单克隆抗体(HI_(30))-丝裂霉素免疫偶合物的研究

Preparation of a Monoclonal Antibody (HI_(30))-mitomycin C Conjugate Utilizing Dextran T-40 and its Specific Cytotoxicity against Human Leukemia Cell Line CEM

用Dextran T-40的氧化产物葡聚糖多聚醛(polyaldehyde,PAD)作为中间载体,将鼠抗人T淋巴细胞表面分化抗原的单克隆抗体HI_(30)与抗癌药丝裂霉素(mitomgcin C,MMC)形成共价连接,制备HI_(30)-PAD-MMC免疫偶合物。偶合物的特异性毒性依赖于单克隆抗体(单抗)和靶细胞表面抗原位点的结合。偶合物基本上保持原有的抗体结合活性及药物细胞毒,并具有良好的稳定性。

The anticancer drug mitomycin C (MMC)was conjugated with an affinity - purified murine monoclonal antibody (HI30 )to a human Tlymphocyte surface differentiation antigen with dextran T-40 as the intermediate carrier . The conjugate (HI30:MMC molar ratio , 1 :7) retained full antibody binding activity as determined by an indirect immunofluorescence assay . E. Coli HB101 growth inhibition test showed that the antimicrobial activity [MMC eqivalent (μg/ml)] of the conjugate was about 29.2% as potent as free MMC .In a cytotoxicity test , the conjugate was about 3-10 times more cytotoxic against the antibody-reactive human T lymphocyte leukemia CEM cells than was free MMC or the mixture of HI30 and MMC [IC50 of the MMC equivalent (μg/ml) was 0. 4147,2. 212,2. 171, respectively] and was less cytotoxic against The antibody-nonreactive L1210 cells (IC50 were 1. 311, 0. 8683 , 0. 7308 , respectively ). The selective cytotoxicity was also confirmed by competitive inhibition with free antibody , showing a dependence on antibody binding of the target cell surface antigen . There was no detectable free MMC released from HI30 -Dex-MMC conjugate stored at 4℃ for over one month as measured by chromatography on a Sephadex G - 25 column .