A Modular T4 Phage-Based Nanoparticle Displaying Multiepitopes Provides Cross-Serotype Protection against...

Area of Science:

• Veterinary Immunology
• Vaccine Development
• Microbial Pathogenesis

Background:

• Streptococcus suis is a significant zoonotic pathogen impacting the global swine industry.
• Previous research identified the bacterial elongation factor IF-2 protein as protective against S. suis infection.

Purpose of the Study:

• To develop and evaluate novel T4 nanoparticle-based vaccines derived from IF-2 for broad-spectrum protection against Streptococcus suis.
• To assess the immunoprotective efficacy of these nanoparticles in mouse and swine models, comparing different immunization routes.

Main Methods:

• Prediction and concatenation of T-cell and B-cell epitopes from IF-2 to create IF2-1 and IF2-2 polypeptides.
• Construction of IF2-1-T4 and IF2-2-T4 nanoparticles using the T4 in vivo assembly platform.
• Evaluation of vaccine efficacy in mouse models and a swine model, including comparisons of intramuscular and needle-free immunization.

Main Results:

• Both IF2-1-T4 and IF2-2-T4 nanoparticles demonstrated superior immunoprotective efficacy compared to the native IF-2 protein in mice.
• The IF2-2-T4 nanoparticle exhibited the strongest protection and potential for cross-protection against multiple S. suis serotypes.
• The study confirmed the efficacy of the T4 phage-based vaccine in a swine model, with needle-free immunization showing promise.

Conclusions:

• T4 nanoparticle-based vaccines, particularly IF2-2-T4, represent a promising strategy for developing broad-spectrum vaccines against Streptococcus suis.
• These findings provide a foundation for applying T4 nanoparticle vaccines in swine and offer insights into designing cross-protective vaccines for bacterial pathogens.