Scalable chromatography-based purification of virus-like particle carrier for epitope based influenza A vaccine produced in Escherichia coli

• Purification of recombinant virus-like particle-based influenza A vaccine produced in Escherichia coli.
• Purification based on multimodal size-exclusion chromatography medium in combination with detergent extraction and size-exclusion polishing.
• The results provide an industry compatible strategy to purify virus-like particles based vaccines.

Virus-like particles (VLPs) are promising molecular structures for the design and construction of novel vaccines, diagnostic tools, and gene therapy vectors. Size, oligomer assembly and repetitiveness of epitopes are optimal features to induce strong immune responses. Several VLP-based vaccines are currently licensed and commercialized, and many vaccine candidates are now under preclinical and clinical studies. In recent years, the development of genetically engineered recombinant VLPs has accelerated the need for new, improved downstream processes. In particular, a rapid low cost purification process has been identified as a remaining key challenge in manufacturing process development. In the present study we set up a size-exclusion chromatography-based, scalable purification protocol for the purification of a VLP-based influenza A vaccine produced in Escherichia coli. Recombinant VLPs derived from the RNA bacteriophage MS2 displaying an epitope from the ectodomain of Matrix 2 protein from influenza A virus were produced and purified. The 3 steps purification protocol uses a recently developed multimodal size-exclusion chromatography medium (Capto™ Core 700) in combination with detergent extraction and size-exclusion polishing to reach a 89% VLP purity with a 19% yield. The combination of this downstream strategy following production in E. coli would be suited for production of VLP-based veterinary vaccines targeting livestock and companion animals where large amounts of doses must be produced at an affordable price.