1. Cancer cells impair monocyte-mediated T cell stimulation to evade immunity
- Author
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Elewaut, Anais, Estivill, Guillem, Bayerl, Felix, Castillon, Leticia, Novatchkova, Maria, Pottendorfer, Elisabeth, Hoffmann-Haas, Lisa, Schönlein, Martin, Nguyen, Trung Viet, Lauss, Martin, Andreatta, Francesco, Vulin, Milica, Krecioch, Izabela, Bayerl, Jonas, Pedde, Anna-Marie, Fabre, Naomi, Holstein, Felix, Cronin, Shona M., Rieser, Sarah, Laniti, Denarda Dangaj, Barras, David, Coukos, George, Quek, Camelia, Bai, Xinyu, Muñoz i Ordoño, Miquel, Wiesner, Thomas, Zuber, Johannes, Jönsson, Göran, Böttcher, Jan P., Vanharanta, Sakari, and Obenauf, Anna C.
- Abstract
The tumour microenvironment is programmed by cancer cells and substantially influences anti-tumour immune responses1,2. Within the tumour microenvironment, CD8+T cells undergo full effector differentiation and acquire cytotoxic anti-tumour functions in specialized niches3, 4, 5, 6–7. Although interactions with type 1 conventional dendritic cells have been implicated in this process3, 4–5,8, 9–10, the underlying cellular players and molecular mechanisms remain incompletely understood. Here we show that inflammatory monocytes can adopt a pivotal role in intratumoral T cell stimulation. These cells express Cxcl9, Cxcl10and Il15, but in contrast to type 1 conventional dendritic cells, which cross-present antigens, inflammatory monocytes obtain and present peptide–major histocompatibility complex class I complexes from tumour cells through ‘cross-dressing’. Hyperactivation of MAPK signalling in cancer cells hampers this process by coordinately blunting the production of type I interferon (IFN-I) cytokines and inducing the secretion of prostaglandin E2(PGE2), which impairs the inflammatory monocyte state and intratumoral T cell stimulation. Enhancing IFN-I cytokine production and blocking PGE2secretion restores this process and re-sensitizes tumours to T cell-mediated immunity. Together, our work uncovers a central role of inflammatory monocytes in intratumoral T cell stimulation, elucidates how oncogenic signalling disrupts T cell responses through counter-regulation of PGE2and IFN-I, and proposes rational combination therapies to enhance immunotherapies.
- Published
- 2025
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