title: Expression of granzyme A in human polymorphonuclear neutrophils.
abstract: Polymorphonuclear neutrophils (PMNs) are the first line of defence against invading pathogens. They contain a multitude of antimicrobial and potentially cytotoxic substances packed in granules and secretory vesicles. Here, we show that granzyme A (GzmA) is constitutively expressed in human PMNs, but not in the promyelocytic cell line HL-60, by performing flow cytometry, western blot, enzyme-linked immunosorbent assay and quantitative polymerase chain reaction. To further track the intracellular localization of GzmA, we performed subcellular fractionation and found GzmA to be present in peroxidase-negative granules. Finally, stimulation with opsonized Escherichia coli or the bioincompatible haemodialysis membrane cuprophane led to up-regulation of GzmA expression at the transcriptional level as well as at the translational level. In conclusion, we provide clear evidence that GzmA is constitutively expressed in human PMNs and can be up-regulated upon stimulation. These findings may also indicate a role for GzmA in PMNs in defence against invading pathogens.
authors.affiliation: Clinical Division of Nephrology, Innsbruck Medical University, Innsbruck, Austria.
authors.forename: Kathrin
authors.initials: K
authors.lastname: Hochegger
authors.forename: Philipp
authors.initials: P
authors.lastname: Eller
authors.forename: Julia M
authors.initials: JM
authors.lastname: Huber
authors.forename: David
authors.initials: D
authors.lastname: Bernhard
authors.forename: Gert
authors.initials: G
authors.lastname: Mayer
authors.forename: Gerhard J
authors.initials: GJ
authors.lastname: Zlabinger
authors.forename: Alexander R
authors.initials: AR
authors.lastname: Rosenkranz
mesh_terms: D002458:Cell Fractionation; D002478:Cells, Cultured; D015971:Gene Expression Regulation, Enzymologic; D053804:Granzymes / Q000097:blood* / Q000235:genetics; D018922:HL-60 Cells; D006801:Humans; D009504:Neutrophils / Q000201:enzymology*; D010587:Phagocytosis; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D013347:Subcellular Fractions / Q000201:enzymology; D015854:Up-Regulation
chemical_list: D053804:Granzymes