Regulation and Function of Macrophage CD163

描述（由申请人提供）：最近的关键观察结果表明，CD 163在炎症调节中起重要作用。CD 163仅在单核细胞（Mo）和巨噬细胞（MO）上表达，去年被证明是血红蛋白-触珠蛋白（Hb/Hp）复合物的内吞清道夫受体。值得注意的是，触珠蛋白具有两种对CD 163具有不同亲和力的等位基因形式，并且触珠蛋白表型是糖尿病肾病和冠状动脉血管成形术后再狭窄的预测因子。此外，单核细胞上的CD 163表达被糖皮质激素和IL-10显著增加，糖皮质激素和IL-10是响应于创伤或感染而快速增加的两种介质，并且被充分表征为减少脂多糖（LPS）毒性。使用新开发的ELISA，我们显示（i）在暴露于低至50 pg/ml的脂多糖（LPS）后，CD 163的胞外结构域迅速从单核细胞脱落，以及（ii）在心肺转流心脏手术期间以及在将LPS推注到实验人类受试者中之后，血浆中的可溶性CD 163（sCD 163）迅速且显著地升高。因此，有必要更好地了解CD 163的产生和功能。该RO 3应用的目标是生成试剂和试点数据，使PI能够建立一个新的研究计划，重点是了解CD 163在调节炎症中的作用。本研究旨在阐明糖皮质激素、细胞因子和LPS对CD 163表达和脱落的影响的分子机制。此外，将新测序的鼠CD 163与人CD 163在合成、脱落和Hb/Hp摄取方面进行比较，以建立用于未来研究的适当鼠模型。还将开发新的单克隆抗体（mAb）、可溶性CD 163融合蛋白和表达人和鼠CD 163的转染子。将使用原代Mo培养物、Mo细胞系和转染子检测融合蛋白和mAb对通过CD 163摄取Hb/Hp复合物的抑制作用。这些试剂也将用于初步实验，以探测表面和可溶性CD 163对免疫功能的影响。机制和功能信息的发展，人类和小鼠试剂的产生，以及小鼠模型的潜在验证，应该为更精确地确定CD 163在炎症控制中的作用的扩展应用奠定基础。

DESCRIPTION (provided by applicant): Recent key observations suggest that CD163 plays an important role in the regulation of inflammation. Expressed only on monocytes (Mo) and macrophages (MO), CD163 was shown last year to be an endocytic scavenger receptor for hemoglobin-haptoglobin (Hb/Hp) complexes. It is notable that haptoglobin has two allelic forms with different affinities for CD163, and haptoglobin phenotype is a predictor of diabetic nephropathy and of restenosis after coronary angioplasty. Moreover, CD163 expression on monocytes is markedly increased by glucocorticoids and IL-10--two mediators that increase rapidly in response to trauma or infection and are well characterized for reducing lipopolysaccharide (LPS) toxicity. Using a newly developed ELISA we show (i) that the extracellular domain of CD163 is rapidly shed from the monocyte after exposure to as little as 50 pg/ml of lipopolysaccharide (LPS) and (ii) that soluble CD163 (sCD163) in plasma rises rapidly and markedly during cardiac surgery with cardiopulmonary bypass, as well as following a bolus injection of LPS into experimental human subjects. A better understanding of the production and function of CD163 is therefore warranted. The goal of this RO3 application is the generation of reagents and pilot data that will enable the PI to establish a new research program focused on understanding the role that CD163 plays in regulating inflammation. The Specific Aims are designed to elucidate the molecular mechanisms of glucocorticoid, cytokine and LPS effects on CD163 expression and shedding. In addition, the newly sequenced murine CD163 will be compared to the human CD163 in terms of synthesis, shedding and Hb/Hp uptake in order to establish an appropriate murine model for future studies. New monoclonal antibodies (mAbs), soluble CD163 fusion proteins, and transfectants expressing both human and murine CD163 will also be developed. Fusion proteins and mAbs will be tested for inhibition of uptake of Hb/Hp complexes via CD163 using primary Mo cultures, Mo cell lines and transfectants. These reagents will also be used in pilot experiments to probe the effect of surface and soluble CD163 on immunological functions. The development of mechanistic and functional information, the generation of human and mouse reagents, and the potential validation of a mouse model should lay the foundation for an expanded application to determine more precisely the role of CD163 in the control of inflammation.