicine
Extracellular
Humans
Immunology and Allergy
Microscopy, Confocal
biology
Pseudomonas aeruginosa
Biofilm
Extracellular Fluid
Neutrophil extracellular traps
biology.organism_classification
Cell biology
chemistry
Biofilms
Cytokines
Bacteria
DNA
Subjects
Details
- ISSN :
- 15506606 and 00221767
- Volume :
- 184
- Database :
- OpenAIRE
- Journal :
- The Journal of Immunology
- Accession number :
- edsair.doi.dedup.....a45cdc3ead1ee4836d3ea5cb96879226