DNA-encoded delivery of antibodies presents a labor- and cost-effective alternative to conventional antibody therapeutics. This study aims to improve the potency and safety of this approach by evaluating various plasmid backbones and expression cassettes. In vitro, antibody levels consistently improved with decreasing sizes of backbone, ranging from conventional to minimal. In vivo, following intramuscular electrotransfer in mice, the correlation was less consistent. While the largest conventional plasmid (10.2 kb) gave the lowest monoclonal antibody (mAb) levels, a regular conventional plasmid (8.6 kb) demonstrated similar levels as a minimal Nanoplasmid (6.8 kb). A reduction in size beyond a standard conventional backbone thus did not improve mAb levels in vivo. Cassette modifications, such as swapping antibody chain order or use of two versus a single encoding plasmid, significantly increased antibody expression in vitro, but failed to translate in vivo. Conversely, a significant improvement in vivo but not in vitro was found with a set of muscle-specific promoters, of which a newly engineered variant gave roughly 1.5- to 2-fold higher plasma antibody concentrations than the ubiquitous CAG promoter. In conclusion, despite the limited translation between in vitro and in vivo, we identified various clinically relevant improvements to our DNA-based antibody platform, both in potency and biosafety.

中文翻译：

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通过质粒骨架和表达盒工程提高 DNA 编码抗体治疗的效力和安全性

DNA 编码的抗体递送是传统抗体疗法的一种劳动力和成本效益高的替代方案。本研究旨在通过评估各种质粒骨架和表达盒来提高这种方法的效力和安全性。在体外，抗体水平随着骨架尺寸的减小而不断提高，从常规到最小。在体内，小鼠肌内电转移后，相关性不太一致。虽然最大的常规质粒 (10.2 kb) 的单克隆抗体 (mAb) 水平最低，但常规常规质粒 (8.6 kb) 的水平与最小的纳米质粒 (6.8 kb) 相似。因此，超出标准常规骨架的尺寸减小并未提高体内mAb 水平. 盒式修饰，例如交换抗体链顺序或使用两个与单个编码质粒，显着增加体外抗体表达，但未能在体内转化。相反，发现一组肌肉特异性启动子在体内但在体外没有显着改善，其中一种新改造的变体产生的血浆抗体浓度比普遍存在的 CAG 启动子高大约 1.5 到 2 倍。总之，尽管体外和体内之间的转化有限，但我们确定了我们基于 DNA 的抗体平台在效力和生物安全性方面的各种临床相关改进。