Ibanez-Molero and Veldman et al. isolated heterotypic clusters of CD8+ T cells with tumor cells and antigen-presenting cells (APCs) from melanoma metastases, revealing stable conjugates normally excluded by single-cell gating. These clustered T cells showed enriched tumor-reactive and exhausted signatures, increased TCR clonality, and binding to specific APC and tumor subtypes expressing synapse-forming ligands. Cluster-derived T cells produced higher IFNγ/TNF and showed greater cytotoxicity against autologous melanoma ex vivo. In matched PDX models, adoptive transfer of cluster-derived T cells showed higher infiltration, activation, and tumor control.
Contributed by Shishir Pant
ABSTRACT: Emerging evidence suggests a correlation between CD8(+) T cell-tumour cell proximity and anti-tumour immune response(1,2). However, it remains unclear whether these cells exist as functional clusters that can be isolated from clinical samples. Here, using conventional and imaging flow cytometry, we show that from 21 out of 21 human melanoma metastases, we could isolate heterotypic clusters, comprising CD8(+) T cells interacting with one or more tumour cells and/or antigen-presenting cells (APCs). Single-cell RNA-sequencing analysis revealed that T cells from clusters were enriched for gene signatures associated with tumour reactivity and exhaustion. Clustered T cells exhibited increased TCR clonality indicative of expansion, whereas TCR-matched T cells showed more exhaustion and co-modulation when conjugated to APCs than when conjugated to tumour cells. T cells that were expanded from clusters ex vivo exerted on average ninefold increased killing activity towards autologous melanomas, which was accompanied by enhanced cytokine production. After adoptive cell transfer into mice, T cells from clusters showed improved patient-derived melanoma control, which was associated with increased T cell infiltration and activation. Together, these results demonstrate that tumour-reactive CD8(+) T cells are enriched in functional clusters with tumour cells and/or APCs and that they can be isolated and expanded from clinical samples. Typically excluded by single-cell gating in flow cytometry, these distinct heterotypic T cell clusters are a valuable source to decipher functional tumour-immune cell interactions and may also be therapeutically explored.
Author Info: (1) Division of Molecular Oncology and Immunology, Oncode Institute, Netherlands Cancer Institute, Amsterdam, The Netherlands. (2) Division of Molecular Oncology and Immunology, On
Author Info: (1) Division of Molecular Oncology and Immunology, Oncode Institute, Netherlands Cancer Institute, Amsterdam, The Netherlands. (2) Division of Molecular Oncology and Immunology, Oncode Institute, Netherlands Cancer Institute, Amsterdam, The Netherlands. (3) Division of Molecular Oncology and Immunology, Oncode Institute, Netherlands Cancer Institute, Amsterdam, The Netherlands. (4) Division of Tumor Biology and Immunology, Netherlands Cancer Institute, Amsterdam, The Netherlands. (5) Division of Molecular Oncology and Immunology, Oncode Institute, Netherlands Cancer Institute, Amsterdam, The Netherlands. (6) Division of Molecular Oncology and Immunology, Oncode Institute, Netherlands Cancer Institute, Amsterdam, The Netherlands. (7) Division of Molecular Oncology and Immunology, Oncode Institute, Netherlands Cancer Institute, Amsterdam, The Netherlands. (8) BioImaging Facility, Netherlands Cancer Institute, Amsterdam, The Netherlands. (9) BioImaging Facility, Netherlands Cancer Institute, Amsterdam, The Netherlands. (10) Division of Molecular Oncology and Immunology, Oncode Institute, Netherlands Cancer Institute, Amsterdam, The Netherlands. (11) Division of Molecular Oncology and Immunology, Oncode Institute, Netherlands Cancer Institute, Amsterdam, The Netherlands. (12) Division of Molecular Oncology and Immunology, Oncode Institute, Netherlands Cancer Institute, Amsterdam, The Netherlands. (13) Division of Molecular Oncology and Immunology, Oncode Institute, Netherlands Cancer Institute, Amsterdam, The Netherlands. (14) Division of Molecular Oncology and Immunology, Oncode Institute, Netherlands Cancer Institute, Amsterdam, The Netherlands. (15) Core Facility Molecular Pathology & Biobanking, Netherlands Cancer Institute, Amsterdam, The Netherlands. (16) Department of Pathology, Netherlands Cancer Institute, Amsterdam, The Netherlands. (17) Biostatistics Unit, Netherlands Cancer Institute, Amsterdam, The Netherlands. (18) Genomic Core Facility, Netherlands Cancer Institute, Amsterdam, The Netherlands. (19) Flow Cytometry Facility, Netherlands Cancer Institute, Amsterdam, The Netherlands. (20) Laboratory for Molecular Cancer Biology, Department of Oncology, VIB Center for Cancer Biology, KU Leuven, Leuven, Belgium. (21) Flow Cytometry Facility, Sanquin, Amsterdam, The Netherlands. (22) Flow Cytometry Facility, Sanquin, Amsterdam, The Netherlands. (23) Sahlgrenska Center for Cancer Research, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden. (24) Sahlgrenska Center for Cancer Research, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden. Harry Perkins Institute of Medical Research and University of Western Australia, Perth, Western Australia, Australia. (25) Sahlgrenska Center for Cancer Research, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden. Harry Perkins Institute of Medical Research and University of Western Australia, Perth, Western Australia, Australia. (26) Division of Molecular Oncology and Immunology, Oncode Institute, Netherlands Cancer Institute, Amsterdam, The Netherlands. (27) Department of Medical Oncology, Netherlands Cancer Institute, Amsterdam, The Netherlands. (28) Division of Molecular Oncology and Immunology, Oncode Institute, Netherlands Cancer Institute, Amsterdam, The Netherlands. d.peeper@nki.nl.
