Production, purification and characterization of virus-like particles from chimeric HPV-HIV L1P18 protein expressed in Pichia pastoris: Lessons learned

Abstract

[eng] In this thesis, two recombinant Pichia pastoris strains producing chimeric HPV-HIV L1P18 protein were constructed. One intracellularly produces the chimeric protein while the other secrets it. For the former, several purification methods were systematically tested and the purification process was optimized. After cell lysis, virus like particles (VLPs) from L1P18 protein were purified by a combination of ammonium sulfate precipitation, size exclusion chromatography, ultracentrifugation and ultrafiltration. At the end of the purification process, the chimeric VLPs were recovered with 96% purity and 9.2% overall yield, and the morphology of VLPs were confirmed by transmission electron microscopy. This work contributes towards the development an alternative platform for production of a bivalent vaccine against HPV and HIV in P. pastoris.