Release of elastase from purified human lung mast cells and basophils. Identification as a Hageman factor cleaving enzyme.
Elastase, a serine protease, is capable of inducing severe lung destruction in experimental animal models. We now report that this proteinase exists preformed in neutrophil-free sonicates of purified human lung mast cells (greater than 98% purity) and in circulating peripheral blood basophils (greater than 97% purity). The elastase levels in both cell types (41-174 ng/10(6) cells) represents approximately 3-20% of those found in human neutrophils; both cell types released their elastase following anti-IgE and ionophore A23187 challenge. The apparent molecular size of the mast cell enzyme on Sephadex G-100 gel filtration, as well as its inhibition profile, was identical to that of purified human neutrophil elastase. This mast cell elastase is identical to our previously reported mast cell-derived Hageman factor cleaving activity. Mast cell-, basophil-, and neutrophil-derived elastases cleave Hageman factor into fragments of 52,000 and 28,000 Da; cleavage by all three enzymes is inhibited by preincubation with polyclonal antibodies directed against human neutrophil elastase.
Meier
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HL
Biochemical Pharmacology Branch, USAMRICD Aberdeen Proving Ground, Maryland 21010.
Schulman
E S
ES
Heck
L W
LW
MacGlashan
D
D
Newball
H H
HH
Kaplan
A P
AP
D001345:Autoradiography; D001491:Basophils / Q000201:enzymology*; D002478:Cells, Cultured; D005174:Factor XII / Q000378:metabolism*; D015956:Factor XIIa; D006801:Humans; D007073:Immunoglobulin E / Q000502:physiology; D008168:Lung / Q000201:enzymology*; D008407:Mast Cells / Q000201:enzymology*; D008970:Molecular Weight; D009504:Neutrophils / Q000201:enzymology; D010196:Pancreatic Elastase / Q000378:metabolism*; D012697:Serine Endopeptidases / Q000378:metabolism*
D007073:Immunoglobulin E; D005174:Factor XII; D012697:Serine Endopeptidases; D010196:Pancreatic Elastase; D015956:Factor XIIa