Mouse Crry/p65. Characterization of monoclonal antibodies and the tissue distribution of a functional homologue of human MCP and DAF.
Mouse Crry/p65. Characterization of monoclonal antibodies and the tissue distribution of a functional homologue of human MCP and DAF.
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DOI：
10.4049/jimmunol.151.8.4295
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发表时间：
1993-10
影响因子：
4.4
通讯作者：
Bin Li;C. Sallee;M. Dehoff;S. Foley;Hector Molina;V. Holers
中科院分区：
文献类型：
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作者：
Bin Li;C. Sallee;M. Dehoff;S. Foley;Hector Molina;V. Holers
在以前的研究中，我们已经证明了小鼠Crry/p65调节补体成分C3在自体膜上的沉积，这一功能特性是人类衰变加速因子(DAF)和膜辅助因子蛋白(MCP)都表现出来的。我们提出，Crry/p65在小鼠体内具有与MCP和DAF相似的生物学作用，是这两种蛋白中的一种或两种的小鼠类似物。为了解决这一假说并进一步研究Crry/p65蛋白，我们制备了抗Crry/p65蛋白的鼠单抗和兔多克隆抗体。利用这些试剂，我们证明，像人的MCP和DAF一样，Crry/p65的组织分布非常广泛。大多数非神经细胞来源的细胞都表达这种蛋白。此外，免疫组织化学分析表明，CRY/P65在免疫复合物沉积和损伤的潜在部位，如肾小球系膜和动脉血管内皮细胞，有较高的表达。通过蛋白质印迹分析，可以证明蛋白质的异构体。然而，与人类DAF不同的是，在淋巴细胞或红细胞上不存在磷脂酰肌醇特异性磷脂酶C敏感的Cry/p65蛋白形式。6株抗Crry/p65单抗中有5株能部分或完全逆转Crry/P65阻断C3在细胞膜上沉积的能力。对四种鼠抗Crry/p65抗体的分析表明，可以检测到两个主要的独立表位。总体而言，Crry/p65保留了人类MCP和DAF的许多主要特征，这些试剂的使用应该会进一步了解这类补体调节蛋白的生物学作用。
In previous studies we have demonstrated that mouse Crry/p65 regulates complement component C3 deposition on self membranes, a functional property that both human decay-accelerating factor (DAF) and membrane cofactor protein (MCP) exhibit. We have proposed that Crry/p65 has a similar biologic role in mouse as MCP and perhaps DAF and is the mouse analogue of one or both of these proteins. In order to address this hypothesis and further study Crry/p65, we have prepared rat mAb and a rabbit polyclonal Ab to this protein. Using these reagents we demonstrate that, like human MCP and DAF, the tissue distribution of Crry/p65 is very broad. Most if not all cells of nonneuronal origin express this protein. In addition, by immunohistochemical analysis, Crry/p65 is shown to be more highly expressed in some tissues at potential sites of immune complex deposition and damage, such as the mesangium of the renal glomerulus and the arterial vessel endothelium. By Western blot analysis, protein isoforms can be demonstrated. Unlike human DAF, however, no phosphatidylinositol-specific phospholipase C-sensitive Crry/p65 protein form can be demonstrated on lymphocytes or erythrocytes. Five of six anti-Crry/p65 mAb can partially or completely reverse the capacity of Crry/p65 to block C3 deposition on cell membranes. Analysis of four IgG rat anti-Crry/p65 mAb demonstrates that two major independent epitopes can be detected. Overall, Crry/p65 retains many of the major features of human MCP and DAF, and the use of these reagents should further the understanding of the biologic roles of this class of complement regulatory proteins.