FLI1 promotes IFN-γ-induced kynurenine production to impair anti-tumor immunity (RNA-Seq)
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ABSTRACT: Nasopharyngeal carcinoma (NPC)-mediated immunosuppression within the tumor microenvironment (TME) frequently culminates in the failure of otherwise promising immunotherapies, underscoring the imperative to develop strategies to counteract the tumor's ability to foster an immunologically "cold" TME. In this study, we identify tumor-intrinsic FLI1 as a critical mediator in impairing T cell anti-tumor immunity through bioinformatic analysis. A mechanistic inquiry reveals that FLI1 orchestrates the expression of CBP and STAT1, facilitating chromatin accessibility and transcriptional activation of IDO1 in response to T cell-released IFN-γ. This regulatory cascade ultimately leads to augmented IDO1 expression, resulting in heightened synthesis of kynurenine (Kyn) in tumor cells. This, in turn, fosters CD8+ T cell exhaustion and regulatory T cell (Treg) differentiation, a process that redounds to the advantage of tumor cell survival.
Project description:Nasopharyngeal carcinoma (NPC)-mediated immunosuppression within the tumor microenvironment (TME) frequently culminates in the failure of otherwise promising immunotherapies, underscoring the imperative to develop strategies to counteract the tumor's ability to foster an immunologically "cold" TME. In this study, we identify tumor-intrinsic FLI1 as a critical mediator in impairing T cell anti-tumor immunity through bioinformatic analysis. A mechanistic inquiry reveals that FLI1 orchestrates the expression of CBP and STAT1, facilitating chromatin accessibility and transcriptional activation of IDO1 in response to T cell-released IFN-γ. This regulatory cascade ultimately leads to augmented IDO1 expression, resulting in heightened synthesis of kynurenine (Kyn) in tumor cells. This, in turn, fosters CD8+ T cell exhaustion and regulatory T cell (Treg) differentiation, a process that redounds to the advantage of tumor cell survival.
Project description:Nasopharyngeal carcinoma (NPC)-mediated immunosuppression within the tumor microenvironment (TME) frequently culminates in the failure of otherwise promising immunotherapies, underscoring the imperative to develop strategies to counteract the tumor's ability to foster an immunologically "cold" TME. In this study, we identify tumor-intrinsic FLI1 as a critical mediator in impairing T cell anti-tumor immunity through bioinformatic analysis. A mechanistic inquiry reveals that FLI1 orchestrates the expression of CBP and STAT1, facilitating chromatin accessibility and transcriptional activation of IDO1 in response to T cell-released IFN-γ. This regulatory cascade ultimately leads to augmented IDO1 expression, resulting in heightened synthesis of kynurenine (Kyn) in tumor cells. This, in turn, fosters CD8+ T cell exhaustion and regulatory T cell (Treg) differentiation, a process that redounds to the advantage of tumor cell survival.
Project description:Metabolic deregulation and immune escape are pivotal hallmarks of cancer; however, the profile of metabolic reprogramming in oral squamous cell carcinoma (OSCC) and how it drives immune escape remain unclear. We identified significant metabolic disorders in OSCC. Amino acid metabolism, especially tryptophan/kynurenine metabolism, was altered. Here, we found that kynurenine promotes migration, invasion, and proliferation in vitro and in vivo. In addition, most immune checkpoints were upregulated in patients with high kynurenine levels. We then identified that kynurenine can promote Siglec-15 expression via AhR activation. Furthermore, tumor-derived kynurenine can directly exhaust CD8+ T cells, whereas blocking of kynurenine transporters reversed this effect. Moreover, we found that ectopic expression of Siglec-15 can promote immune escape in tumor microenvironment (TME) by suppressing T cell infiltration and inducing CD8+ T cell exhaustion in vivo, while targeting AhR reduces kynurenine-mediated immune escape. Finally, we design NH2-MSNs nanoparticles to deliver Siglec-15 small interfering RNA, which successfully remodels the TME and enhances anti-PD-1 efficacy in tumor-bearing immunocompetent mice. Clinically, Siglec-15 expression is correlated with AhR expression and high infiltration of exhausted CD8+ T cells. These findings reveal that the Kyn/AhR/Siglec-15 signaling pathway is a novel immunometabolism mechanism in OSCC, thus opening a new therapeutic avenue for metabolic immunotherapy.
Project description:Abnormally elevated plasma kynurenine (Kyn) was detected in the patient cohort and single nuclues sequecing revealed its molecular role
Project description:We report the gene expression (obtained by next generation RNAseq) of inducible CD103+ dendritic cells, iCD103 cells, stimulated with both murine herpesvirus-68 and the immunomodulatory tryptophan derivative kynurenine (kyn). This study provides data on how tryptophan derivatives can modulate pro-inflammatory cytokine expression in virus treated dendritic cells.
Project description:<p><strong>OBJECTIVES:</strong> High activity of Indoleamine 2,3-dioxygenase1 (IDO1) in lung cancer patients converts tryptophan (Trp), which is the essential amino acid for T cell metabolism, to kynurenine (Kyn) and consequently suppresses anti-tumor immune responses. We aimed to track the dynamics of IDO1 activity in stage III non-small cell lung cancer (NSCLC) patients who received first-line radiotherapy (RT) and explore its association with survival outcomes.</p><p><strong>MATERIALS AND METHODS:</strong> Systemic IDO1 activity was calculated by Kyn:Trp ratio. Plasma levels of Kyn and Trp in 113 thoracic RT-received stage III NSCLC patients were measured by high-performance liquid chromatography before the initiation of RT. Dynamic change of IDO1 activity was followed in 24 patients by measuring Kyn:Trp ratio before, during and after RT administration.</p><p><strong>RESULTS:</strong> In 24 patients with dynamic tracking of plasma IDO1 activity, there was no significant alterations observed among the 3 time points (Friedman test, p=0.13). The changing pattern of Kyn:Trp ratio was divided into 4 groups: decreased consistently during RT, first increased then decreased, increased consistently, first decreased then increased. Patients whose Kyn:Trp ratio kept decreasing or first increased then decreased were defined as good-change group. The good-change status was identified as an independent positive factor for overall survival (OS) and progression-free survival (PFS) (p=0.04; p=0.01) in multivariate analysis among evaluated parameters. Patients with good change showed significantly superior local control than bad-change group (p=0.01, HR=0.22). In 113 stage III NSCLC patients with pre-radiation Kyn:Trp ratio, a trend that high baseline IDO1 activity was associated with short OS was observed (p=0.079).</p><p><strong>CONCLUSION: </strong>Favorable change of IDO1 activity during RT was associated with superior OS, PFS and local control. IDO1 activity is a promising biomarker for prognosis in stage III NSCLC patients.</p>
Project description:Kynurenine is generated from tryptophan by indoleamine 2,3-dioxygenase (IDO1) and binds to the aryl hydrocarbon receptor (AhR). We found that kynurenine generated by human embryonic stem cells (hESCs) and induced pluripotent stem cells (iPSCs) stimulated the AhR to bind selectively to the promoters and enhancers of self-renewal genes, thus enhancing their transcription. The kynurenine-AhR complex also directly stimulated the expression of IDO1 and AHR, activating a positive feedback loop. Substantial amounts of kynurenine that were not complexed with AhR were present in the culture medium, providing a paracrine signal for maintenance of the undifferentiated state. Kynurenine was not present in the medium of differentiated ESCs and iPSCs. When cells were induced to undergo ectodermal differentiation, the abundance of kynurenine in the medium was reduced through activation of the main kynurenine catabolic pathway mediated by aminotransferase 2 (KAT2), resulting in the secretion of 2-aminoadipic acid (2-AAA) into the culture medium. Thus, kynurenine in the culture medium is a biomarker for the undifferentiated state, and 2-AAA in the culture medium is a biomarker for ESCs and iPSCs that have committed to differentiate along the ectoderm lineage.
Project description:Impaired cerebral glucose metabolism is a pathologic feature of Alzheimer Disease (AD), and recent proteomic studies highlight a disruption of glial carbohydrate metabolism with disease progression. Here, we report that inhibition of indoleamine-2,3-dioxygenase 1 (IDO1), which metabolizes tryptophan to kynurenine (KYN) in the first step of the kynurenine pathway, rescues hippocampal memory function and plasticity in preclinical models of amyloid and tau pathology by restoring astrocytic metabolic support of neurons. Activation of IDO1 in astrocytes by amyloid-beta42 and tau oligomers, two major pathological effectors in AD, increases KYN and suppresses glycolysis in an AhR-dependent manner. Conversely, pharmacological IDO1 inhibition restores glycolysis and lactate production. In amyloid-producing APPSwe-PS1∆E9 and 5XFAD mice and in tau-producing P301S mice, IDO1 inhibition restores spatial memory and improves hippocampal glucose metabolism by metabolomic and MALDI-MS analyses. IDO1 blockade also rescues hippocampal long-term potentiation (LTP) in a monocarboxylate transporter (MCT)-dependent manner, suggesting that IDO1 activity disrupts astrocytic metabolic support of neurons. Indeed, in vitro mass-labeling of human astrocytes demonstrates that IDO1 regulates astrocyte generation of lactate that is then taken up by human neurons. In co-cultures of astrocytes and neurons derived from AD subjects, deficient astrocyte lactate transfer to neurons was corrected by IDO1 inhibition, resulting in improved neuronal glucose metabolism. Thus, IDO1 activity disrupts astrocytic metabolic support of neurons across both amyloid and tau pathologies and in a model of AD iPSC-derived neurons. These findings also suggest that IDO1 inhibitors developed for adjunctive therapy in cancer could be repurposed for treatment of amyloid- and tau-mediated neurodegenerative diseases.
Project description:The interferon-inducible transcription factor STAT1 is a tumor suppressor in various malignancies. We investigated STAT1 functions in intestinal tumorigenesis of ApcMin mice. Surprisingly, loss of STAT1 in intestinal epithelial cells (STAT1ΔIEC) interfered with ApcMin induced intestinal tumor formation and tumor progression. RNASeq data demonstrated reduced expression of Indoleamine-2,3-dioxygenase-1 (IDO1) in STAT1ΔIEC ApcMin tumors. IDO1 is implicated in synthesis of kynurenine, a metabolite that induces ß-Catenin nuclear localisation and suppresses anti-tumor immune responses.
Project description:Transcriptome analysis of U87 cells under different treatments to identify IDO1-regulated genes Indoleamine 2, 3-dioxygenase 1 (IDO1) is a tryptophan (Trp) catabolic enzyme that converts Trp into downstream kynurinine (Kyn). Many studies have indicated that IDO1 is a critical suppressive immune checkpoint molecule invovled in various types of cancer. Canonically, the underlying mechanism of IDO1 immunosuppressive role is related with its enzyme activity, that is the depletion of Trp and accumulation of Kyn lead to increased tumor infiltrating suppressive regulatory T cells. Recent studies, however, challenged this hypothesis and imply that tumor cell-derived IDO1 can mediate immunosuppression independent of its enzyme activity. In this study, we aim to identify genes that are regulated by IDO1 in human glioblastoma cells, a gene expression regulatory function of IDO1 that is indepent of its enzyme activity.