Structural characterization of N-glycans from the freshwater snail Biomphalaria glabrata cross-reacting with Schistosoma mansoni glycoconjugates
Structural characterization of N-glycans from the freshwater snail Biomphalaria glabrata cross-reacting with Schistosoma mansoni glycoconjugates
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DOI：
10.1093/glycob/cwl048
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发表时间：
2007-01-01
期刊：
影响因子：
4.3
通讯作者：
Geyer, Rudolf
中科院分区：
文献类型：
--
作者：
Lehr, Tobias;Geyer, Hildegard;Geyer, Rudolf
人类寄生吸虫曼氏血吸虫具有复杂的生命周期，其中包括淡水蜗牛光滑双脐吸虫作为中间宿主。在每个阶段，寄生虫都会合成多种糖复合物，部分地表现出独特的碳水化合物结构。此外，寄生虫表达最终的类宿主糖表位，例如Lewis X决定簇，支持碳水化合物介导的分子拟态作为入侵和生存策略的概念。在本研究中，我们研究了常见的碳水化合物决定因素是否也发生在中间宿主水平。为此，对光滑拟杆菌的血淋巴糖蛋白-N-聚糖进行了结构表征。 N-聚糖从胰蛋白酶糖肽中释放并用 2-氨基吡啶标记。使用针对血吸虫卵抗原的多克隆抗血清通过免疫亲和层析分离与曼氏血吸虫糖缀合物发生血清学交叉反应的糖链，并通过金黄色粉虱凝集素亲和层析和高效液相层析进行分级。通过不同的质谱技术以及单糖成分和键联分析来分析获得的聚糖。结果揭示了高度异质的寡糖模式。交叉反应种类约占总聚糖的 5%，并表现出末端 Fuc(α1-3)GalNAc 单元、(1-2) 连接的木糖基残基或两种类型的结构基序。总之，我们的研究表明，曼氏链球菌及其中间宿主水平上也存在常见的碳水化合物表位。
The human parasitic trematode Schistosoma mansoni has a complex life cycle that includes the freshwater snail Biomphalaria glabrata as intermediate host. Within each stage, the parasite synthesizes a wide array of glycoconjugates, exhibiting, in part, unique carbohydrate structures. In addition, the parasite expresses definitive host-like sugar epitopes, such as Lewis X determinants, supporting the concept of carbohydrate-mediated molecular mimicry as an invasion and survival strategy. In the present study, we investigated whether common carbohydrate determinants occur also at the level of the intermediate host. To this end, a structural characterization of hemolymph glycoprotein-N-glycans of B. glabrata was performed. N-glycans were released from tryptic glycopeptides and labeled with 2-aminopyridine. Sugar chains serologically cross-reacting with S. mansoni glycoconjugates were isolated by immunoaffinity chromatography using a polyclonal antiserum directed against schistosomal egg antigens and fractionated by Aleuria aurantia lectin affinity chromatography and high-performance liquid chromatography. Obtained glycans were analyzed by different mass spectrometric techniques as well as by monosaccharide constituent and linkage analysis. The results revealed a highly heterogeneous oligosaccharide pattern. Cross-reacting species represented about 5% of the total glycans and exhibited a terminal Fuc(alpha 1-3)GalNAc unit, a (1-2)-linked xylosyl residue, or both types of structural motifs. In conclusion, our study demonstrates the presence of common carbohydrate epitopes also at the level of S. mansoni and its intermediate host.