Mølgaard K, Compte M, Nuñez-Prado N, Harwood S L, Sanz L, Alvarez-Vallina L
Immunotherapy and Cell Engineering, Department of Engineering, Aarhus University, Aarhus, Denmark.
Molecular Immunology Unit, Hospital Universitario Puerta de Hierro Majadahonda, Madrid, Spain.
Gene Ther. 2017 Apr;24(4):208-214. doi: 10.1038/gt.2017.3. Epub 2017 Jan 11.
Adoptive transfer of genetically engineered human cells secreting bispecific T-cell engagers has shown encouraging therapeutic effects in preclinical models of cancer. However, reducing the toxicity and improving the effectiveness of this emerging immunotherapeutic strategy will be critical to its successful application. We have demonstrated that for gene-based bispecific antibody strategies, two-chain diabodies have a better safety profile than single-chain tandem scFvs (single-chain variable fragments), because their reduced tendency to form aggregates reduces the risk of inducing antigen-independent T-cell activation. Here, we demonstrate that the incorporation of a 2A self-processing peptide derived from foot-and-mouth disease virus conveying co-translational cleavage into a two-chain anti-CD3 × anti-CEA diabody gene enables near-equimolar expression of diabody chains 1 and 2, and thus increases the final amount of assembled diabody. This was found to maximize diabody-mediated T-cell activation and cytotoxicity against carcinoembryonic antigen-positive tumor cells.
分泌双特异性T细胞衔接子的基因工程化人细胞的过继转移在癌症临床前模型中已显示出令人鼓舞的治疗效果。然而，降低这种新兴免疫治疗策略的毒性并提高其有效性对于其成功应用至关重要。我们已经证明，对于基于基因的双特异性抗体策略，双链双抗体比单链串联单链抗体片段（单链可变片段）具有更好的安全性，因为它们形成聚集体的倾向降低，从而降低了诱导抗原非依赖性T细胞活化的风险。在这里，我们证明将源自口蹄疫病毒的2A自切割肽并入双链抗CD3×抗CEA双抗体基因中，该肽可进行共翻译切割，从而使双抗体链1和链2实现近等摩尔表达，进而增加了组装双抗体的最终产量。结果发现，这可使双抗体介导的T细胞活化以及对癌胚抗原阳性肿瘤细胞的细胞毒性最大化。
