Olfactomedin 4 defines a subset of human neutrophils

Abstract

OLFM4 was identified initially as a gene highly induced in myeloid stem cells by G-CSF treatment. A bioinformatics method using a global meta-analysis of microarray data predicted that OLFM4 would be associated with specific granules in human neutrophils. Subcellular fractionation of peripheral blood neutrophils demonstrated complete colocalization of OLFM4 with the specific granule protein NGAL, and stimulation of neutrophils with PMA resulted in corelease of NGAL and OLFM4, proving that OLFM4 is a genuine constituent of neutrophil-specific granules. In accordance with this, OLFM4 mRNA peaked at the MY/MM stage of maturation. OLFM4 was, however, present in only 20-25% of peripheral blood neutrophils, as determined by immunocytochemistry and flow cytometry, whereas mRNA for OLFM4 was present in all MY/MM, indicating post-transcriptional regulation as a basis for the heterogeneous expression of OLFM4 protein.

Plasma levels of OLFM4 in normals and patients with gastrointestinal cancer

“…Notably, both monoclonal antibodies stain only a subset of neutrophils as observed previously using both commercial monoclonal antibodies and an in‐house rabbit antibody, generated against another synthetic peptide 3.…”

Postnatal Age Is a Critical Determinant of the Neonatal Host Response to Sepsis

“…IL-1R2 is a decoy receptor for IL-1 and highlights the tightly regulated activity of IL-1 in neonates (21). Several innate immunityrelated genes with biology significance were represented among the top 10 in three of the four infected groups, including MMP-8 (metalloproteinase-8, a neutrophil-derived collagenase involved in the degradation of type I collagen [22]), olfactomedin 4 (OLFM4; present in neutrophil granules [23] and potentially important in neutrophil extracellular trap [NET] formation [24]), membranespanning 4-domains, subfamily A, member 4A (MS4A4A; tetraspanin; important for cell migration [25]) and IL-18R1 (receptor for proinflammatory cytokine IL-18 [21] and also ranked eleventh in the early sepsis group). Top downregulated genes were far more varied among groups compared with those that were upregulated.…”

An Interactive Network of Elastase, Secretases, and PAR-2 Protein Regulates CXCR1 Receptor Surface Expression on Neutrophils

“…Subcellular Fractionation of Neutrophils-Subcellular fractionation of neutrophils was performed by nitrogen cavitation and sedimentation of the postnuclear supernatant on a fourlayer Percoll density gradients, as described previously in detail by Clemmensen et al (11,12) and our studies (10,13). In brief, neutrophils isolated from peripheral blood were resuspended in disruption buffer (100 mM KCl, 3 mM NaCl, 1 mM Na 2 ATP 3.5 mM MgCl 2 , 10 mM PIPES, pH 7.2) with a protease inhibitor mixture added as described by the manufacturer (11836153001, Roche Applied Science).…”