Bennett J E
Infect Immun. 1981 Apr;32(1):373-80. doi: 10.1128/iai.32.1.373-380.1981.
Antigen capable of eliciting delayed hypersensitivity reactions in the skin of sensitized guinea pigs could be extracted from Cryptococcus neoformans cells by stirring the cells from 3 to 5 days in concentrated urea or guanidine. Hydrolysis of urea to ammonia by cryptococcal urease accompanied urea extraction, but alkalinity appeared neither necessary nor sufficient for extraction. Antigen from live cells gave larger delayed skin reactions than did antigen from Formalin-killed cells. Peak skin test reactivity appeared to reside in protein-rich fraction having an elution volume on Sephadex G50 corresponding to a molecular weight of 10(4). Activity precipitated with half-saturated ammonium sulfate and could be detected in a single, narrow, rapidly migrating band on disc electrophoresis. Dialyzable proteinaceous antigen and high-molecular-weight, serologically active polysaccharide were present in the antigen, but not active in the delayed hypersensitivity reactions.
通过在浓尿素或胍中搅拌新型隐球菌细胞3至5天，可从该细胞中提取出能在致敏豚鼠皮肤中引发迟发型超敏反应的抗原。尿素被隐球菌脲酶水解成氨的过程伴随着尿素提取，但碱性对于提取而言似乎既非必要条件也非充分条件。来自活细胞的抗原比来自福尔马林灭活细胞的抗原引发的皮肤迟发型反应更大。皮肤试验反应峰值似乎存在于富含蛋白质的组分中，该组分在Sephadex G50上的洗脱体积对应于分子量为10⁴。活性物质用半饱和硫酸铵沉淀，并且在圆盘电泳上可在一条单一、狭窄、快速迁移的条带中检测到。抗原中存在可透析的蛋白质抗原和高分子量、具有血清学活性的多糖，但它们在迟发型超敏反应中无活性。
