Production of codon-optimized type 52 L1 virus-like particles in BG10 expression system.

Cervical cancer caused by (HPV) is one of the most common causes of cancer death in women worldwide. Even though the disease can be avoided by immunization, the expensive price of HPV vaccines makes it hard to be accessed by women in middle-low-income countries. Thus, the development of generic HPV vaccines is needed to address inequalities in life-saving access. This study aimed to develop the HPV52 L1 VLP-based recombinant vaccine using expression system. The gene was codon-optimized based on codon usage resulting CAI value of 0.804. The gene was inserted into the pD902 plasmid under the regulation of the promoter. The linear plasmid was transformed into BG10 genome and screened in YPD medium containing zeocin antibiotic. Colony of transformant that grown on highest zeocin concentration was characterized by genomic PCR and sequencing. The positive clone was selected and expressed using BMGY/BMMY medium induced with various methanol concentrations. The SDS-PAGE and Western blot analyses showed that 55 kDa L1 protein was successfully expressed using an optimum concentration of 1% methanol. The self-assembly of HPV52 L1 protein was also proven using TEM analysis. Moreover, we also analyzed the B-cell epitope of HPV52 L1 protein based on several criteria, including antigenicity, surface accessibility, flexibility, and hydrophilicity. We assumed that epitope GLQARPKLKRPASSAPRTSTKKKKV could be developed as an epitope-based vaccine with a neutralizing antibody response toward HPV52 infection. Finally, our study provided the alternative for developing low-cost HPV vaccines, either VLP or epitope-based.