Identification of a Variable Number of Tandem Repeats Polymorphism and Characterization of LEF-1 Response Elements in the Promoter of the IDO1 Gene

Indoleamine 2,3-dioxygenase (IDO) catalyzes the first and rate-limiting step of the kynurenine pathway that is an important component of immunomodulatory and neuromodulatory processes. The IDO1 gene is highly inducible by IFN-γ and TNF-α through interaction with cis-acting regulatory elements of the promoter region. Accordingly, functional polymorphisms in the IDO1 promoter could partly explain the interindividual variability in IDO expression that has been previously documented.A PCR-sequencing strategy, applied to DNA samples from healthy Caucasians, allowed us to identify a VNTR polymorphism in the IDO1 promoter, which correlates significantly with serum tryptophan concentration, controlled partially by IDO activity, in female subjects, but not in males. Although this VNTR does not appear to affect basal or cytokine-induced promoter activity in gene reporter assays, it contains novel cis-acting elements. Three putative LEF-1 binding sites, one being located within the VNTR repeat motif, were predicted in silico and confirmed by chromatin immunoprecipitation. Overexpression of LEF-1 in luciferase assays confirmed an interaction between LEF-1 and the predicted transcription factor binding sites, and modification of the LEF-1 core sequence within the VNTR repeat motif, by site-directed mutagenesis, resulted in an increase in promoter activity.The identification of a VNTR in the IDO1 promoter revealed a cis-acting element interacting with the most downstream factor of the Wnt signaling pathway, suggesting novel mechanisms of regulation of IDO1 expression. These data offer new insights, and suggest further studies, into the role of IDO in various pathological conditions, particularly in cancer where IDO and the Wnt pathway are strongly dysregulated

Immune monitoring in melanoma and urothelial cancer patients treated with anti-PD-1 immunotherapy and SBRT discloses tumor specific immune signatures

Background: Blockade of the PD-1/PD-L1 pathway has revolutionized the oncology field in the last decade. However, the proportion of patients experiencing a durable response is still limited. In the current study, we performed an extensive immune monitoring in patients with stage III/IV melanoma and stage IV UC who received anti-PD-1 immunotherapy with SBRT. (2) Methods: In total 145 blood samples from 38 patients, collected at fixed time points before and during treatment, were phenotyped via high-parameter flow cytometry, luminex assay and UPLC-MS/MS. (3) Results: Baseline systemic immunity in melanoma and UC patients was different with a more prominent myeloid compartment and a higher neutrophil to lymphocyte ratio in UC. Proliferation (Ki67+) of CD8+ T-cells and of the PD-1+/PD-L1+ CD8+ subset at baseline correlated with progression free survival in melanoma. In contrast a higher frequency of PD-1/PD-L1 expressing non-proliferating (Ki67−) CD8+ and CD4+ T-cells before treatment was associated with worse outcome in melanoma. In UC, the expansion of Ki67+ CD8+ T-cells and of the PD-L1+ subset relative to tumor burden correlated with clinical outcome. (4) Conclusion: This study reveals a clearly different immune landscape in melanoma and UC at baseline, which may impact immunotherapy response. Signatures of proliferation in the CD8+ T-cell compartment prior to and early after anti-PD-1 initiation were positively correlated with clinical outcome in both cohorts. PD-1/PD-L1 expression on circulating immune cell subsets seems of clinical relevance in the melanoma cohort

aImplication du gène de l'indoleamine 2,3-dioxygénase (IDO1) dans les troubles comportementaux induits par l'interféron-a

L indoleamine 2,3-dioxygénase (IDO) catalyse la première étape limitante de la voie dite des kynurénines , qui est en compétition directe avec la voie de la sérotonine pour l utilisation dutryptophane. IDO est décrit comme étant un acteur important des phénomènes de neuromodulation et d immunorégulation. Des hypothèses avancées suggèrent que des variations d expression d IDO1 puissent s associer à un risque d apparition de maladies neuropsychiatriques (dont le syndrome dépressif), via une diminution de sérotonine d une part, et l augmentation de dérivés kynuréniques potentiellement neurotoxiques d autre part. L activité d IDO est fortement induite par l IFNg et l immunothérapie par IFNa entraîne le développement d effets indésirables d ordre neuropsychiatrique chez environ 30 % des patients traités. Nous émettons ainsi l hypothèse que des variations d expression et/ou d activité de l enzyme IDO, d origine génétique, puissent être impliquées dans la survenue de ces effets indésirables. Un polymorphisme de répétition du type VNTR ayant été identifié dans le promoteur d IDO1, un génotypage et un phénotypage d IDO ont étéréalisés chez 26 patients traités par l IFNa dans le cadre d une hépatite C, et ayant développé ou non des troubles neurocomportementaux pendant leur traitement. Cette approche in vivo a été complétée par une analyse fonctionnelle in vitro du VNTR, et par l étude de l effet de l IFNa sur l expression d IDO1 dans une lignée cellulaire humaine.LILLE2-BU Santé-Recherche (593502101) / SudocSudocFranceF

Development and validation of a GC-MS/MS method for the determination of ethylglucuronide in human urine and serum

Objectives: Ethyl-β-D-6-glucuronide (EtG) is a minor phase-II metabolite of ethanol. The aim of this work was to develop and validate a gas chromatography negative chemical ionization tandem mass spectrometry (GC-NCI-MS/MS) method to measure EtG levels in human urine and serum with both high sensitivity and specificity. Methods: EtG was extracted and purified from 1 mL urine or 0.5 mL serum by solid-phase extraction (SPE) using Mixed-mode Anion-eXchange (Oasis®MAX) extraction cartridges, followed by derivatization with pentafluoropropionic anhydride (PFPA). The analysis was performed in the multiple reaction monitoring (MRM) mode using the transitions m/z 496→163 (for EtG quantification), m/z 347→163 and m/z 496→119 (for identification), and m/z 501→163 for the internal standard EtG-D5. The validation procedure was performed according to the guidelines of the French Society of Analytical Toxicology (SFTA) and the French Committee of Accreditation (COFRAC; LAB GTA 04). Results: Calibration curves were linear in the concentration range of 10 to 10 000 ng/mL and 5 to 1 000 ng/mL in urine and serum, respectively, with a coefficient of correlation (r) above 0.996. The LOD and LOQ values were 5 and 10 ng/mL, respectively, for both matrices. The intra- and inter-day precision (relative standard deviation RSD%) and relative bias were less than 20%. Conclusion: To our knowledge, this is the first report of the application of a GC-MS/MS method for EtG measurement in urine and serum. The LOQ achieved appears to be better than those reported in the literature using other validated analytical techniques. This method could be used routinely for EtG measurement in various clinical and forensic contexts

Life-threatening irinotecan-induced toxicity in an adult patient with alveolar rhabdomyosarcoma: the role of a ugt1a1 polymorphism

International audienceAlveolar rhabdomyosarcoma (AR) in adult patients is an exceptional malignancy. Management of AR is based on (neo)adjuvant chemotherapy combining ifosfamide, vincristine, and actinomycin D and local curative-intent surgery/radiotherapy. In cases of relapsing AR, the combination of temozolomide/irinotecan is regarded as a possible option. Here we describe life-threatening long-lasting toxicity related to the 1st cycle of irinotecan-based chemotherapy in a 56-year-old woman suffering from locally advanced and metastatic head and neck AR. The patient experienced grade 4 vomiting and diarrheas resulting in acute functional renal failure, associated with grade 4 neutropenia complicated by severe septic shock. The hospital stay duration was 40 days. The analysis of the uridine diphosphate glucuronosyltransferase 1A1 (UGT1A1) gene revealed homozygous UGT1A1 ⁎

Hypoglycémie sévère et arrêt cardiorespiratoire attribués au tramadol – à propos d’un cas

International audienc

Induction of TDO2 and IDO2 in Liver by High-Fat Feeding in Mice: Discrepancies with Human Obesity

Low-grade and chronic inflammation is elicited in white adipose tissue in human obesity. The presence of inflammatory molecules leads to an increased tryptophan catabolism through the induction of indoleamine-2,3-dioxygenase-1 (IDO1). In order to characterize the mechanisms underlying this dysregulation, we have studied 2 mouse models of obesity. Unexpectedly, we did not detect any IDO1 expression in obese or lean mice adipose tissue. In a previous study, we did not find any significant difference in the liver for IDO2 and tryptophan-2,3-dioxygenase (TDO2) gene expression between normal weight and obese patients. IDO2 and TDO2 expression was increased in the liver of high-fat fed mice, but not in ob/ob mice, and was strongly correlated with hydroxysteroid-(11-beta) dehydrogenase-1 (HSD11B1) expression, an enzyme that generates active cortisol within tissues. In conclusion, despite a dysregulation of tryptophan metabolism, obese mice display discrepancies with human obesity metabolism, rendering them inappropriate for further investigations in this animal model

Risk factors associated to tobacco and alcohol use in a large French cohort of pregnant women

International audienc

Prévalence et déterminants de la malnutrition des enfants âgés de moins de 5 ans dans le quartier Bongonga de Lubumbashi

info:eu-repo/semantics/publishe

Using unusual drug-drug interactions to maximize voriconazole treatment efficacy.

International audienc