Ghezzi M C, Raponi G, Angeletti S, Mancini C
I Chair of Clinical Microbiology, Faculty of Medicine, "La Sapieza" University of Rome, Italy.
J Infect Dis. 1998 Dec;178(6):1743-9. doi: 10.1086/314484.
The role of serum in the production of tumor necrosis factor-alpha (TNF-alpha) by human monocytes stimulated with yeast-form Candida albicans was studied. Pre-exposure of C. albicans to human pooled serum enhanced both TNF-alpha mRNA and cytokine secretion compared with C. albicans preincubated with medium only. Serum factors involved were >30 kDa, were efficiently inhibited by D-mannose, and recognized both Ca++-dependent and -independent pathways. Preincubation of yeasts with rabbit mannose-binding protein (MBP) resulted in dose-related enhancement of TNF-alpha secretion, through a Ca++-dependent pathway inhibited by D-mannose. TNF-alpha levels were similarly induced in C. albicans preincubated with vitronectin and with serum. Ca++ depletion did not affect cytokine release, while D-mannose supplementation displayed inhibition. The latter effect was abolished after Ca++ depletion. These data call for an involvement of both MBP and vitronectin in the serum-mediated enhancement of TNF-alpha release upon stimulation of monocytes with yeast forms of C. albicans.
研究了血清在酵母型白色念珠菌刺激的人单核细胞产生肿瘤坏死因子-α（TNF-α）中的作用。与仅用培养基预孵育的白色念珠菌相比，将白色念珠菌预先暴露于人类混合血清中可增强TNF-α mRNA和细胞因子的分泌。所涉及的血清因子分子量> 30 kDa，能被D-甘露糖有效抑制，并识别钙依赖性和非依赖性途径。酵母与兔甘露糖结合蛋白（MBP）预孵育导致TNF-α分泌呈剂量依赖性增强，通过D-甘露糖抑制的钙依赖性途径实现。用玻连蛋白和血清预孵育的白色念珠菌中TNF-α水平也有类似诱导。钙耗竭不影响细胞因子释放，而补充D-甘露糖则显示出抑制作用。钙耗竭后，后一种作用消失。这些数据表明，在酵母型白色念珠菌刺激单核细胞时，MBP和玻连蛋白均参与血清介导的TNF-α释放增强过程。
