title: Alpha-1-antitrypsin is produced by human neutrophil granulocytes and their precursors and liberated during granule exocytosis.
abstract: Alpha-1-antitrypsin (A1AT) is an important inhibitor of neutrophil proteases including elastase, cathepsin G, and proteinase 3. Transcription profiling data suggest that A1AT is expressed by human neutrophil granulocytes during all developmental stages. A1AT has hitherto only been found associated with azurophile granules in neutrophils indicative of A1AT expression being restricted to the promyelocyte stage. We examined the localization and production of A1AT in healthy donor neutrophils and found A1AT to be a constituent of all granule subtypes and to be released from neutrophils following stimulation. A1AT is produced at all stages of myeloid maturation in the bone marrow. The production increases as neutrophils enter circulation and increases further upon migration to tissues as observed in skin windows and when blood neutrophils are incubated with granulocyte colony-stimulating factor. Neutrophils from patients with A1AT-deficiency carrying the (PI)ZZ mutation in the A1AT gene appeared structurally and functionally normal, but A1AT produced in leukocytes of these patients lacked the ability to bind proteases efficiently. We conclude that A1AT generation and release from neutrophils add significantly to the antiprotease levels in tissues during inflammation. Impaired binding of neutrophil A1AT to serine proteases in patients with (PI)ZZ mutations may enhance their susceptibility to the development of emphysema.
authors.affiliation: The Granulocyte Research Laboratory, Department of Hematology, National University Hospital, Copenhagen, Denmark.
authors.forename: Stine N
authors.initials: SN
authors.lastname: Clemmensen
authors.forename: Lars C
authors.initials: LC
authors.lastname: Jacobsen
authors.forename: Sara
authors.initials: S
authors.lastname: Rørvig
authors.forename: Bjarke
authors.initials: B
authors.lastname: Askaa
authors.forename: Karin
authors.initials: K
authors.lastname: Christenson
authors.forename: Martin
authors.initials: M
authors.lastname: Iversen
authors.forename: Marianne H
authors.initials: MH
authors.lastname: Jørgensen
authors.forename: Maria T
authors.initials: MT
authors.lastname: Larsen
authors.forename: Bo
authors.initials: B
authors.lastname: van Deurs
authors.forename: Ole
authors.initials: O
authors.lastname: Ostergaard
authors.forename: Niels H
authors.initials: NH
authors.lastname: Heegaard
authors.forename: Jack B
authors.initials: JB
authors.lastname: Cowland
authors.forename: Niels
authors.initials: N
authors.lastname: Borregaard
mesh_terms: D016022:Case-Control Studies; D015550:Cell Degranulation / Q000187:drug effects; D002454:Cell Differentiation; D003594:Cytoplasmic Granules / Q000378:metabolism; D004804:Eosinophils / Q000201:enzymology; D005089:Exocytosis / Q000187:drug effects; D005838:Genotype; D016179:Granulocyte Colony-Stimulating Factor / Q000494:pharmacology; D006801:Humans; D066298:In Vitro Techniques; D016031:Liver Transplantation; D016040:Lung Transplantation; D046529:Microscopy, Electron, Transmission; D009154:Mutation; D009504:Neutrophils / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins; D012884:Skin Window Technique; D000515:alpha 1-Antitrypsin / Q000096:biosynthesis* / Q000235:genetics; D019896:alpha 1-Antitrypsin Deficiency / Q000201:enzymology / Q000235:genetics / Q000473:pathology / Q000601:surgery
chemical_list: D012333:RNA, Messenger; D011994:Recombinant Proteins; C043392:SERPINA1 protein, human; D000515:alpha 1-Antitrypsin; D016179:Granulocyte Colony-Stimulating Factor