Adeno-associated virus (AAV) is successfully developed as a major gene therapy vector, but it is still susceptible to a significant delivery limitation specifically when the vector encounters neutralizing antibodies from a pre-existing immune response or at readministration. Here thermoresponsive polymer elastin-like polypeptides (ELPs) are utilized to crosslink with AAV serotypes 2, 8, and 9 and polyplex AAV vectors are formed by creating a shield of nonviral polymer around them in nanoscale. Neutralizing antibody (NAb) assays are performed which reveal that ELP-AAV nanoparticles significantly improve expression at high NAb titers for AAV 2 and 9. The ELP-AAV nanoparticles are stable for an extended period in neutralizing serum and ELP appears to follow the AAV capsid during uncoating and degradation. No toxicity is found after subretinal, intramuscular, and retro-orbital injections of ELP-AAV. After passive transfer of human NAbs in vivo, ELP-AAV significantly increases transduction at a low systemic AAV dose (10¹² vg kg⁻¹) in mice compared to free AAV. In an in vivo readministration paradigm, ELP-AAV significantly improves the reporter gene expression compared to free AAV and does not change the AAV tropism. This method has strong potential to overcome the AAV-associated neutralizing antibody response in gene therapy without redesigning the AAV virion.

中文翻译：

---

弹性蛋白样多肽在预先存在的中和抗体存在下促进腺相关病毒转导

腺相关病毒 (AAV) 已成功开发为主要的基因治疗载体，但它仍然容易受到显着的传递限制，特别是当载体遇到来自预先存在的免疫反应或重新给药的中和抗体时。在这里，热响应聚合物弹性蛋白样多肽 (ELP) 用于与 AAV 血清型 2、8 和 9 交联，并通过在纳米级周围创建非病毒聚合物盾来形成复合 AAV 载体。进行的中和抗体 (NAb) 测定表明，ELP-AAV 纳米颗粒显着提高了 AAV 2 和 9 在高 NAb 滴度下的表达。ELP-AAV 纳米颗粒在中和血清中长时间稳定，ELP 似乎跟随 AAV 衣壳在脱涂层和降解过程中。视网膜下后未发现毒性，ELP-AAV 的肌内和眼眶后注射。在体内被动转移人 NAb 后，ELP-AAV 在低全身 AAV 剂量下显着增加转导 (10¹²  vg kg ⁻¹ ) 在小鼠中与游离 AAV 相比。在体内再给药范例中，ELP-AAV 与游离 AAV 相比显着提高了报告基因表达，并且不会改变 AAV 向性。这种方法在不重新设计 AAV 病毒粒子的情况下，具有克服基因治疗中 AAV 相关中和抗体反应的强大潜力。