Wright C D, Bowie J U, Gray G R, Nelson R D
Infect Immun. 1983 Oct;42(1):76-80. doi: 10.1128/iai.42.1.76-80.1983.
We have previously demonstrated the ability of human neutrophil myeloperoxidase to bind to mannan isolated from Candida albicans. Mannan may therefore be a primary component of the yeast cell wall which provides for binding of myeloperoxidase, a requirement potentially important for the candidacidal activity of the enzyme. In this report, we describe experiments to consider the relationship of the mannan-binding activity of myeloperoxidase to its candidacidal activity and the possibility that free mannan may inhibit myeloperoxidase-mediated candidacidal activity. We observed that binding of myeloperoxidase to the target yeasts was required for killing of C. albicans. We also observed that addition of soluble mannan significantly reduced myeloperoxidase-mediated killing of the yeasts in a dose-dependent manner by antagonizing binding of myeloperoxidase. Soluble mannan was demonstrated to have a similar dose-dependent inhibitory effect on neutrophil-mediated candidacidal activity without influencing phagocytosis of the organism. On the basis of these observations, we speculate that mannan solubilized in plasma and tissue fluid may interfere with neutrophil-mediated host defense against Candida infection.
我们之前已经证明了人类中性粒细胞髓过氧化物酶能够与从白色念珠菌中分离出的甘露聚糖结合。因此，甘露聚糖可能是酵母细胞壁的主要成分，它为髓过氧化物酶的结合提供了条件，这一条件对于该酶的杀念珠菌活性可能具有重要意义。在本报告中，我们描述了一些实验，以探讨髓过氧化物酶的甘露聚糖结合活性与其杀念珠菌活性之间的关系，以及游离甘露聚糖可能抑制髓过氧化物酶介导的杀念珠菌活性的可能性。我们观察到，髓过氧化物酶与靶酵母的结合是杀死白色念珠菌所必需的。我们还观察到，添加可溶性甘露聚糖会通过拮抗髓过氧化物酶的结合，以剂量依赖的方式显著降低髓过氧化物酶介导的酵母杀伤作用。可溶性甘露聚糖对中性粒细胞介导的杀念珠菌活性具有类似的剂量依赖性抑制作用，而不影响该生物体的吞噬作用。基于这些观察结果，我们推测血浆和组织液中溶解的甘露聚糖可能会干扰中性粒细胞介导的宿主对念珠菌感染的防御。
