John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, 02138, USA.
Wyss Institute for Biologically Inspired Engineering at Harvard University, Boston, MA, 02115, USA.
Adv Sci (Weinh). 2022 Aug;9(24):e2201293. doi: 10.1002/advs.202201293. Epub 2022 Jul 3.
Adeno-associated virus (AAV)-mediated gene therapy is a promising therapeutic modality for curing many diseases including monogenic diseases. However, limited tissue-targeting and restricted re-administration due to the vector immunogenicity largely restrict its therapeutic potential. Here, using a red blood cell (RBC) as the carrier vehicle for AAV is demonstrated to improve its tissue-targeted transduction and enable its re-administration. Anchoring AAV to the RBC surface minimally affected its infectability toward endothelial cells. Meanwhile, AAV anchored onto RBCs is predominantly delivered to and shows efficient transduction in the lungs by virtue of the biophysical features of RBCs. RBC-anchored AAVs lead to a four- to five-fold enhancement in target gene expression in the lungsas compared to free AAVs following a single- or dual-dosing regimen. While RBC anchoring does not prevent the induction of adaptive immune responses against AAV, it results in successful transgene expression upon re-administration following prior AAV exposure. The ability to re-administer is partially attributed to the delayed and reduced AAV neutralization by neutralizing antibodies, resulting from the combination of limited exposure of physically confined AAVs and the short time required to reach the lungs. This study's findings suggest that the RBC-mediated approach is a promising strategy for repetitive, targeted AAV gene therapy.
腺相关病毒 (AAV) 介导的基因治疗是一种很有前途的治疗方法，可用于治疗包括单基因疾病在内的许多疾病。然而，由于载体的免疫原性，有限的组织靶向性和再给药限制了其治疗潜力。在这里，使用红细胞 (RBC) 作为 AAV 的载体来提高其组织靶向转导能力并实现再给药。将 AAV 锚定在 RBC 表面对其感染内皮细胞的能力影响最小。同时，由于 RBC 的物理特性，锚定在 RBC 上的 AAV 主要被递送到肺部，并在肺部表现出高效的转导。与游离 AAV 相比，RBC 锚定的 AAV 在单次或双剂量方案后，在肺部的靶基因表达水平提高了 4 到 5 倍。虽然 RBC 锚定并不能防止针对 AAV 的适应性免疫反应的诱导，但在先前 AAV 暴露后再次给药时，它会导致成功的转基因表达。能够再次给药部分归因于中和抗体对 AAV 的中和作用的延迟和减少，这是由于物理受限的 AAV 的有限暴露和到达肺部所需的时间较短所致。这项研究的结果表明，RBC 介导的方法是一种有前途的重复、靶向 AAV 基因治疗策略。
