T Cell Recognition of Tumor Neoantigens and Insights Into T Cell Immunotherapy

Area of Science:

• Immunology
• Oncology
• Structural Biology

Background:

• Cancer cells acquire non-synonymous DNA mutations, leading to altered proteins and neoantigens.
• Neoantigens are presented by human leukocyte antigens (HLA) and recognized by T-cell receptors (TCRs).
• Distinguishing neoantigens from self-proteins poses a challenge for the immune system.

Purpose of the Study:

• To review structural insights into how TCRs detect cancer neoantigens.
• To delineate mechanistic categories of neoantigen recognition by TCRs.
• To discuss the implications for anti-tumor immune responses and immunotherapy.

Main Methods:

• Review of structural studies on TCR-neoantigen interactions.
• Categorization of neoantigen recognition mechanisms.
• Analysis of structural differences between mutated self-peptides and anchor-modified peptides.

Main Results:

• Two primary TCR recognition mechanisms for neoantigens identified: mutated self-peptides and novel non-self-peptides via anchor residue modifications.
• Mutated self-peptides differ by a single amino acid from self-epitopes.
• Anchor residue modifications create entirely new, previously unrecognized epitopes.

Conclusions:

• Structural differences in neoantigen recognition mechanisms may influence anti-tumor immune responses.
• T-cells specific for anchor-mutation-derived neoantigens can exhibit high affinity.
• These findings offer insights for developing adoptive T-cell transfer immunotherapies targeting cancer.