{
  "abstract": "Background: The tumor microenvironment exerts intense survival pressure on CD8 ⁺ tumor-infiltrating lymphocytes (TILs), yet the cellular basis for an earlier, less-exhausted state associated with response to immune checkpoint blockade (ICB) in non-small-cell lung cancer (NSCLC) remains unclear. We previously identified BCL2A1 as a CD8 ⁺ TIL-derived marker predictive of a response to PD-1 blockade. Here we combine deep single-cell discovery with experimental validation in primary human T cells to characterise the BCL2A1-associated CD8 ⁺ TIL state and its candidate upstream signal.\n\nMethods: We integrated four transcriptomic cohorts—pre-treatment bulk RNA-seq with CD8 ⁺ TIL deconvolution (n=60), on-treatment scRNA-seq/TCR-seq (n=11), longitudinal scRNA-seq/TCR-seq (n=18), and an independent post-treatment cohort (n=59)—with in silico perturbation, pathway, and metabolic-flux analyses, and experimentally tested a key prediction of this state by flow cytometry in primary human CD8 ⁺ T cells.\n\nResults: BCL2A1 high CD8 ⁺ TILs showed elevated BCL2A1 expression without coordinated upregulation of anti-apoptotic BCL2-family genes, maintained minimal exhaustion, and occupied an early, BCL6 -, TCF7 -, and NFKB1 -regulated pseudotime state. Across longitudinal and post-treatment cohorts, they formed diverse, low-expansion repertoires rather than dominant expanded clones, with reduced biosynthetic flux (branched-chain amino acid and purine metabolism) consistent with a non-proliferative state. NF-κB signaling was elevated, and TNF-α was nominated as the leading candidate upstream ligand of BCL2A1 . We then experimentally tested this prediction: in primary human CD8 ⁺ T cells, TNF-α induced BCL2A1 protein ≈13-fold (44.5% vs. 3.4% BCL2A1 ⁺ ; MFI 2.93-fold; P < 0.0001), whereas CD3/CD28 activation alone did not, establishing a TNF-α-specific, protein-level response.\n\nConclusions: Combining integrative single-cell analysis with experimental validation in primary human T cells, we define BCL2A1 as a marker of an early, less-exhausted CD8 ⁺ TIL state associated with improved ICB outcomes in NSCLC; a survival-related role is supported by these associations but was not functionally tested.",
  "abstract_shown": true,
  "affiliations": [
    "International Ph.D. Program in Medicine, College of Medicine, Taipei Medical University",
    "Department of Oncology, Faculty of Medicine, Can Tho University of Medicine and Pharmacy",
    "Department of Microbiology and Immunology, School of Medicine, College of Medicine, Taipei Medical University",
    "School of Respiratory Therapy, College of Medicine, Taipei Medical University",
    "Division of Pulmonary Medicine, Department of Internal Medicine, Shuang Ho Hospital, Taipei Medical University",
    "Division of Pulmonary Medicine, Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University",
    "Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University",
    "TMU Research Center of Thoracic Medicine, Taipei Medical University",
    "Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University",
    "Core Laboratory of Immune Monitoring, Office of Research & Development, Taipei Medical University"
  ],
  "article_type": "research support, non u.s. gov't",
  "arxiv": null,
  "author_total": 6,
  "authors": [
    {
      "affs": [
        0,
        1,
        2
      ],
      "name": "Hoang Minh Quan Pham"
    },
    {
      "affs": [
        3
      ],
      "name": "Chia-Ling Chen"
    },
    {
      "affs": [
        4,
        5
      ],
      "name": "Po-Hao Feng"
    },
    {
      "affs": [
        3,
        4,
        6,
        7
      ],
      "name": "Kang-Yun Lee"
    },
    {
      "affs": [
        8,
        2
      ],
      "name": "Yu-Ping Hung"
    },
    {
      "affs": [
        0,
        2,
        7,
        8,
        9
      ],
      "name": "Chiou-Feng Lin"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/eve6zzmf19v25.bib",
  "cited_by": 0,
  "doi": "10.3389/fimmu.2026.1908216",
  "fulltext_url": "https://europepmc.org/articles/PMC13683672",
  "id": "eve6zzmf19v25",
  "issns": [
    "1664-3224"
  ],
  "landing_url": "https://www.frontiersin.org/articles/10.3389/fimmu.2026.1908216/full",
  "language": "eng",
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "2730|Cancer Immunotherapy and Biomarkers"
    ]
  ],
  "openalex": "W7220834593",
  "pdf_url": "https://europepmc.org/articles/PMC13683672?pdf=render",
  "pmcid": "PMC13683672",
  "pmid": "42909010",
  "published": "2026-10-07",
  "publisher": "Frontiers Media SA",
  "ris": "https://research.draconitic.com/paper/eve6zzmf19v25.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:19:15Z",
      "native_id": "10.3389/fimmu.2026.1908216",
      "source": "crossref",
      "url": "https://www.frontiersin.org/articles/10.3389/fimmu.2026.1908216/full"
    },
    {
      "first_seen": "2026-10-30T12:20:10Z",
      "native_id": "MED:42909010",
      "source": "europepmc",
      "url": "https://europepmc.org/article/MED/42909010"
    }
  ],
  "subjects": [
    {
      "field": "medicine",
      "origin": "openalex:2730|Cancer Immunotherapy and Biomarkers",
      "subfield": "oncology"
    }
  ],
  "title": "BCL2A1 marks an early, less-exhausted CD8+ tumor-infiltrating lymphocyte state associated with PD-1 blockade response in NSCLC",
  "title_text": "BCL2A1 marks an early, less-exhausted CD8+ tumor-infiltrating lymphocyte state associated with PD-1 blockade response in NSCLC",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:20:10Z",
  "url": "https://research.draconitic.com/paper/eve6zzmf19v25",
  "venue": "Frontiers in Immunology",
  "versions": []
}