目的：制备抗CEA单抗-β-葡萄糖苷酶偶联物，检测其免疫反应性及酶活性，并观察其体外激活苦杏仁甙前药对LoVo细胞的靶向杀伤效应。方法：通过异型双功能交联剂N-琥珀酰亚胺 间（N-马来酰亚胺基）苯甲酸酯（MBS）将抗CEA单克隆抗体与β-葡萄糖苷酶交联，制备抗CEA单抗-β 葡萄糖苷酶偶联物， ELISA法检测偶联物的抗体亲和力及酶活性，MTT法检测其对苦杏仁甙前药激活后对表达CEA的大肠癌细胞株LoVo和无CEA表达的乳腺癌细胞株MCF-7的杀伤作用。结果：抗CEA单抗-β-葡萄糖苷酶偶联物既保持了与靶细胞的特异性免疫反应性又保持了酶活性，体外能有效激活苦杏仁甙前药,对LoVo细胞产生剂量依赖性靶向杀伤作用,而对对照乳腺癌MCF-7细胞无明显的杀伤作用。结论：抗CEA单抗-β-葡萄糖苷酶偶联物具有良好的体外结合大肠癌LoVo细胞的能力，并能有效激活苦杏仁甙前药发挥对靶细胞的特异性杀伤作用,该方法有可能进一步用于大肠癌的治疗。

Objective: To prepare anti-CEA monoclonal antibody-β-glucosidase conjugate(Anti-CEA McAb-β-glucosidase conjugate)， evaluate its immunoreactivity and enzymatic activity, and study its killing effect against LoVo cells in combination with amygdalin in vitro.Methods: Anti-CEA monoclonal antibody-β-glucosidase conjugate was prepared to use heterobifunctional crosslinking reagent 3-maleimidobenzoic acid N-succinimidyl ester (MBS) conjugating β-glucosidase to a anti-CEA monoclonal antibody, the immunoreactivity and enzymatic activity of the conjugate was tested by ELISA method. The cytotoxicity to targeted cells and untargeted cells following specific activation of amygdalin by the conjugate was evaluated by MTT assy in vitro.Results: Anti-CEA McAb-β-glucosidase conjugate kept both immunoreactivity and enzymatic activty. Anti-CEA McAb-β-glucosidase conjugate could bird LoVo cells specifically and activate amygdalin to kill Love cells in a dose-dependent manner, but it had not the same effect against MCF-7 cells.Conclusion: Anti-CEA McAb-β-glucosidase conjugate has a good character for binding LoVo cells in vitro and can activate amygdalin prodrug to kill targeted cells specifically.This way might become a hopeful model of colorectal carcinoma immuonotherapy.

国家自然科学基金（30170921）