Virtual Evolution of HVEM Segment for Checkpoint Inhibitor Discovery

Area of Science:

• Immunology
• Structural Biology
• Computational Chemistry

Background:

• Immune checkpoint inhibitors (ICIs) like PD-1/PD-L1 antibodies are effective cancer treatments.
• Other immune checkpoints, including B and T lymphocyte attenuator (BTLA) and herpes virus entry mediator (HVEM), are emerging as potential drug targets.
• The HVEM (26-38) fragment is identified as the core binding interface for BTLA/HVEM interaction.

Purpose of the Study:

• To computationally evolve the HVEM (26-38) core sequence to identify mutants with improved binding affinity to BTLA.
• To synthesize and validate the efficacy of these mutated peptides in blocking BTLA/HVEM interaction.
• To elucidate the mechanistic basis of the observed effects through computational analysis.

Main Methods:

• In silico saturation mutagenesis was employed to generate virtual variants of the HVEM (26-38) sequence.
• Mutants with predicted lower binding energy were selected for further investigation.
• Experimental validation using wet-lab techniques confirmed higher binding affinity for selected mutants.
• Computational analysis was performed to understand the mechanism of action.

Main Results:

• Virtual evolution identified several HVEM (26-38) mutants with significantly lower binding energy to BTLA.
• Wet-lab experiments confirmed that these selected mutants exhibit enhanced binding affinity to BTLA.
• Extended peptides based on the optimal mutant demonstrated improved inhibitory efficacy.
• Computational analysis provided insights into the mechanism underlying the enhanced binding and efficacy.

Conclusions:

• The discovered mutated peptides are potent inhibitors capable of blocking the BTLA/HVEM interaction.
• These findings offer a novel approach to developing inhibitors for immune checkpoint pairs.
• The study expands the understanding of inhibitor discovery strategies for immune checkpoints.