Ma Hongxia, Lu Yuanqing, Lowe Keith, van der Meijden-Erkelens Lonneke, Wasserfall Clive, Atkinson Mark A, Song Sihong
College of Animal Science and Technology, Jilin Agricultural University, Changchun 130118, China.
Department of Pharmaceutics, University of Florida, Gainesville, FL 32610, USA.
J Clin Med. 2019 Aug 28;8(9):1321. doi: 10.3390/jcm8091321.
We, and others, have previously achieved high and sustained levels of transgene expression from viral vectors, such as recombinant adeno-associated virus (rAAV). However, regulatable transgene expression may be preferred in gene therapy for diseases, such as type 1 diabetes (T1D) and rheumatoid arthritis (RA), in which the timing and dosing of the therapeutic gene product play critical roles. In the present study, we generated a positive feedback regulation system for human alpha 1 antitrypsin (hAAT) expression in the rAAV vector. We performed quantitative kinetics studies in vitro and in vivo demonstrating that this vector system can mediate high levels of inducible transgene expression. Transgene induction could be tailored to occur rapidly or gradually, depending on the dose of the inducing drug, doxycycline (Dox). Conversely, after withdrawal of Dox, the silencing of transgene expression occurred slowly over the course of several weeks. Importantly, rAAV delivery of inducible hAAT significantly prevented T1D development in non-obese diabetic (NOD) mice. These results indicate that this Dox-inducible vector system may facilitate the fine-tuning of transgene expression, particularly for hAAT treatment of human autoimmune diseases, including T1D.
我们以及其他研究人员之前已从病毒载体，如重组腺相关病毒（rAAV），实现了高水平且持续的转基因表达。然而，对于1型糖尿病（T1D）和类风湿性关节炎（RA）等疾病的基因治疗，可调控的转基因表达可能更为可取，因为在这些疾病中治疗性基因产物的时机和剂量起着关键作用。在本研究中，我们构建了一个用于rAAV载体中人类α1抗胰蛋白酶（hAAT）表达的正反馈调节系统。我们在体外和体内进行了定量动力学研究，证明该载体系统可介导高水平的诱导型转基因表达。转基因诱导可根据诱导药物强力霉素（Dox）的剂量快速或逐渐发生。相反，在撤去Dox后，转基因表达的沉默在数周内缓慢发生。重要的是，诱导型hAAT的rAAV递送显著预防了非肥胖糖尿病（NOD）小鼠的T1D发展。这些结果表明，这种Dox诱导型载体系统可能有助于转基因表达的微调，特别是用于hAAT治疗包括T1D在内的人类自身免疫性疾病。
