The complex and specific pMHC interactions with diverse HIV-1 TCR clonotypes reveal a structural basis for...

Area of Science:

• Immunology
• Structural Biology
• Virology

Background:

• Immune control of viral infections relies on T cell receptors (TCRs) recognizing peptide-MHC complexes.
• The structural basis for varying T cell receptor (TCR) clonotype effectiveness against viruses remains unclear.

Purpose of the Study:

• To investigate the structural determinants of T cell receptor (TCR) and peptide-MHC (pMHC) interactions.
• To understand how TCR structure influences cytotoxic T lymphocyte (CTL) antiviral function against HIV-1.

Main Methods:

• In silico molecular modeling, including molecular dynamics and free energy perturbation calculations.
• In vivo mutagenesis assays and experimental validation of computational predictions.

Main Results:

• Differences in hydrophobic side-chain packing, not just salt bridges, significantly impact TCR-pMHC binding and CTL function.
• Non-specific hydrogen bonding allows for greater tolerance to viral peptide variants.
• Computational predictions of point mutations on the KK10 peptide accurately matched experimental mutagenesis data.

Conclusions:

• Structural variations in TCRs provide a direct basis for heterogeneous CTL antiviral responses.
• Understanding TCR-pMHC interactions can inform the design of more effective antiviral immunotherapies.