急非淋M_5型白血病单克隆抗体与柔红霉素偶合物的制备及体外细胞毒作用

Preparation and Cytotoxic Effect of Monoclonal Antibody-Daunorubicin Conjugate to Leukemic Cell Line in Vitro

用ＰＥＧ沉淀法及ＤＥＡＥ─Ｓｅｐｈａｃｅｌ离子交换层析和Ｓｅｐｈａｃｒｙｌｓ─３００凝胶层析提纯的抗急非淋Ｍ_５型白血病单克隆抗体ＩＡ_１（Ｍ_ｃＡｂ１Ａ_１），纯度为９９．９％。用葡聚糖作中间体将Ｍ_ｃＡｂ_１Ａ_１与柔红霉素（ＤＮＲ）偶联，制备的免疫偶合物仍保持较好的抗体活性及药物活性。在４８小时杀伤实验中，此偶合物对Ｕ_（９３７）靶细胞的杀伤作用与游离ＤＮＲ相近（Ｐ＞０．０５），明显大于对照偶合物（Ｐ＜０．０１）；在１小时预杀伤实验中，此偶合物对靶细胞的杀伤作用明显大于游离ＤＮＲ及对照偶合物（Ｐ＜０．０１）。在两个实验中，此偶合物对Ｗｉｓｈ非靶细胞的毒性都明显小于游离ＤＮＲ（Ｐ＜０．０１）；表明此偶合物在体外具有较好的选择性细胞毒作用。

Monoclonal antibody 1A1 specific for acute nonlymphocytic M 5 leukemia was purified from ascitic fluid by precipitation with PEG,DEAE-sephacel ion exchange and Sephacryl S-300 gel chromatography.Purity of the M cAb1A 1 was 99.9%.Daunorubicin was linked covalently to the purified M cAb1A 1 via a dextran bridge.M cAb1A 1-PAD-DNR conjugate retained substantially the original immunological and pharmacological activities.In chronic 48h test,the cytotoxicity of M cAb1A 1-PAD-DNR conjugate on U 937 cells was similar to that of free DNR,but greater than that of irrevalent conjugate.In 1h pretreatment test,the conjugate showed stronger cytotoxicity for U 937 cells than free DNR and irrevalent conjugate.In the two test,the M cAb1A 1-PAD-DNR conjugate showed only less cytotoxic effect upon nontarget cells,compared with free DNR.The immunoconjugate showed highiy selective cytotoxicity to target cells.