PDF(Pubmed)
Abstract：
Monogenic blood diseases are among the most common genetic disorders worldwide. These diseases result in significant pediatric and adult morbidity, and some can result in death prior to birth. Novel ex vivo hematopoietic stem cell (HSC) gene editing therapies hold tremendous promise to alter the therapeutic landscape but are not without potential limitations. In vivo gene editing therapies offer a potentially safer and more accessible treatment for these diseases but are hindered by a lack of delivery vectors targeting HSCs, which reside in the difficult-to-access bone marrow niche. Here, we propose that this biological barrier can be overcome by taking advantage of HSC residence in the easily accessible liver during fetal development. To facilitate the delivery of gene editing cargo to fetal HSCs, we developed an ionizable lipid nanoparticle (LNP) platform targeting the CD45 receptor on the surface of HSCs. After validating that targeted LNPs improved messenger ribonucleic acid (mRNA) delivery to hematopoietic lineage cells via a CD45-specific mechanism in vitro, we demonstrated that this platform mediated safe, potent, and long-term gene modulation of HSCs in vivo in multiple mouse models. We further optimized this LNP platform in vitro to encapsulate and deliver CRISPR-based nucleic acid cargos. Finally, we showed that optimized and targeted LNPs enhanced gene editing at a proof-of-concept locus in fetal HSCs after a single in utero intravenous injection. By targeting HSCs in vivo during fetal development, our Systematically optimized Targeted Editing Machinery (STEM) LNPs may provide a translatable strategy to treat monogenic blood diseases before birth.
摘要：
单基因血液病是全世界最常见的遗传疾病之一。这些疾病导致显著的儿童和成人发病率，有些人可能会在出生前死亡。新型离体造血干细胞（HSC）基因编辑疗法在改变治疗前景方面具有巨大的希望，但并非没有潜在的限制。体内基因编辑疗法为这些疾病提供了潜在的更安全和更容易获得的治疗，但由于缺乏靶向HSC的递送载体而受到阻碍。它位于难以接近的骨髓生态位。这里,我们认为，这种生物屏障可以通过利用HSC在胎儿发育过程中容易进入的肝脏中的优势来克服。为了便于将基因编辑货物运送到胎儿HSC，我们开发了一种可电离的脂质纳米颗粒（LNP）平台，靶向HSC表面的CD45受体。在验证靶向LNP在体外通过CD45特异性机制改善了信使核糖核酸（mRNA）向造血谱系细胞的递送后，我们证明了这个平台介导的安全，强力，以及在多种小鼠模型中体内HSC的长期基因调节。我们在体外进一步优化了该LNP平台以封装和递送基于CRISPR的核酸货物。最后,我们发现,经过优化和靶向的LNPs增强了子宫内单次静脉注射后胎儿HSC概念验证基因座处的基因编辑.通过在胎儿发育过程中体内靶向HSC，我们的系统优化目标编辑机械(STEM)LNP可能提供一种可翻译的策略来治疗出生前的单基因血液病.
