The capsule of the fungal pathogen Cryptococcus neoformans.
The capsule of the fungal pathogen Cryptococcus neoformans.
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DOI：
10.1016/s0065-2164(09)01204-0
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发表时间：
2009
影响因子：
--
通讯作者：
Casadevall, Arturo
中科院分区：
文献类型：
--
作者：
Zaragoza, Oscar;Rodrigues, Marcio L.;De Jesus, Magdia;Frases, Susana;Dadachova, Ekaterina;Casadevall, Arturo
近几十年来，人们对真菌病原体新型隐球菌的荚膜进行了广泛的研究，现在科学界可以获得大量的信息。众所周知的方面的胶囊包括其结构，抗原特性和其功能作为一种毒力因子。胶囊主要由两种多糖，葡糖醛酸甘露聚糖（GXM）和半乳糖甘露聚糖（GalXM），以及较小比例的甘露糖蛋白（MP）组成。大多数关于胶囊组成的研究都集中在GXM上，GXM占胶囊多糖质量的90%以上。然而，GalXM由于其免疫学特性而引起了特别的科学兴趣。这些多糖的分子结构非常复杂，尚未完全阐明。GXM和GalXM都是高分子量聚合物，GXM的质量大约等于GalXM的10倍。然而，最近的研究结果表明，实际的Mw可能与传统上认为的不同。除了它们在多糖胶囊中的结构作用外，这些分子还与对免疫应答的许多有害作用有关。因此，荚膜成分被认为是新型隐球菌的关键毒力决定因素，这促使它们在疫苗中的使用，并使其成为单克隆抗体治疗的靶点。在这篇综述中，我们将提供一个更新的知识，目前的C。neoformans荚膜，涵盖了与其结构，合成，特别是其作为毒力因子的作用有关的方面。
The capsule of the fungal pathogen Cryptococcus neoformans has been studied extensively in recent decades, and a large body of information is now available to the scientific community. Well-known aspects of the capsule include its structure, antigenic properties and its function as a virulence factor. The capsule is composed primarily of two polysaccharides, glucuronoxylomannan (GXM) and galactoxylomannan (GalXM), in addition to a smaller proportion of mannoproteins (MP). Most of the studies on the composition of the capsule have focused on GXM, which comprises more than 90% of the capsule's polysaccharide mass. It is GalXM, however, that is of particular scientific interest because of its immunological properties. The molecular structure of these polysaccharides is very complex and has not yet been fully elucidated. Both GXM and GalXM are high molecular mass polymers with the mass of GXM equaling roughly 10 times that of GalXM. Recent findings suggest, however, that the actual Mw might be different to what it has traditionally been thought to be. In addition to their structural roles in the polysaccharide capsule, these molecules have been associated with many deleterious effects on the immune response. Capsular components are therefore considered key virulence determinants in Cryptococcus neoformans, which has motivated their use in vaccines and made them targets for monoclonal antibody treatments. In this review we will provide an update on the current knowledge of the C. neoformans capsule, covering aspects related to its structure, synthesis, and particularly, its role as a virulence factor.