Hideshima T, Iwasaki A, Baba M, Yamashita Y, Shirakusa T, Okada H
Second Department of Surgery, School of Medicine, Fukuoka University, Nanakuma, Jonan-ku, Japan.
Surg Today. 1996;26(2):83-8. doi: 10.1007/BF00311769.
A mouse anti-human carcinoembryonic antigen (CEA) x anti-human CD3 bispecific antibody, AB5C10UCHT1, was developed. This antibody-heteroconjugate was chemically prepared by cross-linking the AB5C10 monoclonal antibody reactive with human CEA with the monoclonal antibody, UCHT1, which binds to CD3 on human T-lymphocytes. The AB5C10UCHT1 recognized both CEA expressed on the KATOIII cell line and CD3 expressed on T-lymphocytes, as determined using flowcytometry. Next, AB5C10UCHT1-mediated cytolysis was analyzed by 51Cr-release assay. When 51Cr-labeled target KATOIII cells were incubated for 6 h with effector cells that had been pretreated with AB5C10UCHT1 for 60 min at 4 degrees C, the percentage specific lysis was significantly increased compared to that of untreated effector cells. Using peripheral blood mononuclear cells (PBMC) and lymphokine-activated killer (LAK) cells pretreated with AB5C10UCHT1 for effector cells, the percentage specific lysis was determined to be 16.3% and 57.4% at effector: target (E:T) ratios of 100:1 and 12.5:1, respectively. On the other hand, the percentage specific lysis of untreated PBMC and LAK cells determined to be 3.0% and 35.8% at E:T ratios of 100:1 and 12.5:1, respectively. The minimum effective dose of AB5C10UCHT1 required for antibody-mediated cytotoxicity was 0.1 mu g/ml. The results of this study suggest that AB5C10*UCHT1 could be useful for augmenting the cytotoxicity of CD3-positive T-cells against CEA-positive target cells in vitro.
研发出了一种小鼠抗人癌胚抗原（CEA）x抗人CD3双特异性抗体AB5C10UCHT1。这种抗体异源缀合物是通过将与人CEA反应的AB5C10单克隆抗体与结合人T淋巴细胞上CD3的单克隆抗体UCHT1交联而化学制备的。使用流式细胞术测定，AB5C10UCHT1可识别KATOIII细胞系上表达的CEA和T淋巴细胞上表达的CD3。接下来，通过51Cr释放试验分析AB5C10UCHT1介导的细胞溶解作用。当用AB5C10UCHT1在4℃预处理60分钟的效应细胞与51Cr标记的靶KATOIII细胞孵育6小时时，与未处理的效应细胞相比，特异性裂解百分比显著增加。使用用AB5C10UCHT1预处理的外周血单个核细胞（PBMC）和淋巴因子激活的杀伤（LAK）细胞作为效应细胞，在效应细胞与靶细胞（E:T）比例为100:1和12.5:1时，特异性裂解百分比分别确定为16.3%和57.4%。另一方面，未处理的PBMC和LAK细胞在E:T比例为100:1和12.5:1时，特异性裂解百分比分别确定为3.0%和35.8%。抗体介导的细胞毒性所需的AB5C10UCHT1的最小有效剂量为0.1μg/ml。本研究结果表明，AB5C10*UCHT1在体外增强CD3阳性T细胞对CEA阳性靶细胞的细胞毒性方面可能有用。
