Noor Dashti and Frank Sainsbury*

 

Australian Institute for Bioengineering and Nanotechnology
The University of Queensland
St Lucia, Queensland, Australia

 

Evolved to contain and protect nucleic acids and proteins, viruses exhibit a wide variety of cell uptake mechanisms designed to delivery sensitive cargo to the cytosol or nucleus of cells. We repurpose their self-assembling protein shells, or capsids, into recombinant virus-like nanoparticles (VNPs) that have the potential to address the major challenges in nanoparticle therapeutics: cargo-loading, cell delivery and efficient uptake. Understanding their assembly mechanisms and elucidating structural details to near-atomic resolution enables both the molecular engineering and bioprocess engineering of VNPs as novel tools in bionanotechnology.1 I will present our recent work with Polyomavirus VNPs, for which self-assembly can be triggered in vitro from purified subunits. This permits the controlled, stoichiometric co-encapsidation of cargo proteins non-covalently anchored to coat protein subunits. Förster resonance energy transfer (FRET) between co-encapsidated fluorescent proteins combined with particle-based analysis of VNPs by nanoparticle tracking and super resolution microscopy has shed light onto the co-operative self-assembly process and concomitant loading of protein cargos. VNPs containing one or two fluorescent protein variants are externally indistinguishable and maintain efficient cell uptake by Human umbilical vein endothelial cells (HUVECs). Moreover, two proteins may be simultaneously transfected by mixed particle populations or by a single population of mosaic particles. These results lay the groundwork for the development of an efficient biocompatible protein transfection reagent for therapeutic and research use.

1 Brillault, L., Jutras, P. V., Dashti, N., Thuenemann,E.C., Morgan, G., Lomonossoff, G.P., Landsberg, M.J. and Sainsbury, F. ACS Nano, 2017, 114: 3476-3484. Engineering recombinant virus-like nanoparticles from plants for cellular delivery.

 

Biographic details

Name: Frank Sainsbury

Title: Dr

Affiliation, Country: The University of Queensland, Australia

Phone: +61 (0)7 3346 3179  E-mail: f.sainsbury@uq.edu.au

My research is focused in the areas of biomolecular engineering, protein self-assembly, plant biotechnology and nanotechnology. I am credited with inventing an innovative method for high yielding protein expression in plant leaves which has been applied to engineer virus-like particles (VLPs) for various bionanotechnological applications including next-generation vaccines. I also lead research into the structure-function relationship of peptide-stabilised nanoscale emulsions that hold considerable promise in drug delivery, molecular imaging and designer vaccines. More recently my research has focused on bioengineering VLPs for guest protein encapsidation. Fundamental understanding of the supramolecular self-assembly mechanisms of different VLPs is leading to applications in therapeutic delivery and biocatalytic nanoreactors.