Structural Determinants and Membrane Functionalization of Enveloped Protein Nanocages

Abstract

There is an unmet need for better intracellular drug and therapeutic molecule delivery vehicles. As a potential avenue to combine the targeting capabilities of viruses, the modularity and tractability of artificial systems, and the biological compatibility of Extracellular Vesicles (EV), our lab worked to adapt our self-assembling protein nanocages into Enveloped Protein Nanocages (EPN). Expression of these EPN in mammalian producer cells results in the exocytosis of vesicles containing multiple self-assembling protein nanoparticles. Here I describe my efforts to gain additional control over our EPN platform and endow it with new capabilities by functionalizing the EPN membrane via specific recruitment of different transmembrane proteins (TMP). Incorporation of these designed TMP has allowed us to target EPN to specific cells in a mixed population and complete a successful preliminary immunogenicity study using mRNA-delivery of EPN constructs. Furthermore, continued characterization of different EPN constructs has led to new insights about the basic biology behind protein-protein and protein-lipid interactions within membrane-bound nanoparticles.