Structural and functional properties of the Trichosporon asahii glucuronoxylomannan
Structural and functional properties of the Trichosporon asahii glucuronoxylomannan
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DOI：
10.1016/j.fgb.2009.03.003
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发表时间：
2009-06-01
影响因子：
3
通讯作者：
Rodrigues, Marcio L.
中科院分区：
文献类型：
--
作者：
Fonseca, Fernanda L.;Frases, Susana;Rodrigues, Marcio L.
尽管其作为人类浅表性和侵袭性疾病的病原体的相关性越来越大，但阿萨希丝孢酵母的毒力属性实际上是未知的。葡糖醛酸甘露聚糖（GXM）是隐球菌属致病菌的一种重要毒力因子。GXM也由丝孢酵母属的物种产生，并且两种多糖共享抗原决定簇，但与隐球菌GXM不同，对丝孢酵母GXM的研究相对较少。在本研究中，我们分析了T. asahii的，并将它们与隐球菌多糖的性质进行比较。毛孢子菌多糖与隐球菌多糖GXM具有相同的抗原反应性，但毛孢子菌多糖的有效直径较小，带负电荷。GXM锚定到细胞壁被二甲亚砜干扰，并需要几丁质衍生的低聚物与多糖的相互作用。来自Tasahii上清液的GXM被新型隐球菌的无囊突变体掺入，这使得这些细胞对小鼠巨噬细胞的吞噬作用更具抗性。总之，我们的研究结果表明，尽管在细胞壁锚定，抗原性和抗吞噬特性的相似性，毛孢子菌和隐球菌GXM表现出主要的结构差异，可能直接影响多糖组装在真菌表面。(C)2009 Elsevier Inc. All rights reserved.
The virulence attributes of Trichosporon asahii are virtually unknown, despite its growing relevance as causative agent of superficial and invasive diseases in humans. Glucuronoxylomannan (GXM) is a well described virulence factor of pathogenic species in the Cryptococcus genus. GXM is also produced by species of the Trichosporon genus, and both polysaccharides share antigenic determinants, but unlike cryptococcal GXM, relatively little work has been done on trichosporal GXMs. In this study, we analyzed structural and functional aspects of GXM produced by T. asahii and compared them to the properties of the cryptococcal polysaccharide. Trichosporal and cryptococcal GXM shared antigenic reactivity, but the former polysaccharide had smaller effective diameter and negative charge. GXM anchoring to the cell wall was perturbed by dimethylsulfoxide and required interactions of chitin-derived oligomers with the polysaccharide. GXM from T asahii supernatants are incorporated by acapsular mutants of Cryptococcus neoformans, which renders these cells more resistant to phagocytosis by mouse macrophages. In summary, our results establish that despite similarities in cell wall anchoring, antigenic and antiphagocytic properties, trichosporal and cryptococcal GXMs manifest major structural differences that may directly affect polysaccharide assembly at the fungal surface. (C) 2009 Elsevier Inc. All rights reserved.