Myers C D, Thorpe P E, Ross W C, Cumber A J, Katz F E, Tax W, Greaves M F
Blood. 1984 May;63(5):1178-85.
A conjugate of the monoclonal antibody WT1 and ricin A-chain was studied for its suitability for purging marrow of leukemic T cells for autologous transplantation in T cell acute lymphocytic leukemia (T-ALL). The conjugate was powerfully cytotoxic to the human T-ALL cell line, GH1, which expresses the WT1 antigen at a high density. Treatment of the cells with the conjugate at 10(-11) M reduced their rate of protein synthesis by 50%, and the inclusion of 6 mM ammonium chloride in the cultures enhanced the potency of cytotoxic effect by 10-100-fold. Clonogenic assays indicated that less than 0.1% of GH1 cells survived 3-hr exposure to the conjugate in ammonium chloride. WT1 alone did not react with multipotent (CFU-GEMM) hematopoietic progenitors in normal human bone marrow, as measured by fluorescence-activated cell sorting. Under conditions giving maximal killing of GH1 cells, there was no toxicity to multipotential progenitors in normal human marrow.
对单克隆抗体WT1与蓖麻毒素A链的偶联物进行了研究，以评估其是否适合用于清除T细胞急性淋巴细胞白血病（T-ALL）患者骨髓中的白血病T细胞，用于自体移植。该偶联物对人T-ALL细胞系GH1具有强大的细胞毒性，GH1细胞高密度表达WT1抗原。用10^(-11) M的偶联物处理细胞可使其蛋白质合成速率降低50%，培养物中加入6 mM氯化铵可使细胞毒性作用的效力提高10至100倍。集落形成试验表明，在氯化铵存在的情况下，暴露于偶联物3小时后，存活的GH1细胞不到0.1%。通过荧光激活细胞分选测定，单独的WT1不与正常人骨髓中的多能（CFU-GEMM）造血祖细胞发生反应。在能最大程度杀伤GH1细胞的条件下，对正常人骨髓中的多能祖细胞没有毒性。
