Extracellular DNA: A major proinflammatory component of Pseudomonas aeruginosa biofilms

• Autores: Fuxman Bass, J.I.; Russo, D.M.; Gabelloni, M.L.; Geffner, J.R.; Giordano, M.; Catalano, M.; Zorreguieta, Á.; Trevani, A.S.
• Año de publicación: 2010
• Idioma: inglés
• Tipo de recurso: artículo
• Fuente: J. Immunol. 2010;184(11):6386-6395
• Materia: CD11b antigen; CD18 antigen; CD66b antigen; deoxyribonuclease I; DNA; interleukin 1beta; interleukin 8; lymphocyte antigen; unclassified drug; bacterial DNA; cytokine; article; bacterial strain; biofilm; controlled study; cytokine release; degradation; extracellular matrix; human; leukocyte activation; nonhuman; phagocytosis; priority journal; Pseudomonas aeruginosa; upregulation; biosynthesis; chemistry; confocal microscopy; extracellular fluid; growth, development and aging; immunology; leukocyte activation; metabolism; microbiology; neutrophil; physiology; Biofilms; Cytokines; DNA, Bacterial; Extracellular Fluid; Humans; Microscopy, Confocal; Neutrophil Activation; Neutrophils; Pseudomonas aeruginosa
• Institución: Universidad Nacional de Buenos Aires. Facultad de Ciencias Exactas y Naturales

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. Copyright © 2010 by The American Association of Immunologists, Inc.
Fil:Fuxman Bass, J.I. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.
Fil:Russo, D.M. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.
Fil:Gabelloni, M.L. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.
Fil:Giordano, M. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.
Fil:Zorreguieta, Á. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.
Fil:Trevani, A.S. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.