ABSTRACT: Although the role of macrophage colony stimulating factor (M-CSF/CSF-1) in homeostasis and disease processes has been studied extensively in mice, little is known of the impact of this cytokine on differentiated human macrophages. Here we show that, in contrast to its effects on mouse bone marrow-derived macrophages (BMM), CSF-1 did not induce expression of urokinase plasminogen activator mRNA, repress expression of apolipoprotein E mRNA, or prime LPS-induced TNF secretion in human monocyte-derived macrophages (HMDM) from several independent donors. Using expression profiling, we show that CSF-1 dynamically regulated the expression of several genes that encode chemokines and chemokine receptors (e.g. CXCL10/IP-10, CXCL2, CCL7, SDF2L1, CXCR4) in HMDM. CSF-1 also upregulated the expression of several genes encoding enzymes of the cholesterol biosynthetic pathway (HMGCR, MVD, IDI1, FDPS, SQLE, CYP51A1, EBP, NSDHL, DHCR7 and DHCR24), while expression of ABCG1, encoding a cholesterol efflux transporter, was repressed. Although the CSF-1/CSF-1R system has been proposed as a target for the treatment of inflammatory and metastatic disease based on studies in rodents, this is the first systematic analysis of the effects of CSF-1 on mature human macrophages. Our data demonstrates that CSF-1 represents a further link between inflammation and cardiovascular disease, inflammtion and immunity. Keywords: Stimulus response