ABSTRACT
The pathogenic yeast
Candida albicans
displays at its cell surface β-1,2 oligomannosides (β-1,2-Mans). In contrast to the ubiquitous α-Mans, β-1,2-Mans bind to galectin-3, a major endogenous lectin expressed on epithelial cells. The specific role of β-1,2-Mans in colonization of the gut by
C. albicans
was assessed in a mouse model. A selected virulent strain of
C. albicans
(expressing more β-1,2-Man epitopes) induced more intense and sustained colonization than an avirulent strain (expressing less β-1,2-Man epitopes). Synthetic (Σ) β-and α-linked tetramannosides with antigenicities that mimicked the antigenicities of
C. albicans
-derived oligomannosides were then constructed. Oral administration of Σβ-1,2-Man (30 mg/kg of body weight) prior to inoculation with the virulent strain resulted in almost complete eradication of yeasts from stool samples, whereas administration of Σα-Man at the same dose did not. As most cases of human systemic candidiasis are endogenous in origin, this first demonstration that a synthetic analogue of a yeast adhesin can prevent yeast colonization in the gut opens the possibility of new prophylactic strategies.
摘要
致病酵母菌
白色念珠菌
细胞表面有 β-1,2-低聚甘露糖苷(β-1,2-Mans)。与无处不在的 α-Mans 不同,β-1,2-Mans 与上皮细胞上表达的一种主要内源性凝集素 galectin-3 结合。β-1,2-喃在白僵菌定植肠道过程中的特殊作用
白僵菌
在小鼠模型中进行了评估。一种经过挑选的毒性
白僵菌
(表达较多的β-1,2-Man 表位)比无毒菌株(表达较少的β-1,2-Man 表位)能诱导更强烈、更持久的定植。抗原性与白僵菌抗原性相似的合成(Σ)β 和 α 链接四甘露糖苷
白僵菌
-然后构建了低聚甘露糖苷。在接种毒性菌株之前,口服 Σβ-1,2-曼(30 毫克/千克体重)几乎能完全根除粪便样本中的酵母菌,而口服相同剂量的 Σα-Man 则不能。由于大多数人体系统性念珠菌病都是内源性的,因此首次证明一种酵母粘附蛋白的合成类似物可以防止酵母菌在肠道内定植,这为新的预防策略提供了可能性。