Peeling back the layers of immunogenicity in Cas9-based genomic medicine

The CRISPR-Cas9 genome editing system is rewriting the treatment of genetic disorders, offering unprecedented potential for detrimental and previously untreatable diseases. As this technology advances toward wider utilization in clinical applications, the immunogenicity of Cas9 nuclease has emerged as a potential challenge for in vivo therapies. Immune recognition of CRISPR-Cas9 components can trigger both innate and adaptive responses. The complex interactions between Cas9, delivery vectors, and host immune reactivity play a crucial role in determining the safety and efficacy of CRISPR-based treatments. Recent advances in mitigating Cas9 immunogenicity include epitope engineering, optimized delivery systems, and nucleic acid modifications. These strategies, explored across various tissue contexts and delivery methods, show promise in enhancing the tolerability of CRISPR-based therapies. However, pre-existing immunity to Cas9 and the potential for long-term adaptive immune responses remain important considerations. Addressing these immunological challenges requires an integrated approach, combining insights from immunology with innovative engineering solutions. As the field progresses, overcoming Cas9 immunogenicity will be crucial for realizing the full therapeutic potential of the CRISPR-Cas9 system in diverse clinical applications.