In vivo production of an anti-HIV antibody in mice by non-viral gene knockin in primate hematopoietic stem and progenitor cells.

Gene editing strategies that do not rely on viral vectors are being explored for their potential to support durable biologics production. While clinical trials have shown that adeno-associated virus encoding broadly neutralizing antibodies can protect against HIV, these interventions often yield limited, short-lived responses. The development of non-viral gene editing approaches in hematopoietic stem and progenitor cells holds promise for long-term antibody production. In this study, we evaluated CRISPR-Cas9 and CRISPR-Cas12a for gene knockin at the immunoglobulin heavy chain locus in non-human primate (NHP) hematopoietic stem and progenitor cells (HSPCs). Delivering the nuclease as a protein alongside a custom DNA template, we optimized editing with Cas12a and demonstrated higher knockin efficiency and fewer non-specific edits than with Cas9. Transplantation of edited NHP HSPCs into MISTRG mice led to engraftment, B cell differentiation, and transgene expression of a reporter transgene or anti-HIV antibody after gp120 antigen immunization with detectable titers in circulation. These findings demonstrate the feasibility of using non-viral knockin in HSPCs as a potential strategy for sustained biologics production in the treatment of chronic diseases. Future work will assess the efficacy of this approach in an NHP model of HIV infection.