Sandin R L
Department of Botany and Plant Pathology, Michigan State University, East Lansing 48824.
J Med Microbiol. 1987 Sep;24(2):145-50. doi: 10.1099/00222615-24-2-145.
Candida albicans cells were treated with alkali and acid to extract preferentially the cell wall alpha-mannan. Cells were recovered at three stages, as extraction proceeded from mild to more extensive: Alk-1, Alk-2 and Alk + Acid. Yeast adhesion to human epithelial cells was then examined with an in-vitro adherence assay. Yeasts from all three stages of extraction adhered in significantly lower numbers to buccal mucosal cells than did unextracted yeasts. Adhesion was as low for Alk-1 cells as for those submitted to more complete mannan extraction. When yeast cells from all three stages were treated with Concanavalin A (Con A), a lectin probe with strong affinity for yeast alpha-mannans, and then subjected to the adherence assay, there was no significant change in adhesion. When yeast agglutinability by Con A was examined in tests with treated and untreated yeast cells, abundant agglutination occurred only with the untreated cells. However, Alk-1 cells, though lacking in adhesive capacity towards mucosal cells, showed significant agglutination. The results suggest that candidal adhesion is mediated by an alkali-soluble, mannan-containing moiety(ies) which appears to be lost early in the extraction process. Blockage of this moiety by Con A inhibits the adhesion of unextracted cells. Extracted cells lack this moiety but still possess enough structural mannan for Con A recognition and agglutination.
白色念珠菌细胞用碱和酸处理，以优先提取细胞壁α-甘露聚糖。随着提取从温和到更广泛进行，在三个阶段回收细胞：Alk-1、Alk-2和Alk + Acid。然后用体外黏附试验检测酵母与人上皮细胞的黏附情况。与未提取的酵母相比，来自所有三个提取阶段的酵母黏附到颊黏膜细胞上的数量显著减少。Alk-1细胞的黏附情况与经过更完全甘露聚糖提取的细胞一样低。当用刀豆球蛋白A（Con A）处理来自所有三个阶段的酵母细胞，Con A是一种对酵母α-甘露聚糖具有强亲和力的凝集素探针，然后进行黏附试验时，黏附情况没有显著变化。当在处理过和未处理过的酵母细胞试验中检测Con A对酵母的凝集能力时，只有未处理的细胞发生大量凝集。然而，Alk-1细胞虽然对黏膜细胞缺乏黏附能力，但显示出显著的凝集。结果表明，念珠菌的黏附是由一种碱溶性、含甘露聚糖的部分介导的，该部分似乎在提取过程的早期就丢失了。Con A对该部分的阻断抑制了未提取细胞的黏附。提取的细胞缺乏该部分，但仍然拥有足够的结构甘露聚糖用于Con A识别和凝集。
