scholarly journals Different kynurenine pathway enzymes limit quinolinic acid formation by various human cell types

1997 ◽  
Vol 326 (2) ◽  
pp. 351-356 ◽  
Author(s):  
Melvyn P. HEYES ◽  
Cai Y. CHEN ◽  
Eugene O. MAJOR ◽  
Kuniaki SAITO
Keyword(s):  
Quinolinic Acid ◽  
Fetal Brain ◽  
Cell Types ◽  
Interferon Γ ◽  
Kynurenine Pathway ◽  
Human Cells ◽  
Hydroxylase Activity ◽  
Human Fetal Brain ◽  
Indoleamine 2,3 Dioxygenase ◽  
A Cell

Substantial increases in the tryptophan–kynurenine pathway metabolites, L-kynurenine and the neurotoxin quinolinic acid, occur in human brain, blood and systemic tissues during immune activation. Studies in vitrohave shown that not all human cells are capable of synthesizing quinolinate. To investigate further the mechanisms that limit L-kynurenine and quinolinate production, the activities of kynurenine pathway enzymes and the ability of different human cells to convert pathway intermediates into quinolinate were compared. Stimulation with interferon γ substantially increased indoleamine 2,3-dioxygenase activity and L-kynurenine production in primary peripheral blood macrophages and fetal brains (astrocytes and neurons), as well as cell lines derived from macrophage/monocytes (THP-1), U373MG astrocytoma, SKHEP1 liver and lung (MRC-9). High activities of kynurenine 3-hydroxylase, kynureninase or 3-hydroxyanthranilate 3,4-dioxygenase were found in interferon-γ-stimulated macrophages, THP-1 cells and SKHEP1 cells, and these cells made large amounts of quinolinate when supplied with L-tryptophan, L-kynurenine, 3-hydroxykynurenine or 3-hydroxyanthranilate. Quinolinate production by human fetal brain cultures and U373MG cells was restricted by the low activities of kynurenine 3-hydroxylase, kynureninase and 3-hydroxyanthranilate 3,4-dioxygenase, and only small amounts of quinolinate were synthesized when cultures were supplied with L-tryptophan or 3-hydroxyanthranilate. In MRC-9 cells, quinolinate was produced only from 3-hydroxykynurenine and 3-hydroxyanthranilate, consistent with their low kynurenine 3-hydroxylase activity. The results are consistent with the notion that indoleamine 2,3-dioxygenase is an important regulatory enzyme in the production of L-kynurenine and quinolinate. Kynurenine 3-hydroxylase and, in some cells, kynureninase and 3-hydroxyanthranilate 3,4-dioxygenase are important determinants of whether a cell can make quinolinate.

scholarly journals Human microglia convert l-tryptophan into the neurotoxin quinolinic acid

1996 ◽  
Vol 320 (2) ◽  
pp. 595-597 ◽  
Author(s):  
Melvyn P. HEYES ◽  
Cristian L. ACHIM ◽  
Clayton A. WILEY ◽  
Eugene O. MAJOR ◽  
Kuniaki SAITO ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Quinolinic Acid ◽  
Inflammatory Diseases ◽  
Fetal Brain ◽  
Interferon Γ ◽  
Ionization Mass ◽  
Human Fetal Brain ◽  
Human Microglia ◽  
The Central Nervous System

Immune activation leads to accumulations of the neurotoxin and kynurenine pathway metabolite quinolinic acid within the central nervous system of human patients. Whereas macrophages can convert l-tryptophan to quinolinic acid, it is not known whether human brain microglia can synthesize quinolinic acid. Human microglia, peripheral blood macrophages and cultures of human fetal brain cells (astrocytes and neurons) were incubated with [13C6]l-tryptophan in the absence or presence of interferon γ. [13C6]Quinolinic acid was identified and quantified by gas chromatography and electron-capture negative-chemical ionization mass spectrometry. Both l-kynurenine and [13C6]quinolinic acid were produced by unstimulated cultures of microglia and macrophages. Interferon γ, an inducer of indoleamine 2,3-dioxygenase, increased the accumulation of l-kynurenine by all three cell types (to more than 40 µM). Whereas large quantities of [13C6]quinolinic acid were produced by microglia and macrophages (to 438 and 1410 nM respectively), minute quantities of [13C6]quinolinic acid were produced in human fetal brain cultures (not more than 2 nM). Activated microglia and macrophage infiltrates into the brain might be an important source of accelerated conversion of l-tryptophan into quinolinic acid within the central nervous system in inflammatory diseases.

scholarly journals Parallel induction of tetrahydrobiopterin biosynthesis and indoleamine 2,3-dioxygenase activity in human cells and cell lines by interferon-γ

1989 ◽  
Vol 262 (3) ◽  
pp. 861-866 ◽  
Author(s):  
E R Werner ◽  
G Werner-Felmayer ◽  
D Fuchs ◽  
A Hausen ◽  
G Reibnegger ◽  
...  
Keyword(s):  
Cell Lines ◽  
Interferon Gamma ◽  
Interferon Γ ◽  
Human Cells ◽  
Gtp Cyclohydrolase I ◽  
Gtp Cyclohydrolase ◽  
Indoleamine 2,3 Dioxygenase ◽  
Cell Extracts ◽  
Dioxygenase Activity

In all of eight tested human cells and cell lines with inducible indoleamine 2,3-dioxygenase (EC 1.13.11.17) tetrahydrobiopterin biosynthesis was activated by interferon-gamma. This was demonstrated by GTP cyclohydrolase I (EC 3.5.4.16) activities and intracellular neopterin and biopterin concentrations. Pteridine synthesis was influenced by extracellular tryptophan. In T 24-cell extracts, submillimolar concentrations of tetrahydrobiopterin stimulated the indoleamine 2,3-dioxygenase reaction.

scholarly journals Checks and balances between human cytomegalovirus replication and indoleamine-2,3-dioxygenase

2014 ◽  
Vol 95 (3) ◽  
pp. 659-670 ◽  
Author(s):  
Albert Zimmermann ◽  
Sebastian Hauka ◽  
Marco Maywald ◽  
Vu Thuy Khanh Le ◽  
Silvia K. Schmidt ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Human Cytomegalovirus ◽  
Cell Types ◽  
Interferon Γ ◽  
Counter Measures ◽  
Indoleamine 2,3 Dioxygenase ◽  
Infected Cells ◽  
Hcmv Replication ◽  
Ifn Γ ◽  
The Impact

Despite a rigorous blockade of interferon-γ (IFN-γ) signalling in infected fibroblasts as a mechanism of immune evasion by human cytomegalovirus (HCMV), IFN-γ induced indoleamine-2,3-dioxygenase (IDO) has been proposed to represent the major antiviral restriction factor limiting HCMV replication in epithelial cells. Here we show that HCMV efficiently blocks transcription of IFN-γ-induced IDO mRNA both in infected fibroblasts and epithelial cells even in the presence of a preexisting IFN-induced antiviral state. This interference results in severe suppression of IDO bioactivity in HCMV-infected cells and restoration of vigorous HCMV replication. Depletion of IDO expression nonetheless substantially alleviated the antiviral impact of IFN-γ treatment in both cell types. These findings highlight the effectiveness of this IFN-γ induced effector gene in restricting HCMV productivity, but also the impact of viral counter-measures.

scholarly journals Nitric Oxide-Mediated Regulation of Gamma Interferon-Induced Bacteriostasis: Inhibition and Degradation of Human Indoleamine 2,3-Dioxygenase

2004 ◽  
Vol 72 (5) ◽  
pp. 2723-2730 ◽  
Author(s):  
Christian Hucke ◽  
Colin R. MacKenzie ◽  
Koku D. Z. Adjogble ◽  
Osamu Takikawa ◽  
Walter Däubener
Keyword(s):  
Nitric Oxide ◽  
Gene Transcription ◽  
Kynurenine Pathway ◽  
Gamma Interferon ◽  
Human Cells ◽  
Epithelial Cell Line ◽  
Tryptophan Depletion ◽  
No Production ◽  
Indoleamine 2,3 Dioxygenase ◽  
Ifn Γ

ABSTRACT Tryptophan depletion resulting from indoleamine 2,3-dioxygenase (IDO) activity within the kynurenine pathway is one of the most prominent gamma interferon (IFN-γ)-inducible antimicrobial effector mechanisms in human cells. On the other hand, nitric oxide (NO) produced by the inducible isoform of NO synthase (iNOS) serves a more immunoregulatory role in human cells and thereby interacts with tryptophan depletion in a number of ways. We investigated the effects of NO on IDO gene transcription, protein synthesis, and enzyme activity as well as on IDO-mediated bacteriostasis in the human epithelial cell line RT4. IFN-γ-stimulated RT4 cells were able to inhibit the growth of Staphylococcus aureus in an IDO-mediated fashion, and this bacteriostatic effect was abolished by endogenously produced NO. These findings were supported by experiments which showed that IDO activity in extracts of IFN-γ-stimulated cells is inhibited by the chemical NO donors diethylenetriamine diazeniumdiolate, S-nitroso-l-cysteine, and S-nitroso-N-acetyl-d,l-penicillamine. Furthermore, we found that both endogenous and exogenous NO strongly reduced the level of IDO protein content in RT4 cells. This effect was not due to a decrease in IDO gene transcription or mRNA stability. By using inhibitors of proteasomal proteolytic activity, we showed that NO production led to an accelerated degradation of IDO protein in the proteasome. This is the first report, to our knowledge, that demonstrates that the IDO is degraded by the proteasome and that NO has an effect on IDO protein stability.

scholarly journals 4-Chloro-3-hydroxyanthranilate, 6-chlorotryptophan and norharmane attenuate quinolinic acid formation by interferon-γ-stimulated monocytes (THP-1 cells)

1993 ◽  
Vol 291 (1) ◽  
pp. 11-14 ◽  
Author(s):  
K Saito ◽  
C Y Chen ◽  
M Masana ◽  
J S Crowley ◽  
S P Markey ◽  
...  
Keyword(s):  
Interferon Gamma ◽  
Quinolinic Acid ◽  
Immune Activation ◽  
Mononuclear Cells ◽  
Kynurenine Pathway ◽  
Liver Cells ◽  
Acid Formation ◽  
Peripheral Blood Mononuclear ◽  
Indoleamine 2,3 Dioxygenase ◽  
Ic50 Values

Accumulation of quinolinic acid and L-kynurenine occurs in the brain and/or blood following immune activation, and may derive from L-tryptophan following induction of indoleamine 2,3-dioxygenase and other kynurenine-pathway enzymes. In the present study a survey of various cell lines derived from either brain or systemic tissues showed that, while all cells examined responded to interferon-gamma by increased conversion of L-[13C6]tryptophan into L-kynurenine (human: B-lymphocytes, neuroblastoma, glioblastoma, lung, liver, kidney; rat brain: microglia, astrocytes and oligodendrocytes), only macrophage-derived cells (peripheral-blood mononuclear cells; THP-1, U-937) and certain liver cells (SKHep1) synthesized [13C6]quinolinic acid. Tumour necrosis factor-alpha enhanced the effects of interferon-gamma in THP-1 cells. Norharmane, 6-chloro-DL-tryptophan and 4-chloro-3-hydroxyanthranilate attenuated quinolinic acid formation by THP-1 cells with IC50 values of 51 microM, 58 microM and 0.11 microM respectively. Norharmane and 6-chloro-DL-tryptophan attenuated L-kynurenine formation with IC50 values of 43 microM and 51 microM respectively, whereas 4-chloro-3-hydroxyanthranilate had no effect on L-kynurenine accumulation. The reductions in L-kynurenine and quinolinic acid formation are consistent with the reports that norharmane is an inhibitor of indoleamine 2,3-dioxygenase, 6-chloro-DL-tryptophan is metabolized through the kynurenine pathway, and 4-chloro-3-hydroxyanthranilate is an inhibitor of 3-hydroxyanthranilate 3,4-dioxygenase. These results suggest that many tissues may contribute to the production of L-kynurenine following indoleamine 2,3-dioxygenase induction and immune activation. Quinolinic acid may be directly synthesized from L-tryptophan in both macrophages and certain types of liver cells, although uptake of quinolinic acid precursors from blood may contribute to quinolinic acid synthesis in cells that cannot convert L-kynurenine into quinolinic acid.

scholarly journals Localization of Indoleamine 2,3-Dioxygenase-1 and Indoleamine 2,3-Dioxygenase-2 at the Human Maternal-Fetal Interface

2020 ◽  
Vol 13 ◽  
pp. 117864692098416
Author(s):  
Yoshiki Kudo ◽  
Iemasa Koh ◽  
Jun Sugimoto
Keyword(s):  
Interferon Γ ◽  
Kynurenine Pathway ◽  
Explant Culture ◽  
Immunohistochemical Localization ◽  
Tryptophan Metabolism ◽  
Indoleamine 2,3 Dioxygenase ◽  
Cellular Expression ◽  
Normal Human ◽  
Protein Immunoreactivity ◽  
Maternal Fetal Interface

Immunohistochemical localization of indoleamine 2,3-dioxygenase-1 and indoleamine 2,3-dioxygenase-2, the first and rate-limiting enzyme in tryptophan metabolism along the kynurenine pathway, has been studied in order to better understand the physiological significance of these enzymes at the maternal-fetal interface of human pregnancy with a gestational age of 7 weeks (n = 1) and term placentas (37-40 weeks of gestation, n = 5). Indoleamine 2,3-dioxygenase-1 protein immunoreactivity was found in glandular epithelium of the decidua and the endothelium of the fetal blood vessels in the villous stroma with some additional positive cells in the villous core and in the decidua. The syncytiotrophoblast stained strongly for indoleamine 2,3-dioxygenase-2. Immunoreactivity of kynurenine, the immediate downstream product of indoleamine 2,3-dioxygenase-mediated tryptophan metabolism, showed the same localization as that of indoleamine 2,3-dioxygenase-1 and indoleamine 2,3-dioxygenase-2, suggesting these are functional enzymes. Interferon-γ added to placental villous explant culture markedly stimulated expression level of both mRNA and immunoreactivity of indoleamine 2,3-dioxygenase-1. The different cellular expression and interferon-γ sensitivity of these enzymes at the maternal-fetal interface suggests distinct physiological roles for each enzyme in normal human viviparity.

scholarly journals Investigation of the Tissue Distribution and Physiological Roles of Indoleamine 2,3-Dioxygenase-2

2017 ◽  
Vol 10 ◽  
pp. 117864691773509 ◽  
Author(s):  
Felicita F Jusof ◽  
Supun M Bakmiwewa ◽  
Silvia Weiser ◽  
Lay Khoon Too ◽  
Richard Metz ◽  
...  
Keyword(s):  
Immune Cell ◽  
Cell Types ◽  
Tissue Expression ◽  
Kynurenine Pathway ◽  
Indoleamine 2,3 Dioxygenase ◽  
Splicing Pattern ◽  
Inflammatory Stimuli ◽  
Ido1 Expression ◽  
Tryptophan Catabolism ◽  
Restricted Pattern

Indoleamine 2,3-dioxygenase-2 (IDO2) is 1 of the 3 enzymes that can catalyze the first step in the kynurenine pathway of tryptophan metabolism. Of the 2 other enzymes, tryptophan 2,3-dioxygenase is highly expressed in the liver and has a role in tryptophan homeostasis, whereas indoleamine 2,3-dioxygenase-1 (IDO1) expression is induced by inflammatory stimuli. Indoleamine 2,3-dioxygenase-2 is reportedly expressed comparatively narrow, including in liver, kidney, brain, and in certain immune cell types, and it does not appear to contribute significantly to systemic tryptophan catabolism under normal physiological conditions. Here, we report the identification of an alternative splicing pattern, including the use of an alternative first exon, that is conserved in the mouse Ido1 and Ido2 genes. These findings prompted us to assess IDO2 protein expression and enzymatic activity in tissues. Our analysis, undertaken in Ido2 +/+ and Ido2−/− mice using immunohistochemistry and measurement of tryptophan and kynurenine levels, suggested an even more restricted pattern of tissue expression than previously reported. We found IDO2 protein to be expressed in the liver with a perinuclear/nuclear, rather than cytoplasmic, distribution. Consistent with earlier reports, we found Ido2 −/− mice to be phenotypically similar to their Ido2+/+ counterparts regarding levels of tryptophan and kynurenine in the plasma and liver. Our findings suggest a specialized function or regulatory role for IDO2 associated with its particular subcellular localization.

scholarly journals Tryptophan catabolism is associated with acute GVHD after human allogeneic stem cell transplantation and indicates activation of indoleamine 2,3-dioxygenase

Blood ◽  
2011 ◽  
Vol 118 (26) ◽  
pp. 6971-6974 ◽  
Author(s):  
Karin Landfried ◽  
Wentao Zhu ◽  
Magdalena C. Waldhier ◽  
Ute Schulz ◽  
Julia Ammer ◽  
...  
Keyword(s):  
Stem Cell ◽  
Stem Cell Transplantation ◽  
Cell Transplantation ◽  
Allogeneic Stem Cell Transplantation ◽  
Quinolinic Acid ◽  
Acute Gvhd ◽  
Kynurenine Pathway ◽  
Indoleamine 2,3 Dioxygenase ◽  
Tryptophan Degradation ◽  
Liquid Chromatography Tandem Mass

Abstract Induction of indoleamine 2,3-dioxygenase (IDO), the rate-limiting enzyme in tryptophan degradation along the kynurenine pathway, acts as a potent immunoregulatory loop. To address its role in human allogeneic stem cell transplantation, we measured major tryptophan metabolites, such as quinolinic acid and kynurenine, in serial urine specimens from 51 patients by liquid chromatography-tandem mass spectrometry. Samples were collected between admission and day 90 after transplantation, and metabolite levels were correlated with early clinical events and outcome. In selected patients, IDO gene expression was assessed by quantitative RT-PCR in intestinal biopsies. Surviving patients had significantly lower metabolite levels on days 28, 42, and 90, respectively, compared with patients dying of GVHD and associated complications (n = 10). Kynurenine levels were directly correlated with severity and clinical course of GVHD: Mean urinary quinolinic acid levels were 4.5 ± 0.3 μmol/mmol creatinine in the absence of acute GVHD, 8.0 ± 1.1 μmol/mmol creatinine for GVHD grade 1 or 2, and 13.5 ± 2.7 μmol/mmol creatinine for GVHD grade 3 or 4 (P < .001), respectively. GVHD-dependent induction of IDO was further suggested by increased expression of IDO mRNA in intestinal biopsies from patients with severe GVHD. Our data indicate reactive release of kynurenines in GVHD-associated inflammation.

scholarly journals B-Cell-Targeted 3DNA Nanotherapy Against Indoleamine 2,3-Dioxygenase 2 (IDO2) Ameliorates Autoimmune Arthritis in a Preclinical Model

2020 ◽  
Vol 13 ◽  
pp. 2632010X2095181
Author(s):  
Lauren MF Merlo ◽  
Jessica Bowers ◽  
Tony Stefanoni ◽  
Robert Getts ◽  
Laura Mandik-Nayak
Keyword(s):  
B Cells ◽  
B Cell ◽  
Cell Types ◽  
Preclinical Model ◽  
Autoimmune Arthritis ◽  
Specific Cell ◽  
Dna Nanostructures ◽  
Intracellular Protein ◽  
Indoleamine 2,3 Dioxygenase ◽  
A Cell

The tryptophan catabolizing enzyme indoleamine 2,3-dioxygenase 2 (IDO2) has been identified as an immunomodulatory agent promoting autoimmunity in preclinical models. As such, finding ways to target the expression of IDO2 in B cells promises a new avenue for therapy for debilitating autoimmune disorders such as rheumatoid arthritis. IDO2, like many drivers of disease, is an intracellular protein expressed in a range of cells, and thus therapeutic inhibition of IDO2 requires a mechanism for targeting this intracellular protein in specific cell types. DNA nanostructures are a promising novel way of delivering small molecule drugs, antibodies, or siRNAs to the cytoplasm of a cell. These soluble, branched structures can carry cell-specific targeting moieties along with their therapeutic deliverable. Here, we examined a 3DNA nanocarrier specifically targeted to B cells with an anti-CD19 antibody. We find that this 3DNA is successfully delivered to and internalized in B cells. To test whether these nanostructures can deliver an efficacious therapeutic dose to alter autoimmune responses, a modified anti-IDO2 siRNA was attached to B-cell-directed 3DNA nanocarriers and tested in an established preclinical model of autoimmune arthritis, KRN.g7. The anti-IDO2 3DNA formulation ameliorates arthritis in this system, delaying the onset of joint swelling and reducing total arthritis severity. As such, a 3DNA nanocarrier system shows promise for delivery of targeted, specific, low-dose therapy for autoimmune disease.

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