Podzorski R P, Gray G R, Nelson R D
Department of Microbilogy, University of Minnesota, Minneapolis 55455.
J Immunol. 1990 Jan 15;144(2):707-16.
Yeast cell wall mannan polysaccharide has been proposed to contribute to immune dysfunction associated with chronic infections involving Candida albicans. This influence of mannan has been suggested based partially upon studies of the in vitro immunoinhibitory effects of mannans prepared from Saccharomyces cerevisiae or C. albicans by precipitation with Fehling's reagent, which provides a structurally modified product contaminated with copper. We have therefore evaluated the immunoinhibitory influence of a more native C. albicans mannan prepared by complexation with cetyltrimethylammonium bromide (CTAB). CTAB mannan was a potent stimulator of lymphoproliferation when added to human PMBC from donors responsive to Candida; it has no inhibitory influence on lympho-proliferation induced by Candida or other Ag. In contrast, members of a family of mannose oligosaccharides (disaccharide through hexasaccharide) derived from the CTAB mannan by weak alkaline degradation did not stimulate lymphoproliferation, but were potent inhibitors of lymphoproliferation stimulated by Candida and other Ag. Fifty percent inhibitory doses were 260 to 34 microM, respectively. Compositional analyses of these immunoinhibitory oligomers showed them to be composed of mannose and free of contaminating protein. We propose that mannan-derived oligosaccharides produced by catabolism of mannan in vivo are immunoinhibitory and contribute to the deficit in cell-mediated immune function associated with chronic candidiasis.
酵母细胞壁甘露聚糖被认为与白色念珠菌引起的慢性感染相关的免疫功能障碍有关。甘露聚糖的这种影响部分是基于对通过费林试剂沉淀从酿酒酵母或白色念珠菌制备的甘露聚糖的体外免疫抑制作用的研究提出的，费林试剂会产生一种被铜污染的结构修饰产物。因此，我们评估了通过与十六烷基三甲基溴化铵（CTAB）络合制备的更天然的白色念珠菌甘露聚糖的免疫抑制作用。当将CTAB甘露聚糖添加到对念珠菌有反应的供体的人外周血单核细胞（PMBC）中时，它是淋巴细胞增殖的有效刺激剂；它对念珠菌或其他抗原诱导的淋巴细胞增殖没有抑制作用。相比之下，通过弱碱性降解从CTAB甘露聚糖衍生的一系列甘露糖寡糖（二糖至六糖）成员不会刺激淋巴细胞增殖，但却是念珠菌和其他抗原刺激的淋巴细胞增殖的有效抑制剂。半数抑制剂量分别为260至34微摩尔。对这些免疫抑制性寡聚物的成分分析表明，它们由甘露糖组成且不含污染蛋白。我们提出，体内甘露聚糖分解代谢产生的甘露聚糖衍生寡糖具有免疫抑制作用，并导致与慢性念珠菌病相关的细胞介导免疫功能缺陷。
