Deep Mutational Scans as a Guide to Engineering High Affinity T Cell Receptor Interactions with Peptide-bound Major
Daniel T Harris1, Ningyan Wang1, Timothy P Riley2
1From the Department of Biochemistry, University of Illinois, Urbana, Illinois 61801 and.
The Journal of Biological Chemistry
|September 30, 2016
Summary
Engineered proteins achieve higher affinity through directed evolution and deep sequencing. This method rapidly surveys entire protein interfaces, yielding stable T cell receptors (TCRs) with over 200-fold affinity increases.
Area of Science:
- Protein engineering
- Immunology
- Computational biology
Background:
- Proteins are engineered for higher ligand affinity to enhance therapeutic effects.
- Traditional methods like phage or yeast display have limitations in assessing entire protein interfaces.
Purpose of the Study:
- To develop a method for rapid assessment and evolution of protein-protein interactions across the entire interface.
- To engineer high-affinity T cell receptors (TCRs) for therapeutic benefit.
Main Methods:
- Combining directed evolution with deep sequencing to create sequence fitness landscapes.
- Performing deep mutational scans of T cell receptor (TCR)-peptide-MHC interactions.
- Utilizing in silico binding analyses for comparison with experimental data.
Main Results:
- Achieved stable TCRs with >200-fold affinity increases.
- Identified specific amino acid substitutions that significantly enhance TCR affinity.
- Demonstrated that combining beneficial mutations further improved affinity.
- Computational modeling accurately predicted affinity changes for mutations near the interface but struggled with distal mutations.
Conclusions:
- Deep mutational scanning coupled with yeast surface display is effective for engineering high-affinity TCRs.
- Computational modeling and experimental approaches have complementary strengths in protein engineering.
- This integrated approach enables efficient optimization of protein-ligand interactions.
