KLRG1 marks tumor-infiltrating CD4 T cell subsets associated with tumor progression and immunotherapy response

• Published in: Journal for immunotherapy of cancer Vol. 11; no. 9; p. e006782
• Main Authors: Ager, Casey R, Zhang, Mingxuan, Chaimowitz, Matthew, Bansal, Shruti, Tagore, Somnath, Obradovic, Aleksandar, Jugler, Collin, Rogava, Meri, Melms, Johannes C, McCann, Patrick, Spina, Catherine, Drake, Charles G, Dallos, Matthew C, Izar, Benjamin
• Format: Journal Article
• Language: English
• Published: England BMJ Publishing Group Ltd 01.09.2023; BMJ Publishing Group LTD; BMJ Publishing Group
• Subjects: Antibodies; Biomarkers; Cancer; Cancer therapies; Carcinoma, Renal Cell; CD4-Positive T-Lymphocytes; Cells; Dimensional analysis; Flow cytometry; Humans; Immune checkpoint inhibitors; Immunotherapy; Immunotherapy Biomarkers; Kidney cancer; Kidney Neoplasms; Laboratory animals; Lectins, C-Type; Lymphatic system; lymphocytes, tumor-infiltrating; Medical research; Penicillin; Receptors, Immunologic; renal cell carcinoma; Stains & staining; T-Lymphocyte Subsets; Tumors; New York; United States > US; Basel Switzerland; California; Switzerland; Maryland; New Jersey; renal cell carcinoma; immune checkpoint inhibitors; CD4-positive T-lymphocytes; lymphocytes, tumor-infiltrating; immunotherapy
• ISSN: 2051-1426; 2051-1426
• DOI: 10.1136/jitc-2023-006782

Current methods for biomarker discovery and target identification in immuno-oncology rely on static snapshots of tumor immunity. To thoroughly characterize the temporal nature of antitumor immune responses, we developed a 34-parameter spectral flow cytometry panel and performed high-throughput analyses in critical contexts. We leveraged two distinct preclinical models that recapitulate cancer immunoediting (NPK-C1) and immune checkpoint blockade (ICB) response (MC38), respectively, and profiled multiple relevant tissues at and around key inflection points of immune surveillance and escape and/or ICB response. Machine learning-driven data analysis revealed a pattern of KLRG1 expression that uniquely identified intratumoral effector CD4 T cell populations that constitutively associate with tumor burden across tumor models, and are lost in tumors undergoing regression in response to ICB. Similarly, a Helios-KLRG1+ subset of tumor-infiltrating regulatory T cells was associated with tumor progression from immune equilibrium to escape and was also lost in tumors responding to ICB. Validation studies confirmed KLRG1 signatures in human tumor-infiltrating CD4 T cells associate with disease progression in renal cancer. These findings nominate KLRG1+ CD4 T cell populations as subsets for further investigation in cancer immunity and demonstrate the utility of longitudinal spectral flow profiling as an engine of dynamic biomarker discovery.