Synthesis and Assembly of a New-generation Bifunctional Lipid Nanoparticle for Selective Delivery of mRNA to Antigen Presenting Cells

Described here is the synthesis and assembly of a new-generation mRNA-bifunctional lipid nanoparticle (mRNA-BLNP3) for selective delivery of mRNA to antigen-presenting cells (APCs). Compared to mRNA-BLNP1 and BLNP2 (BioRxiv,doi.org/10.1101/2023.12.26.572282), the mRNA-BLNP3, incorporating a glycolipid with the lipid moiety designed to target the CD1d receptor on dendritic cells (DCs) and the sugar head group targeting the mannose-binding receptors on APCs is more selective with stronger target-specific immune responses. It was shown that vaccination in mice with mRNA-BLNP1 elicited enhanced cytokine induction and antibody responses compared to traditional mRNA-LNPs, and the mRNA-BLNP2 vaccine, incorporating a mannose-glycolipid, further improved DC targeting. However, BLNP3, incorporating the glycolipid with an aryl-mannose head group targeting the mannose receptor on APCs and the same lipid moiety targeting the Cd1d receptor on DCs, showed superior lymph node targeting <i>in vivo</i> with reduced liver accumulation, enhanced mRNA expression in DCs and macrophages, and increased DC maturation. Immunization in mice with mRNA-BLNP3 elicited enhanced humoral and cellular immune responses compared to mRNA-BLNP1 and mRNA-BLNP2, with higher antigen-specific IgG titers and granzyme B-producing CD8⁺ T cells, demonstrating that BLNP3 is a promising bifunctional lipid nanoparticle for delivery of mRNA vaccines with improved efficacy and safety.