Nepom J T, Hellström I, Hellström K E
J Immunol. 1976 Nov;117(5 Pt.2):1846-52.
The purification of a blocking factor from the sera of tumor-bearing mice is described. Whole serum with blocking activity-the ability to inhibit specific cell-mediated anti-tumor immunity in microcytotoxicity tests-was fractionated on immunoadsorbent columns containing Sepharose-bound syngeneic normal mouse immunoglobulins and immunoglobulins from tumor-immune donors. The blocking serum was derived from mice which had carried a transplanted methylocholanthrene-induced sarcoma for 21 to 28 days. Elution of the immunoadsorbents recovered the blocking activity in a single fraction. This fraction was blocking activity in a single fraction. This fraction was radiolabeled and analyzed by SDS gel electrophoresis and Sephadex G-200 column chromatography. The active component of the blocking serum was shown to be a polypeptide of m.w. 56,000. Specificity testing implied that the factor was likely to be either tumor antigen or an antigen-specific suppressor molecule.
本文描述了从荷瘤小鼠血清中纯化一种阻断因子的过程。具有阻断活性（即在微量细胞毒性试验中抑制特异性细胞介导的抗肿瘤免疫的能力）的全血清在含有与琼脂糖结合的同基因正常小鼠免疫球蛋白和来自肿瘤免疫供体的免疫球蛋白的免疫吸附柱上进行分级分离。阻断血清取自携带甲基胆蒽诱导的移植肉瘤21至28天的小鼠。免疫吸附剂的洗脱在单一馏分中回收了阻断活性。该馏分在单一馏分中具有阻断活性。该馏分用放射性标记，并通过SDS凝胶电泳和葡聚糖凝胶G-200柱色谱进行分析。阻断血清的活性成分显示为一种分子量为56,000的多肽。特异性测试表明该因子可能是肿瘤抗原或抗原特异性抑制分子。
