肝癌候选标志物HCCR单克隆抗体的制备和鉴定

Preparation and characterization of monoclonal antibody against HCCR protein

目的:制备肝癌候选标志物HCCR蛋白的单克隆抗体(mAb)。方法:重组表达HCCR-1167-360蛋白用于动物免疫,用含有HCCR蛋白抗原表位YLGTRR的重组蛋白(Ep-HCCR)检测血清抗体效价及筛选阳性克隆。通过ELISA、Western blot、免疫荧光和免疫组化方法鉴定制备的HCCR抗体的性质。结果:获得1株分泌HCCR抗体杂交瘤细胞株,通过ELISA方法测定抗体的亲和力常数为5.4×106L/mol;Western blot结果显示,该抗体能特异识别肝癌HepG2细胞中HC-CR-1和HCCR-2蛋白;免疫荧光检测显示,HCCR蛋白主要分布在细胞质和细胞膜中;免疫组化检测到肝癌组织中有HCCR蛋白表达但在正常组织中没有。结论:成功制备了1株抗HCCR特异性mAb,为建立基于HCCR的肝癌检测方法奠定了基础。

AIM： Preparation of monoclonal antibody （mAb） to HCCR, which is a candidate biomarker for human hepatocellular carcinoma （HCC）. METHODS： The recombinant protein HCCR-1167-360 was expressed and was used as immunogen to immunize mouse for generation of mAb against HCCR. The protein Ep-HCCR, which displayed a epitope of HCCR, was also expressed and purified to use to detect serum antibody titer and to screen the positive clones of hybridmas. The properties of HCCR antibody were analyzed by ELISA, Western blot, immunofluorescence and immunohistochemistry. RESULTS： A hybridmas clone, which secreted anti-HCCR mAb, was obtained. The affinity constant （Kaff） of the mAb is 5.4×106 L/mol analyzed by ELISA; Western blot showed that the mAb could specifically recognize HCCR-1 and HCCR-2 expressed in HepG2 cells; The mAb was also used to detect the expression of HCCR proteins in hepatoma cells and HCC tissues. The results of immunofluorescence indicated that HCCR proteins mainly localized on the plasma membrane and cytoplasm of HepG2 cells. In addition, HCCR was found high-expressed in HCC tissues but not in normal liver tissue detected by Immunohistochemistry. CONCLUSION： A specific mAb against HCCR was successfully generated, which laid the foundation for establishing HCC detection method based on HCCR.