Processing and in vitro Assembly of Virus Like Particle Nanostructures

Virus-like-particles (VLPs) are self-assembling biomolecular nano-structures with current and potential uses in drug delivery, gene therapy and most notably as vaccines (the world's first successful cancer vaccine is composed of VLPs). The production process for murine polyomavirus VLPs is described, involving expression of the major precursor (VP1) in Escherichia coli with an N-terminal GST tag. Affinity chromatography is used to capture the tagged precursor on resin and subsequent release of the precursor is achieved by enzymatic cleavage. Size exclusion chromatography is used to isolate precursor intermediate structures (capsomeres) from contaminants and these are then assembled in vitro into VLPs by dialysis. VLP structure has been validated qualitatively by transmission electron microscopy (TEM).