Preclinical development of anti-BCMA immunotoxins targeting multiple myeloma.
Preclinical development of anti-BCMA immunotoxins targeting multiple myeloma.
复制标题
DOI：
10.1093/abt/tby004
复制
发表时间：
2018-06
影响因子：
--
通讯作者：
Bera TK
中科院分区：
文献类型：
--
作者：
Shancer Z;Williams M;Igelman A;Nagata S;Ise T;Pastan I;Bera TK
多发性骨髓瘤（MM）是一种B细胞恶性肿瘤，对大多数患者来说是不可治愈的。迫切需要新的治疗方法。重组免疫毒素（RIT）是由融合至细菌毒素的抗体的Fv或Fab部分组成的嵌合蛋白。B细胞成熟抗原（BCMA）是一种谱系限制性分化蛋白，是MM抗体治疗的理想靶点。RIT是通过在大肠杆菌中表达编码抗BCMA RIT组分的质粒，然后制备包涵体，溶解，复性和柱层析纯化而产生的。通过WST-8测定法在体外测试RIT的细胞毒性活性。我们还测量了它们与人和小鼠血清白蛋白和BCMA的结合，并测量了它们在小鼠中的血清半衰期。使用来自不同抗BCMA抗体的Fv，我们产生了在体外特异性杀死表达BCMA的MM细胞的RIT。为了增加体内血清半衰期，我们产生了与白蛋白结合结构域（ABD）融合的RIT。与亲本RIT相比，所有具有ABD的RIT具有一定程度的活性降低，这不是由于与BCMA的结合降低。产生并评价了各种新的抗BCMA免疫毒素。这些都没有比LMB-75（抗BCMA BM 306-二硫化物稳定的Fv-LRggs）更好，支持LMB-75的进一步临床前开发。
Multiple myeloma (MM) is a B-cell malignancy that is incurable for the majority of patients. New treatments are urgently needed. Recombinant immunotoxins (RITs) are chimeric proteins that are composed of the Fv or Fab portion of an antibody fused to a bacterial toxin. B-cell maturation antigen (BCMA) is a lineage-restricted differentiation protein and an ideal target for antibody-based treatments for MM. RITs were produced by expressing plasmids encoding the components of the anti-BCMA RITs in Escherichia coli followed by inclusion body preparation, solubilization, renaturation, and purification by column chromatography. The cytotoxic activity of RITs was tested in vitro by WST-8 assays. We also measured their binding to human and mouse serum albumins and to BCMA and measured their serum half-life in mice. Using Fvs from different anti-BCMA antibodies, we produced RITs that specifically kill BCMA-expressing MM cells in vitro. To increase the serum half-life in vivo, we generated RITs that are fused with albumin-binding domains (ABDs). All RITs with ABDs have some decreased activity compared to the parent RIT, which is not due to decreased binding to BCMA. Various new anti-BCMA immunotoxins were produced and evaluated. None of these were better than LMB-75 (anti-BCMA BM306-disulfide-stabilized Fv-LRggs) supporting the further preclinical development of LMB-75.