Murine bone marrow macrophages and human monocytes do not express atypical chemokine receptor 1

The atypical chemokine receptor 1 (ACKR1) was discovered on erythrocytes as the Duffy blood group antigen (Cutbush et al., 1950), also called Duffy-antigen/receptor for chemokines, or DARC (Novitzky-Basso and Rot, 2012). Erythrocytes are terminally differentiated anuclear cells with no transcription and limited translation. Accordingly, within the erythroid lineage ACKR1 expression occurs first and is the highest in erythroblasts (Duchene et al., 2017). Additionally, ACKR1 expression characterizes venular endothelial cells (ECs) (Pruenster et al., 2009; Thiriot et al., 2017), including those lining bone marrow (BM) sinusoids (Duchene et al., 2017).