Xing Wu, Siyu Jin, Yufei Pan, Wenyu Zhen, Sensen Yu, Yulong Zhang, Fei Xu, Ruixue Wang, Mingyue Wu, Wansu Sun, Jie Xu, Xiaodong Zang, Hengguo Zhang
Stem cell transplantation (SCT) holds significant promise for regenerative medicine, yet immune rejection remains a major obstacle. To address this, recent advances leverage CRISPR/Cas9 to engineer hypoimmunogenic induced pluripotent stem cells. These modified cells lack classical immune recognition markers (HLA class I/II) yet retain immune-tolerant molecules such as HLA-E, HLA-G, and CD47, enabling their universal use across different individuals. Additionally, mesenchymal stem cell-derived exosomes and immune checkpoint modulators (e.g., PD-L1) have shown clinical effectiveness by reducing graft-versus-host disease and autoimmune reactions. They achieve this through mechanisms such as suppressing inflammatory T-cell activation, promoting regulatory T-cell expansion, and modulating macrophage polarization. Despite these advances, several challenges remain. One key concern is the potential tumorigenic risk caused by genomic instability during genome editing and long-term cell expansion. Emerging precision editing platforms, including base editing and prime editing, provide strategies to reduce double-strand DNA break-induced chromosomal rearrangements and improve genomic safety. Future research priorities include integrating AI-based immune profiling, precision genome editing, and advanced 3D-bioprinting technologies. Together, these innovations represent a paradigm shift toward developing safer, more effective, universally compatible stem cell therapies for diseases previously deemed untreatable.