Establishment of Immune-Evasive iPSCs from PBMCs Using B2M Knockout and CD47/HLA-E Overexpression

Induced pluripotent stem cells (iPSCs) represent a promising source for regenerative therapies, yet allogeneic transplantation is limited by immune rejection. While strategies for generating hypoimmune iPSCs have been proposed, their efficacy after differentiation into lineage-specific cell types remains underexplored.

A human iPSC line (36A) from peripheral blood mononuclear cells using a Sendai virus-based reprogramming protocol. Hypoimmune properties were conferred via CRISPR-Cpf1-mediated B2M knockout, combined with lentiviral overexpression of HLA-E and CD47. Immune evasion was validated using NK cell cytotoxicity assays. Endothelial differentiation was induced using a defined, stepwise protocol, and in vivo functionality was evaluated in humanized NSG mice.

The hypoimmune iPSCs retained pluripotency, exhibited stable karyotype, and demonstrated > 99% expression of HLA-E/CD47. NK cell-mediated lysis was significantly reduced in edited cells, although IFN-γ levels remained elevated. Upon differentiation, the hypoimmune iPSCs yielded > 98% CD31⁺CD144⁺ endothelial cells, which showed enhanced survival in vivo compared to wild-type controls.

Multiplex gene editing successfully conferred durable immune evasion in both undifferentiated and endothelial-differentiated iPSCs. These findings support the clinical potential of hypoimmune iPSC-derived cell therapies for allogeneic transplantation without immunosuppression.