Håkansson L, Fredman P, Svennerholm L
J Biochem. 1985 Sep;98(3):843-9. doi: 10.1093/oxfordjournals.jbchem.a135343.
Immune complexes in the serum of tumor-bearing patients were adsorbed from whole blood or plasma on a protein A-Sepharose column. The adsorbed material was eluted, precipitated and analyzed for gangliosides. All precipitates obtained from eight patients at different treatment occasions contained gangliosides at concentrations varying from 0.1 to 12.2 nmol sialic acid/mg protein. The compositions of gangliosides were similar among the patients, regardless of the type of cancer, and quite different from that of normal serum. Most (75-85% of total sialic acid) belonged to the gangliotetraose series, of which 26-33% was GM1, 26-34% GD1a, 8-17% GD1b, and 5-13% GT1b. However, the dominant ganglioside in normal serum, GM3, was present in only trace amounts, which ruled out a nonspecific adsorption of serum ganglioside by protein A-Sepharose. Similar results were obtained for whole blood and plasma treatments, and these results suggest a specific interaction between gangliosides of the gangliotetraose series and serum immunoglobulins, either by the gangliosides acting as antigens and forming immune complexes or by their binding to already formed complexes.
荷瘤患者血清中的免疫复合物通过蛋白A-琼脂糖凝胶柱从全血或血浆中吸附。吸附的物质被洗脱、沉淀，并分析其神经节苷脂。从8名患者在不同治疗阶段获得的所有沉淀物都含有神经节苷脂，其浓度在0.1至12.2 nmol唾液酸/毫克蛋白之间变化。无论癌症类型如何，患者之间神经节苷脂的组成相似，且与正常血清的组成有很大不同。大多数（占总唾液酸的75-85%）属于神经节四糖系列，其中GM1占26-33%，GD1a占26-34%，GD1b占8-17%，GT1b占5-13%。然而，正常血清中的主要神经节苷脂GM3仅以痕量存在，这排除了蛋白A-琼脂糖凝胶对血清神经节苷脂的非特异性吸附。全血和血浆处理获得了相似的结果，这些结果表明神经节四糖系列的神经节苷脂与血清免疫球蛋白之间存在特异性相互作用，要么是神经节苷脂作为抗原形成免疫复合物，要么是它们与已形成的复合物结合。
