Abstract
Human papillomavirus virus-like particles (HPV VLPs) have been shown to be effective in preventing cervical cancer when used as a prophylactic vaccine. However, little attention has been paid to the process of L1 expression and self-assembly of VLPs in vivo. In this study, the methanol concentration is optimized during fermentation to optimize L1 expression and self-assembly into VLPs. HPV 16 L1 was expressed in Pichia pastoris GS115, and successfully self-assembled into HPV 16 VLPs. The results demonstrate that there is a strong correlation between methanol concentration and the expression of HPV L1 as well as VLP formation. During the methanol induction phase, low concentrations of residual methanol (0.1-0.3%) promoted the expression of free L1 and increased the total content of L1, whereas a higher residual methanol concentration (0.32-0.6%) was conducive for the self-assembly of LI into VLPs. To conclude, if the residual methanol concentration is too low or too high, the levels of L1 can easily decrease during the fermentation process.
Highlights
Cervical cancer has become the second largest cause of cancer death among women after breast cancer [1]
Several large clinical trials have shown that Human papillomavirus (HPV) viruslike particles (VLPs) can been prepared into prophylactic vaccines and provide a sustained immune response against HPV infection
We investigated the effects of the methanol concentration in the fermentation process on the expression of HPV 16 L1 and L1 self-assembly into HPV 16 VLPs in P. pastoris cells in vivo
Summary
Cervical cancer has become the second largest cause of cancer death among women after breast cancer [1]. L1 monomers can be expressed in eukaryotic systems such as insect and yeast cells and can self-assemble into virus-like particles [5,6] Due to their strong hydrophobicity, L1 monomers rely on interactions between an α-helix, β-fold, and a β-loop forming a hydrophobic region between the monomers, which combine to form pentamers. Changes in pH, ionic strength, and/ or redox potential can result in the depolymerization and reassembly of VLPs [9] These self-assembling VLPs can mimic the natural virus to a certain extent, which is a critical step in the vaccine development process. The morphology and immunogenicity of the self-assembling VLPs is similar to HPV virions; the VLPs lack viral DNA, and do not stimulate potentially harmful oncogenes so as to provide a safe immune response. After injection of the vaccine, the systematic generation of high levels of anti-HPV L1 IgG antibodies can be achieved, providing HPV subtype-specific immunity as well as immunity against related subtypes
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
