title: Inactivation of a subpopulation of human neutrophils by exposure to ultrahigh-molecular-weight polyethylene wear debris.
abstract: Polymorphonuclear neutrophils, a first line of defence against invading microbial pathogens, may be attracted by inflammatory mediators triggered by ultrahigh-molecular-weight polyethylene (UHMWPE) wear particles released from orthopaedic prostheses. Phagocytosis of UHMWPE particles by neutrophils may indirectly compromise their phagocytic-bactericidal mechanisms, thus enhancing host susceptibility to microbial infections. In an in vitro assay, pre-exposure of purified human neutrophils to UHMWPE micrometre- and submicrometre-sized wear particles interfered with subsequent Staphylococcos aureus uptake in a heterogeneous way, as assessed by a dual label fluorescence microscopic assay that discriminated intracellular rhodamine-labelled UHMWPE particles from fluorescein isothiocyanate-labelled S. aureus. Indeed, a higher percentage (44%) of neutrophils having engulfed UHMWPE particles lost the ability to phagocytize S. aureus, compared with UHMWPE-free neutrophils (<3%). Pre-exposure of neutrophils to UHMWPE wear particles did not impair but rather stimulated their oxidative burst response in a chemoluminescence assay. The presence of UHMWPE wear particles did not lead to significant overall consumption of complement-mediated opsonic factors nor decreased surface membrane display of neutrophil complement receptors. In conclusion, engulfment of UHMWPE wear particles led to inactivation of S. aureus uptake in nearly half of the neutrophil population, which may potentially impair host clearance mechanisms against pyogenic infections.
authors.affiliation: Service of Orthopaedic Surgery, Geneva University Hospital, Switzerland.
authors.forename: Louis
authors.initials: L
authors.lastname: Bernard
authors.forename: Pierre
authors.initials: P
authors.lastname: Vaudaux
authors.forename: Elzbieta
authors.initials: E
authors.lastname: Huggler
authors.forename: Richard
authors.initials: R
authors.lastname: Stern
authors.forename: Claude
authors.initials: C
authors.lastname: Fréhel
authors.forename: Patrice
authors.initials: P
authors.lastname: Francois
authors.forename: Daniel
authors.initials: D
authors.lastname: Lew
authors.forename: Pierre
authors.initials: P
authors.lastname: Hoffmeyer
mesh_terms: D002478:Cells, Cultured; D003165:Complement System Proteins / Q000276:immunology; D005456:Fluorescent Dyes; D006801:Humans; D008163:Luminescent Measurements; D050296:Microbial Viability; D008856:Microscopy, Fluorescence; D009504:Neutrophils / Q000276:immunology*; D010316:Particle Size; D010587:Phagocytosis; D011095:Polyethylenes; D011951:Receptors, Complement / Q000378:metabolism; D016897:Respiratory Burst / Q000502:physiology*; D013194:Staining and Labeling; D013211:Staphylococcus aureus / Q000276:immunology
chemical_list: D005456:Fluorescent Dyes; D011095:Polyethylenes; D011951:Receptors, Complement; C111601:ultra-high molecular weight polyethylene; D003165:Complement System Proteins