Neutrophils from patients after burn injury express a deficiency of the oxidase components p47-phox and p67-phox.
Infection is a major cause of morbidity and mortality in patients after thermal injury. This predisposition to infections is related, in part, to abnormal polymorphonuclear leukocyte (PMN) function and a diminished respiratory burst. To evaluate the biochemical basis for the defective respiratory burst after major burns, the status of the oxidase enzyme system and its components was investigated. PMNs were isolated from 24 patients with 12% to 62% burns. Oxidase activity of intact PMNs, measured as superoxide anion (O2-) generation or oxygen consumption, was decreased in burn compared with healthy controls. Subcellular fractions from patient PMNs generated less O2- in the sodium dodecyl sulfate cell-free system, and this was related to a diminished contribution by cytosol but not by plasma membrane. Subsequently, cytosol was separated with CM-Sepharose, yielding two fractions; one contained the p47-phox and p67-phox (47/67 mix) and the other contained the remaining cytosolic components (run through [RT]). Although the contribution to oxidase activity made by RT from patient cytosol was similar to that of control, the activity of p47/67 mix from PMNs of burn patients was deficient. Quantitative assays using an immunoautoradiographic technique showed a consistent, but significant decrease in both p47-phox and p67-phox. The addition of purified or human recombinant p47-phox but not p67-phox corrected the diminished oxidase activity of cytosol from burn patients. Thus, decreased respiratory burst activity found in PMNs from individuals with thermal injury was associated with a specific, quantitative deficiency of p47-phox.
Rosenthal
J
J
Department of Pediatrics, University of Colorado School of Medicine, Denver, USA.
Thurman
G W
GW
Cusack
N
N
Peterson
V M
VM
Malech
H L
HL
Ambruso
D R
DR
D000328:Adult; D002056:Burns / Q000201:enzymology / Q000276:immunology*; D002474:Cell-Free System; D003573:Cytochrome b Group / Q000172:deficiency; D003600:Cytosol / Q000201:enzymology; D004198:Disease Susceptibility; D005260:Female; D006801:Humans; D016867:Immunocompromised Host; D007239:Infections / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D019255:NADPH Oxidases / Q000172:deficiency* / Q000502:physiology; D009504:Neutrophils / Q000187:drug effects / Q000201:enzymology*; D010100:Oxygen / Q000378:metabolism; D010750:Phosphoproteins / Q000172:deficiency*; D010972:Platelet Activating Factor / Q000494:pharmacology; D016897:Respiratory Burst / Q000187:drug effects; D013347:Subcellular Fractions / Q000201:enzymology; D013481:Superoxides / Q000378:metabolism; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D003573:Cytochrome b Group; D010750:Phosphoproteins; D010972:Platelet Activating Factor; C079789:neutrophil cytosol factor 67K; D013481:Superoxides; D009240:N-Formylmethionine Leucyl-Phenylalanine; C036888:cytochrome b558; D019255:NADPH Oxidases; C060505:neutrophil cytosolic factor 1; D013755:Tetradecanoylphorbol Acetate; D010100:Oxygen