Changes in gene expression of granulocytes during in vivo granulocyte colony-stimulating factor/dexamethasone mobilization for transfusion purposes

• Published in: Blood Vol. 113; no. 23; pp. 5979 - 5998
• Main Authors: Drewniak, Agata, van Raam, Bram J., Geissler, Judy, Tool, Anton T.J., Mook, Olaf R.F., van den Berg, Timo K., Baas, Frank, Kuijpers, Taco W.
• Format: Journal Article
• Language: English
• Published: Washington, DC Elsevier Inc 04-06-2009; Americain Society of Hematology
• Subjects: Apoptosis - drug effects; Biological and medical sciences; Blood Transfusion; Calpain - antagonists & inhibitors; Calpain - metabolism; Dexamethasone - pharmacology; Enzyme Inhibitors - pharmacology; Female; Flow Cytometry; Gene Expression Profiling; Gene Expression Regulation - drug effects; Gene Expression Regulation - genetics; Granulocyte Colony-Stimulating Factor - pharmacology; Granulocytes - drug effects; Granulocytes - metabolism; Hematologic and hematopoietic diseases; Humans; Male; Medical sciences; Neutrophils - drug effects; Neutrophils - metabolism; RNA, Messenger - genetics; Corticosteroid; In vivo; Mobilization; Granulocyte colony stimulating factor; Dexamethasone; Transfusion; Hematology; Steroid hormone; Granulocyte; Gene expression
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood-2008-10-182147

The treatment of healthy donors with granulocyte colony-stimulating factor (G-CSF) and dexamethasone results in sufficient numbers of circulating granulocytes to prepare granulocyte concentrates for clinical purposes. Granulocytes obtained in this way demonstrate relatively normal functional behavior combined with a prolonged life span. To study the influence of mobilizing agents on granulocytes, we used oligonucleotide microarrays to identify genes that are differentially expressed in mobilized granulocytes compared with control granulocytes. More than 1000 genes displayed a differential expression pattern, with at least a 3-fold difference. Among these, a large number of genes was induced that encode proteins involved in inflammation and the immune response, such as C-type lectins and leukocyte immunoglobulin-like receptors. Because mobilized granulocytes have a prolonged life span, we focused on genes involved in the regulation of apoptosis. One of the most prominent among these was CAST, the gene encoding calpastatin. Calpastatins are the endogenous inhibitors of calpains, a family of calcium-dependent cysteine proteases recently shown to be involved in neutrophil apoptosis. Transcriptional activity of the CAST gene was induced by G-CSF/dexamethasone treatment both in vivo and in vitro, whereas the protein expression of CAST was stabilized during culture. These studies provide new insight in the genotypic changes as well as in the regulation of the immunologic functions and viability of mobilized granulocytes used for clinical transfusion purposes.