Journal article
Compromised host defense on Pseudomonas aeruginosa biofilms: characterization of neutrophil and biofilm interactions
The Journal of immunology (1950), Vol.171(8), pp.4329-4339
10/15/2003
Handle:
https://hdl.handle.net/2376/117991
PMID: 14530358
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen that forms biofilms on tissues and other surfaces. We characterized the interaction of purified human neutrophils with P. aeruginosa, growing in biofilms, with regard to morphology, oxygen consumption, phagocytosis, and degranulation. Scanning electron and confocal laser microscopy indicated that the neutrophils retained a round, unpolarized, unstimulated morphology when exposed to P. aeruginosa PAO1 biofilms. However, transmission electron microscopy demonstrated that neutrophils, although rounded on their dorsal side, were phagocytically active with moderate membrane rearrangement on their bacteria-adjacent surfaces. The settled neutrophils lacked pseudopodia, were impaired in motility, and were enveloped by a cloud of planktonic bacteria released from the biofilms. The oxygen consumption of the biofilm/neutrophil system increased 6- and 8-fold over that of the biofilm alone or unstimulated neutrophils in suspension, respectively. H(2)O(2) accumulation was transient, reaching a maximal measured value of 1 micro M. Following contact, stimulated degranulation was 20-40% (myeloperoxidase, beta-glucuronidase) and 40-80% (lactoferrin) of maximal when compared with formylmethionylleucylphenylalanine plus cytochalasin B stimulation. In summary, after neutrophils settle on P. aeruginosa biofilms, they become phagocytically engorged, partially degranulated, immobilized, and rounded. The settling also causes an increase in oxygen consumption of the system, apparently resulting from a combination of a bacterial respiration and escape response and the neutrophil respiratory burst but with little increase in the soluble concentration of H(2)O(2). Thus, host defense becomes compromised as biofilm bacteria escape while neutrophils remain immobilized with a diminished oxidative potential.
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Details
- Title
- Compromised host defense on Pseudomonas aeruginosa biofilms: characterization of neutrophil and biofilm interactions
- Creators
- Algirdas J Jesaitis - Department of Microbiology, Montana State University, Bozeman, MT 59717-3520, USA. umbaj@montana.eduMichael J FranklinDeborah BerglundMaiko SasakiConnie I LordJustin B BleazardJames E DuffyHaluk BeyenalZbigniew Lewandowski
- Publication Details
- The Journal of immunology (1950), Vol.171(8), pp.4329-4339
- Academic Unit
- Chemical Engineering and Bioengineering, School of
- Publisher
- United States
- Grant note
- R01-AI22735 / NIAID NIH HHS 1PZORR16455 / ORS NIH HHS AI-46588 / NIAID NIH HHS R01 AI 26711 / NIAID NIH HHS
- Identifiers
- 99900548021501842
- Language
- English
- Resource Type
- Journal article