Consumables

CD163 is a 130 kDa membrane protein with a short cytoplasmic tail, a single transmembrane segment, and a large ectodomain consisting of 9 scavenger receptor class B domains. CD163 expression is restricted to the monocytic-macrophage lineage with high expression in red pulp macrophages, bone marrow macrophages, liver macrophages (Kupffer cells), and lung macrophages. Low or absent CD163 expression is seen in other monocyte-derived cells, such as dendritic cells, Langerhans cells, and white pulp macrophages in the spleen. CD163 is a high-affinity receptor of human haptoglobin (Hp)-hemoglobin (Hb) complexes. The removal of Hb and the generation of heme metabolites result in a localized anti-inflammatory response. It has been reported (Maniecki et al., 2011) that calcium inhibits the binding of clone GHI/61 to CD163. Use calcium-free staining buffer such as Maxpar® Cell Staining Buffer (201068). Also, detection of CD16-positive monocytes is highly variable depending on use of different anticoagulants during cellular collection and preparation. Heparin has the highest inhibitory effect on clone GHI/61 and should be avoided.