Torosantucci A, Palma C, Boccanera M, Ausiello C M, Spagnoli G C, Cassone A
Laboratory of Bacteriology and Medical Mycology, Istituto Superiore de Sanità, Rome, Italy.
J Gen Microbiol. 1990 Nov;136(11):2155-63. doi: 10.1099/00221287-136-11-2155.
Two major proteoglycan constituents (designated F1 and F2) of the cell wall of Candida albicans were separated by ion-exchange chromatography from a crude carbohydrate-rich extract (GMP), and investigated for their chemical and molecular composition, antigenicity and immunomodulatory properties in cultures of human peripheral blood mononuclear cells (PBMC). Both fractions consisted predominantly of Periodic acid-Schiff (PAS) and concanavalin A (Con A)-reactive material consisting of greater than 90% mannose, 3-5% protein and small amounts of phosphorus; each was recognized by an anti-Candida rabbit serum as well as by a monoclonal antibody (mAb AF1) directed against an oligosaccharide epitope present on the fungal cell surface. When F1 and F2 were subjected to SDS-PAGE, transblotted and stained with enzyme-conjugated mAb AF1 or Con A, most of the antibody or lectin bound to high molecular mass (greater than 200 kDa) polydisperse material, some of which was present in F2 (as in the starting GMP extract) but absent in F1. This difference was also observed in PAS-stained gels of the two fractions. The F2, but not the F1, constituent was as active as the unfractionated GMP extract in inducing lymphoproliferation, production of the cytokines interleukin-2 and interferon-gamma, and generation of cytotoxicity against a natural-killer-sensitive target cell line (K562). These immunomodulatory properties were, like those possessed by GMP, protease-sensitive and heat-stable. Treatment of PMBC cultures with a modulatory anti-T-cell receptor antibody abolished the lymphoproliferation induced by GMP and F2 but not that induced by phytohaemagglutinin, showing that the mannoprotein materials of C. albicans acted through interaction with the antigen receptor complex.
白色念珠菌细胞壁的两种主要蛋白聚糖成分（分别命名为F1和F2）通过离子交换色谱法从富含碳水化合物的粗提物（GMP）中分离出来，并对其化学和分子组成、抗原性以及在人外周血单个核细胞（PBMC）培养物中的免疫调节特性进行了研究。这两个组分主要由过碘酸希夫（PAS）阳性和刀豆球蛋白A（Con A）反应性物质组成，其中甘露糖含量超过90%，蛋白质含量为3 - 5%，还有少量磷；二者均能被抗白色念珠菌兔血清以及一种针对真菌细胞表面存在的寡糖表位的单克隆抗体（mAb AF1）识别。当F1和F2进行SDS - PAGE、转印并用酶联mAb AF1或Con A染色时，大部分抗体或凝集素与高分子质量（大于200 kDa）的多分散物质结合，其中一些存在于F2中（如起始的GMP提取物中），但F1中不存在。在这两个组分的PAS染色凝胶中也观察到了这种差异。F2组分（而非F1组分）在诱导淋巴细胞增殖、细胞因子白细胞介素 - 2和干扰素 - γ的产生以及对自然杀伤敏感靶细胞系（K562）产生细胞毒性方面与未分级的GMP提取物具有相同活性。这些免疫调节特性与GMP所具有的特性一样，对蛋白酶敏感且热稳定。用一种调节性抗T细胞受体抗体处理PBMC培养物可消除GMP和F2诱导的淋巴细胞增殖，但不能消除植物血凝素诱导的增殖，这表明白色念珠菌的甘露糖蛋白物质通过与抗原受体复合物相互作用发挥作用。
