Development and characterization of an enterovirus 71 (EV71) virus-like particles (VLPs) vaccine produced in Pichia pastoris

Area of Science:

• Virology
• Vaccinology
• Biotechnology

Background:

• Enterovirus 71 (EV71) is a primary cause of hand, foot, and mouth disease (HFMD) in children.
• Existing inactivated virus-based vaccines have limitations; thus, alternative vaccine strategies are needed.
• Virus-like particles (VLPs) offer a promising alternative for EV71 vaccine development due to their safety and manufacturing potential.

Purpose of the Study:

• To develop an efficient recombinant technology for producing EV71 virus-like particles (VLPs) in Pichia pastoris.
• To evaluate the immunogenicity and protective efficacy of the yeast-produced EV71 VLPs as a vaccine candidate.

Main Methods:

• Constructed and expressed codon-optimized P1 and 3C genes of EV71 in Pichia pastoris.
• Characterized the expressed EV71 VLPs using biochemical and biophysical analyses.
• Assessed the immune response and protective efficacy in mouse models following immunization with EV71 VLPs and adjuvant.

Main Results:

• Achieved high yield (270 mg/L) of EV71 VLPs in the Pichia pastoris expression system.
• Confirmed that the produced EV71 VLPs possess the correct structure (~35nm spherical particles composed of VP0, VP1, and VP3).
• Demonstrated that low doses of EV71 VLPs (1-5 µg/dose) with adjuvant induced robust neutralizing antibodies and provided protection against lethal EV71 challenge in mice.

Conclusions:

• The Pichia pastoris system provides an efficient method for producing high-yield EV71 VLPs.
• Yeast-produced EV71 VLPs are a viable and promising candidate for developing a safe and effective HFMD vaccine.
• This VLP-based vaccine approach offers advantages in large-scale manufacturing and potential safety profile compared to traditional vaccines.