^(90)Y间接法标记单克隆抗体的实验研究

Study on the Indirect Labeling Method of Labeling Monoclonal Antibody with Yttrium 90

目的:采用间接法对抗CEA单抗(McAb)及CD45McAb进行90Y标记,并确定最佳标记条件,为90Y放射免疫导向治疗CEA分泌性肿瘤及急性白血病奠定基础。方法:利用DTPA环酐(cDTPAa)作为络合剂,将90Y偶联至CEAMcAb与CD45McAb上,确定cDTPAa与抗体偶联的最佳条件,并测定偶联物的免疫活性及在体外的稳定性。结果:在抗体浓度为20mg/ml时,最佳偶联条件为:抗CEA单抗与cDTPAa的摩尔比为1:20,偶联反应中pH值8.2,在最佳偶联条件下,90Y标记CEAMcAb与CD45McAb的标记率均>93,放化纯度均>95,体外稳定性良好,并且两类标记物均保持较好的免疫活性。结论:90Y标记的CEAMcAb与CD45McAb是较理想的放射免疫靶向治疗制剂,可用于下一步的CEA分泌性肿瘤及急性白血病的治疗研究。

Objective To prepare yttrium - 90 labelled anti - CEA monoclonal antibody （MeAb） and anti - CD45 MeAb with indirect labelling method for possible use in targeting therapy of CEA - expressing tumors and acute leukemia. Methods Anti - CEA MeAb and and - CD45 MeAb were labelled with ^90Y by indirect method （with eyelie DTPA anhydride （cDTPAa） as chelating agent）. The optimal conjugate conditions between the antibody and eDTPAa were studied. The labelling rate, radiochemical purity, immunore- activity and in vitro stability of labelled McAbs were determined. Results With the optimal molar ratio of cDTPAa/MeAb （20 ： 1 ）, the labelling rate was over 93%, radiochemical purity was over 95% , and the immunoreaactivity of both labelled MeAbs were not significantly different from those of unlabelled McAbs. Both ^90Y labelled conjugates were stable in vitro with no changes in the protein binding distribution in serum observed. Conclusion ^90Y radidabelled CEA McAb and CD45 McAb might be suitable radioimmuno- therapy agents for the possible further targeting therapy research on CEA - expressing tumors and acute leukemia.