Legoedec J, Gasque P, Jeanne J F, Fontaine M
Institut Fédératif de Recherches Multidisciplinaires sur les Peptides, INSERM U-78, Bois-Guillaume, France.
Eur J Immunol. 1995 Dec;25(12):3460-6. doi: 10.1002/eji.1830251238.
In this study, we demonstrate expression in vitro of complement alternative pathway components C3, factor B, factor H and factor I by normal human myoblasts and human rhabdomyosarcoma cell lines CRL1558 and HTB153. Proteins in culture supernatants were detected by Western (protein) blot analysis and biosynthetic labeling followed by immunoprecipitation experiments, and quantified by ELISA. Newly secreted proteins were structurally and functionally similar to their serum counterparts. An additional polypeptide of 43 kDa with factor H immunoreactivity was detected, which could correspond to the N-terminal truncated form found in plasma. Protein expression was correlated with mRNA expression by reverse transcriptase-polymerase chain reaction analysis. The major proteins of complement alternative pathway C3, factor B and factor H were produced constitutively by skeletal muscle cells at a rate of 50 to 150 ng/10(6) cells/ml and factor I was expressed 20 ng/10(6) cells/ml. These syntheses in vitro were regulated by inflammatory cytokines. Interferon-gamma significantly upregulated C3, factor B and factor H expression, but had no effect on factor I production. Interleukin-1 beta strongly enhanced C3 and factor B production and had a weak enhancing or no effect on factor I and factor H secretion. Human myoblast cell lines constitute an interesting model to analyze complement biosynthesis by human skeletal muscle cells. Local complement expression by skeletal muscle in vivo may be implicated in some muscular inflammatory or pathological processes.
在本研究中，我们证明了正常人成肌细胞以及人横纹肌肉瘤细胞系CRL1558和HTB153在体外可表达补体替代途径成分C3、B因子、H因子和I因子。通过蛋白质免疫印迹分析、生物合成标记后进行免疫沉淀实验检测培养上清液中的蛋白质，并通过酶联免疫吸附测定进行定量。新分泌的蛋白质在结构和功能上与其血清对应物相似。检测到一种具有H因子免疫反应性的43 kDa额外多肽，其可能与血浆中发现的N端截短形式相对应。通过逆转录-聚合酶链反应分析将蛋白质表达与mRNA表达相关联。补体替代途径的主要蛋白质C3、B因子和H因子由骨骼肌细胞组成性产生，产生速率为50至150 ng/10(6)个细胞/ml，I因子的表达量为20 ng/10(6)个细胞/ml。体外的这些合成受炎性细胞因子调节。γ干扰素显著上调C3、B因子和H因子的表达，但对I因子的产生没有影响。白细胞介素-1β强烈增强C3和B因子的产生，对I因子和H因子的分泌有微弱增强作用或无影响。人成肌细胞系构成了一个分析人骨骼肌细胞补体生物合成的有趣模型。体内骨骼肌的局部补体表达可能与某些肌肉炎症或病理过程有关。
