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.