Abstract C022: T-cell IL-6 expression defines a subset of memory T cells, and correlates with response to immune checkpoint inhibitors in patients with melanoma

Le résumé fourni par la source

Abstract While immune checkpoint inhibitors (ICIs) have revolutionized the treatment for various types of cancer, they benefit only a subset of patients, are costly, and may cause serious immune-related adverse events. Therefore, biomarkers that can predict their efficacy are urgently needed. Growing evidence has shown that an early on-treatment decrease of serum/plasma interleukin 6 (IL-6) level is associated with response to ICIs and improved survival in several types of cancer. However, the causes and mechanisms underlying changes in IL-6 during ICI therapy remain unclear. Here, using a modified method of intracellular staining for flow cytometry, we found a subset of peripheral blood (PB) CD3+ T cells that express IL-6 without ex vivo stimulation. This subset can be identified within CD45RA– CCR7+ central memory T cells (Tcm) and CD45RA– CCR7– effector memory T cells (Tem), but not in CD45RA+ CCR7+ naïve T cells (Tn) or CD45RA+ CCR7– terminally effector memory re-expressing antigenic cells (Temra). This subset is also found in melanoma-infiltrating T cells. IL-6 is expressed in proliferating T cells upon activation with anti-CD3/CD28 antibody or monocyte-derived dendritic cells in the presence of peptide pool of major histocompatibility complex class I- or II-restricted epitopes. Importantly, an early on-treatment decrease of PB IL-6+ T cells correlates with response and better progression-free and overall survival in patients with melanoma. Collectively, these results suggest that PB IL-6+ T cells may be a novel population that present transversally in memory T cells, and changes in their frequency may serve as an early predictor of treatment response in patients receiving ICIs. Citation Format: Hisashi Kanemaru, Ryutaro Kajihara, Paul K. Wallace, Brahm H. Segal, Gino K. In, Igor Puzanov, Mark S. Ernstoff, Fumito Ito. T-cell IL-6 expression defines a subset of memory T cells, and correlates with response to immune checkpoint inhibitors in patients with melanoma [abstract]. In: Proceedings of the AACR Immuno-Oncology Conference (AACR IO): Discovery and Innovation in Cancer Immunology: Revolutionizing Treatment through Immunotherapy; 2026 Feb 18-21; Los Angeles, CA. Philadelphia (PA): AACR; Cancer Immunol Res 2026;14(2 Suppl):Abstract nr C022.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.