Indoleamine 2,3-dioxygenase Gene Expression Research Articles

Upregulation of IDO gene expression reduces the immunogenicity of epidermal cells and strengthens the immune protection of epidermal cells during transplantation treatment of wounds

BackgroundEpidermal cell transplantation is a feasible treatment option for large wounds; however, sources of autologous epidermal cells are often limited. Allogeneic epidermal cells can be cultured conveniently; however, related immune rejection needs to be addressed. Herein, we hypothesized that the immunogenicity of epidermal cells with high indoleamine 2,3-dioxygenase (IDO) expression may be reduced by gene transfection. Methods/ResultsTo test this hypothesis, we obtained stable transfectants by transfecting epidermal stem cells with a lentiviral vector encoding the IDO gene and screening them for puromycin resistance (a marker for successful transfection). The phenotype tested using cell counting kit −8 and Transwell assays confirmed that IDO-transfected epidermal cells maintained their characteristics. Co-culture of IDO-transfected epidermal cells with allogeneic CD4+ T cells in vitro showed that the upregulation of IDO expression in epidermal cells inhibited the proliferation of CD4+ T cells (P < 0.001, P < 0.001, and P < 0.001, respectively) and promoted their apoptosis (P = 0.00028, P = 0.0006, and P = 0.00247, respectively) and transformation into functional regulatory T cells (Tregs) (P = 0.0051, P = 0.0132, and P = 0.0248, respectively) compared with Con, NC, and 1-MT groups. The increased proportion of Tregs may be related to the overexpression of IDO, which promoted the expression of transforming growth factor beta (TGF-β) (P = 0.0001, P = 0.0013, and, P = 0.0009) and interleukin (IL) 10 (IL-10) (P = 0.0062, P = 0.0058, and P = 0.0119) while inhibited the expression of IL-2 (P = 0.0012, P = 0.0126, and P = 0.0066). We further verified these effects in vivo as transplanted IDO-transfected epidermal stem cells were effective in treating wounds in mice. On days 5 and 7, wounds treated with IDO cells healed faster than those in the other groups (day 5: P = 0.012 and P = 0.0136; day 7: P = 0.0242 and P = 0.0187, respectively), whereas this effect was significantly inhibited by 1-methyltryptophan (1-MT) (day 5: P = 0.0303; day 7: P = 0.0105). Immunofluorescence staining detected IDO and CD4+ Foxp3+ Tregs in the transplanted wounds, which may promote Foxp3+ Tregs in the wound tissue (day 5: P < 0.0001, P < 0.0001, and P < 0.0001; day 7: P < 0.0001, P < 0.0001, and P < 0.0001), respectively) and decrease CD4+ T cells (day 5: P < 0.0001, P < 0.0001, and P < 0.0001; day 7: P < 0.0001, P < 0.0001, and P < 0.0001). ConclusionOur results suggest that the upregulation of IDO expression in epidermal stem cells can reduce their immunogenicity by promoting Tregs, thus inducing the immune protection of epidermal stem cells.

The effects of Ellagic acid supplementation on neurotrophic, inflammation, and oxidative stress factors, and indoleamine 2, 3-dioxygenase gene expression in multiple sclerosis patients with mild to moderate depressive symptoms: A randomized, triple-blind, placebo-controlled trial

BackgroundDepression is one of the most common psychological disorders among multiple sclerosis (MS) patients that characterized as the first symptoms. Ellagic acid is a natural polyphenol that may have neuroprotective properties through antioxidant, anti-inflammatory, and immunomodulatory effects. PurposeThe aim of the present study was to investigate the effects of Ellagic acid on circulating levels of brain derived neurotrophic factor (BDNF), interferon-γ (IFN-ƴ), nitric oxide (NO), nuclear factor erythroid-2-related factor 2 (Nrf2), cortisol, serotonergic system, and indoleamine 2, 3-dioxygenase (IDO) gene expression in MS patients with mild to moderate depressive symptoms. Study designA randomized triple-blind clinical trial. MethodsThe eligible patients according to the inclusion criteria were randomly divided into two groups: either 180 mg Ellagic acid (Axenic company) (n = 25) or 180 mg maltodextrin (n = 25) group for 12 weeks. The Ellagic acid supplement were identical to placebo in shape, color and odor. Serum BDNF, NO, Nrf2, cortisol, serotonin, and IFN-ƴ were measured by ELISA kit in the baseline and end of the study. Also, demographic characteristics, anthropometric measurements, physical activity, food intake, Beck Depression Inventory-II (BDI-II) and expanding disability status scale (EDSS) questionnaires, as well as IDO gene expression were assessed. SPSS software version 24 was used for statistical analysis. ResultsFifty patients were evaluated, and a significant decrease in BDI-II (p = 0.001), IFN-ƴ (p = 0.001), NO (p = 0.004), cortisol (p = 0.015), IDO gene expression (p = 0.001) and as well as increased the level of BDNF (p = 0.006) and serotonin (p = 0.019) was observed among those who received 90 mg Ellagic acid twice a day for 12 weeks versus control group. However, there were no significant differences between groups for Nrf2 levels (p>0.05) at the end of study. ConclusionThe current study indicates that Ellagic acid intervention has a favorable effect on depression in MS patients. This is achieved by reducing BDI-II scores, as well as levels of NO, cortisol, IFN-ƴ, and IDO gene expression. Furthermore, we found a significant elevation in circulating levels of BDNF and serotonin.

Toxoplasma gondii induced cognitive impairment in rats via dysregulation of dopamine receptors and indoleamine 2,3 dioxygenase

Toxoplasma gondii (T. gondii) is a parasite capable of residing in the brain of their host which influences behaviour changes due to alterations in the neurotransmitters. Consequently, dopamine receptors (DRD) and indoleamine 2, 3 dioxygenase (IDO) dysregulation facilitate the progression of behaviour changes in a host as a response to infection. This study tested the effect of neurotransmitter changes as a result of T. gondii infection on rats cognitive impairment. The T. gondii strain of type I, II and III from Malaysia were previously identified by standard procedures. Sporulated oocysts each of type I, II and III were inoculated separately into three groups of Wistar rats (n = 9) respectively. Two separate control groups received either phosphate buffered saline (PBS) or MK-801 (dizocilpine). Behaviour changes were evaluated at nine weeks post infection in a square box, elevated plus maze and gene expression level of DRD and IDO compounds. The study revealed increased fatal feline attraction, reduced anxiety, decreased DRD and increased IDO gene expression in the T. gondii infected groups and MK-801 compared to the PBS control group. In conclusion, T. gondii infection alter the level of neurotransmitters in rat which cause cognitive impairment. This implies that all the T. gondii strain can cause behaviour changes if human were infected.

Expression of tolerogenic dendritic cells in the small intestinal tissue of patients with celiac disease

Tolerogenic dendritic cells (tolCDs) play an important role in the regulation of inflammation in autoimmune diseases such as celiac disease (CeD). Dendritic cells express CD207, CD11c, and CD103 on their surface. In addition to the receptors mentioned above, tolCDs can express the immune-regulating enzyme indoleamine 2,3-dioxygenase (IDO). This study aimed to determine the mRNA and protein expression of CD11c, CD103 and CD207 markers, and also IDO gene expression in intestinal tissues of CeD patients in comparison to the healthy individuals. Duodenal biopsies were collected from 60 CeD patients and 60 controls. Total RNA was extracted and gene expression analysis was performed using Real-time PCR SYBR® Green method. Additionally, biopsy specimens were paraffinized and protein expression was evaluated using immunohistochemistry (IHC) for expression of CD11c+, CD207+and CD103+. Gene expression levels of CD11c (P = 0.045), CD103 (P < 0.001), CD207 (P < 0.001) and IDO (P = 0.01) were significantly increased in CeD patients compared to the control group. However, only CD103 protein expression was found to be significantly higher in CeD patients in comparison to the control group (P < 0.001). The result of this study showed that the expresion levels of CD11c, CD103, CD207 and IDO markers were higher in CeD patients compared to the controls, indicating the effort of dendritic cells to counterbalance the gliadin-triggered abnormal immune responses in CeD patients.

Evaluating the effect of anti-nausea drugs in IDO enzyme gene expression and preventing postoperative vomiting and nausea in patients undergoing general anesthesia: A Meta-analysis.

Nausea and vomiting are known as side effects after surgery. Since serotonin antagonist drugs are widely used to prevent nausea and vomiting after surgery, the present study was conducted to compare the effectiveness of this group's drugs, namely, ondansetron and palonosetron. On the other hand, recent studies have shown that the metabolites of the kynurenine pathway in the Suppression of the immune response play a role. Indoleamine 2,3 dioxygenase (IDO) is the main enzyme controlling this pathway. Therefore, the effect of these two drugs on IDO gene expression was evaluated. The present study is a systematic review with meta-analysis. The search was conducted in the Cochrane, PubMed, Clinical K, and CRD databases for randomized clinical trial articles that compared two drugs, palonosetron, and ondansetron, regarding nausea and vomiting in patients undergoing surgery with general anesthesia. In the end, eight studies were included in the meta-analysis. STATA13 statistical software was used to estimate the overall risk, relative risk, and data analysis. The results showed that the number of samples in all articles was 739. The analysis of the results between 0 and 24 hours showed that palonosetron reduces the incidence of nausea by 50% and the incidence of vomiting by 79% compared to ondansetron (p=0.001). Also, there was no difference between the IDO gene expression in the two drug groups (p>0.05). In general, the analysis of the results related to the effectiveness of palonosetron and ondansetron 24 hours after surgery with a dose of 0.075 mg of palonosetron versus 4 mg of ondansetron showed that palonosetron is more effective in reducing the incidence of nausea and vomiting in patients than ondansetron.

The immunotherapeutic role of indoleamine 2,3-dioxygenase in head and neck squamous cell carcinoma: A systematic review.

BackgroundNovel cancer immunotherapy seeks to harness the body's own immune system and tip the balance in favour of antitumour activity. The intracellular enzyme indoleamine 2,3‐dioxygenase (IDO) is a critical regulator of the tumour microenvironment (TME) via tryptophan metabolism. The potential immunotherapeutic role of IDO in head and neck squamous cell carcinoma (HNSCC) requires further exploration. We aim to assess the evidence on IDO in HNSCC.MethodsA systematic review of literature and clinical trials databases.ResultsWe included 40 studies: seven involved cell lines: eight assessed tumour immunohistochemistry: ten measured IDO gene transcription: 15 reported on clinical trials. Increased cell line IDO expression was postulated to adversely affect tumour metabolism and apoptosis. Immunohistochemical IDO expression correlated with worse survival. Gene transcription studies associated IDO with positive PD‐L1 and human papillomavirus (HPV) status. Phase I/II clinical trials showed (a) overall response (34%‐55%) and disease control rates (62%‐70%) for IDO1 inhibitor in combination with a PD‐1 inhibitor, (b) similar safety profiles when both are used in combination therapy compared to each as monotherapies and (c) IDO gene expression as a predictive biomarker for response to PD‐L1 therapy.ConclusionsIDO expression is increased in the TME of HNSCC, which correlates with poor prognosis. However, the exact mechanism of IDO‐driven immune modulation in the TME is an enigma. Future translational studies should map IDO activity during HNSCC treatment and elucidate its precise role in the TME, such research will underpin the development of clinical trials establishing the efficacy of IDO inhibitors in HNSCC.

Regulation of indoleamine 2, 3-dioxygenase in hippocampal microglia by NLRP3 inflammasome in lipopolysaccharide-induced depressive-like behaviors.

In the brain, NLRP3 (Nucleotide-binding oligomerization domain, leucine-rich repeat, and pyrin-domain-containing 3) inflammasome is mainly expressed in microglia located in the hippocampus and other mood-regulated regions, which are particularly susceptible to stress. The activation of NLRP3 inflammasome and production of the activation products may contribute to the development of depressive disorder and memory deficits. Indoleamine 2, 3-dioxygenase (IDO) is a key factor mediating inflammation and major depressive disorder (MDD). We here generated NLRP3 and apoptosis-associated speck-like protein containing caspase recruitment domain (ASC)-knockout mice, respectively, to verify the effects of NLRP3 or ASC deficiency on lipopolysaccharide (LPS)-induced depressive-like behaviors, neuroinflammation, and regulation of IDO expression. Furthermore, we treated these mice with the antidepressant clomipramine (CLO) to observe its effect on depressive-like behaviors and the expression of the NLRP3 inflammasome and LPS-induced IDO. We found that intraperitoneal LPS administration led to marked depressive-like behavior and neuroinflammation. NLRP3 or ASC deficiency attenuated LPS-induced depressive-like symptoms and increased IDO gene expression, which was accompanied by inhibition of LPS-induced microglial activation, suggesting that IDO may be a downstream mediator of the NLRP3 inflammasome in inflammation-mediated depressive-like behaviors. Clomipramine administration ameliorated depressive-like behavior in LPS-treated mice by regulating the expression of ASC and IDO. In conclusion, NLRP3 inflammasome is involved in LPS-induced depressive-like behaviors, and that NLRP3 and ASC may play roles in regulating IDO expression in microglia. This may be a potential mechanism for its involvement in MDD. The antidepressant effect of clomipramine may be exerted through the regulation of ASC-mediated expression of IDO.

Evaluation of the andrographolides role and its indoleamine 2,3-dioxygenase inhibitory potential and attendant molecular mechanism against STZ-induced diabetic rats.

The study is to scrutinize andrographolides with Indoleamine 2,3-dioxygenase (IDO) inhibitory potential, its molecular mechanism against streptozotocin (STZ) diabetic retinopathy (DR) in Wistar rats. Oxidative stress markers such as Kynurenine metabolites, retinal histopathological changes have been studied. Further, IDO gene expression and docking studies have been performed. Andrographolide treated rats have been reducing the level of thiobarbituric acid reactive substances and protein carbonyls Kynurenine metabolites with an improvement in the level of GSH and expression of IDO as revealed by morphological changes in inner and outer nuclear layer of the retina. The current results of this study have been generated information about an activity of the andrographolide in the essential pocket of IDO. Our results explain, involving IDO and andrographolide would constitute an attempt to identify natural products with therapeutic value and further studies in this direction would be of immense significance in the administration of diabetes and its related problems.

Chemoresistance was correlated with elevated expression and activity of indoleamine 2,3-dioxygenase in breast cancer.

Indoleamine 2,3-dioxygenase (IDO) catalyses degradation of the essential amino acid tryptophan leading to the production of immunosuppressive kynurenine and tryptophan exhausting. IDO expression and activity contribute to aggressive tumor growth, inferior therapeutic gain and poor prognosis. The aim of this study was to explore the association between chemoresistance and IDO expression, activity in breast cancer METHODS: Immunohistochemistry was applied for evaluating IDO expression in biopsy tissues. Serum IDO activity was examined via High-performance liquid chromatography (HPLC). Western blots (WB), HPLC and Real-time PCR (RT-PCR) were used to analyze IDO protein, IDO enzyme activity and IDO gene expression in original and paclitaxel-resistant cells respectively. Logistic regression and survival analysis were applied to explore the association between chemoresistance and IDO expression, activity in breast cancer. IDO expression in tumor tissues was associated with serum IDO activity (P = 0.004). Both IDO expression in tumor and serum activity were associated with clinical tumor stage, node stage and estrogen receptor (ER) status (all P < 0.05); clinical response and pathologic complete response (pCR) to NAC were both related to IDO expression and activity prior NAC (all P < 0.05). Multivariate analysis showed IDO activity before NAC was the only independent factor affected pCR (P = 0.032). ROC curves showed that the IDO expression and activity had discriminative ability for predicting the clinical response and pCR. In the prognostic analysis, patients with high IDO expression had significantly impaired overall survival (5year survival rate: 53.57% vs 80.00%) and progression-free survival (5year survival rate: 46.43% vs 72.00%, P = 0.031 and P = 0.046). In vitro, significantly increased IDO protein, IDO mRNA expression and IDO enzyme activity in paclitaxel-resistant cells were demonstrated in comparing of sensitive cells. IDO expression and activity associated with advanced breast cancer, poor response to neoadjuvant chemotherapy and prognosis. IDO expression and activity were significantly increased in paclitaxel-resistant breast cancer cells.

Abstract LB-184: The immunotherapeutic role of indoleamine 2,3-dioxygenase (IDO) in head and neck squamous cell carcinoma: a systematic review

Abstract Background: Novel cancer immunotherapy includes application of immune checkpoint inhibitors to the treatment of solid tumors. The body’s own immune system is thereby harnessed to tip the balance in favor of antitumor activity. The intracellular enzyme indoleamine 2,3-dioxygenase (IDO) is a critical regulator of the tumor microenvironment (TME) via tryptophan metabolism. Programmed death protein 1 (PD-1) and programmed death-ligand 1 (PD-L1) are immune checkpoints involved in T-cell inhibition and immunosuppression. Another immune checkpoint, IDO1, breaks down tryptophan into its metabolites which results in immunosuppression in the TME. Aim: To assess the evidence on IDO in head and neck squamous cell carcinoma (HNSCC). Methods: Medline, EMBASE using Ovid, Scopus, Web of Science, Cochrane Library databases, and ClinicalTrials.gov were searched from inception until present day. Results: We included 32 studies. Of those, 5 involved cell lines, 7 assessed tumor immunohistochemistry, 6 measured IDO gene transcription, and 14 reported on clinical trials. The human cell lines studied commonly were SCC4, SCC15, and SCC25 in which IDO expression and activation by the Stimulator of Interferon Genes (STING) pathway played a central role. Retrospective immunohistochemistry studies of lower lip, oral cavity, tongue, tonsil, and larynx found that relatively high IDO expression correlated with worse survival. Gene transcription studies showed increased IDO in tumors that expressed PD-L1 and harbored human papillomavirus (HPV). Phase I/II clinical trials showed 1) objective responses (34%) and disease control rates (62%) for IDO1 inhibitor in combination with a PD-1 inhibitor, 2) consistent safety profile in combination versus monotherapy, and 3) IDO gene expression as a predictive biomarker for response to PD-L1 therapy. Conclusions: IDO is integral to TME immunity in HNSCC particularly in HPV positive tumors, modulating existing therapies and application in combinatorial immunotherapy. Retrospective studies have shown the presence of IDO in the TME and suggest a link to prognosis and prediction of HNSCC treatment outcome. However, the exact mechanism of IDO-driven immune modulation in the HNSCC TME remains unclear. We now require prospective longitudinal studies to track IDO activity and expression throughout HNSCC treatment, thence optimise IDO-based immunotherapy. Citation Format: Daniel J. Lin, James C. Ng, Lei Huang, Max Robinson, James O'Hara, Janet A. Wilson, Andrew L. Mellor. The immunotherapeutic role of indoleamine 2,3-dioxygenase (IDO) in head and neck squamous cell carcinoma: a systematic review [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr LB-184.

Cyclooxygenase‐2 Regulates the Renal Expression of Indoleamine 2,3‐dioxygenase

Chronic kidney disease (CKD) affects approximately 10% of the population. In CKD patients, the majority of metabolic pathways are in disarray, which most likely contributes to the wide variety of comorbidities observed in these patients. However, few studies have focused on the unique regulatory aspects of enzyme systems during CKD development and progression. The cyclooxygenase‐2 (COX‐2)/prostaglandin (PG) system plays a dominant role in the progression of renal injury. Interestingly, it has been shown that the COX‐2/PG system modulates the activity of indoleamine 2,3‐dioxygenase (IDO) in tumors. Catabolism of tryptophan by IDO gives rise to numerous biologically active metabolites implicated in CKD progression. Therefore, the aim of this project is to explore the interplay between the COX‐2 and IDO enzyme systems during renal injury.We studied the gene expression of IDO, COX‐2 as well as several fibrosis and inflammatory markers in human and murine precision‐cut kidney slices (PCKS) and COX‐2 KO mice. Furthermore, we evaluated the gene expression profile after treatment with butaprost, an EP2 receptor agonist, in hPCKS and following treatment with SC‐236, a selective COX‐2 inhibitor, in mPCKS.Our results demonstrated that IDO gene expression was markedly increased in both human and mouse PCKS during the first 24h of culturing, after which levels dropped again. This expression profile was similar to the gene expression of various cytokines (e.g. IL‐6 and CXCL1), suggesting a potential pro‐inflammatory role of IDO. In addition, in COX‐2 KO animals, constitutive gene expression of IDO was increased as compared to wild‐type mice, and the knockout animals appeared to be more prone to renal fibrosis. Moreover, treatment with butaprost suppressed IDO gene expression, while exposure to SC‐236 induced IDO mRNA expression as well as the gene levels of IL‐6 and IL‐8.Taken together, it appears that COX‐2 suppresses IDO gene expression. In addition, our findings suggest a potential pro‐inflammatory role of IDO. However, the precise role of IDO in CDK development and progression requires further study.Support or Funding InformationThis work was kindly supported by Lundbeckfonden, grant number R231‐2016‐2344.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Immunomodulatory and immunogenic properties of mesenchymal stem cells derived from bovine fetal bone marrow and adipose tissue

Little information is currently available on therapeutic features of bovine mesenchymal stem cells (MSCs), despite the development of large animal experimental models including cattle may open alternative strategies for investigating MSC physiology and eventual applications for regenerative therapy. The aim of the present study was to compare in vitro immunomodulatory and immunogenic potentials of bovine fetal MSCs (bfMSCs) derived from bovine fetal bone marrow (BM-MSCs) and adipose tissue (AT-MSCs). Immunomodulatory analyses in bfMSCs were performed by determination of the effect of interferon-γ (IFNγ) on mRNA levels of indoleamine 2, 3-dioxygenase (IDO), transforming growth factor β1 (TGFβ1), prostaglandin E receptor 2 (PTGER2), interleukin-6 and -10 (IL-6 and IL-10), and IDO enzymatic activity. The effect of conditioned medium from IFNγ-stimulated bfMSCs on the proliferation of alloantigen-activated peripheral blood lymphocytes (PBLs) was assessed. Immunogenicity of bfMSCs was determined by quantification of mRNA levels of major histocompatibility complex I and II (MHC-I and -II), CD80 and CD86, and the proportion of cells positive for MHC-I and -II by flowcytometry (FACS) analyses. IFNγ treatment increased IL-6, PTGER2 and IDO gene expression and activity in bfMSCs but did not affect suppressive effect on proliferation of PBLs. Lower proportion of AT-MSCs expressed MHC-I and MHC-II in comparison to BM-MSCs. In conclusion, BM-MSCs and AT-MSCs upregulated expression of immunomodulatory genes in a similar way after IFNγ stimuli. BM-MSCs and AT-MSCs in basal condition and treated with IFNγ displayed similar in vitro immunomodulatory ability. Lower expression of MHC-I and MHC-II suggest that AT-MSCs might be less immunogenic compared to BM-MSCs.

Expression of Indoleamine 2,3-Dioxygenase Induced by IFN-γ and TNF-α as Potential Biomarker of Prostate Cancer Progression.

Inflammation has been suggested to play an important role in onset and progression of prostate cancer (PCa). Histological analysis of prostatectomy specimens has revealed focal inflammation in early stage lesions of this malignancy. We addressed the role of inflammatory stimuli in the release of PCa-specific, tumor-derived soluble factors (PCa-TDSFs) already reported to be mediators of PCa morbidity, such as indoleamine 2,3-dioxygenase (IDO) and interleukin (IL)-6. Inflammation-driven production and functions of PCa-TDFSs were tested “in vitro” by stimulating established cell lines (CA-HPV-10 and PC3) with IFN-γ or TNF-α. Expression of genes encoding IDO, IL-6, IFN-γ, TNF-α, and their receptors was investigated in tumor tissues of PCa patients undergoing radical prostatectomy, in comparison with benign prostatic hyperplasia (BPH) specimens. IFN-γ and TNF-α-treatment resulted in the induction of IDO and IL-6 gene expression and release in established cell lines, suggesting that the elicitation of PCa-TDSFs by these cytokines might contribute to progression of cancer into an untreatable phenotype. An analysis based on timing of biochemical recurrence revealed the prognostic value of IDO but not IL-6 gene expression in predicting recurrence-free survival in patients (RFS) with PCa. In addition, a urine-based mRNA biomarker study revealed the diagnostic potential of IDO gene expression in urines of men at risk of PCa development.

Feiji Recipe inhibits the growth of lung cancer by modulating T-cell immunity through indoleamine-2,3-dioxygenase pathway in an orthotopic implantation model

ObjectiveEscape from the body’s immune response is a basic characteristic of lung cancer, and indoleamine-2,3-dioxygenase (IDO) plays a key role in mediating immune escape of non-small-cell lung cancer, which leads to recurrence and metastasis. Feiji Recipe, a compound Chinese herbal medicine, has the effect of stabilizing lesions and prolonging survival in patients with lung cancer. The purpose of this study was to investigate the mechanisms underlying the anticancer properties of Feiji Recipe. MethodsAn orthotopic transplant model of mouse Lewis lung cancer, with stable expression of IDO gene, was established in C57BL/6 mice. Optical imaging was used to observe the effects of Feiji Recipe in the treatment of lung cancer in vivo. The effects of Feiji Recipe on the proliferation of mouse Lewis lung cancer cell line 2LL, 2LL-enhanced green fluorescent protein (2LL-EGFP) and 2LL-EGFP-IDO were investigated, and the apoptosis of T-cells was examined by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide using flow cytometry. Chemical composition of Feiji Recipe was validated by high-performance liquid chromatography. ResultsCompared to the control group, the survival of animals treated with Feiji Recipe was significantly prolonged (P = 0.0074), and the IDO protein level decreased (P = 0.0072); moreover, the percentages of CD4+CD25+ T-cells and Foxp3+ T-cells were significantly decreased (P < 0.05). The molecular mechanism of Feiji Recipe against lung cancer may relate to the regulation of immune cells, such as T-cells and regulatory T-cells. ConclusionThe molecular mechanism of Feiji Recipe in treatment of lung cancer is to restore the function of T-cells in the cancer microenvironment through interfering with the IDO pathway.

P38 predicts depression and poor outcome in esophageal cancer.

p38 mitogen-activated protein kinase (MAPK) signaling has been implicated in the cancer development and progression. However, the precise mechanism of this association remains unknown. The aim of the present study was to evaluate the association between p38 and cancer progression, including investigations into the effects on cell proliferation, resistance to thalidomide, indoleamine 2,3-dioxygenase (IDO) expression and prognosis in patients with esophageal cancer. The present retrospective study included patients with stage I–III esophageal cancer. A total of 228 patients with esophageal cancer were recruited to analyze the expression of phosphorylated (p)-p38 and IDO in tumor, and normal tissues through immunohistochemistry. Depression status was measured using the Zung Self-Rating Depression Scale. P38 cDNA was transfected into esophageal cancer cells to assess tumor cell viability, sensitivity to thalidomide treatment and IDO gene expression. Western blotting and flow cytometry was used to analyze protein expression alterations, and apoptosis in esophageal cancer cells. P-p38 protein was expressed in 68.9% of cancer tissues, and was significantly associated with depressive symptoms, tumor recurrence and poor survival of patients. In vitro experiments revealed that the expression of p-p38 induced esophageal cancer Eca-109 and TE-1 cell viability, and resistance to thalidomide treatment, as well as in the expression of IDO without the application of lipopolysaccharides. Further follow-up of patients revealed that depression was also an independent factor for early recurrence and overall survival rate. Altered p38 MAPK expression was associated with poor outcome in patients with esophageal cancer. p38 may be a potential biomarker for the prediction of depressive symptoms and prognosis in patients with esophageal cancer.

Expression of Indoleamine 2,3-Dioxygenase Gene Is a Feature of Poorly Differentiated Non-muscle-invasive Urothelial Cell Bladder Carcinomas.

To evaluate indoleamine 2,3-dioxygenase (IDO) gene expression in non-muscle-invasive urothelial cell bladder carcinoma (NMIBC). Seventy-four patients undergoing surgical treatment for NMIBC were enrolled in the study. IDO gene expression was assessed by quantitative real-time polymerase chain reaction (qRT-PCR). IDO gene expression was detectable significantly more frequently (48/74, 64.86% vs. 5/21, 23.81%, p<0.001) and to significantly higher extents (p=0.01) in cancer tissues than in normal bladder mucosa. IDO gene expression was observed significantly more frequently in large (p=0.02), high-grade (p=0.05) and stage T1 (p=0.03) than in small, low-grade and stage Ta tumors. Expression levels were also significantly higher in large, high-grade and stage T1 tumors (p<0.01, p=0.05 and p=0.03, respectively). A direct positive correlation between IDO gene expression in tumor tissues and tumor size (R=0.24, p=0.04), grade (R=0.23, p=0.05) and stage (R=0.25, p=0.03) was detected. Multivariate analysis suggested a trend (p=0.08) towards longer overall survival in patients bearing tumors that did not express IDO gene. These data indicate that IDO gene expression is a feature of aggressive NMIBC, suggesting a potential immunosuppressive role of IDO.

Low indoleamine 2,3-dioxygenase activity in persistent food allergy in children.

Indoleamine 2,3-dioxygenase (IDO), which degrades tryptophan (Trp) to kynurenine (Kyn), has been demonstrated to contribute to modulation of allergic responses. However, the role of IDO in food allergy has not yet been elucidated. Serum Trp and Kyn concentrations were analyzed by high-pressure liquid chromatography. Expression of IDO gene was measured by real-time PCR. The levels of interleukin (IL)-4, IL-10, and interferon (IFN)-γ in cell culture supernatants were measured by ELISA. Kyn/Trp (IDO activity) was significantly lower in subjects with food allergy (n = 100) than in aged-matched healthy controls (n = 112) (P = 0.004). Kyn/Trp was decreased from healthy through completely tolerant, partially tolerant, and reactive ones [LN transformation (mean ± SEM) healthy: 3.9 ± 0.02 μM/mM; completely tolerant: 3.83 ± 0.04; partially tolerant: 3.8 ± 0.06; reactive: 3.7 ± 0.04] (P = 0.008). The frequency of genetic polymorphisms of IDO did not reveal a significant association with Trp, Kyn, and Kyn/Trp in healthy and food-allergic cases. Culture of PBMC experiments yielded that IDO mRNA expression was not different between tolerant and reactive groups. IL-4 synthesis when stimulated with casein increased significantly in subjects who are reactive and tolerant to foods (P = 0.042, P = 0.006, respectively). Increase in IL-10 synthesis was observed only in children tolerant to milk, but not in reactive ones. IFN-γ synthesis, when stimulated with IL-2 and β-lactoglobulin in cell culture, was significantly higher in subjects tolerant to milk than in the reactive ones (P = 0.005 and P = 0.029, respectively). Our results imply the probability of involvement of IDO in development of tolerance process, and we presume that high IDO activity is associated with nonresponsiveness to food allergens despite allergen sensitization.

Immunosuppressive properties of Wharton's jelly-derived mesenchymal stromal cells in vitro.

Recent studies have reported that mesenchymal stromal cells (MSCs) migrate to areas of inflammation and suppress adverse immune reactions. Bone marrow (BM)-derived MSCs have been successfully used in patients with acute graft versus host disease (GVHD), but the harvesting of BM carries certain risks for the donor. To circumvent these, we obtained MSCs from Wharton's jelly (WJ) derived from umbilical cord and investigated their potential for immunosuppression. In a mixed lymphocyte reaction (MLR), responder T cell proliferation triggered by allogeneic dendritic cells was inhibited efficiently by WJ-MSCs derived from the same donor of responder cells or those from a third party donor. These inhibitory effects were reversed in a dose-dependent manner in the presence of 1-methyl-DL-tryptophan, an inhibitor of the soluble factor indoleamine 2, 3-dioxygenase (IDO). Immunosuppression by WJ-MSCs was also attenuated by blocking cell-cell contact between WJ-MSCs and responder T cells using a Transwell chamber. Moreover, IDO gene expression was induced in both WJ- and BM-MSCs by inflammatory cytokine IFN-γ, but HLA-DR was expressed in BM-MSCs and not in WJ-MSCs upon stimulation by a relatively low concentration of IFN-γ. These results indicate that WJ-MSCs exert their immunosuppressive effects by cell-cell contact with activated T cells and in part through IDO, and suggest the need for cells rather than soluble factors secreted from MSCs to achieve immunosuppressive therapy in severe cases of GVHD.

Indoleamine 2,3 Dioxygenase (IDO) Expression and Activity in Relapsing-Remitting Multiple Sclerosis.

BackgroundInterferon gamma (IFN-γ) production induces the transcription of indoleamine 2,3 dioxygenase (IDO) resulting in the reduction of T-cell activation and proliferation through the depletion of tryptophan and the elicitation of Treg lymphocytes. IDO was shown to be involved in the pathogenesis of autoimmune diseases; we investigated whether changes in IDO gene expression and activity could be indicative of onset of relapse in multiple sclerosis (MS) patients.MethodsIDO and interferon-γ (IFN-γ) gene expression, serum IDO activity (Kynurenine/Tryptophan ratio) and serum neopterin concentration – a protein released by macrophages upon IFN-γ stimulation – were measured in 51 individuals: 36 relapsing remitting (RR)-MS patients (21 in acute phase -AMS, 15 in stable phase -SMS) and 15 healthy controls (HC). PBMCs samples in AMS patients were collected before (BT-AMS) and during glucocorticoids-based therapy (DT-AMS).ResultsIDO expression was increased and IFN-γ was decreased (p<0.001) in BT-AMS compared to SMS patients. Glucocorticoids-induced disease remission resulted in a significant reduction of IDO and IFN-γ gene expression, IDO catalytic activity (p<0.001). Serum neopterin concentration followed the same trend as IDO expression and activity.ConclusionsMeasurement of IDO gene expression and activity in blood could be a useful marker to monitor the clinical course of RR-MS. Therapeutic interventions modulating IDO activity may be beneficial in MS.

Evaluation of Indoleamine 2,3- Dioxygenase Gene Expression and Activation in Chronic Spontaneous Urticaria

chronic spontaneous urticaria (CSU) is a common skin disorder characterized by the emergence of hives for at least six weeks without any known etiologic agent. Indoleamine 2,3- dioxygenase (IDO) which catalyzes tryptophan (Trp) to kynorenin (KYN) is an immunomedulatory enzyme and complicated in immunological diseases. This study, Trp, KYN and IDO gene expression in CSU patients were analyzed.