Chemical and immunological characterization of the extracellular galactomannan of Aspergillus fumigatus
Chemical and immunological characterization of the extracellular galactomannan of Aspergillus fumigatus
复制标题
烟曲霉胞外半乳甘露聚糖的化学和免疫学特征
作者：
J. Latgé;H. Kobayashi;J. Debeaupuis;M. Diaquin;J. Sarfati;J. Wieruszeski;E. Parra;J. Bouchara;B. Fournet
对烟曲霉胞外生产的半乳甘露聚糖（GM）进行了双序肼-亚硝酸盐处理培养滤液的乙醇沉淀物的纯化。核磁共振和气液相色谱-质谱分析对完整的甘露聚糖、酸水解的甘露聚糖和酸水解的甘露聚糖低聚物进行了分析。结果表明，烟曲霉的甘露聚糖是由一个线性甘露聚糖核心和一个α -(1-6)键连接的甘露聚糖重复单元组成。由平均4到5个β -(1-5)-半乳糖呋喃糖单元组成的侧链连接到甘露糖的α -(1-2)-连接甘露糖单元的C-6和C-3位置。用曲霉病患者血清和抗半乳糖呋喃单克隆抗体研究了GM和盐酸水解GM的免疫反应性。α -(1-2)(1-6)-甘露聚糖核心不具有抗原性。免疫原性半乳糖呋喃存在于几种细胞外糖蛋白中。根据以GM作为检测抗原的直接酶联免疫吸附试验，曲霉菌瘤患者的血清样本（全部通过免疫扩散试验呈阳性）的光密度值优于用对照血清获得的值的平均值+/- 3个标准差估计的截止值。
The galactomannan (GM) produced extracellularly by Aspergillus fumigatus has been purified by a double sequential hydrazine-nitrous acid treatment of the ethanol precipitate of the culture filtrate. Nuclear magnetic resonance and gas-liquid chromatography-mass spectrometry analysis have been performed on intact GM, acid-hydrolyzed GM, and oligomers resulting from the acetolysis of the acid-hydrolyzed GM. Results show that A. fumigatus GM is composed of a linear mannan core with an alpha-(1-2)-linked mannotetraose repeating unit attached via alpha-(1-6) linkage. Side chains composed of an average of 4 to 5 beta-(1-5)-galactofuranose units are linked to C-6 and C-3 positions of alpha-(1-2)-linked mannose units of the mannan. The immunoreactivity of GM and HCl-hydrolyzed GM was studied by use of human sera from aspergillosis patients and an antigalactofuran monoclonal antibody. The alpha-(1-2) (1-6)-mannan core is not antigenic. The immunogenic galactofuran is found amongst several exocellular glycoproteins. According to a direct enzyme-linked immunosorbent assay with GM as the detector antigen, only 26% of the serum samples from aspergilloma patients (all positive by immunodiffusion assays) give optical density values superior to a cutoff estimated as the mean +/- 3 standard deviations of values obtained with control sera.