van der Wielen P A, Holmes A R, Cannon R D
Sir John Walsh Research Institute, University of Otago Faculty of Dentistry, Dunedin, New Zealand.
Oral Dis. 2016 Jan;22(1):69-74. doi: 10.1111/odi.12397.
Candida albicans attaches to oral surfaces via a number of mechanisms including adherence mediated by salivary components adsorbed to the C. albicans cell surface. Our goal was to identify the salivary molecules involved.
Biotinylated salivary polypeptides that were bound by C. albicans were detected in extracts from washed, saliva-treated yeast cells by polyacrylamide gel electrophoresis and electroblot or immunoblot transfer analysis and purified by electroelution. Purified material was tested for the ability to promote the adherence of radiolabelled C. albicans yeast cells to cultured epithelial monolayers.
Three of the polypeptides bound by C. albicans cells were identified as components of secretory IgA, including secretory component. Using non-denaturing polyacrylamide gel electrophoresis, we demonstrated that secretory component could be detected in its free form in saliva, and was bound by yeast cells. Secretory component which was purified by electroelution from non-denaturing PAGE-separated saliva, without detectable complete IgA, promoted adherence of yeast cells to cultured epithelial monolayers in a dose-dependent fashion.
These results indicate that despite the inhibitory effect on adherence of IgA specific to C. albicans, IgA components, in particular secretory component, also promote binding to cultured epithelial monolayers.
白色念珠菌通过多种机制附着于口腔表面，包括由吸附在白色念珠菌细胞表面的唾液成分介导的黏附。我们的目标是鉴定其中涉及的唾液分子。
通过聚丙烯酰胺凝胶电泳、电印迹或免疫印迹转移分析，在经洗涤、唾液处理的酵母细胞提取物中检测被白色念珠菌结合的生物素化唾液多肽，并通过电洗脱进行纯化。测试纯化后的物质促进放射性标记的白色念珠菌酵母细胞黏附于培养的上皮细胞单层的能力。
被白色念珠菌细胞结合的三种多肽被鉴定为分泌型IgA的成分，包括分泌成分。使用非变性聚丙烯酰胺凝胶电泳，我们证明分泌成分可以以游离形式在唾液中检测到，并被酵母细胞结合。通过电洗脱从非变性PAGE分离的唾液中纯化得到的分泌成分（未检测到完整的IgA），以剂量依赖的方式促进酵母细胞黏附于培养的上皮细胞单层。
这些结果表明，尽管白色念珠菌特异性IgA对黏附有抑制作用，但IgA成分，特别是分泌成分，也促进与培养的上皮细胞单层的结合。
