抗MHCⅡ类抗原单克隆抗体人血清蛋白氨甲喋呤结合物的制备及活性研究

Characteristics of a Human Serum Albumin-Mediated Conjugate of Methotrexate with Anti-MHC Class Ⅱ Monoclonal Antibody

作者采用间接偶联法,以人血清白蛋白作为中间载体制成氨甲噪吟-人血清白蛋白-鼠抗人MHCⅡ类抗原单克隆抗体结合物。经体外活性检测,证实该结合物对靶细胞Raii的IC50为0.6μg/ml,对非靶细胞Molt 4的IC50为10μg/ml,游离McAb HI43能竞争抑制这种作用。而相同浓度的结合物对造血干细胞克隆无抑制效应。

In the studies on antibody-drug conjugates as potential purging agents in bone marrow transplantation, MTX, coupled with HSA by means of carbondiimide, was conjugated with a kind of murine monoclonal antibody to MHC Ⅱ antigen using HSA as an intermediator. MTX-HSA was conditioned to have about 1 mol of thiol group per mol of HSA by dithiothreitol treatment, the resulting SH-HSA-MTX then being reacted with immunoglobulin modified with the PDP group.The conjugates H143-HSA-MTX, which inhibited 80% of growth rate of target cell-Kaji and 40% of growth rate of nontarget cell-Molt 4 at a dose of 8μg/ml of MTX, retained both antibody binding and drug activities. The cytotoxicity was blocked by unconjugated H143. When the conjugates reached the dosage capable of maximal killing Raji cells, there was no toxicity to multipotential progenitors ( CFU-GM ) in normal human bone marrow.