Michalska Marta, Schultze-Seemann Susanne, Kuckuck Irina, Wolf Philipp
Department of Urology, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.
Department of Urology, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
Anticancer Res. 2018 Jan;38(1):61-69. doi: 10.21873/anticanres.12192.
We generated humanized/de-immunized immunotoxins targeting the prostate-specific membrane antigen (PSMA) and tested their cytotoxic activity against prostate cancer cells in vitro.
The humanized/de-immunized version of our murine anti-PSMA single-chain antibody fragment (scFv) D7, termed hD7-1(VL-VH), was ligated to the 40-kDa toxin domain of Pseudomonas aeruginosa exotoxin A (PE40), and to the deimmunized 24-kDa toxin domains PE24 or PE24mut. The immunotoxins designated as hD7-1(VL-VH)-PE40, hD7-1(VL-VH)-PE24 and hD7-1(VL-VH)-PE24mut were bacterially expressed and purified by affinity chromatography. Binding and cytotoxicity were examined by flow cytometry and viability assay, respectively.
All immunotoxins revealed strong binding to prostate cancer cells expressing PSMA and specific cytotoxicity, with half-maximal inhibitory concentration values in the picomolar range.
We successfully created powerful anti-PSMA immunotoxins with reduced immunogenicity for further clinical development and application against advanced prostate cancer.
我们制备了靶向前列腺特异性膜抗原（PSMA）的人源化/去免疫化免疫毒素，并在体外测试了它们对前列腺癌细胞的细胞毒活性。
将我们的鼠抗PSMA单链抗体片段（scFv）D7的人源化/去免疫化版本，即hD7-1（VL-VH），与铜绿假单胞菌外毒素A（PE40）的40 kDa毒素结构域，以及去免疫化的24 kDa毒素结构域PE24或PE24mut连接。命名为hD7-1（VL-VH）-PE40、hD7-1（VL-VH）-PE24和hD7-1（VL-VH）-PE24mut的免疫毒素通过细菌表达，并通过亲和层析进行纯化。分别通过流式细胞术和活力测定来检测结合和细胞毒性。
所有免疫毒素均显示出与表达PSMA的前列腺癌细胞有强结合及特异性细胞毒性，半数最大抑制浓度值在皮摩尔范围内。
我们成功制备了免疫原性降低的强效抗PSMA免疫毒素，用于进一步的临床开发及针对晚期前列腺癌的应用。
