A Novel Codon-optimized SIV Gag-pol Immunogen for Gene-based Vaccination

Area of Science:

• Virology
• Immunology
• Vaccine Development

Background:

• Simian immunodeficiency virus (SIV) serves as a model for HIV vaccine research.
• The SIV gag-pol protein is a conserved target with potential for multivalent immune responses.
• Native SIV gene expression is limited by codon bias and translational frameshifting.

Purpose of the Study:

• To develop an improved SIV gag-pol immunogen for gene-based vaccination.
• To enhance the expression of SIV gag-pol proteins.
• To assess the immunogenicity of the engineered SIV gag-pol construct.

Main Methods:

• Codon optimization of the SIVmac239 gag-pol sequence.
• Engineering in-frame expression of gag and pol to bypass frameshifting.
• Inclusion of self-cleaving sequences for protein fragmentation.
• In vitro expression analysis and assessment of antibody and T cell responses.

Main Results:

• Engineered SIV gag-pol immunogens showed robust expression in vitro.
• Both codon-optimized and in-frame constructs improved expression.
• The presence of self-cleaving sequences did not significantly alter antibody or T cell responses.

Conclusions:

• Optimized SIV gag-pol constructs can overcome native expression limitations.
• Engineered immunogens are suitable for gene-based vaccine strategies.
• Further studies are warranted to evaluate in vivo efficacy.