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Updated: Mar 12, 2026
Visualization, Quantification, and Mapping of Immune Cell Populations in the Tumor Microenvironment
Published on: March 25, 2020
Spatial single-cell proteotyping reveals immunotherapy-resistant features within the complex tumor microenvironment
Kohsuke Isomoto1, Koji Haratani1,2, Takahiro Tsujikawa3
1Department of Medical Oncology, Kindai University Faculty of Medicine, Osaka-Sayama, Japan.
Abstract:
BACKGROUNDImmune checkpoint inhibitors (ICIs) targeting the programmed cell death 1 axis have revolutionized metastatic non-small cell lung cancer (mNSCLC) treatment. However, disease progression remains a concern, and the role of the complex tumor microenvironment (TME) in treatment failure is not fully understood.METHODSIn this biomarker study involving 103 patients with mNSCLC, including 81 patients who received ICI treatment, we evaluated the association between heterogeneous immune cell subsets and ICI efficacy through single-cell spatial profiling of pretreatment tumor tissue, using a 29-marker multiplex IHC platform built for in-depth dissection of the TME.RESULTSAmong various types of intratumoral lymphocytes, including Th1, Treg, and NK cells, only CD8+ T cells (tumor-infiltrating lymphocytes [TILs]) were associated with ICI efficacy. Computational tissue segmentation underscored the importance of direct physical interactions between CD8+ TILs and cancer cells for ICI efficacy. TIL phenotyping identified CD39/CD103/Ki-67 positivity as a hallmark of exhausted yet functional tumor-reactive CD8+ TILs. Immunosuppressive tumor-associated macrophages (TAMs) and cancer-associated fibroblasts were independent unfavorable adversaries. High CD73 expression on cancer cells was suggested to confer tolerance to ICI in EGFR/ALK-oncogene+ NSCLC, potentially through M2-TAM accumulation and aberrant angiogenesis.CONCLUSIONOur study delineates the clinical relevance of heterogeneous immune cell subsets in ICI-treated mNSCLC, aiding the development of targeted therapeutic strategies.FUNDINGOsaka Cancer Society, KANAE Foundation for the Promotion of Medical Science, SGH Foundation, and YOKOYAMA Foundation for Clinical Pharmacology.
Insights
Immune checkpoint inhibitors (ICIs) show promise in metastatic non-small cell lung cancer (mNSCLC). This study identifies CD8+ T cells as key to ICI efficacy and reveals factors contributing to treatment resistance in the tumor microenvironment.
Area of Science:
- Oncology
- Immunology
- Cancer Research
Background:
- Immune checkpoint inhibitors (ICIs) have transformed metastatic non-small cell lung cancer (mNSCLC) treatment.
- Tumor microenvironment (TME) complexity influences ICI treatment failure.
- Understanding immune cell roles in mNSCLC is crucial for improving outcomes.
Purpose of the Study:
- To investigate the association between immune cell subsets and ICI efficacy in mNSCLC.
- To identify biomarkers within the TME predictive of ICI response.
- To explore mechanisms of ICI resistance in mNSCLC.
Main Methods:
- Biomarker study of 103 mNSCLC patients (81 treated with ICI).
- Single-cell spatial profiling of pretreatment tumor tissue using multiplex immunohistochemistry.
- Evaluation of heterogeneous immune cell subsets and their spatial interactions with cancer cells.
Main Results:
- CD8+ T cells (TILs) were positively associated with ICI efficacy.
- Direct physical interactions between CD8+ TILs and cancer cells are critical for ICI response.
- CD39/CD103/Ki-67 positive CD8+ TILs represent an exhausted yet functional phenotype.
- Immunosuppressive tumor-associated macrophages (TAMs) and cancer-associated fibroblasts were unfavorable prognostic factors.
- High CD73 expression on cancer cells may confer ICI tolerance, potentially via M2-TAMs and angiogenesis, in EGFR/ALK-oncogene+ NSCLC.
Conclusions:
- The study highlights the clinical relevance of immune cell heterogeneity in ICI-treated mNSCLC.
- Findings aid in developing targeted therapeutic strategies for mNSCLC.
- Identification of specific immune cell subsets and markers can guide treatment decisions.
