Year: 2026
Type: conference-abstract
Abstract: Background Cancer immunotherapies depend on the frequency and phenotypic states of tumor-reactive tumor-infiltrating lymphocytes(TILs). Adoptive cell therapy(ACT) seeks to harness these cells by expanding them in vitro and reinfusing them into patients to mediate tumor regression. Studies have shown that tumor-reactive TIL possess distinct transcriptional programs within resected tumor deposits1–8; however, the influence of the tumor itself on TIL phenotype remains incompletely understood. Investigating how factors, including histology, tumor genotype, and tumor deposit site, influence the transcriptional programs of tumor-reactive T cells may provide critical insights for optimizing ACT and improving survival outcomes in patients with metastatic cancer. Here, by mapping the phenotypic states of more than 380 antitumor T cell clonotypes, we investigate how tumor histology, harvest site, and tumor genomic features shape the transcriptional states of both global and tumor-specific TIL from 77 metastatic cancer patients across more than 15 solid tumor histologies and 8 anatomical sites, including lung, liver, and lymph node(LN) metastases.Methods TIL from metastatic tumor deposits underwent single-cell TCR/RNA sequencing(10X Genomics). Whole exome and bulk RNA sequencing was performed on these same resections to capture tumor genomic data. Rigorous quality control was performed. Seurat was used to integrate this data and characterize transcriptomic profiles for 712,958 T cells for downstream transcriptomic analyses.Results TIL composition was largely conserved across tumor histology. In contrast, TIL resection site was associated with significant differences in TIL transcriptional programs. Cell proportion analyses indicated that lung-derived metastases were significantly enriched for exhausted TIL populations, whereas LN-derived TIL were transcriptionally distinct from both lung- and liver-derived TIL and were enriched for memory-like populations with fewer differentiated TIL. Tumor-reactive transcriptional signatures also varied by resection site: lung-derived TIL exhibited a more exhausted phenotype relative to liver and LN-derived TIL. Importantly, at the patient-level, higher NeoTCR transcriptional signature scores were associated with increased numbers of neoantigens identified indicating a strong association between terminal-exhausted TIL and neoantigen-reactivity in patients. Additionally, patterns of clonal expansion differed between CD8 + and CD4+ T cell subsets with CD8+ TIL on average displaying more hyperexpanded clonotypes than CD4+TIL.Conclusions Our pilot findings suggest that the metastatic microenvironment, particularly resection site, has a greater impact on TIL transcriptional phenotype than source tumor histology. Lung metastases are associated with more differentiated and dysfunctional TIL states, whereas LN metastases harbor more stem-like T cell populations. Furthermore, NeoTCR-associated transcriptional programs correlate with neoantigen discovery, supporting their potential utility for identifying tumor-reactive TIL and informing ACT strategies.References He J, et al. Defined tumor antigen-specific T cells potentiate personalized TCR-T cell therapy and prediction of immunotherapy response. Cell Res. 2022;32(6):530–542.Lowery FJ, et al. Molecular signatures of antitumor neoantigen-reactive T cells from metastatic human cancers. Science 2022;375(6583):877–884.Oliveira G, et al. Phenotype, specificity and avidity of antitumour CD8(+) T cells in melanoma. Nature 2021;596(7870):119–125.Hanada KI, et al. A phenotypic signature that identifies neoantigen-reactive T cells in fresh human lung cancers. Cancer Cell. 2022;40(5):479–493 e6.Caushi JX, et al. Transcriptional programs of neoantigen-specific TIL in anti-PD-1-treated lung cancers. Nature 2021;596(7870):126–132.Sade-Feldman M, et al. Defining T Cell States Associated with Response to Checkpoint Immunotherapy in Melanoma. Cell 2018;175(4)998–1013 e20.Lowery FJ, et al. Neoantigen-specific tumor-infiltrating lymphocytes in gastrointestinal cancers: a phase 2 trial. Nat Med. 2025;31(6):1994–2003.Sri Krishna, et al. Stem-like CD8 T cells mediate response of adoptive cell immunotherapy against human cancer. Science 2020;370:1328–1334.
Institutions: National Institutes of Health, National Cancer Institute
Language: English
Subfield: Oncology
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $2,490
OpenAlex ID: W7225201583