In vivo genome editing of human hematopoietic stem cells for treatment of blood disorders by mRNA delivery

SUMMARY Ex vivo autologous hematopoietic stem cells (HSCs) gene therapy provides promising new treatments for hematological disorders. However, current methods involve complex processes and chemotherapeutic conditioning, leading to limited accessibility for treatment and significant side effects. Here, we developed an antibody-free targeted lipid nanoparticles (LNPs) for mRNA delivery to HSCs in vivo , enabling efficient base editing of the HBG target in human HSCs to reactivate fetal hemoglobin in derived erythroid cells. Delivery of ABE8e/sgRNA mRNA with optimized structure LNPs achieves efficient in vivo base editing of HBG in transfusion-dependent β-thalassemia (TDT) patients derived HSCs engrafted in immunodeficient NCG-X mice, showing restored globin chain balance in erythroid cells. Our research indicated that utilizing LNPs for delivery of genome editor achieves efficient editing of endogenous genes of human HSCs. Notably, this non-viral delivery system eliminates the need for harvesting or mobilizing HSCs, providing a potent and one-time treatment potential for blood disorders like sickle cell disease (SCD) and TDT. Highlights Antibody-free targeted LNPs system achieves efficient mRNA delivery and base editing in human bone marrow cells including HSCs via one-time intravenous injection. Delivery of ABE8e/sgRNA mRNA with optimized LNPs achieves efficient in vivo base editing of HBG in TDT patients derived HSCs engrafted in immunodeficient NCG-X mice, showing restored globin chain balance in erythroid cells. LNPs efficiently deliver gene editing system to the BM for in vivo editing of human HSCs, providing preclinical evidence for the next generation non-viral gene therapy for blood disorders.