Graversen Jonas Heilskov, Madsen Mette, Moestrup Søren K
Department of Medical Biochemistry, University of Aarhus, Ole Worms Alle, Building 170, 8000 Aarhus C, Denmark.
Int J Biochem Cell Biol. 2002 Apr;34(4):309-14. doi: 10.1016/s1357-2725(01)00144-3.
CD163 is a highly expressed macrophage membrane protein belonging to the scavenger receptor cysteine rich (SRCR) domain family. The CD163 expression is induced by interleukin-6, interleukin-10 and glucocorticoids. Its function has remained unknown until recently when CD163 was identified as the endocytic receptor binding hemoglobin (Hb) in complex with the plasma protein haptoglobin (Hp). This specific receptor-ligand interaction leading to removal from plasma of the Hp-Hb complex-but not free Hp or Hb-now explains the depletion of circulating Hp in individuals with increased intravascular hemolysis. Besides having a detoxificating effect by removing Hb from plasma, the CD163-mediated endocytosis of the Hp-Hb complex may represent a major pathway for uptake of iron in the tissue macrophages. The novel functional linkage of CD163 and Hp, which both are induced during inflammation, also reveal some interesting perspectives relating to the suggested anti-inflammatory properties of the receptor and the Hp phenotypes.
CD163是一种高表达的巨噬细胞膜蛋白，属于富含半胱氨酸的清道夫受体（SRCR）结构域家族。CD163的表达由白细胞介素-6、白细胞介素-10和糖皮质激素诱导。直到最近CD163被鉴定为与血浆蛋白触珠蛋白（Hp）结合的内吞受体结合血红蛋白（Hb）时，其功能仍不清楚。这种导致从血浆中清除Hp-Hb复合物（而非游离的Hp或Hb）的特异性受体-配体相互作用，现在解释了血管内溶血增加个体循环中Hp的消耗。除了通过从血浆中清除Hb具有解毒作用外，CD163介导的Hp-Hb复合物内吞作用可能是组织巨噬细胞摄取铁的主要途径。CD163和Hp在炎症过程中均被诱导，它们之间新的功能联系也揭示了一些与该受体和Hp表型的抗炎特性相关的有趣观点。
