Immunological profiling of tumorinfiltrating CD8(+) T lymphocytes in non-small cell lung cancer, head and neck squamous cell carcinoma, breast cancer, and renal cell cancer

Abstract To explore whether the variation in clinical response to immune checkpoint blockade (ICB) reflects intrinsic characteristics of tumor-infiltrating lymphocytes (TIL), TILs from multiple tumor types were analyzed by multiparameter flow cytometry. Recent work identified CD39+CD103+ double positive (DP) CD8 TIL as tumor-reactive, therefore we assessed this phenotype in primary NSCLC (n=28), BCa (n=23), HNSCC (n=23), and RCC (n=23) specimens. TILs from NSCLC and HNSCC had significantly higher frequencies of DP T cells than BCa and RCC (NSCLC: median=34.2, IQR=15.0–53.8%; HNSCC: median=28.6%, IQR=13.5–44.5%), while TILs from BCa and RCC had low frequencies of DP T cells (BCa: median=2.4%, IQR=1.1–3.9%; RCC: median=4.2%, IQR=1.5–16.6%). Additionally, DP cells in NSCLC and HNSCC were co-expressed immune checkpoint markers PD-1, TIM-3, and LAG-3 at a higher frequency than RCC or BCa (P<0.05). DP CD8 T cells in NSCLC and HNSCC also exhibited increased effector potential (granzyme B+) as compared to BCa and RCC, suggesting functional differences. Expression of the transcription factor Eomesodermin, associated with T cell exhaustion, was higher in effector CD8 T cells from RCC (median=84.5%, IQR=44.9–97.4%) as compared to NSCLC (median=28.7%, IQR=20.7–61.4%), BCa (median=30.1%, IQR=0–50%), and HNSCC (median=40.3%, IQR=20.1–61.2%). Additionally, 4-1BB, an indicator of TCR engagement, trended higher in RCC (mean=8.6%, IQR=1.4–46.7%) as compared to BCa (median=1.9%, IQR=0.4–8.6%). These data highlight the heterogeneity of human TILs isolated from distinct tumor types and provide insight into the basal expression of actionable therapeutic targets. Supported by GlaxoSmithKline and the Providence Portland Medical Foundation