Codon-Optimized Signal Peptides for Bacterial Protein Secretion
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Solution Overview
Problem
Current bacterial expression systems, particularly Listeria-based vaccines, face challenges in optimizing the efficiency of heterologous protein expression and secretion, which affects the potency of vaccines and the immune response they induce.
Innovation Solution
The development of novel polynucleotides and expression cassettes that include codon-optimized signal peptides and polypeptides, allowing for enhanced expression and secretion of heterologous proteins in bacteria, including the use of fusion proteins and protein chimeras, to improve vaccine efficacy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional bacterial expression systems are used, then the system is simple and easy to manufacture, but the efficiency of heterologous protein expression and secretion is insufficient
Solution Approach 1:
The patent applies parameter changes by codon-optimizing the signal peptide sequence to match the host bacterial organism's codon usage preferences. This optimization of the nucleotide sequence parameters (codon selection, GC content, codon usage frequency) enhances the efficiency of heterologous protein expression and secretion without fundamentally changing the expression system architecture, thereby resolving the contradiction between productivity improvement and system complexity.
2Productivity
If native signal peptides are used, then the expression system is straightforward, but the secretion efficiency of heterologous proteins is limited
Solution Approach 1:
The patent modifies the signal peptide's nucleotide sequence parameters through codon optimization to match the host organism's preferences, thereby improving secretion efficiency while maintaining the same functional signal peptide sequence. This approach enhances productivity without significantly complicating the manufacturing process, as it involves sequence optimization rather than fundamental system redesign.
3Reliability
If heterologous antigens are expressed in bacteria, then vaccine potency can be improved, but the immune response may be insufficient without optimization
Solution Approach 1:
The patent optimizes the signal peptide codon usage to match the host bacterial organism, thereby enhancing the expression and secretion efficiency of heterologous antigens. This parameter optimization ensures sufficient antigen production to elicit robust immune responses, resolving the contradiction between maintaining vaccine potency and achieving sufficient immune response strength.
Data Source
AI summary
The present invention provides recombinant nucleic acid molecules, expression cassettes, and vectors useful for expression of polypeptides, including heterologous polypeptides, such as antigens, in bacteria. Some of the recombinant nucleic acid molecules, expression cassettes and vectors comprise codon-optimized sequences encoding the polypeptides and/or signal peptides. Some of the recombinant nucleic acid molecules, expression cassettes, and expression vectors comprise sequences encoding non-Listerial and/or non-secA1 signal peptides for secretion of the polypeptides. The invention also provides bacteria comprising the nucleic acid molecules, expression cassettes, and expression vectors, as well as compositions such as vaccines comprising the bacteria. Methods of making and using the bacteria, recombinant nucleic acid molecules, and expression cassettes are also provided.