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Expression of granzyme A in human polymorphonuclear neutrophils
Author(s) -
Hochegger Kathrin,
Eller Philipp,
Huber Julia M.,
Bernhard David,
Mayer Gert,
Zlabinger Gerhard J.,
Rosenkranz Alexander R.
Publication year - 2007
Publication title -
immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.297
H-Index - 133
eISSN - 1365-2567
pISSN - 0019-2805
DOI - 10.1111/j.1365-2567.2006.02551.x
Subject(s) - granzyme a , biology , western blot , cell fractionation , flow cytometry , cytotoxic t cell , granzyme , microbiology and biotechnology , granzyme b , biochemistry , gene , perforin , enzyme , in vitro
Summary 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.