Hoffman M P, Haidaris C G
Department of Microbiology, University of Rochester School of Medicine and Dentistry, New York 14642.
Infect Immun. 1993 May;61(5):1940-9. doi: 10.1128/iai.61.5.1940-1949.1993.
Clearance of Candida albicans from the oral cavity is thought to be mediated via specific receptor-ligand interactions between salivary constituents and the fungus. Since surfaces in the oral cavity are normally coated with a saliva-derived pellicle, specific interactions between salivary constituents and C. albicans may also contribute to adhesion of C. albicans to the oral mucosa and dental prostheses. Therefore, the purpose of this study was to identify salivary constituents to which C. albicans is capable of binding. A solid-phase overlay assay was used in which electrophoretically separated rat and human salivary constituents bound to membrane filters were incubated with radiolabelled C. albicans cells. C. albicans adhered to a single salivary component from each host. Correlation of cell-binding activity with specific monoclonal antibody (MAb)-binding activity indicated that the constituent bound by C. albicans in human saliva was low-molecular-weight mucin (MG2) and that in rat saliva was rat submandibular gland (RSMG) mucin. Further studies showed an identical cell hybridization signal and MAb colocalization by using RSMG ductal saliva and an aqueous RSMG extract in the solid-phase overlay assay. Analysis of cell binding to the aqueous extract of RSMG fractionated by anion-exchange chromatography demonstrated that C. albicans binding was restricted to an acidic subfraction of the RSMG extract, which also bound the RSMG mucin-specific MAb. The Candida-binding fraction contained predominantly RSMG mucin glycoprotein and also a noncovalently associated, chloroform-extractable material. Furthermore, we identified two strains of C. albicans which differed severalfold in the ability to bind RSMG mucin in the overlay assay. These results suggest that C. albicans binds to only a specific subfraction of RSMG mucin and that the two C. albicans strains tested differ in the ability to bind RSMG mucin subfractions.
白色念珠菌从口腔中的清除被认为是通过唾液成分与真菌之间特定的受体 - 配体相互作用介导的。由于口腔表面通常覆盖有源自唾液的薄膜，唾液成分与白色念珠菌之间的特定相互作用也可能有助于白色念珠菌黏附于口腔黏膜和假牙。因此，本研究的目的是鉴定白色念珠菌能够结合的唾液成分。使用了一种固相覆盖分析方法，其中将与膜过滤器结合的经电泳分离的大鼠和人类唾液成分与放射性标记的白色念珠菌细胞一起孵育。白色念珠菌黏附于每个宿主的单一唾液成分。细胞结合活性与特异性单克隆抗体（MAb）结合活性的相关性表明，人类唾液中白色念珠菌结合的成分是低分子量黏蛋白（MG2），而大鼠唾液中的是大鼠下颌下腺（RSMG）黏蛋白。进一步的研究表明，在固相覆盖分析中使用RSMG导管唾液和RSMG水提取物时，细胞杂交信号和MAb共定位相同。对通过阴离子交换色谱分离的RSMG水提取物的细胞结合分析表明，白色念珠菌的结合仅限于RSMG提取物的酸性亚组分，该亚组分也结合RSMG黏蛋白特异性MAb。念珠菌结合部分主要包含RSMG黏蛋白糖蛋白以及一种非共价结合的、可氯仿提取的物质。此外，我们鉴定出两株白色念珠菌，它们在覆盖分析中结合RSMG黏蛋白的能力相差数倍。这些结果表明，白色念珠菌仅结合RSMG黏蛋白的特定亚组分，并且所测试的两株白色念珠菌在结合RSMG黏蛋白亚组分的能力上存在差异。
