抗HIF-1α肺腺癌人源单链抗体的制备和放射免疫显像

Preparation of human anti-HIF-1α scFv of lung adenocarcinoma and its radioimmunoimaging

目的利用噬菌体抗体库技术制备特异性的抗缺氧诱导因子1α(hypoxia-inducible factor,HIF-1α)肺腺癌人源单链抗体(scFv),并用于荷人肺腺癌裸鼠体内放射免疫显像(radioimmunoimaging,RII)研究。方法利用噬菌体抗体库技术筛选特异性抗HIF-1α肺腺癌人源scFv,并将其感染大肠杆菌HB2151,进行scFv的可溶性表达。接种肺腺癌A549细胞复制荷瘤裸鼠模型,尾静脉注射131I标记可溶scFv,于注射后24、48、72、120h进行SPECT平面静态检查,观察肿瘤内放射性浓聚情况,用感兴趣区(region of interest,ROI)技术分析T/NT值,取平面静态检查肿瘤显影清晰时进行SPECT/CT图像融合。结果经鉴定证实制备出特异性的抗HIF-1α肺腺癌人源scFv,荷瘤裸鼠体内RII结果显示131I-可溶scFv可以选择性地积聚于肿瘤组织,肿瘤区放射性浓聚、T/NT值均在72h达到高峰,利用ROI技术得到的T/NT值此时最大可达3.19。72h时融合图像肿瘤显像良好,图像清晰。结论成功制备特异性抗HIF-1α肺腺癌人源scFv,131I标记后荷人肺腺癌裸鼠RII肿瘤显影良好。

Objective To prepare the human anti-HIF-1α scFv of lung adenocarcinoma from phage antibody library and to study the radioimmunoimaging （RII） of scFv in nude mice xenografted with A549 tumor cells in vivo. Methods Specific anti-HIF-1α scFv of lung adenocarcinoma was selected from the phage antibody library. Expression of soluble scFv was induced by infecting E.coli HB2151. 131I-labeled scFv was injected into the tail veins of nude mice xenografted with A549 tumor cells. Static imaging was performed by SPECT 24,48,72 and 120 h after injection of soluble scFv to observe the radioactivity in tumor. Radioactivity ratio of tumor and non-tumor （T/NT） was assayed using the ROI technique. When the tumor was clearly visible,image fusion was performed by SPECT/CT. Results The specific human anti-HIF-1α scFv of lung adenocarcinoma was successfully prepared. The RII showed that the 131I-labeled scFv was selectively accumulated in lung adenocarcinoma tissue. Radioisotope uptake and T/NT reached their peak value of 3.19 in the tumor and the image was well fused with the tumor clearly seen 72 h after injection of soluble scFv. Conclusion Human anti-HIF-1α scFv of lung adenocarcinoma can be successfully prepared. 131I-labeled scFv can clearly show the tumor on RII in nude mice xenografted with A549 tumor cells,thus laying a foundation for further study on the diagnosis and treatment of lung adenocarcinoma.