A Novel Piggyback Strategy for mRNA Delivery Exploiting Adenovirus Entry Biology (preprint)

Molecular therapies exploiting mRNA vectors embody enormous potential, as evidenced by the utility of this technology for the context of the COVID-19 pandemic. None-the-less, broad implementation of these promising strategies has been restricted by the limited repertoires of delivery vehicles capable of mRNA transport. On this basis, we explored a strategy based on exploiting the well characterized entry biology of adenovirus. To this end, we studied an adenovirus-polylysine (AdpL) that embodied “piggyback” transport of the mRNA on the capsid exterior of adenovirus. We hypothesized that the efficient steps of Ad binding, receptor-mediated entry, and capsid-mediated endosome escape could provide an effective pathway for transport of mRNA to the cellular cytosol for transgene expression. Our studies confirmed that AdpL could mediate effective gene transfer of mRNA vectors in vitro and in vivo. Facets of this method may offer key utilities to feasibilize the promise of mRNA-based therapeutics.

Understanding SARS-CoV-2 budding through molecular dynamics simulations of M and E protein complexes (preprint)

SARS-CoV-2 and other coronaviruses pose a major threat to global health, yet treatment efforts have largely ignored the process of envelope assembly, a key part of the coronaviral life cycle. When expressed together, the M and E proteins are sufficient to facilitate coronavirus envelope assembly. Envelope assembly leads to budding of coronavirus particles into the ER-Golgi intermediate compartment (ERGIC) and subsequent maturation of the virus, yet the mechanisms behind the budding process remain poorly understood. Better understanding of budding may enable new types of antiviral therapies. To this end, we ran atomistic molecular dynamics (MD) simulations of SARS-CoV-2 envelope assembly using the Feig laboratory's refined structural models of the M protein dimer and E protein pentamer. Our MD simulations consisted of M protein dimers and E protein pentamers in patches of virtual ERGIC membrane. By examining how these proteins induce membrane curvature in silico, we have obtained insights around how the budding process may occur. In our simulations, M protein dimers acted cooperatively to induce membrane curvature. By contrast, E protein pentamers kept the membrane planar. These results could help guide the development of novel antiviral therapeutics which inhibit coronavirus budding.