Neutrophil inhibitory factor prevents neutrophil-dependent lung injury.
Neutrophil inhibitory factor (NIF) is a recently cloned 41-kDa protein from the canine hookworm that binds CD11b/CD18 and inhibits CD11b/CD18-dependent neutrophil adhesion. We evaluated NIF's effects on neutrophil-dependent lung injury in guinea pigs. Pulmonary vascular endothelial CD54 (ICAM-1) was induced in buffer-perfused lungs by 90-min exposure to 1000 U/ml TNF-alpha. Human neutrophils (2 x 10(7)) were added to the perfusate and activated by 5 x 10(-9) PMA; in some lungs, the neutrophils were pretreated with NIF (100 nM) before their addition to the perfusate. Lung injury was assessed by wet:dry weight ratio, and neutrophil uptake by lung myeloperoxidase (MPO) activity. HUVEC exposed to TNF-alpha for 90 min were assayed for neutrophil adhesion, and we compared PMA-stimulated neutrophil adhesion to endothelial cells and fibrinogen-coated plates. PMA-induced pulmonary edema (lung wet:dry ratio increased from 8.8 +/- 0.7 to 18.8 +/- 4.4) was inhibited by NIF (10.0 +/- 1.0). Lung MPO activity concomitantly decreased from 17.1 +/- 6.1 to 8.7 +/- 1.8 U/mg dry lung tissue in the NIF-treated group, similar to controls (6.9 +/- 2.0). Endothelial monolayer experiments confirmed that NIF reduced neutrophil adherence (basal adhesion of 11 +/- 3% increased to 30 +/- 5% with TNF-alpha pretreatment of endothelial cells, an increase that was reduced to 10 +/- 4% with NIF). Moreover, NIF prevented PMA-induced neutrophil adhesion to fibrinogen, a CD11b/CD18-dependent event, but produced a smaller decrease in adherence to endothelial cells, which also involves CD11a/CD18 integrins. These studies indicate that NIF prevents neutrophil-dependent lung vascular injury by inhibiting neutrophil adhesion to the TNF-alpha-activated endothelium.
Barnard
J W
JW
Department of Pharmacology, Rush Presbyterian-St. Luke's Medical Center, Chicago, IL 60612, USA.
Biro
M G
MG
Lo
S K
SK
Ohno
S
S
Carozza
M A
MA
Moyle
M
M
Soule
H R
HR
Malik
A B
AB
D000818:Animals; D002448:Cell Adhesion / Q000187:drug effects; D002478:Cells, Cultured; D004285:Dogs; D004727:Endothelium / Q000276:immunology* / Q000473:pathology; D006023:Glycoproteins / Q000494:pharmacology*; D006168:Guinea Pigs; D015801:Helminth Proteins / Q000494:pharmacology*; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000276:immunology; D008168:Lung / Q000276:immunology* / Q000473:pathology; D008297:Male; D008565:Membrane Proteins; D018375:Neutrophil Activation; D009504:Neutrophils / Q000276:immunology* / Q000473:pathology; D010703:Phorbol Esters / Q000494:pharmacology; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
D006023:Glycoproteins; D015801:Helminth Proteins; D008565:Membrane Proteins; D010703:Phorbol Esters; D014409:Tumor Necrosis Factor-alpha; D018799:Intercellular Adhesion Molecule-1; C086581:NIF protein, Ancylostoma caninum