Mechanisms of human neutrophil oxidant production after severe injury.
BACKGROUND
The purpose of this study was to determine the mechanisms of enhanced oxidant production after severe injury.


METHODS
Neutrophils were harvested from patients within 24 hours of admission who had an injury severity score greater than 16. Nonadherent and adherent neutrophil oxidant production was measured after N-formyl-methionyl-leucyl-phenylalanine (fMLP) stimulation. Translocation of cytochrome b558 and cytosolic components p47phox and p67phox were determined by oxidation-reduction spectroscopy and immunoblotting, respectively. Flow cytometry measured integrin expression. Integrin and p47phox colocalization was examined by confocal microscopy.


RESULTS
Eighteen patients were studied within 15 +/- 1.4 hours. Four women and 14 men suffered a blunt injury and had a mean injury severity score of 22 (range, 16 to 34). Nonadherent patient neutrophils showed a decrease in fMLP-stimulated oxidant production, whereas adherent neutrophil oxidant production was increased in both the vehicle control and fMLP-stimulated groups. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase components p47phox and cytochrome b558 were mobilized to the plasma membrane, whereas p67phox showed minimal change. Integrin CD11b a chain showed a significant increase in expression. Confocal microscopy showed colocalization of p47phox and a chain CD11b on the plasma membrane of patient neutrophils.


CONCLUSIONS
Colocalization of NADPH oxidase components and integrins may regulate the enhanced oxidant production in human neutrophils after severe injury.
Quaid
G
G
Department of Surgery, University of Cincinnati, College of Medicine, Cincinnati, Ohio 45267-0558, USA.
Cave
C
C
Williams
M A
MA
Hennigan
R F
RF
Bokoch
G
G
Solomkin
J S
JS
D000293:Adolescent; D000328:Adult; D000368:Aged; D018821:CD18 Antigens / Q000096:biosynthesis; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D019255:NADPH Oxidases / Q000096:biosynthesis; D009504:Neutrophils / Q000378:metabolism*; D010545:Peroxides / Q000378:metabolism; D010750:Phosphoproteins / Q000096:biosynthesis; D013481:Superoxides / Q000378:metabolism; D014947:Wounds and Injuries / Q000378:metabolism*
D018821:CD18 Antigens; D010545:Peroxides; D010750:Phosphoproteins; C079789:neutrophil cytosol factor 67K; D013481:Superoxides; D009240:N-Formylmethionine Leucyl-Phenylalanine; D019255:NADPH Oxidases