Team:Wageningen UR



1. Introduction

The Wageningen UR team has worked on the modification of virus-like particles (VLPs) to make them interesting platforms for vaccine production and/or site specific drug delivery. VLPs are empty virus capsids, meaning that they do not contain any viral genome and proteins except for the coat proteins. Coat proteins of some viruses have shown the ability to self-assemble in absence of its viral genome and other viral proteins, and thus form VLPs. Our human body model gives us an inside about how our drug delivery system would improve drug application.

2. Plug 'n Apply

A big challenge of our project is the attachment of ligands and functional proteins on either the outside or inside of a virus-like particle (VLP). We decided to use a noncovalent anchor-like system, which consists of two different coiled-coil proteins. We call it the Plug-and-Apply-system (PnA-system).

3. Virus Like

A Virus-Like Particle (VLP) is a shell of viral Coat Proteins (CPs) that spontaneously assemble with the right conditions. Although a VLP resembles the original virus in shape and size, it lacks both the external sites that are usually required for the infection of cells and the internal machinery needed for viral replication. Moreover, they also lack the viral genetics to be transcribed and replicated.

4. Outside

The monomers of virus-like particles (VLPs) have been subject to many modifications of which some are aimed at changing the appearance of the particle. By changing the outside, the VLP acquires new properties which have been used mainly in vaccine development . The modification we pursue is adding a coil to the protein subunits, at any location that is exposed on the outside of the VLP. This can be a fusion to a C or N-terminal, but a modification in a loop is possible as well.

5. Inside

Since virus-like particles (VLPs) lack genetic content, they enclose an empty space. This space can be filled with proteins such as antibiotics, hormones, and all sorts of pharmaceuticals. Modifications on the inside of the VLPs can increase binding affinity to the loaded substance. The first modifications we pursue is adding the K-coil to the protein subunits at any location that is exposed on the inside of the VLP.

6. Detection

A key part of our project is the detection of VLPs. We need sufficient visualization to get conclusive evidence of VLP formation. Besides standard approaches, we will investigate alternative methods to detect the formation and stability of Virus-Like Particles.

7. Applications

The goal of our project is to construct standardized self-assembling particles with a simple and versatile attachment system for either packaging molecules, presenting ligands/epitopes, or both. By combining the PnA (Plug 'n Apply) System and Virus-Like Particles (VLPs), we create a tool that can be applied in numerous applications.

8. The Constructor

The registry is the substrate to make complex devices. We designed a web tool that facilitates an automatic cloning recommendation which outcompetes manual querying of the BioBrick parts from the registry. Besides constructing the best cloning strategy, The Constructor also allows the user to select for BioBrick quality and availability.

9. Final

"If it turns out that the combination of delivery and medicine has a superior ability to cure, everything is achievable in the modern world." Senior Project Leader in veterinary medicine at MSD. "Having in place a system that can rapidly develop a vaccine against unexpected viral agents would be of great importance for public health." ECDC Program Leader Vaccine Preventable Diseases


A standardized tool for site specific drug delivery using Virus-Like Particles

Medicines are generally active in a non-site-specific fashion, affecting the whole patient, including healthy tissue. Therefore, we attempt to specifically target diseased areas by packaging medicines inside Virus-Like Particles (VLPs). VLPs are not infectious, as they are built solely from viral coat proteins. We designed a modular Plug and Apply system that enables modifications to these coat proteins. The system facilitates the linkage of numerous ligands to the coat protein, thereby creating site-specific carriers. After expression of coat protein genes in Escherichia coli the VLPs were assembled in vitro, yielding modified Virus-Like Particles. Medicines can be packed using the Plug and Apply system or simply by addition during VLP assembly. Concluding, VLPs can be used as universal carriers for site-specific drug delivery, which is confirmed by our human body model. The device allows customization to a variety of diseases while decreasing side effects for patients during treatment.