Miura N N, Miura T, Ohno N, Adachi Y, Watanabe M, Tamura H, Tanaka S, Yadomae T
Laboratory for Immunopharmacology of Microbial Products, School of Pharmacy, Tokyo University of Pharmacy and Life Science, Hachioji, Japan.
FEMS Immunol Med Microbiol. 1998 Jun;21(2):123-9. doi: 10.1111/j.1574-695X.1998.tb01157.x.
Candida spp. is a medically important fungi which induces disseminated candidiasis and candidemia in hospitalized immunocompromised patients. The cell wall of Candida is mainly composed of two polysaccharides, mannan and beta-glucan, and at least part of beta-glucan is basically insoluble in H2O or NaOH. We became interested in when and how particulate beta-glucan changes to the soluble form. However, the fate of wall components has not been examined in detail. In this study, modification and solubilization of the cell wall beta-glucan were analyzed in vivo and in vitro. Cells of Candida, intravenously administered to mice (1 mg/mouse), were immediately deposited mainly in liver as determined by 3H-labeled cells. Beta-Glucans were detected in these mice for at least for 6 months by the beta-glucan specific assay. During this period, the insoluble cell wall beta-glucan was gradually solubilized in these organs, probably by oxidative stress of macrophages. Candida cells and particulate beta-glucans were also gradually solubilized in vitro using sodium hypochlorite solution, but part of the cell wall beta-glucan was still insoluble even after treatment with concentrated hypochlorite solution for one day at room temperature. These findings strongly suggested that the fungal cell wall beta-glucans were quite resistant to oxidative metabolism in vivo and in vitro, and thus deposited for quite long period in the host.
念珠菌属是一种具有重要医学意义的真菌，可在住院的免疫功能低下患者中引发播散性念珠菌病和念珠菌血症。念珠菌的细胞壁主要由两种多糖组成，即甘露聚糖和β-葡聚糖，并且至少部分β-葡聚糖基本不溶于水或氢氧化钠。我们开始关注颗粒状β-葡聚糖何时以及如何转变为可溶形式。然而，细胞壁成分的命运尚未得到详细研究。在本研究中，对体内和体外细胞壁β-葡聚糖的修饰和溶解情况进行了分析。通过3H标记的细胞确定，静脉注射给小鼠（1毫克/只）的念珠菌细胞主要立即沉积在肝脏中。通过β-葡聚糖特异性检测在这些小鼠中至少6个月都能检测到β-葡聚糖。在此期间，不溶性细胞壁β-葡聚糖在这些器官中逐渐溶解，可能是由于巨噬细胞的氧化应激。念珠菌细胞和颗粒状β-葡聚糖在体外使用次氯酸钠溶液时也会逐渐溶解，但即使在室温下用浓次氯酸钠溶液处理一天后，部分细胞壁β-葡聚糖仍不溶解。这些发现强烈表明，真菌细胞壁β-葡聚糖在体内和体外对氧化代谢具有相当的抗性，因此会在宿主体内长时间沉积。
