Immune checkpoint inhibitors (ICIs), including inhibitors of cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4), programmed death-1 (PD-1) and programmed death-ligand 1 (PD-L1) have demonstrated prominent clinical benefits in a variety of cancers and have been rapidly applied to treat a variety of carcinomas such as melanoma, non-small-cell lung cancer, and head and neck cancer.
Analysis of the head and neck cancer TCGA cohort revealed high CTLA-4 and MDSC-related chemokine and an MDSC-rich gene expression profile with a T-cell inflamed phenotype in > 60% of patients.
We examined the expression patterns of immune checkpoint receptors (including PD-1, CTLA-4, and TIM-3) and cytolytic molecules (including granzyme B and perforin) of CD8<sup>+</sup> tumor-infiltrating lymphocytes (TIL) and compared them with those of peripheral blood T lymphocytes (PBL) in patients with head and neck cancer (HNSCC) during cetuximab therapy.
CTLA-4⁺ Regulatory T Cells Increased in Cetuximab-Treated Head and Neck Cancer Patients Suppress NK Cell Cytotoxicity and Correlate with Poor Prognosis.