Atypical chemokine receptor 2 (ACKR2/D6) [], previously known as CCR9 or CCR10 [], is a chemokine-scavenging receptor or chemokine decoy receptor. It is capable of internalising and effectively scavenging its ligands through beta-arrestin-dependent activation of the cofilin pathway [, ]. ACKR2 is highly promiscuous and can bind the majority of (if not all) inflammatory CC-chemokines []. It plays an essential role in the resolution of the inflammatory response [, , ]. Although it lacks the canonical DRYLAIV motif necessary for classical signalling, ACKR2/D6 may be involved in 'atypical' signalling pathways downstream of ligand binding []. It has been shown to be involved in regulating vessel density [].
CXC chemokine receptor 4 (CXCR4), also known as fusin, which is a specific receptor for a CXCL12 (or SDF1). CXCR4 has a wide cellular distribution, with expression on most immature and mature hematopoietic cell types [, , , , ]. In addition, CXCR4 can also be found on vascular endothelial cells and neuronal/nerve cells []. Upon binding to CXCR4, CXCL12 causes mobilisation of intracellular calcium and chemotaxis [, , ]. CXCL12 is known to be important in hematopoietic stem cell homing to the bone marrow and in hematopoietic stem cell quiescence. CXCR4 has a rather broad activity, and has been linked to cardiac, cerebellar gastric vasculature development [, ]and to hematopoiesis []. Atypical chemokine receptor 2 (ACKR2/D6) []is a chemokine-scavenging receptor or chemokine decoy receptor. It is capable of internalising and effectively scavenging its ligands through beta-arrestin-dependent activation of the cofilin pathway [, ]. ACKR2 is highly promiscuous and can bin the majority of (if not all) inflammatory CC-chemokines []. It plays an essential role in the resolution of the inflammatory response [, , ]. Although it lacks the canonical DRYLAIV motif necessary for classical signalling, ACKR2/D6 may be involved in 'atypical' signaling pathways downstream of ligand binding []. It has been shown to be involved in regulating vessel density [].