LPS-induced expression of a novel chemokine receptor (L-CCR) in mouse glial cells in vitro and in vivo.

There is increasing evidence that chemokines, specialized regulators of the peripheral immune system, are also involved in the physiology and pathology of the CNS. It is known that glial cells (astrocytes and microglia) express various chemokine receptors like CCR1, -3, -5, and CXCR4. We have investigated the possible expression of the known CC chemokine receptors (CCR1-8 and D6) in murine glial cells. In addition, we examined possible glial expression of the orphan CC chemokine receptor L-CCR that has been identified previously in murine macrophages. We report here expression of L-CCR mRNA in murine astrocytes and microglia. Furthermore, L-CCR mRNA expression was strongly induced after application of bacterial lipopolysaccharide (LPS), both in vitro and in vivo. Functional studies and binding experiments using biotinylated monocyte chemoattractant protein (MCP)-1 (CCL2) indicate that CCL2 could be a candidate chemokine ligand for glial L-CCR. Based on the data presented, it is suggested that L-CCR is a functional glial chemokine receptor that is important in neuroimmunology. Copyright 2003 Wiley-Liss, Inc.