ABSTRACT
Expansion of antigen-experienced CD8+ T cells is critical for the success of tumour-infiltrating lymphocyte (TIL)-adoptive cell therapy (ACT) in patients with cancer1. Interleukin-2 (IL-2) acts as a key regulator of CD8+ cytotoxic T lymphocyte functions by promoting expansion and cytotoxic capability2,3. Therefore, it is essential to comprehend mechanistic barriers to IL-2 sensing in the tumour microenvironment to implement strategies to reinvigorate IL-2 responsiveness and T cell antitumour responses. Here we report that prostaglandin E2 (PGE2), a known negative regulator of immune response in the tumour microenvironment4,5, is present at high concentrations in tumour tissue from patients and leads to impaired IL-2 sensing in human CD8+ TILs via the PGE2 receptors EP2 and EP4. Mechanistically, PGE2 inhibits IL-2 sensing in TILs by downregulating the IL-2Rγc chain, resulting in defective assembly of IL-2Rß-IL2Rγc membrane dimers. This results in impaired IL-2-mTOR adaptation and PGC1α transcriptional repression, causing oxidative stress and ferroptotic cell death in tumour-reactive TILs. Inhibition of PGE2 signalling to EP2 and EP4 during TIL expansion for ACT resulted in increased IL-2 sensing, leading to enhanced proliferation of tumour-reactive TILs and enhanced tumour control once the cells were transferred in vivo. Our study reveals fundamental features that underlie impairment of human TILs mediated by PGE2 in the tumour microenvironment. These findings have therapeutic implications for cancer immunotherapy and cell therapy, and enable the development of targeted strategies to enhance IL-2 sensing and amplify the IL-2 response in TILs, thereby promoting the expansion of effector T cells with enhanced therapeutic potential.
Subject(s)
CD8-Positive T-Lymphocytes , Cell Proliferation , Dinoprostone , Interleukin-2 , Lymphocytes, Tumor-Infiltrating , Mitochondria , Signal Transduction , Animals , Humans , Mice , CD8-Positive T-Lymphocytes/cytology , CD8-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/metabolism , Dinoprostone/metabolism , Down-Regulation , Ferroptosis , Interleukin Receptor Common gamma Subunit/biosynthesis , Interleukin Receptor Common gamma Subunit/deficiency , Interleukin Receptor Common gamma Subunit/metabolism , Interleukin-2/antagonists & inhibitors , Interleukin-2/immunology , Interleukin-2/metabolism , Interleukin-2 Receptor beta Subunit/metabolism , Lymphocytes, Tumor-Infiltrating/cytology , Lymphocytes, Tumor-Infiltrating/immunology , Lymphocytes, Tumor-Infiltrating/metabolism , Mitochondria/metabolism , Oxidative Stress , Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha/metabolism , Receptors, Prostaglandin E, EP2 Subtype/metabolism , Receptors, Prostaglandin E, EP2 Subtype/antagonists & inhibitors , Receptors, Prostaglandin E, EP4 Subtype/metabolism , Receptors, Prostaglandin E, EP4 Subtype/antagonists & inhibitors , TOR Serine-Threonine Kinases/metabolism , Tumor Microenvironment/immunologyABSTRACT
Ovarian cancer (OC) represents ecosystems of highly diverse tumor microenvironments (TMEs). The presence of tumor-infiltrating lymphocytes (TILs) is linked to enhanced immune responses and long-term survival. In this review we present emerging evidence suggesting that cellular crosstalk tightly regulates the distribution of TILs within the TME, underscoring the need to better understand key cellular networks that promote or impede T cell infiltration in OC. We also capture the emergent methodologies and computational techniques that enable the dissection of cell-cell crosstalk. Finally, we present innovative ex vivo TME models that can be leveraged to map and perturb cellular communications to enhance T cell infiltration and immune reactivity.