Engineering viruses, cells, and bioprocesses for biologics manufacturing
The Aucoin Laboratory develops insect-cell technologies for producing vaccines, recombinant proteins, virus-like particles, and other biological nanoparticles. Our research treats the baculovirus expression vector system as an integrated and tunable manufacturing platform in which the virus, host cell, infection process, and downstream recovery strategy can all be engineered.
A central theme of our work is that biologics manufacturing involves multiple, sometimes competing objectives. High product yield must be balanced against inoculum requirements, infectious baculovirus production, total particle burden, product quality, process robustness, and downstream purification. We combine molecular biology, cell and virus engineering, quantitative imaging, particle characterization, bioreactor studies, and computational analysis to understand and control these trade-offs.
Programmable baculovirus expression systems
The baculovirus expression vector system is widely used to produce recombinant proteins, vaccines, and complex virus-like particles. However, baculovirus infection is a dynamic process involving extensive interactions among viral genes, host-cell functions, recombinant products, and process conditions. These interactions determine not only how much product is made, but also how much infectious and noninfectious baculovirus is co-produced.
We use CRISPR-Cas9–based transient gene perturbation to investigate the functions of baculovirus genes during infection. Stable Cas9-expressing insect cells allow selected viral genes to be targeted without first constructing a permanently modified baculovirus genome. Recombinant-protein production, VLP production, infectious-virus yield, and other infection outcomes can therefore be evaluated independently.
This work has shown that baculovirus genes cannot always be classified simply as essential or non-essential. Their effects can depend on the host cell, recombinant product, stage of infection, and manufacturing objective. Our goal is to use this functional information to guide the rational design of baculovirus vectors and insect-cell lines for specific applications.
Enveloped VLPs and next-generation vaccine platforms
Virus-like particles reproduce important structural features of viruses without functioning as infectious viruses. Enveloped VLPs are particularly attractive vaccine candidates because they can display viral membrane proteins in a native-like lipid environment. Their manufacture is challenging, however, because VLPs, baculovirus vectors, extracellular vesicles, and other host-derived particles can have similar sizes, compositions, and surface properties.
Our laboratory develops enveloped VLPs and engineered baculoviruses for vaccine applications. Current work includes the production of influenza and other viral antigens, engineering the baculovirus envelope for antigen display, and developing vectors capable of presenting or expressing multiple antigens. This includes BacMam systems that use baculovirus particles to deliver genes to vertebrate cells and the development of multivalent animal-vaccine candidates.
These studies examine how antigen design, promoter selection, envelope-protein trafficking, infection conditions, and host-cell choice affect antigen presentation, particle formation, and vaccine performance.
Viral nanoparticle characterization and purification
Reliable bioprocess development requires more than measuring infectious baculovirus titre. A culture may contain recombinant product, infectious baculovirus, noninfectious baculovirus particles, VLPs, extracellular vesicles, cell debris, and soluble host-cell components. Measurements that capture only one of these populations can therefore give an incomplete or misleading picture of process performance.
We combine infectivity assays, total-particle measurements, flow cytometry and flow virometry, fluorescence-based assays, immunoblotting, light-scattering methods, nanoparticle analysis, and particle fractionation to characterize these complex mixtures. Of particular interest are the relationships among VLP concentration, infectious baculovirus, total baculovirus-associated particles, and product recovery.
This analytical framework supports the development of filtration, density-based separation, affinity capture, and other downstream operations. Our objective is to design upstream and downstream processes together so that the composition of the material entering purification is controlled rather than treated as fixed.
Quantitative infection biology and bioprocess engineering
Population averages can conceal substantial differences among infected cells. Individual cells may become infected at different times, express recombinant products at different rates, or contribute differently to virus and VLP production. These sources of heterogeneity influence infection kinetics, optimal harvest time, and the reproducibility of the manufacturing process.
We use live-cell imaging, single-cell tracking, flow cytometry, infection time courses, and mathematical or statistical analysis to connect individual-cell behaviour with population-level measurements. This work investigates how multiplicity of infection, cell line, cell state, infection history, and culture conditions determine the distribution of cellular responses.
At the process scale, we study cell-line selection, bioreactor operation, oxygen transfer, mixing, infection strategy, and harvest timing. Rather than seeking a single universally optimal condition, we use multi-objective analysis to identify operating conditions that balance productivity, product quality, infectious-virus burden, and process efficiency.
Cell-free biomanufacturing
We are extending our expertise in insect-cell biology beyond conventional cell culture through the development of insect cell-free protein synthesis systems. Cell-free platforms provide direct control over the biochemical environment and can enable rapid protein production, pathway testing, and assembly of complex biological products without maintaining viable cells during production.
Current applications include recombinant-protein synthesis and the production and purification of viral structural proteins and VLPs. This research complements our cellular BEVS program by providing an alternative platform for studying protein expression, particle assembly, and biomanufacturing constraints.