Role of Glucosyltransferase B in Interactions of Candida albicans with Streptococcus mutans and with an Experimental Pellicle on Hydroxyapatite Surfaces
Role of Glucosyltransferase B in Interactions of Candida albicans with Streptococcus mutans and with an Experimental Pellicle on Hydroxyapatite Surfaces
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DOI：
10.1128/aem.05203-11
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发表时间：
2011-09-01
影响因子：
4.4
通讯作者：
Koo, H.
中科院分区：
文献类型：
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作者：
Gregoire, S.;Xiao, J.;Koo, H.
白色念珠菌和变形链球菌经常在患有早期儿童龋齿的幼儿的牙菌斑生物膜中检测到。变形链球菌分泌的糖基转移酶（Gtfs）与唾液包裹的磷灰石（sHA）和细菌表面结合，原位合成外聚合物，促进细胞聚集和粘附在牙釉质上。我们研究了Gtfs可能在介导白色念珠菌SC5314和变形念珠菌UA159之间的相互作用以及与sHA表面的相互作用中发挥的潜在作用。通过闪烁光谱和荧光成像确定，GtfB以酶活性形式有效粘附在白色念珠菌酵母细胞表面。酵母细胞表面生成的葡聚糖对葡聚糖酶的敏感性明显高于在溶液中合成的葡聚糖（P < 0.05），表明酵母细胞表面α -1,6链葡萄糖含量明显升高。荧光成像显示，与没有表面葡聚糖（未包被）的酵母细胞相比，与表面有葡聚糖的白色念珠菌细胞结合的变形链球菌细胞数量更多。通过一种新的单细胞微力学方法确定，原位形成的葡聚糖也增强了白色念珠菌与sHA的相互作用。此外，葡聚糖包被的酵母细胞显著增加了变形链球菌在sHA表面的积累（与单独孵育或与未包被的白色念珠菌混合孵育的变形链球菌相比，P < 0.05）。这些数据揭示了一种新的跨界相互作用，这种相互作用是由细菌GtfB介导的，它很容易附着在酵母细胞表面。表面结合的GtfB促进原位富葡聚糖基质的形成，并可能增强变形链球菌在牙釉质表面的积累，从而调节毒性生物膜的发展。
Candida albicans and mutans streptococci are frequently detected in dental plaque biofilms from toddlers afflicted with early childhood caries. Glucosyltransferases (Gtfs) secreted by Streptococcus mutans bind to saliva-coated apatite (sHA) and to bacterial surfaces, synthesizing exopolymers in situ, which promote cell clustering and adherence to tooth enamel. We investigated the potential role Gtfs may play in mediating the interactions between C. albicans SC5314 and S. mutans UA159, both with each other and with the sHA surface. GtfB adhered effectively to the C. albicans yeast cell surface in an enzymatically active form, as determined by scintillation spectroscopy and fluorescence imaging. The glucans formed on the yeast cell surface were more susceptible to dextranase than those synthesized in solution or on sHA and bacterial cell surfaces (P < 0.05), indicating an elevated alpha-1,6-linked glucose content. Fluorescence imaging revealed that larger numbers of S. mutans cells bound to C. albicans cells with glucans present on their surface than to yeast cells without surface glucans (uncoated). The glucans formed in situ also enhanced C. albicans interactions with sHA, as determined by a novel single-cell micromechanical method. Furthermore, the presence of glucan-coated yeast cells significantly increased the accumulation of S. mutans on the sHA surface (versus S. mutans incubated alone or mixed with uncoated C. albicans; P < 0.05). These data reveal a novel cross-kingdom interaction that is mediated by bacterial GtfB, which readily attaches to the yeast cell surface. Surface-bound GtfB promotes the formation of a glucan-rich matrix in situ and may enhance the accumulation of S. mutans on the tooth enamel surface, thereby modulating the development of virulent biofilms.