摘要
IL 15及IL 15受体 (IL 15R)阳性细胞在成人T淋巴细胞性白血病 (ATL)、多发性骨髓瘤及炎症性自身免疫性疾病病理过程中起着重要作用。为研制特异的可消除IL 15受体阳性异常细胞的新型导向药物 ,将人IL 15拮抗剂 (IL 15M)基因片段与人工改造的绿脓杆菌外毒素 (PE)变异体 (PEΔ2 93)基因按正确的阅读框架融合 ,定向克隆在pET16b表达载体T7启动子的下游 ,得到质粒pET IL15M PEΔ2 93。从大肠杆菌相应重组菌株中通过Ni2 + NTA亲和层析纯化出融合蛋白IL15M PEΔ2 93。IL15M PEΔ2 93对IL 15R阳性红白血病细胞系K5 6 2及其多药耐药细胞系K5 6 2 AO2 均具有杀伤作用 ,对IL 15R阴性细胞系Jur kat则没有明显的杀伤作用 ,而且过量的重组IL 15可以完全阻断融合蛋白对K5 6 2的细胞毒效应 ,说明融合蛋白的细胞毒作用具有靶向性。这些结果提示本文构建的融合蛋白在与IL 15 IL 15R异常表达相关的疾病甚至耐药性肿瘤的治疗中具有潜在的应用价值。
IL 15 and IL 15 receptors(IL 15R) play a crucial role in the pathogenesis of adult T cell leukemia(ATL), multiple myeloma and inflammatory autoimmune diseases. To develop a novel therapeutic agent capable of eliminating IL 15R over expressing abnormal cells, the gene coding for human IL 15 antagonist(IL 15M) was fused with a DNA fragment coding for the mutated form of Pseudomonas exotoxin, PEΔ293. The resulting gene fusion was cloned into pET16b under the control of T7 promoter, giving rise to the expression plasmid pET IL15M PEΔ293 Using Ni 2+ NTA affinity chromatography, IL15M PEΔ293 was purified from E.coli BL21(DE3)pLysS transformed with pET IL15M PEΔ293 The fusion toxin showed cytotoxicity to IL 15R bearing myelogenous leukemia cell line K562 and K562 derived multidrug resistant cell line K562/AO 2 However, IL 15R negative cell line Jurkat was insensitive to IL15M PEΔ293 In addition, the toxic effect of IL15M PEΔ293 on K562 was completely blocked by excessive amount of recombinant human IL 15 These results demonstrated that the selective cytotoxicity of IL15M PEΔ293 correlated with the appropriate IL 15R expression on target cells. The present data suggest that the chimeric toxin constructed in this report may have therapeutic potential in the treatment of diseases associated with abnormal expression of IL 15/IL 15R, even in the treatment of chemotherapy refractory tumors.
出处
《生物工程学报》
CAS
CSCD
北大核心
2005年第1期42-46,共5页
Chinese Journal of Biotechnology
基金
东南大学科技基金资助 (No .92 2 3 0 0 1160 )。~~
