LPS regulates a set of genes in primary murine macrophages by antagonising CSF-1 action

Abstract

We previously reported that bacterial products such as LPS and CpG DNA down-modulated cell surface levels of the Colony Stimulating Factor (CSF)-1 receptor (CSF-1R) on primary murine macrophages in an all-or-nothing manner. Here we show that the ability of bacterial products to down-modulate the CSF-1R rendered bone marrow-derived macrophages (BMM) unresponsive to CSF-1 as assessed by Akt and ERK1/2 phosphorylation. Using toll-like receptor (tlr)9 as a model CSF-1-repressed gene, we show that LPS induced tlr9 expression in BMM only when CSF-1 was present, suggesting that LPS relieves CSF-1-mediated inhibition to induce gene expression. Using cDNA micro-arrays, we identified a cluster of simi..