Engineering a Rugged Nanoscaffold To Enhance Plug-and-Display Vaccination

Area of Science:

• Nanotechnology
• Immunology
• Protein engineering

Background:

• Nanoscale organization is critical for effective immune stimulation.
• Virus-like particles are established platforms for vaccines, but synthetic alternatives require validation.
• Weakly immunogenic antigens pose challenges for vaccine development.

Purpose of the Study:

• To engineer a synthetic dodecahedral protein nanoparticle (i301) for enhanced uniformity and stability.
• To develop a simplified antigen conjugation method using SpyCatcher-mi3 and SpyTag (Plug-and-Display).
• To evaluate the immunogenicity and stability of the engineered nanoscaffold for vaccine applications.

Main Methods:

• Computational design and rational engineering of the i301 nanoparticle.
• Fusion of SpyCatcher to the engineered i301 particle (SpyCatcher-mi3).
• Antigen conjugation via SpyTag peptide and SpyCatcher interaction.
• Expression in E. coli, purification, and stability testing (temperature, freeze-thaw, lyophilization).
• Conjugation of Plasmodium falciparum antigens and assessment of antibody avidity.

Main Results:

• Engineered i301 (mi3) showed improved particle uniformity and stability.
• SpyCatcher-mi3 achieved high yields in E. coli, exceeding phage-derived nanoparticles.
• High stability demonstrated across various conditions, including long-term storage.
• Efficient (approx. 95%) conjugation of malaria antigens achieved.
• Conjugated CyRPA elicited high avidity antibody responses comparable to virus-like particles.

Conclusions:

• The engineered SpyCatcher-mi3 nanoscaffold is a stable, easily produced, and versatile platform.
• Plug-and-Display technology enables precise and efficient antigen conjugation.
• This nanoscaffold shows significant potential for nanobiotechnology and vaccine development, particularly for challenging antigens.