RESUMO
Genome-wide association studies have identified risk loci associated with the development of inflammatory bowel disease, while epidemiological studies have emphasized that pathogenesis likely involves host interactions with environmental elements whose source and structure need to be defined. Here, we identify a class of compounds derived from dietary, microbial, and industrial sources that are characterized by the presence of a five-membered oxazole ring and induce CD1d-dependent intestinal inflammation. We observe that minimal oxazole structures modulate natural killer T cell-dependent inflammation by regulating lipid antigen presentation by CD1d on intestinal epithelial cells (IECs). CD1d-restricted production of interleukin 10 by IECs is limited through activity of the aryl hydrocarbon receptor (AhR) pathway in response to oxazole induction of tryptophan metabolites. As such, the depletion of the AhR in the intestinal epithelium abrogates oxazole-induced inflammation. In summary, we identify environmentally derived oxazoles as triggers of CD1d-dependent intestinal inflammatory responses that occur via activation of the AhR in the intestinal epithelium.
Assuntos
Colite/patologia , Dieta , Intestinos/patologia , Oxazóis/farmacologia , Receptores de Hidrocarboneto Arílico/metabolismo , Transdução de Sinais/efeitos dos fármacos , Animais , Antígenos CD1d/genética , Antígenos CD1d/metabolismo , Colite/induzido quimicamente , Colite/metabolismo , Modelos Animais de Doenças , Células Epiteliais/citologia , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Interleucina-10/metabolismo , Intestinos/citologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Células T Matadoras Naturais/imunologia , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Receptores de Hidrocarboneto Arílico/antagonistas & inibidores , Receptores de Hidrocarboneto Arílico/genética , Triptofano/metabolismoRESUMO
Monocytic-lineage inflammatory Ly6c+CD103+ dendritic cells (DCs) promote antitumor immunity, but these DCs are infrequent in tumors, even upon chemotherapy. Here, we examined how targeting pathways that inhibit the differentiation of inflammatory myeloid cells affect antitumor immunity. Pharmacologic inhibition of Bruton's tyrosine kinase (BTK) and the tryptophan-degrading enzyme indoleamine 2,3-dioxygenase (IDO) or deletion of Btk or Ido1 allowed robust differentiation of inflammatory Ly6c+CD103+ DCs during chemotherapy, promoting antitumor T cell responses and inhibiting tumor growth. Immature Ly6c+c-kit+ precursor cells had epigenetic profiles similar to conventional DC precursors; deletion of Btk or Ido1 promoted differentiation of these cells. Mechanistically, a BTK-IDO axis inhibited a tryptophan-sensitive differentiation pathway driven by GATOR2 and mTORC1, and disruption of the GATOR2 in monocyte-lineage precursors prevented differentiation into inflammatory DCs in vivo. IDO-expressing DCs and monocytic cells were present across a range of human tumors. Thus, a BTK-IDO axis represses differentiation of inflammatory DCs during chemotherapy, with implications for targeted therapies.
Assuntos
Diferenciação Celular/imunologia , Células Dendríticas/imunologia , Neoplasias/imunologia , Linfócitos T/imunologia , Tirosina Quinase da Agamaglobulinemia/imunologia , Tirosina Quinase da Agamaglobulinemia/metabolismo , Animais , Células Dendríticas/citologia , Células Dendríticas/metabolismo , Feminino , Humanos , Indolamina-Pirrol 2,3,-Dioxigenase/imunologia , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Masculino , Camundongos , Monócitos/citologia , Monócitos/imunologia , Monócitos/metabolismo , Transdução de Sinais/imunologia , Linfócitos T/metabolismo , Serina-Treonina Quinases TOR/imunologia , Serina-Treonina Quinases TOR/metabolismoRESUMO
Despite recent advances, many cancers remain refractory to available immunotherapeutic strategies. Emerging evidence indicates that the tolerization of local dendritic cells (DCs) within the tumor microenvironment promotes immune evasion. Here, we have described a mechanism by which melanomas establish a site of immune privilege via a paracrine Wnt5a-ß-catenin-peroxisome proliferator-activated receptor-γ (PPAR-γ) signaling pathway that drives fatty acid oxidation (FAO) in DCs by upregulating the expression of the carnitine palmitoyltransferase-1A (CPT1A) fatty acid transporter. This FAO shift increased the protoporphyrin IX prosthetic group of indoleamine 2,3-dioxgenase-1 (IDO) while suppressing interleukin(IL)-6 and IL-12 cytokine expression, culminating in enhanced IDO activity and the generation of regulatory T cells. We demonstrated that blockade of this pathway augmented anti-melanoma immunity, enhanced the activity of anti-PD-1 antibody immunotherapy, and suppressed disease progression in a transgenic melanoma model. This work implicates a role for tumor-mediated metabolic reprogramming of local DCs in immune evasion and immunotherapy resistance.
Assuntos
Células Dendríticas/metabolismo , Melanoma/imunologia , Proteína Wnt-5a/metabolismo , beta Catenina/metabolismo , Animais , Linhagem Celular , Células Dendríticas/imunologia , Ensaio de Imunoadsorção Enzimática , Ácidos Graxos/metabolismo , Feminino , Citometria de Fluxo , Immunoblotting , Masculino , Melanoma/metabolismo , Camundongos , Camundongos Transgênicos , PPAR gama/metabolismo , Comunicação Parácrina/fisiologia , Reação em Cadeia da Polimerase , Transdução de Sinais/fisiologiaRESUMO
Tryptophan metabolism plays a crucial role in facilitating various cellular processes essential for maintaining normal cellular function. Indoleamine 2,3-dioxygenase 1 (IDO1) catalyzes the conversion of tryptophan (Trp) into kynurenine (Kyn), thereby initiating the degradation of Trp. The resulting Kyn metabolites have been implicated in the modulation of immune responses. Currently, the role of IDO1-mediated tryptophan metabolism in the process of viral infection remains relatively unknown. In this study, we discovered that classical swine fever virus (CSFV) infection of PK-15 cells can induce the expression of IDO1, thereby promoting tryptophan metabolism. IDO1 can negatively regulate the NF-κB signaling by mediating tryptophan metabolism, thereby facilitating CSFV replication. We found that silencing the IDO1 gene enhances the expression of IFN-α, IFN-ß, and IL-6 by activating the NF-κB signaling pathway. Furthermore, our observations indicate that both silencing the IDO1 gene and administering exogenous tryptophan can inhibit CSFV replication by counteracting the cellular autophagy induced by Rapamycin. This study reveals a novel mechanism of IDO1-mediated tryptophan metabolism in CSFV infection, providing new insights and a theoretical basis for the treatment and control of CSFV.IMPORTANCEIt is well known that due to the widespread use of vaccines, the prevalence of classical swine fever (CSF) is shifting towards atypical and invisible infections. CSF can disrupt host metabolism, leading to persistent immune suppression in the host and causing significant harm when co-infected with other diseases. Changes in the host's metabolic profiles, such as increased catabolic metabolism of amino acids and the production of immunoregulatory metabolites and their derivatives, can also influence virus replication. Mammals utilize various pathways to modulate immune responses through amino acid utilization, including increased catabolic metabolism of amino acids and the production of immunoregulatory metabolites and their derivatives, thereby limiting viral replication. Therefore, this study proposes that targeting the modulation of tryptophan metabolism may represent an effective approach to control the progression of CSF.
Assuntos
Vírus da Febre Suína Clássica , Indolamina-Pirrol 2,3,-Dioxigenase , NF-kappa B , Transdução de Sinais , Triptofano , Replicação Viral , Triptofano/metabolismo , Animais , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Indolamina-Pirrol 2,3,-Dioxigenase/genética , NF-kappa B/metabolismo , Suínos , Vírus da Febre Suína Clássica/fisiologia , Linhagem Celular , Cinurenina/metabolismo , Peste Suína Clássica/virologia , Peste Suína Clássica/metabolismo , AutofagiaRESUMO
Tryptophan catabolism plays an important role in the metabolic reconnection in cancer cells to support special demands of tumor initiation and progression. The catabolic product of the tryptophan pathway, kynurenine, has the capability of suppressing the immune reactions of tumor cells. In this study, we conducted internal and external cohort studies to reveal the importance of tryptophan 2,3-dioxygenase (TDO) for lung adenocarcinoma (LUAD). Our study further demonstrated that the TDO2 expression was associated with the proliferation, survival, and invasion of LUAD cells, and targeting TDO2 for LUAD tumors could be a potential therapeutic strategy.
Assuntos
Adenocarcinoma de Pulmão , Neoplasias Pulmonares , Humanos , Triptofano Oxigenase/genética , Triptofano Oxigenase/metabolismo , Triptofano/metabolismo , Cinurenina/metabolismo , Adenocarcinoma de Pulmão/genética , Neoplasias Pulmonares/genéticaRESUMO
Indoleamine 2,3-dioxygenase (IDO) plays important roles in maternal immune tolerance. Female Sprague Dawley rats (9-11 weeks old) were randomly divided into an autoplastic transplantation group (n = 75) and an allograft transplantation group (n = 300) was further divided into subgroups of ovarian transplantation, allograft ovarian transplantation, allograft ovarian transplantation with cyclosporine A treatment, allograft ovarian transplantation and transfection with IDO-expressing lentiviruses, and allograft ovarian transplantation and transfection with control lentiviruses. IDO was successfully transfected into the transplanted ovarian tissue. The survival rate, success rate of ovarian transplantation, period until estrous cycle restoration, and estrogen levels of rats that received IDO-expressing lentiviruses were significantly different from those of rats that underwent allograft transplantation and with control transfection (all P < 0.05), but not significantly different from those rats that received autoplastic transplantation (all P > 0.05). The number of ovarian follicles in the transplanted ovarian tissue of rats that received IDO-expressing lentiviruses was also significantly higher. The expression level of IDO protein detected by immunohistochemistry and western blotting was especially high in ovaries that had received IDO-containing lentiviruses. Naturally pregnant rats were found in each group postoperatively. These results indicated that IDO-expressing lentiviruses were successfully transfected into transplanted ovarian tissues of rats and that IDO was stably expressed within a certain time. These findings suggest that the expression level of IDO protein is associated with an enhanced success rate of ovarian tissue transplantation and a short restoration period of endocrine function.
Assuntos
Rejeição de Enxerto , Indolamina-Pirrol 2,3,-Dioxigenase , Ovário , Ratos Sprague-Dawley , Animais , Feminino , Indolamina-Pirrol 2,3,-Dioxigenase/genética , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Ovário/transplante , Ovário/metabolismo , Ratos , Rejeição de Enxerto/prevenção & controle , Rejeição de Enxerto/genética , Gravidez , Lentivirus/genética , Transplante HomólogoRESUMO
The L-tryptophan (Trp) transport system is highly selective for Trp with affinity in the nanomolar range. This transport system is augmented in human interferon (IFN)-γ-treated and indoleamine 2,3-dioxygenase 1 (IDO1)-expressing cells. Up-regulated cellular uptake of Trp causes a reduction in extracellular Trp and initiates immune suppression. Recent studies demonstrate that both IDO1 and tryptophanyl-tRNA synthetase (TrpRS), whose expression levels are up-regulated by IFN-γ, play a pivotal role in high-affinity Trp uptake into human cells. Furthermore, overexpression of tryptophan 2,3-dioxygenase (TDO2) elicits a similar effect as IDO1 on TrpRS-mediated high-affinity Trp uptake. In this review, we summarize recent findings regarding this Trp uptake system and put forward a possible molecular mechanism based on Trp deficiency induced by IDO1 or TDO2 and tryptophanyl-AMP production by TrpRS.
Assuntos
Indolamina-Pirrol 2,3,-Dioxigenase , Triptofano-tRNA Ligase , Triptofano , Humanos , Triptofano/metabolismo , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Triptofano-tRNA Ligase/metabolismo , Transporte Biológico , Triptofano Oxigenase/metabolismo , Interferon gama/metabolismoRESUMO
Interferons (IFNs) are critical for immune defense against pathogens. While type-I and -III IFNs have been reported to inhibit SARS-CoV-2 replication, the antiviral effect and mechanism of type-II IFN against SARS-CoV-2 remain largely unknown. Here, we evaluate the antiviral activity of type-II IFN (IFNγ) using human lung epithelial cells (Calu3) and ex vivo human lung tissues. In this study, we found that IFNγ suppresses SARS-CoV-2 replication in both Calu3 cells and ex vivo human lung tissues. Moreover, IFNγ treatment does not significantly modulate the expression of SARS-CoV-2 entry-related factors and induces a similar level of pro-inflammatory response in human lung tissues when compared with IFNß treatment. Mechanistically, we show that overexpression of indoleamine 2,3-dioxygenase 1 (IDO1), which is most profoundly induced by IFNγ, substantially restricts the replication of ancestral SARS-CoV-2 and the Alpha and Delta variants. Meanwhile, loss-of-function study reveals that IDO1 knockdown restores SARS-CoV-2 replication restricted by IFNγ in Calu3 cells. We further found that the treatment of l-tryptophan, a substrate of IDO1, partially rescues the IFNγ-mediated inhibitory effect on SARS-CoV-2 replication in both Calu3 cells and ex vivo human lung tissues. Collectively, these results suggest that type-II IFN potently inhibits SARS-CoV-2 replication through IDO1-mediated antiviral response.
Assuntos
COVID-19 , SARS-CoV-2 , Humanos , SARS-CoV-2/metabolismo , Indolamina-Pirrol 2,3,-Dioxigenase/genética , Replicação Viral , Pulmão , Interferons , Células Epiteliais , Antivirais/farmacologiaRESUMO
BACKGROUND: Indoleamine-2,3-dioxygenase (IDO) helps orchestrate immune suppression and checkpoint inhibitor resistance in hepatocellular carcinoma (HCC). BMS-986,205 is a novel oral drug that potently and selectively inhibits IDO. This Phase I/II study evaluated the safety and tolerability of BMS-986,205 in combination with nivolumab as first-line therapy in advanced HCC. METHODS: Adults with untreated, unresectable/metastatic HCC received BMS-986,205 at two dose levels (50-100 mg orally daily) in combination with fixed dose nivolumab (240mg/m2 IV on Day 1 of each 14-day cycle). The primary objective was to determine the safety and tolerability of this combination; secondary objectives were to obtain preliminary efficacy. RESULTS: Eight patients received a total of 91 treatment cycles in the dose escalation phase. All patients were Child Pugh A and 6 patients had underlying viral hepatitis. In the 6 evaluable patients, no dose-limiting toxicities (DLTs) were observed. The most common treatment-related adverse events (TRAEs) were aspartate transaminase (AST) and alanine transaminase (ALT) elevation (3 patients) and diarrhea, maculopapular rash and increased alkaline phosphatase (2 patients each). Grade 3 events were diarrhea and AST elevation (1 patient), and hyperglycemia and pancreatitis requiring treatment discontinuation (1 patient). No grade 4-5 events occurred. Partial response was observed in 1 patient (12.5%) and stable disease in 3 patients (37.5%), yielding a disease control rate of 50%. Median PFS was 8.5 weeks; median OS was not reached. CONCLUSION: Combination BMS-986,205 and nivolumab showed a manageable safety profile with durable benefit as first-line therapy in a meaningful subset of advanced HCC patients.
Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Adulto , Humanos , Alanina Transaminase , Aspartato Aminotransferases , Carcinoma Hepatocelular/tratamento farmacológico , Diarreia , Neoplasias Hepáticas/tratamento farmacológico , Nivolumabe/efeitos adversos , Nivolumabe/uso terapêuticoRESUMO
BACKGROUND: Pembrolizumab plus epacadostat (indoleamine 2,3-dioxygenase-1 inhibitor) was well tolerated in Japanese patients with advanced solid tumors in part A of the nonrandomized, open-label, phase 1 KEYNOTE-434 study (NCT02862457). We report results from part B, which evaluated epacadostat plus pembrolizumab and chemotherapy in Japanese patients with advanced non-small-cell lung cancer (NSCLC). METHODS: Eligible patients aged ≥ 20 years had histologically or cytologically confirmed stage IIIB or IV NSCLC with no prior systemic therapy, and ECOG performance status of 0 or 1. Patients received epacadostat 100 mg orally twice-daily, pembrolizumab 200 mg intravenously every-3-weeks for ≤ 35 cycles, and 4 cycles of chemotherapy (cohort 1: cisplatin plus pemetrexed, non-squamous; cohort 2: carboplatin plus pemetrexed, non-squamous; cohort 3: carboplatin plus paclitaxel, squamous or non-squamous). Primary endpoint was incidence of dose-limiting toxicities (DLTs). Following unfavorable results from other studies, a protocol amendment removed epacadostat from the treatment combination. RESULTS: Of 19 patients, 7 were enrolled in cohort 1, and 6 each in cohorts 2 and 3. Median follow-up was 13.7 (range, 4.2-27.8) months. Five of 17 (29%) DLT-evaluable patients experienced ≥ 1 DLT (cohort 1, n = 1; cohorts 2 and 3, n = 2 each); most commonly maculopapular rash (grade 3, n = 3) and increased alanine aminotransferase (grade 2, n = 1; grade 3, n = 2). All patients experienced treatment-related adverse events (AEs); 58% experienced grade 3 or 4 treatment-related AEs. Objective response rate was 47%. CONCLUSION: The combination of epacadostat plus pembrolizumab and chemotherapy was found to be tolerable in Japanese patients with advanced NSCLC. TRIAL REGISTRATION: ClinicalTrials.gov , NCT02862457.
Assuntos
Anticorpos Monoclonais Humanizados , Protocolos de Quimioterapia Combinada Antineoplásica , Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Anticorpos Monoclonais Humanizados/efeitos adversos , Anticorpos Monoclonais Humanizados/administração & dosagem , Anticorpos Monoclonais Humanizados/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Carboplatina/administração & dosagem , Carboplatina/uso terapêutico , Carboplatina/efeitos adversos , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/patologia , Cisplatino/administração & dosagem , Cisplatino/efeitos adversos , Cisplatino/uso terapêutico , População do Leste Asiático , Japão , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/patologia , Oximas/administração & dosagem , Oximas/efeitos adversos , Oximas/uso terapêutico , Pemetrexede/administração & dosagem , Pemetrexede/uso terapêutico , Pemetrexede/efeitos adversos , Sulfonamidas/administração & dosagem , Sulfonamidas/uso terapêutico , Sulfonamidas/efeitos adversosRESUMO
Preconditioning of mesenchymal stem/stromal cells (MSCs) with the inflammatory cytokine IFN-γ enhances not only their immunosuppressive activity but also their expression of HLA and proinflammatory genes. We hypothesized that prevention of the upregulation of inflammatory cytokines and HLA molecules in IFN-γ-primed MSCs would render these cells more immunosuppressive and less immunogenic. In this study, we discovered the following findings supporting this hypothesis: (1) activated human T cells induced the expression of IDO1 in MSCs via IFN-γ secretion and those MSCs in turn inhibited T-cell proliferation in an AHR-dependent fashion; (2) there was no difference in the expression of IDO1 and HLA-DR in MSCs after priming with a low dose (25 IU/mL) versus a high dose (100 IU/mL) of IFN-γ; (3) the transient addition of bortezomib, a proteasome inhibitor, to culture MSCs after IFN-γ priming decreased the expression of HLA-DR, inflammatory cytokine genes and Vcam1 while increasing the expression of IDO1 and the production of L-kynurenine; finally, MSCs primed with a combination of a low dose of IFN-γ and bortezomib were more effective in inhibiting Th17-mediated idiopathic pneumonia syndrome (IPS) and chronic colitis than unprimed MSCs. Our results suggest that bortezomib significantly eliminates the unfavorable effects of IFN-γ priming of MSCs (increased expression of MHC molecules and inflammatory cytokines and cell aggregation genes) and simultaneously increases their immunosuppressive activity by upregulating IDO1. Taken together, our newly established MSC priming method may contribute to MSC-based cell therapy for inflammatory diseases.
Assuntos
Citocinas , Interferon gama , Humanos , Bortezomib/farmacologia , Interferon gama/farmacologia , Interferon gama/metabolismo , Células Estromais/metabolismoRESUMO
Neuroinflammation plays crucial role in the development and progression of depression. Large conductance calcium- and voltage-dependent potassium (BK) channels mediate the activation of microglia. Herein, we investigated whether BK channels could serve as a target for the treatment of inflammation-associated depression. Lipopolysaccharide (LPS, 0.83 mg/kg) was injected intraperitoneally (i.p.) to induce neuroinflammation and depressive-like behavior in 6-8 week ICR mice. Adeno-associated virus (AAV) constructs (AAV9-Iba1p-BK shRNA-EGFP (BK shRNA-AAV) or AAV9-Iba1p-NC shRNA-EGFP (NC shRNA-AAV)) were unilaterally injected intracerebroventricularly to selectively knock down BK channels in microglia. The tail suspension test (TST) and forced-swim test (FST) were used to evaluate depressive-like behavior in mice 24 h after LPS challenge. The morphology of microglia, expression of BK channels, levels of cytokines, and expression and activity of indoleamine 2,3-dioxygenase (IDO) were measured by immunohistochemistry, western blot, quantitative real time PCR, and enzyme-linked immunosorbent assay (ELISA), respectively. Either paxilline (i.p.), a specific BK channel blocker, or BK shRNA-AAV effectively inhibited the activation of microglia, reduced the production of IL-1ß in the hippocampus and suppressed the expression and activity of IDO in the hippocampus and prefrontal cortex, resulting in the amelioration of depressive-like behavior in mice. These data suggest for the first time that BK channels are involved in LPS-induced depressive-like behaviors. Thus, microglia BK channels may be a potential drug target for the depression treatment.
Assuntos
Canais de Potássio Ativados por Cálcio de Condutância Alta , Lipopolissacarídeos , Camundongos , Animais , Lipopolissacarídeos/toxicidade , Doenças Neuroinflamatórias , Camundongos Endogâmicos ICR , Depressão/induzido quimicamente , Depressão/tratamento farmacológico , Depressão/metabolismo , RNA Interferente PequenoRESUMO
Soil and groundwater were investigated for the genes encoding soluble and particulate methane monooxygenase/ammonia monooxygenase (sMMO, pMMO/AMO), toluene 4-monooxygenase (T4MO), propane monooxygenase (PMO) and phenol hydroxylase (PH). The objectives were (1) to determine which subunits were present, (2) to examine the diversity of the phylotypes associated with the biomarkers and (3) to identify which metagenome associated genomes (MAGs) contained these subunits. All T4MO and PH subunits were annotated in the groundwater metagenomes, while few were annotated in the soil metagenomes. The majority of the soil metagenomes included only four sMMO subunits. Only two groundwater metagenomes contained five sMMO subunits. Gene counts for the pMMO subunits varied between samples. The majority of the soil metagenomes were annotated for all four PMO subunits, while three out of eight groundwater metagenomes contained all four PMO subunits. A comparison of the blast alignments for the sMMO alpha chain (mmoX) indicated the phylotypes differed between the soil and groundwater metagenomes. For the pMMO/AMO alpha subunit (pmoA/amoA), Nitrosospira was important for the soil metagenomes, while Methylosinus and Methylocystis were dominant for the groundwater metagenomes. The majority of pmoA alignments from both metagenomes were from uncultured bacteria. High quality MAGs were obtained from the groundwater data. Four MAGs (Methylocella and Cypionkella) contained sMMO subunits. Another three MAGs, within the order Pseudomonadales, contained all three pMMO subunits. All PH subunits were detected in seven MAGs (Azonexus, Rhodoferax, Aquabacterium). In those seven, all contained catechol 2,3-dioxagenase, and Aquabacterium also contained catechol 1,2-dioxygenase. T4MO subunits were detected in eight MAGs (Azonexus, Rhodoferax, Siculibacillus) and all, except one, contained all six subunits. Four MAGs (Rhodoferax and Azonexus) contained all subunits for PH and T4MO, as well as catechol 2,3-dixoygenase. The detection of T4MO and PH in groundwater metagenomes and MAGs has important implications for the potential oxidation of groundwater contaminants.
Assuntos
Água Subterrânea , Metagenoma , Oxigenases , Filogenia , Microbiologia do Solo , Água Subterrânea/microbiologia , Água Subterrânea/química , Oxigenases/genética , Oxigenases/metabolismo , Bactérias/genética , Bactérias/classificação , Bactérias/enzimologia , Bactérias/isolamento & purificação , Bactérias/metabolismo , Citocromo P-450 CYP4A/genética , Citocromo P-450 CYP4A/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Oxigenases de Função MistaRESUMO
Enterotoxigenic Escherichia coli (ETEC) is an important cause of diarrhea in children and travelers, especially in low- and middle-income countries. ETEC is a non-invasive gut pathogen colonizing the small intestinal wall before secreting diarrhea-inducing enterotoxins. We sought to investigate the impact of ETEC infection on local and systemic host defenses by examining plasma markers of inflammation and mucosal injury as well as kynurenine pathway metabolites. Plasma samples from 21 volunteers experimentally infected with ETEC were collected before and 1, 2, 3, and 7 days after ingesting the ETEC dose, and grouped based on the level of intestinal ETEC proliferation: 14 volunteers experienced substantial proliferation (SP) and 7 had low proliferation (LP). Plasma markers of inflammation, kynurenine pathway metabolites, and related cofactors (vitamins B2 and B6) were quantified using targeted mass spectrometry, whereas ELISA was used to quantify the mucosal injury markers, regenerating islet-derived protein 3A (Reg3a), and intestinal fatty acid-binding protein 2 (iFABP). We observed increased concentrations of plasma C-reactive protein (CRP), serum amyloid A (SAA), neopterin, kynurenine/tryptophan ratio (KTR), and Reg3a in the SP group following dose ingestion. Vitamin B6 forms, pyridoxal 5'-phosphate and pyridoxal, decreased over time in the SP group. CRP, SAA, and pyridoxic acid ratio correlated with ETEC proliferation levels. The changes following experimental ETEC infection indicate that ETEC, despite causing a non-invasive infection, induces systemic inflammation and mucosal injury when proliferating substantially, even in cases without diarrhea. It is conceivable that ETEC infections, especially when repeated, contribute to negative health impacts on children in ETEC endemic areas.
Assuntos
Escherichia coli Enterotoxigênica , Infecções por Escherichia coli , Criança , Humanos , Cinurenina , Diarreia , Inflamação , PiridoxalRESUMO
The inhibition of kynurenine production is considered a promising target for cancer immunotherapy. In this study, an amino acid derivative, compound 1 was discovered using a cell-based assay with our screening library. Compound 1 suppressed kynurenine production without inhibiting indoleamine 2,3-dioxygenase 1 (IDO1) activity. The activity of 1 was derived from the inhibition of IDO1 by a metabolite of 1, O-benzylhydroxylamine (OBHA, 2a). A series of N-substituted 2a derivatives that exhibit potent activity in cell-based assays may represent effective prodrugs. Therefore, we synthesized and evaluated novel N,O-substituted hydroxylamine derivatives. The structure-activity relationships revealed that N,O-substituted hydroxylamine 2c inhibits kynurenine production in a cell-based assay. We conducted an in vivo experiment with 2c, although the effectiveness of O-substituted hydroxylamine derivatives in vivo has not been previously reported. The results indicate that N,O-substituted hydroxylamine derivatives are promising IDO1 inhibitors.
Assuntos
Hidroxilamina , Indolamina-Pirrol 2,3,-Dioxigenase , Cinurenina , Cinurenina/metabolismo , Indolamina-Pirrol 2,3,-Dioxigenase/antagonistas & inibidores , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Relação Estrutura-Atividade , Humanos , Hidroxilamina/química , Hidroxilamina/farmacologia , Hidroxilaminas/química , Hidroxilaminas/farmacologia , Estrutura Molecular , Animais , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Camundongos , Relação Dose-Resposta a DrogaRESUMO
In this work, we report 14 novel quinazoline derivatives as immune checkpoint inhibitors, IDO1 and PD-L1. The antitumor screening of synthesized compounds on ovarian cancer cells indicated that compound V-d and V-l showed the most activity with IC50 values of about 5 µM. Intriguingly, compound V-d emerges as a stand out, triggering cell death through caspase-dependent and caspase-independent manners. More importantly, V-d presents its ability to hinder tumor sphere formation and re-sensitized cisplatin-resistant A2780 cells to cisplatin treatment. These findings suggest that compound V-d emerges as a promising lead candidate for the future development of immuno anticancer agents.
Assuntos
Antineoplásicos , Desenho de Fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Inibidores de Checkpoint Imunológico , Quinazolinas , Humanos , Quinazolinas/farmacologia , Quinazolinas/química , Quinazolinas/síntese química , Relação Estrutura-Atividade , Inibidores de Checkpoint Imunológico/farmacologia , Inibidores de Checkpoint Imunológico/síntese química , Inibidores de Checkpoint Imunológico/química , Antineoplásicos/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Estrutura Molecular , Linhagem Celular Tumoral , Relação Dose-Resposta a Droga , Proliferação de Células/efeitos dos fármacos , Indolamina-Pirrol 2,3,-Dioxigenase/antagonistas & inibidores , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Antígeno B7-H1/antagonistas & inibidores , Antígeno B7-H1/metabolismoRESUMO
Taking advantage of key interactions between sulfoxide and heme cofactor, we used the sulfoxide as the anchor functional group to develop two series of indoleamine 2, 3-dioxygenase 1 (IDO1) inhibitors: 2-benzylsulfinylbenzoxazoles (series 1) and 2-phenylsulfinylbenzoxazoles (series 2). In vitro enzymatic screening shows that both series can inhibit the activity of IDO1 in low micromolar (series 1) or nanomolar (series 2) levels. They also show inhibitory selectivity between IDO1 and tryptophan 2, 3-dioxygenase 2. Interestingly, although series 1 is less potent IDO1 inhibitors of these two series, it exhibited stronger inhibitory activity toward kynurenine production in interferon-γ stimulated BxPC-3 cells. Enzyme kinetics and binding studies demonstrated that 2-sulfinylbenzoxazoles are non-competitive inhibitors of tryptophan, and they interact with the ferrous form of heme. These results demonstrated 2-sulfinylbenzoxazoles as type II IDO1 inhibitors. Furthermore, molecular docking studies supports the sulfoxide being of the key functional group that interacts with the heme cofactor. Compound 22 (series 1) can inhibit NO production in a concentration dependent manner in lipopolysaccharides (LPS) stimulated RAW264.7 cells, and can relieve pulmonary edema and lung injury in LPS induced mouse acute lung injury models.
Assuntos
Inibidores Enzimáticos , Heme , Indolamina-Pirrol 2,3,-Dioxigenase , Animais , Humanos , Camundongos , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/química , Inibidores Enzimáticos/síntese química , Heme/metabolismo , Indolamina-Pirrol 2,3,-Dioxigenase/antagonistas & inibidores , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Simulação de Acoplamento Molecular , Estrutura Molecular , Relação Estrutura-Atividade , Imidazóis/síntese química , Imidazóis/química , Imidazóis/farmacologia , Benzoxazóis/síntese química , Benzoxazóis/química , Benzoxazóis/farmacologiaRESUMO
Maintaining stable tryptophan levels is required to control neuronal and immune activity. We report that tryptophan homeostasis is largely controlled by the stability of tryptophan 2,3-dioxygenase (TDO), the hepatic enzyme responsible for tryptophan catabolism. High tryptophan levels stabilize the active tetrameric conformation of TDO through binding noncatalytic exosites, resulting in rapid catabolism of tryptophan. In low tryptophan, the lack of tryptophan binding in the exosites destabilizes the tetramer into inactive monomers and dimers and unmasks a four-amino acid degron that triggers TDO polyubiquitination by SKP1-CUL1-F-box complexes, resulting in proteasome-mediated degradation of TDO and rapid interruption of tryptophan catabolism. The nonmetabolizable analog alpha-methyl-tryptophan stabilizes tetrameric TDO and thereby stably reduces tryptophanemia. Our results uncover a mechanism allowing a rapid adaptation of tryptophan catabolism to ensure quick degradation of excess tryptophan while preventing further catabolism below physiological levels. This ensures a tight control of tryptophanemia as required for both neurological and immune homeostasis.
Assuntos
Triptofano Oxigenase/metabolismo , Triptofano/sangue , Triptofano/metabolismo , Ubiquitinação , Animais , Células HEK293 , Homeostase , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Triptofano/análogos & derivadosRESUMO
Chronic inflammatory diseases like rheumatoid arthritis are characterized by a deficit in fully functional regulatory T cells. DNA-methylation inhibitors have previously been shown to promote regulatory T cell responses and, in the present study, we evaluated their potential to ameliorate chronic and acute animal models of rheumatoid arthritis. Of the drugs tested, decitabine was the most effective, producing a sustained therapeutic effect that was dependent on indoleamine 2,3-dioxygenase (IDO) and was associated with expansion of induced regulatory T cells, particularly at the site of disease activity. Treatment with decitabine also caused apoptosis of Th1 and Th17 cells in active arthritis in a highly selective manner. The molecular basis for this selectivity was shown to be ENT1, a nucleoside transporter, which facilitates intracellular entry of the drug and is up-regulated on effector T cells during active arthritis. It was further shown that short-term treatment with decitabine resulted in the generation of a population of regulatory T cells that were able to suppress arthritis upon adoptive transfer. In summary, a therapeutic approach using an approved drug is described that treats active inflammatory disease effectively and generates robust regulatory T cells with the IDO-dependent capacity to maintain remission.
Assuntos
Artrite Experimental/tratamento farmacológico , Artrite Reumatoide/tratamento farmacológico , Doenças Autoimunes/tratamento farmacológico , Decitabina/farmacologia , Linfócitos T Reguladores/efeitos dos fármacos , Células Th1/efeitos dos fármacos , Células Th17/efeitos dos fármacos , Animais , Apoptose/efeitos dos fármacos , Apoptose/imunologia , Artrite Experimental/imunologia , Artrite Experimental/metabolismo , Artrite Reumatoide/imunologia , Artrite Reumatoide/metabolismo , Doenças Autoimunes/imunologia , Doenças Autoimunes/metabolismo , Desmetilação do DNA/efeitos dos fármacos , Transportador Equilibrativo 1 de Nucleosídeo/genética , Transportador Equilibrativo 1 de Nucleosídeo/imunologia , Transportador Equilibrativo 1 de Nucleosídeo/metabolismo , Humanos , Indolamina-Pirrol 2,3,-Dioxigenase/genética , Indolamina-Pirrol 2,3,-Dioxigenase/imunologia , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Camundongos Knockout , Indução de Remissão , Linfócitos T Reguladores/citologia , Linfócitos T Reguladores/imunologia , Células Th1/citologia , Células Th1/imunologia , Células Th17/citologia , Células Th17/imunologiaRESUMO
The biologically significant phenomenon that the fetus can survive immune attacks from the mother has been demonstrated in mammals. The survival mechanism depends on the fetus and placenta actively defending themselves against attacks by maternal T cells, achieved through the localized depletion of the amino acid L-tryptophan by an enzyme called indoleamine 2,3-dioxygenase. These findings were entirely unexpected and pose important questions regarding diseases related to human pregnancy and their prevention during human pregnancy. Specifically, the role of this mechanism, as discovered in mice, in humans remains unknown, as does the extent to which impaired activation of this process contributes to major clinical diseases in humans. We have, thus, elucidated several key aspects of this enzyme expressed in the human placenta both in normal and abnormal human pregnancy. The questions addressed in this brief review are as follows: (1) localization and characteristics of human placental indoleamine 2,3-dioxygenas; (2) overall tryptophan catabolism in human pregnancy and a comparison of indoleamine 2,3-dioxygenase expression levels between normal and pre-eclamptic pregnancy; (3) controlling trophoblast invasion by indoleamine 2,3-dioxygenase and its relation to the pathogenesis of placenta accrete spectrum.