A Danish research team from the University of Copenhagen has designed a simple technique that makes it possible to quickly and easily develop a new type of vaccines. The simple and effective technique will pave the way for effective vaccines against not only infectious diseases but also cancer and other chronic diseases.
The next generation of vaccines may soon see the light of day, because Danish researchers have discovered a completely new and simple method which sets new standards for the development of vaccines.
Ref: Bacterial superglue enables easy development of efficient virus-like particle based vaccines. Journal of Nanobiotechnology (27 April 2016) | DOI: 10.1186/s12951-016-0181-1 (Open Access)
Background: Virus‑like particles (VLPs) represent a significant advance in the development of subunit vaccines, com‑bining high safety and efficacy. Their particulate nature and dense repetitive subunit organization makes them ideal scaffolds for display of vaccine antigens. Traditional approaches for VLP‑based antigen display require labor‑intensive trial‑and‑error optimization, and often fail to generate dense antigen display. Here we utilize the split‑intein (SpyTag/SpyCatcher) conjugation system to generate stable isopeptide bound antigen‑VLP complexes by simply mixing of the antigen and VLP components.
Results: Genetic fusion of SpyTag or SpyCatcher to the N‑terminus and/or C‑terminus of the Acinetobacter phage AP205 capsid protein resulted in formation of stable, nonaggregated VLPs expressing one SpyCatcher, one SpyTag or two SpyTags per capsid protein. Mixing of spy‑VLPs with eleven different vaccine antigens fused to SpyCatcher or SpyTag resulted in formation of antigen‑VLP complexes with coupling efficiencies (% occupancy of total VLP binding sites) ranging from 22–88%. In mice, spy‑VLP vaccines presenting the malaria proteins Pfs25 or VAR2CSA markedly increased antibody titer, affinity, longevity and functional efficacy compared to corresponding vaccines employing monomeric proteins. The spy‑VLP vaccines also effectively broke B cell self‑tolerance and induced potent and durable antibody responses upon vaccination with cancer or allergy‑associated self‑antigens (PD‑L1, CTLA‑4 and IL‑5).
Conclusions: The spy‑VLP system constitutes a versatile and rapid method to develop highly immunogenic VLP‑based vaccines. Our data provide proof‑of‑concept for the technology’s ability to present complex vaccine antigens to the immune system and elicit robust functional antibody responses as well as to efficiently break B cell self‑toler‑ance. The spy‑VLP‑system may serve as a generic tool for the cost‑effective development of effective VLP‑vaccines against both infectious‑ and non‑communicable diseases and could facilitate rapid and unbiased screening of vac‑cine candidate antigens.