^(188)Re标记单克隆抗体 2F7 的方法学研究

A method for monoclonal antibody 2F7 labelling with 188 Re

目的建立１８８Ｒｅ标记抗小细胞肺癌单克隆抗体（ＭＡｂ）２Ｆ７的方法，探讨其标记条件。方法以葡萄糖酸钠为中间螯合剂，用１８８Ｒｅ标记２Ｆ７，β疏基乙醇法还原ＭＡｂ。探讨还原剂ＳｎＣｌ２用量、ｐＨ值、ＭＡｂ浓度等对标记反应的影响。上行纸层析法测定标记率及胶体含量。直线回归外推法测定标记ＭＡｂ的免疫活性分数，并测定其在荷瘤裸鼠体内的生物分布。结果１８８Ｒｅ标记反应的适宜条件为：４０～８０ｇ／ＬＳｎＣｌ２，０１ｍｏｌ／Ｌ葡萄糖酸钠溶液，０５～２ｇ／ＬＭＡｂ，ｐＨ值５４～６８，标记率在２小时后可达９０％以上。荷瘤裸鼠体内生物分布测定表明，注射标记２Ｆ７４８小时后，瘤／血比约为２８，７２小时后则达３２。结论该标记方法操作简便，标记率高，无需在用药前进一步纯化，反应时间短，是较好的１８８Ｒｅ标记ＭＡｂ法。

Purpose To study monoclonal antibody 2F7 against small cell lung cancer radiolabelling with 188 Re using sodium gluconate as chelating agent Methods Various parameters of the radiolabelling reaction, such as SnCl 2 concentration, pH value, MAb concentration were studied in details, as well as the immunoactive fraction of labelled MAb 2F7 and its biodistribution in tumor bearing nude mice The reduction of MAb disulfide bonds was performed with β ME The labelling efficiency of the procedure and the content of colloid were determined by paper chromatography Results The optimal conditions for this 188 Re labelling reaction included 4 0～8 0g/L SnCl 2 in 0 1mol/L sodium gluconate solution, 0 5～2g/L MAb and pH 5 4～6 8, and the labelling efficiency was over 90% after 2 hours The biodistribution in tumor bearing nude mice showed that the labelled MAb 2F7 may be of potential clinical application value in cancer radioimmunotherapy with the tumor/blood ratio of 2 8 and 3 2 by 48 hours and 72 hours after administration Conclusions This method of labelling MAb with 188 Re is convenient and relatively rapid in performance with satisfactory labelling efficiency, and does not need further purification of the labelled radio pharmaceutical before administration