Hostetter M K, Lorenz J S, Preus L, Kendrick K E
Department of Pediatrics, University of Minnesota Medical School, Minneapolis.
J Infect Dis. 1990 Apr;161(4):761-8. doi: 10.1093/infdis/161.4.761.
Patient isolates of Candida albicans from blood, urine, or mucosal sites express a surface receptor for C3 fragment iC3b that is recognized by monoclonal antibodies (MAb) directed against alpha-chain epitopes of the neutrophil iC3b receptor, also known as the type 3 complement receptor (CR3) or CD11b/CD18. Because 60% of these patients were hyperglycemic, the effect of glucose on receptor expression was investigated. As assessed by flow cytometry, yeasts grown in 20 mM D-glucose exhibited a four- to six-fold increase in receptor expression compared with yeasts grown in 20 mM L-glutamate. Receptor expression increased as glucose concentration rose from 0 to 20 mM (equivalent to plasma glucose concentrations of 0-360 mg/dl). Augmentation of receptor expression by growth in glucose led to significant inhibition of phagocytosis compared with that of organisms grown in equimolar L-glutamate. SDS-PAGE, Western blotting, and immunodetection of extracts of yeast cell wall, membrane, and cytosol disclosed a protein of 165 kDa in membrane and cytosolic extracts, consistent with the published Mr of the alpha-chain of neutrophil CR3. These studies provide a mechanism to explain the predilection of C. albicans to infect the hyperglycemic host.
从血液、尿液或黏膜部位分离出的白色念珠菌患者菌株表达一种C3片段iC3b的表面受体，该受体可被针对中性粒细胞iC3b受体α链表位的单克隆抗体（MAb）识别，中性粒细胞iC3b受体也被称为3型补体受体（CR3）或CD11b/CD18。由于这些患者中有60%血糖过高，因此研究了葡萄糖对受体表达的影响。通过流式细胞术评估，在20 mM D-葡萄糖中生长的酵母与在20 mM L-谷氨酸中生长的酵母相比，受体表达增加了4至6倍。随着葡萄糖浓度从0升至20 mM（相当于血浆葡萄糖浓度为0 - 360 mg/dl），受体表达增加。与在等摩尔L-谷氨酸中生长的生物体相比，在葡萄糖中生长导致的受体表达增加显著抑制了吞噬作用。十二烷基硫酸钠-聚丙烯酰胺凝胶电泳（SDS-PAGE）、蛋白质印迹法以及对酵母细胞壁、细胞膜和细胞溶质提取物的免疫检测显示，在细胞膜和细胞溶质提取物中有一种165 kDa的蛋白质，这与已发表的中性粒细胞CR3α链的相对分子质量一致。这些研究提供了一种机制来解释白色念珠菌对感染高血糖宿主的偏好。
