CD45单抗及188Re-亲和素二步法预定位对淋巴瘤Raji细胞的放射免疫效应研究

Effect of the two-step pretargeting radioimmunotherapy of CD45 monoclonal antibody and 188Re-Avidin on lymphoma Raji cell line

目的 探讨CD45单抗及188Re-亲和素（Avidin）二步法预定位对人淋巴瘤Raji细胞的放射免疫效应.方法 188Re对CD45单抗及Avidin的标记采用直接标记法,采用纸层析法测定标记率及放化纯度.分析188Re-CD45单抗与Raji细胞的体外结合能力,并进行体外竞争结合实验,采用CCK-8法测定二步法预定位组、188Re-CD45单抗组、188Re-Avidin组和188ReO4-组对Raji细胞的增殖抑制效应,计算Raji细胞存活率和抑制率.结果 188Re-CD45单抗与Raji细胞的特异性结合率为（70.92±1.91）％,同时加入188Re-CD45单抗和过量的CD45单抗,则细胞结合率平均为（7.96±0.87）％.二步法预定位组、188 Re-CD45单抗组、1888Re-Avidin组和1888ReO4-组对Raji细胞的增殖均有抑制作用,抑制率与放射性活度呈正相关（r=0.907 ～0.992,P＜0.05）;在相同放射性活度下,二步法预定位组在各时间点的抑制作用均高于188 Re-CD45单抗组、188Re-Avidin组和188 ReO4-组（t=124.76 ～ 607.98,P＜0.05）.结论 188 Re-CD45单抗可特异性地与Raji细胞结合,CD45单抗及188 Re-Avidin二步法预定位对人淋巴瘤Raji细胞具有明显的抑制作用.

Objective To study the effect of two-step pretargeting radioimmunotherapy of CD45 McAb and 188Re-Avidin on lymphoma Raji cell line.Methods The CD45 McAb and Avidin were directly labeled with 188Re,and the labeling efficiency and radiochemical purity were measured by the paper chromatography.The specific binding test and competition binding test between 188 Re-CD45 McAb and Raji cells in vitro were also performed.CCK-8 assay was used to determine the inhibition effect on Raji cell proliferation in the pretargeted group,188Re-CD45 McAb,188Re-Avidin and 188ReO4 groups,then the cell survival and proliferation inhibition rate were calculated.Results The specific cell binding rate of 188Re-CD45 McAb with Raji cells was （70.92 ± 1.91） %,in the competition group,the binging rate of 188Re-CD45 McAb with Raji cells was only （7.96 ± 0.87）%.The Raji cells proliferation was inhibited in all groups with 188Re radiolabel,and the inhibition rate was positively correlated with the radioactivity dose （r=0.907-0.992,P 〈0.05）.However,at the same dose,the inhibition effect in the group of two-step pretargeting at each time point were all stronger than those of 188Re-CD45 McAb,188Re-Avidin and 188 ReO4-alone （t =124.76-607.98,P 〈 0.05）.But there was no significantly statistical difference in the inhibitory effect between the groups of 188Re-Avidin and 188ReO4-（P 〉 0.05）.Conclusions It is confirmed that 188Re-CD45 McAb could be specifically bound to Raji cells,and the two-step pretargeting of CD45 McAb and 188Re-Avidin has obvious inhibitory effect on the Raji cell proliferation.