Membrane Expression Enhances Folding, Multimeric Structure Formation, and Immunogenicity of Viral Capsid Proteins

Area of Science:

• Vaccinology
• Virology
• Protein Engineering

Background:

• Viral capsid proteins are crucial for subunit vaccine development but face challenges in production and immunogenicity.
• African swine fever virus (ASFV) capsid proteins P72 and penton are key targets for vaccine strategies.

Purpose of the Study:

• To develop a simple approach combining mRNA vaccine technology and protein engineering to enhance viral capsid protein immunogenicity.
• To engineer membrane-bound and secreted forms of ASFV P72 and penton proteins and compare their immunogenicity to the native intracellular form.

Main Methods:

• Engineered membrane-bound and secreted forms of ASFV P72 and penton proteins.
• Utilized mRNA vaccine technology for delivery in mice and pigs.
• Assessed antibody and T cell responses to compare immunogenicity of different protein forms.

Main Results:

• Engineered membrane-bound and secreted ASFV capsid proteins folded into native structures, preserving conformational epitopes.
• Membrane-bound and secreted forms elicited significantly stronger antibody and T cell responses compared to intracellular forms.
• The approach enhanced protein folding, multimeric structure formation, and overall immunogenicity.

Conclusions:

• Protein engineering combined with mRNA vaccination offers a viable strategy to improve the immunogenicity of viral capsid proteins.
• This method enhances the development of effective subunit vaccines, particularly for challenging viruses like ASFV.
• The findings have broader implications for improving the immunogenicity of intracellular proteins for vaccine development.