Martin B K, Weis J H
Department of Pathology, University of Utah School of Medicine, Salt Lake City 84132.
Eur J Immunol. 1993 Nov;23(11):3037-42. doi: 10.1002/eji.1830231146.
Murine macrophages have been described as possessing complement receptors for C3b and iC3b. These binding activities have been assumed to be due to the presence of the CR1 and CR3 proteins, respectively. The mouse Cr2 gene produces two distinct gene products of approximately 190,000 relative molecular mass (M(r)) (Cr2-190) and 145,000 M(r) (Cr2-145). Because of the similarity in size to human complement receptors, the Cr2-190 protein has been dubbed murine CR1 while the murine Cr2-145 product has been termed murine CR2. In order to define the complement receptor genes expressed by murine macrophages, we investigated the expression patterns of Cr2-190, Cr2-145 and another mouse complement receptor, Crry, in three different mouse macrophage populations: bone marrow-derived macrophages, thioglycollate-elicited peritoneal macrophages and the macrophage cell line, J774. Neither of the Cr2 gene transcripts encoding the Cr2-145 and Cr2-190 proteins could be detected in these populations by RT-RPCR analysis although Crry transcripts were evident. Cr2-145 and Cr2s-190 proteins could not be detected on the surface of thioglycollate-elicited macrophages using a monoclonal antibody that recognizes both proteins. Thus, contrary to previously published data, murine macrophages do not possess the Cr2 gene products.
小鼠巨噬细胞被描述为具有C3b和iC3b的补体受体。这些结合活性分别被认为是由于CR1和CR3蛋白的存在。小鼠Cr2基因产生两种相对分子质量（M(r)）约为190,000（Cr2-190）和145,000 M(r)（Cr2-145）的不同基因产物。由于其大小与人补体受体相似，Cr2-190蛋白被称为小鼠CR1，而小鼠Cr2-145产物被称为小鼠CR2。为了确定小鼠巨噬细胞表达的补体受体基因，我们研究了Cr2-190、Cr2-145和另一种小鼠补体受体Crry在三种不同小鼠巨噬细胞群体中的表达模式：骨髓来源的巨噬细胞、巯基乙酸诱导的腹腔巨噬细胞和巨噬细胞系J774。尽管Crry转录本明显，但通过RT-RPCR分析在这些群体中均未检测到编码Cr2-145和Cr2-190蛋白的Cr2基因转录本。使用识别这两种蛋白的单克隆抗体，在巯基乙酸诱导的巨噬细胞表面未检测到Cr2-145和Cr2s-190蛋白。因此，与先前发表的数据相反，小鼠巨噬细胞不具有Cr2基因产物。
