title: Residence in biofilms allows Burkholderia cepacia complex (Bcc) bacteria to evade the antimicrobial activities of neutrophil-like dHL60 cells.
abstract: Bacteria of the Burkholderia cepacia complex (Bcc) persist in the airways of people with cystic fibrosis (CF) despite the continuous recruitment of neutrophils. Most members of Bcc are multidrug resistant and can form biofilms. As such, we sought to investigate whether biofilm formation plays a role in protecting Bcc bacteria from neutrophils. Using the neutrophil-like, differentiated cell line, dHL60, we have shown for the first time that Bcc biofilms are enhanced in the presence of these cells. Biofilm biomass was greater following culture in the presence of dHL60 cells than in their absence, likely the result of incorporating dHL60 cellular debris into the biofilm. Moreover, we have demonstrated that mature biofilms (cultured for up to 72 h) induced necrosis in the cells. Established biofilms also acted as a barrier to the migration of the cells and masked the bacteria from being recognized by the cells; dHL60 cells expressed less IL-8 mRNA and secreted significantly less IL-8 when cultured in the presence of biofilms, with respect to planktonic bacteria. Our findings provide evidence that biofilm formation can, at least partly, enable the persistence of Bcc bacteria in the CF airway and emphasize a requirement for anti-biofilm therapeutics.
authors.affiliation: Centre for Microbial-Host Interactions, Institute of Technology Tallaght, Dublin 24, Ireland Centre of Applied Science for Health, Institute of Technology Tallaght, Dublin 24, Ireland.
authors.forename: Mark P
authors.initials: MP
authors.lastname: Murphy
authors.affiliation: Centre for Microbial-Host Interactions, Institute of Technology Tallaght, Dublin 24, Ireland Centre of Applied Science for Health, Institute of Technology Tallaght, Dublin 24, Ireland emma.caraher@ittdublin.ie.
authors.forename: Emma
authors.initials: E
authors.lastname: Caraher
mesh_terms: D018441:Biofilms / Q000254:growth & development*; D019121:Burkholderia Infections / Q000276:immunology / Q000382:microbiology; D042602:Burkholderia cepacia complex / Q000276:immunology* / Q000502:physiology*; D016923:Cell Death; D002460:Cell Line; D003550:Cystic Fibrosis / Q000150:complications; D020869:Gene Expression Profiling; D006801:Humans; D016209:Interleukin-8 / Q000096:biosynthesis / Q000378:metabolism; D050296:Microbial Viability; D008954:Models, Biological; D009504:Neutrophils / Q000276:immunology* / Q000502:physiology
chemical_list: D016209:Interleukin-8
keywords: cystic fibrosis; host–pathogen interaction; innate immunity