抗人CD40人-鼠嵌合抗体在CHO细胞中的表达及其功能研究

目的:实现抗人CD40的人-鼠嵌合抗体(ch-5C11)在的CHO细胞中的稳定表达并对其生物学活性进行初步的研究。方法:pIRES/hu5C11嵌合抗体重组表达质粒用脂质体法转染CHO细胞,采用RT-PCR对CHO细胞进行基因水平鉴定,以流式细胞术(FCM)和Western blot对表达上清中ch-5C11人免疫球蛋白Fc段和κ链成分进行检测,利用Protein G亲和层析和Lowry法进行纯化和定量,MTT实验检测表达ch-5C11对Daudi细胞增殖的抑制效应。结果:获得稳定分泌目的蛋白的CHO稳定株,RT-PCR结果表明目的基因成功整合在CHO稳定株中,FCM和Western blot结果表明稳定株上清中含有抗人CD40抗体,且含人免疫球蛋白Fc段和κ链;Lowry法定量ch-5C11浓度为0.535mg/L,并经SDS-PAGE蛋白电泳鉴定纯度良好;ch-5C11能抑制Daudi细胞增殖。结论:获得了持续分泌ch-5C11的CHO稳定株,功能学研究显示ch-5C11能抑制B细胞淋巴瘤细胞株体外增殖。

Expression of human-mouse chimeric antibody against CD40 in CHO cell line and characterization of its function

AIM: To investigate the stable expression of a chimeric antibody against CD40 moleculeèch-5C11éin CHO and its biological activity. METHODS: Human-mouse chimeric antibody against CD40 recombinant plasmid and mock plasmid were transfected into CHO cell line through lipofectamine mediation. Human kappa chain and Fc fragment of ch-5C11 were characterized by FACS and Western blot. The concentration of ch-5C11 in cell supernatants was detected by Lowry assay and the inhibitory effect of ch-5C11 on the proliferation of Daudi cells was detected by MTT assay. RESULTS: RT-PCR showed that target CHO cells integrated chimeric heavy chain and chimeric light chain gene. FACS and Western blot showed that ch-5C11 in cell supernatants maintained the binding activity and specificity to human CD40 molecule, and contained human kappa chain and Fc fragment. Cell supernatants were purified using protein G affinity chromatography. The concentration of human-mouse chimeric antibody against CD40 in cell supernatants was 0.535 mg/L. When co-cultured with B lymphoma cell line Daudi, ch-5C11 induced proliferation arrest of Daudi cells. CONCLUSION: The human-mouse chimeric antibody against CD40 can be expressed in CHO stably and effectively, which inhibits proliferation of Daudi.