Abstract
In the history of vaccine development, the synthetic vaccine is a milestone that is in stark contrast with traditional vaccines based on live-attenuated or inactivated microorganisms. Synthetic vaccines not only are safer than attenuated or inactivated microorganisms but also provide the opportunity for vaccine design for specific purposes. The first generation of synthetic vaccines has been largely based on DNA recombination technology and genetic manipulation. This de novo generation is occasionally time consuming and costly, especially in the era of genomics and when facing pandemic outbreaks of infectious diseases. To accelerate and simplify the R&D process for vaccines, we developed an improved method of synthetic vaccine construction based on protein assembly. We optimized and employed the recently developed SpyTag/SpyCatcher technique to establish a protein assembly system for vaccine generation from pre-prepared subunit proteins. As proof of principle, we chose a dendritic cell (DC)-targeting molecule and specific model antigens to generate desired vaccines. The results demonstrated that a new vaccine generated in this way does not hamper the individual function of different vaccine components and is efficient in inducing both T and B cell responses. This protein assembly strategy may be especially useful for high-throughput antigen screening or rapid vaccine generation.