New Gene Editing Technique Uses Circular DNA to Bypass Immune Response

A novel gene editing approach utilizing circular single-stranded DNA (cssDNA) is showing promise in overcoming a major hurdle in gene therapy: the body’s immune response. Researchers at Mass General Brigham (MGB) and Full Circles Therapeutics have demonstrated successful gene editing with cssDNA, offering a potential pathway toward safer and more effective non-viral gene therapies.

The Challenge of Traditional Gene Editing

Traditional gene editing often relies on delivering genetic material using viral vectors or double-stranded DNA (dsDNA). While effective, these methods can trigger a strong immune response, limiting their therapeutic potential and raising safety concerns. The immune system recognizes dsDNA as foreign, leading to inflammation and potentially rejecting the therapeutic gene.

How cssDNA Overcomes Immune Response

cssDNA, developed by Full Circles Therapeutics, offers a solution by presenting genetic material in a different form. Unlike dsDNA, cssDNA is less likely to activate the innate immune system, allowing for more efficient gene delivery and integration. This is particularly important for delivering large genes, a capability that has been historically challenging with other methods. The technology is based on the company’s C4DNA™ platform.

Key Findings and Research Details

Recent research, highlighted in a press release from Full Circles Therapeutics and detailed in a study published in Nature, demonstrates the successful use of cssDNA in gene editing. The study, conducted in collaboration with researchers at the Center for Genomic Medicine at Massachusetts General Hospital, showed that cssDNA can deliver gene-scale DNA into the genome while minimizing the immune response. The system, termed INSTALL, combines recombinase enzymes with engineered cssDNA donors.

Initial in vitro results showed successful insertion of up to 6 kilobases (kb) of genetic material. In vivo studies demonstrated insertion of up to 2 kb. While genome insertion efficiency was initially 1%, researchers believe this can be improved through further optimization of DNA sequences and delivery methods, drawing parallels to advancements seen in RNA medicine and CRISPR-Cas9 technology. CRISPR Medicine News reports that the GATALYST system, another cssDNA technology from Full Circles Therapeutics, has achieved gene integration rates of 50-70% in some cell types.

Potential Applications and Future Directions

This technology holds significant promise for a range of therapeutic applications, including the treatment of genetic disorders and cancer. Unlike some gene editing approaches focused on correcting single mutations, cssDNA allows for the delivery of entire therapeutic genes, potentially offering a more comprehensive and universal treatment approach.

Further research is focused on improving the efficiency of genome insertion and translating these findings into clinical trials. A study in Scientific Reports too suggests that the tumor microenvironment can enhance cssDNA expression, potentially opening new avenues for cancer therapy.

Key Takeaways

• cssDNA offers a novel approach to gene editing that minimizes the immune response.
• The technology has demonstrated successful gene insertion in vitro and in vivo, with potential for delivering large genes.
• cssDNA could enable the development of universal gene therapies that are not limited by specific mutations.
• Ongoing research aims to improve efficiency and translate these findings into clinical applications.