Complementary Biotherapeutic Delivery Platforms for Enabling Gene Re-delivery

Complementary Biotherapeutic Delivery Platforms for Enabling Gene Re-delivery Project Summary Facing the universal challenge of re-delivering Adeno-associated viruses (AAVs), our project endeavors to pioneer delivery-focused solutions in gene therapy. The core obstacle stems from the host immune system's robust reactions to the vector and cytotoxic responses to its transduced cells & transgenes, highlighting a pressing need for innovative delivery strategies that engage and modulate the corresponding immune responses. Our approach is multifaceted, comprising three distinct delivery platforms, each addressing unique aspects of the antigen-processing machinery and focusing on overcoming specific biological barriers for delivering the “updated” instructions for modulated immune responses. (1) Targeted Cell Delivery of Regulatory T Cell (Treg): While Tregs represent a novel avenue for cell-based therapies, their non-specific delivery can lead to undesired immunosuppression. The first challenge involves directing Treg cells to immunogenic cell death sites caused by transgene persistence. Our strategy to overcome this is to engineer Chimeric Antigen Receptors (CAR) to enhance Treg navigation and delivery of Tregs to transgene persistence sites, enabling rescued and sustained transgene gene expression. (2) Targeted Delivery System for IgG-Protease: The second program targets the selective removal of antigen-specific IgG, specifically for neutralizing antibodies that hinder AAV gene delivery vectors. IgG degrading protease is an effective way of eliminating pre-existing naturalizing antibodies. However, non-specific delivery of IgG will lead to systematic disarming of our immune defense. We are developing antigen/antibody-fused IgG protease to deliver a protease selectively, ensuring that only unwanted, harmful immunogenic antibodies are present. (3) Targeted Lipid Nanoparticles for Cell- Specific RNA-Delivery: The third program addresses the significant challenge of achieving cell-specific RNA delivery for inducing tolerogenic antigen processing. mRNA delivery is a highly effective method for in vivo antigen production, and siRNA delivery is a highly effective immune modulation method. However, non-specific delivery of RNA at the wrong microenvironment might trigger immunogenic instead of tolerogenic responses. By focusing on precision delivery to the antigen-presenting cells and their surroundings, we aim to synthesize and formulate novel lipid nanoparticle formulations for achieving cell-type specific RNA delivery for better controlling the intended tolerogenic response for AAV vectors. By addressing these challenges and pioneering advanced delivery and targeting strategies, our research seeks to unravel the fundamental intricate between the biological barriers in delivery to the immune system and re-enabling viral gene delivery vectors, paving the way for transformative advancements in gene therapy and improved human health.