Controlled Peptide Valency on MS2 Virus-Like Particles
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current phage display technologies face challenges in achieving high-density peptide display on virus-like particles (VLPs), which limits their immunogenicity and the ability to select for peptides with high affinity to antibodies, due to issues with peptide valency and the structural context during affinity selection.
Innovation Solution
The development of plasmid vectors and methods that allow for controlled peptide display valency on MS2 and PP7 VLPs, enabling the adjustment of peptide density from fewer than one to as many as ninety per particle, facilitating the identification and production of immunogenic peptides by affinity selection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If high-density peptide display is achieved on VLPs, then immunogenicity is improved, but the ability to select for peptides with high affinity to antibodies deteriorates due to avidity effects
Solution Approach 1:
The patent employs a single-chain dimer coat protein design where the peptide is inserted into one of two identical AB loops. This creates a dynamic system where the peptide display valency can be controlled - each VLP can display either 0, 1, or 2 peptides per dimer (totaling 0, 90, or 180 peptides per particle). This dynamic control allows researchers to adjust peptide density to optimize both immunogenicity and affinity selection stringency, resolving the contradiction between high peptide density and selection precision.
2Reliability
If peptide valency is increased to enhance immunogenicity, then vaccine effectiveness is improved, but the structural context during affinity selection is compromised
Solution Approach 1:
The invention introduces local quality variation by inserting the heterologous peptide into only one of the two identical AB loops of the single-chain dimer coat protein. This creates asymmetric peptide display at the local level (one peptide per dimer on average) while maintaining the overall symmetric VLP structure. This local quality approach preserves the structural context necessary for accurate affinity selection while still providing sufficient peptide display for immunogenicity.
3Adaptability or versatility
If random sequence peptide libraries are constructed for high complexity selection, then the probability of finding high-affinity peptides is improved, but the complexity of library construction and management increases
Solution Approach 1:
The patent employs a universal single-chain dimer coat protein platform that can accommodate any heterologous peptide sequence in the AB loop region. This universal framework allows construction of high-complexity random sequence libraries without requiring different vector systems for each peptide variant. The single-chain dimer design serves multiple functions: it maintains VLP assembly, provides controlled peptide display, and enables easy library construction through standard molecular biology techniques, thereby managing complexity while maintaining high adaptability.
Data Source
AI summary
The present invention relates to a system and method for controlling peptide display valency on virus-like particles (VLPs), especially including MS2 VLPs. In this method, large amounts of wild-type and low quantities of single-chain dimer coat proteins may be produced from a single RNA. Valency is controlled in immunogen (vaccine) production by providing a system that allows the production of large amounts of wild-type and low quantities of single-chain dimer coating proteins from a single RNA, allowing facile adjustment of display valency levels on VLPs, especially MS2 VLPS over a wide range, from few than one—on average—to as many as ninety per particle. This facilitates the production of immunogens and vaccines, including VLPs exhibiting low valency. Nucleic acid constructs useful in the expression of virus-like particles are disclosed, comprised of a coat polypeptide of MS2 modified by insertion of a heterologous peptide, wherein the heterologous peptide is displayed on the virus-like particle and encapsidates MS2 niRNA. Nucleic acid constructs are also disclosed which are useful in the expression of virus-like particles comprised of a coat polypeptide of PP7 modified by insertion of a heterologous peptide, wherein the heterologous peptide is displayed on the virus-like particle and encapsidates PP7 mRNA.