|
|
||||||||



*
Surgery Branch, Division of Clinical Sciences, National Cancer Institute, Bethesda, MD 20892;
Department of Biology, Indiana University, Bloomington, IN 47405; and
National Cancer Institute-Frederick Cancer Research and Development Center, Frederick, MD 21702
| Abstract |
|---|
|
|
|---|
. IDO produced from
activated DCs was functionally active and capable of metabolizing
tryptophan to kynurenine. Activated T cells were also capable of
inducing IDO production by DCs, which was inhibited by a neutralizing
Ab against IFN-
. DC production of IDO resulted in inhibition of T
cell proliferation, which could be prevented using the IDO inhibitor
1-methyl-DL-tryptophan. These results suggest that
activation of DCs induces the production of functional IDO, which
causes depletion of tryptophan and subsequent inhibition of T cell
proliferation. This may represent a potential mechanism for DCs to
regulate the immune response. | Introduction |
|---|
|
|
|---|
Indoleamine 2,3-dioxygenase (IDO) is the rate-limiting enzyme in the catabolism of tryptophan (4). IDO production by syncytiotrophoblasts (5) or macrophages (6) has recently been demonstrated to result in the inhibition of T cell proliferation due to tryptophan depletion. We hypothesized that IDO may be produced by activated DCs as a possible mechanism to regulate T cell responses.
| Materials and Methods |
|---|
|
|
|---|
Buffy coats were obtained from normal donors or melanoma
patients treated at the Clinical Center, National Institutes of Health
(Bethesda, MD). No differences were observed between cells derived from
normal donors and melanoma patients. PBMC were isolated using a
Ficoll-Hypaque gradient (LSM; ICN Pharmaceuticals, Aurora, OH). Cells
were plated in culture flasks or plates (1 x
108 cells per T-75, 3 x
107 cells per T-25, or 1 x
106 cells/well in 96-well flat-bottom plates, all
from Costar, Corning, NY) using RPMI 1640 medium (Life Technologies,
Gaithersburg, MD) supplemented with 10% human AB serum (Gemini
Biological Products, Calabasas, CA), glutamine, and antibiotics (Life
Technologies), and adherent cells were isolated after overnight culture
at 37°C. Adherent monocytes were cultured in GM-CSF (100 ng/ml, which
is equivalent to 1000 U/ml) and IL-4 (500 ng/ml = 1000 U/ml; both
from PeproTech, Rocky Hill, NJ, and added on days 1, 3, and 5 of
culture) (7, 8). For studies utilizing purified DCs,
monocytes were initially isolated using negative selection instead of
adherence (StemSep Columns; Stem Cell Technologies, Vancouver, Canada).
On day 6 of culture, DCs were activated with soluble CD40L trimer (500
ng/ml; gift from Immunex, Seattle, WA), LPS from Salmonella
typhimurium (5 µg/ml; Sigma, St. Louis, MO), IFN-
(50
ng/ml = 1000 U/ml; Peprotech), or combinations of these agents as
indicated.
Colon cancer (Colo 320, HCT116, Lovo, and LS180) and breast cancer (MDA-MB-231) cell lines were obtained from American Type Culture Collection (Manassas, VA) and were cultured in RPMI 1640 containing 10% FCS.
Northern blot analysis
RNA from DCs was isolated 6 and 24 h after activation. Briefly, total RNA was isolated using a single-step phenol/chloroform extraction procedure (Trizol; Life Technologies). For Northern blotting analysis, 10 µg of total cellular RNA was analyzed by Northern blotting following electrophoresis on a 0.8% formaldehyde agarose gel and hybridized with random-primed 32P-labeled cDNA probes as reported (9). (The human IDO cDNA was a gift from Dr. Sohan Gupta, Hipple Cancer Research Center, Dayton, OH and the chicken ß-actin gene was obtained from Dr. Donald Cleveland, Johns Hopkins University.)
Kynurenine assay
Tryptophan is catabolized by IDO to N-formylkynurenine which is rapidly converted to kynurenine. Measurement of kynurenine levels can provide evidence of functional IDO activity. Because kynurenine can be further metabolized to downstream products, it is not entirely quantitative, but can provide a relative indication of IDO activity.
Approximately 24 h after activation, DCs were washed and resuspended in HBSS containing 100 µM tryptophan (Life Technologies). Cells were incubated for an additional 4 h, followed by harvest of supernatant and quantitation of kynurenine by HPLC. HPLC was performed according to Young and Lau (10) with minor modifications. Briefly, 25 µl of the clarified sample was injected into a Vydac C18 monomeric column and eluted with KH2PO4 buffer (0.01 M KH2PO4 and 0.15 mM EDTA, pH 5.0) containing 10% methanol at a flow rate of 1.0 ml/min. The spectrophotometer was set at 254 nm to detect both kynurenine and tryptophan. The retention time was previously determined with standard solutions of kynurenine and tryptophan. IDO activity was expressed as the concentration in micromolars of kynurenine in the sample, converted from tryptophan by IDO.
T cell cultures and proliferation assay
Autologous T cells were isolated by negative selection using immunoaffinity columns containing Abs against B cells, NK cells, and monocytes (R&D Systems, Minneapolis, MN). DCs were cultured and activated in 96-well plates as described above. Twenty-four hours after DC activation, medium was replaced, and OKT3 (anti-CD3; Ortho-Biotech, Raritan, NJ) and autologous T cells (2 x 105 cells/well) were added in the presence and absence of a variety of concentrations of 1-methyl-DL-tryptophan (1-MT; 250 µg/ml, 500 µg/ml, and 1000 µg/ml; Aldrich Chemical, Milwaukee, WI). Four to 5 days later, T cell proliferation was measured using overnight incubation with [3H]thymidine (1 µCi/well; NEN/DuPont, Boston, MA).
Activation of DCs with T cells and anti-CD3
On day 6 of DC cultures, purified T cells (1 x
107 T cells per T-75) were added in the presence
of 100 ng/ml OKT3. To determine the role of IFN-
, 500 ng/ml of a
neutralizing Ab against IFN-
(from clone 25718.111; R&D Systems) or
an equivalent concentration of an isotype control was added. T cells
were removed 48 h later using anti-CD2-coated magnetic beads
(dynabeads; Dynal, Oslo, Norway). DCs were then replated at a
concentration of 1 x 105 cells/well in a
96-well plate or 1 x 106 cells/well in a
24-well plate in HBSS containing 100 µM tryptophan. Cells were
cultured at 37°C for an additional 8 h, and supernatants were
then harvested for the kynurenine assay as described above.
| Results |
|---|
|
|
|---|
, or combinations of
these, and total RNA was prepared 6 and 24 h after activation.
Using a human IDO cDNA probe, Northern blot analysis revealed a
strongly hybridizing 2.0-kb band from DCs activated with a combination
of CD40L, LPS, and IFN-
. This was seen by 6 h after activation
(Fig. 1
alone and the combination
of CD40L and LPS induced IDO mRNA in six of six and seven of eight DC
cultures, respectively, but the hybridization intensity was variable
and only weakly positive for some cultures. CD40L or LPS alone did not
consistently induce IDO mRNA. No differences were seen between DCs
derived from normal donors or those derived from melanoma patients.
|
, or combinations of
these agents, cells were washed and resuspended in HBSS containing 100
µM tryptophan and incubated at 37°C. Four hours later, supernatants
were harvested and kynurenine was measured by HPLC as described above.
Kynurenine was not detected in supernatants of nonactivated DCs or DCs
activated with soluble CD40L trimer alone. However, kynurenine was
detected in two of five cultures activated with LPS alone (mean, 6.4
µM), and levels increased in supernatants from DCs activated with a
combination of CD40L and LPS (mean, 13.6 µM). IDO activity was also
detected in four of five DC cultures activated with IFN-
alone (mean
kynurenine, 22.2 µM), and kynurenine levels were highest in DC
cultures activated with a combination of CD40L, LPS, and IFN-
(kynurenine detected in five of five cultures; mean, 34.8 µM) or
CD40L and IFN-
(kynurenine detected in four of four cultures; mean,
40.5 µM). (Fig. 2
or CD40L/IFN-
in
the presence of tryptophan resulted in high levels of kynurenine (Table I
or CD40L and IFN-
.
|
|
|
upon contact with activated T cells. To determine
whether activated T cells were capable of eliciting IDO production from
DCs, we cocultured nonactivated DC with resting autologous T cells in
the presence of soluble anti-CD3 (OKT3). An
IFN-
-neutralizing Ab was added to some of the groups to
determine whether IDO production was IFN-
dependent. Two days after
coculture, T cells were removed by positive selection, and the
remaining cells were cultured in the presence of HBSS containing 100
µM tryptophan. As before, nonactivated DCs demonstrated no IDO
activity. Significant IDO activity was seen in DCs that were exposed to
OKT3-activated T cells. IDO activity appeared to be IFN-
dependent,
since kynurenine levels were significantly lower in DCs and T cells
that were cocultured in the presence of an IFN-
-neutralizing Ab.
This experiment was repeated with similar results (Table II
|
were cocultured with autologous T cells and OKT3 in the
presence or absence of a variety of concentrations of 1-MT. In repeated
studies, the presence of increasing concentrations of 1-MT resulted in
enhanced T cell proliferation (Fig. 4
|
| Discussion |
|---|
|
|
|---|
. An alternative explanation is that IDO
may be produced by a subset of inhibitory DCs within the bulk
population, since evidence exists for the presence of inhibitory
or tolerogenic DCs (1, 11). The studies we have described
have utilized bulk monocyte-derived DCs. Further analysis of this
possibility will require additional knowledge concerning the phenotypic
markers for tolerogenic DC subsets. A contrasting explanation may be that IDO production by activated DCs may result in a transient inhibition of proliferation that may protect T cells against activation-induced cell death. Since activation-induced cell death occurs upon activation of proliferating T cells (12), transient tryptophan depletion may inhibit T cell proliferation at the height of activation, thereby preventing T cell death. Tryptophan depletion has been demonstrated to inhibit T cell proliferation at a mid-G1 arrest point, but this was reversible with addition of tryptophan along with T cell stimulation (6). Activated DCs have been shown to be present in the lymph node early in the immune response, but fail to be detected 48 h later (13). This may allow tryptophan levels to return to normal in the T cell microenvironment shortly after activation, thereby providing a milieu that is once again permissive for T cell proliferation.
Attempts are currently underway to utilize activated DCs for viral and
tumor immunotherapy. If IDO production by DCs is indeed inhibitory for
cellular immune responses, it is possible that systemic inhibition of
IDO may enhance the T cell-activating ability of DCs. Munn et al.
(5) demonstrated that systemic administration of 1-MT
resulted in enhanced T cell responses against allogeneic concepti.
Further work is needed to determine whether 1-MT can improve the
antitumor efficacy of infused DCs. In addition, although it has been
demonstrated that IDO production by macrophages, syncytiotrophoblasts,
and now DCs can inhibit T cells, it is not clear whether other tissues
can be induced to produce IDO capable of depleting local concentrations
of tryptophan and inhibiting cellular immune responses. For example, it
is possible that tumor cells may evade immune recognition if they can
be induced to produce functional IDO. Consistent with this hypothesis,
we have observed that tumor cells can produce IDO mRNA upon stimulation
with IFN-
(Fig. 5
). Further studies
are needed to determine the range of cells capable of inhibiting T
cells through tryptophan depletion.
|
| Footnotes |
|---|
2 Abbreviations used in this paper: DC, dendritic cell; IDO, indoleamine 2,3-dioxygenase; CD40L, CD40 ligand; 1-MT, 1-methyl tryptophan. ![]()
Received for publication January 10, 2000. Accepted for publication January 27, 2000.
| References |
|---|
|
|
|---|
, indoleamine 2,3-dioxygenase, and tryptophan catabolism. FASEB J. 5:2516.[Abstract]
exhibit phenotype and function of blood dendritic cells. Adv. Exp. Med. Biol. 378:75.[Medline]
production induced by IL-2 and IL-12 in a human NK cell line. J. Leukocyte Biol. 58:225.[Abstract]
This article has been cited by other articles:
![]() |
M. K. Tulic, P. D. Sly, D. Andrews, M. Crook, F. Davoine, S. O. Odemuyiwa, A. Charles, M. L. Hodder, S. L. Prescott, P. G. Holt, et al. Thymic Indoleamine 2,3-Dioxygenase-Positive Eosinophils in Young Children: Potential Role In Maturation of the Naive Immune System Am. J. Pathol., November 1, 2009; 175(5): 2043 - 2052. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. Jurgens, U. Hainz, D. Fuchs, T. Felzmann, and A. Heitger Interferon-{gamma}-triggered indoleamine 2,3-dioxygenase competence in human monocyte-derived dendritic cells induces regulatory activity in allogeneic T cells Blood, October 8, 2009; 114(15): 3235 - 3243. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. J. Chung, M. Rossi, E. Romano, J. Ghith, J. Yuan, D. H. Munn, and J. W. Young Indoleamine 2,3-dioxygenase-expressing mature human monocyte-derived dendritic cells expand potent autologous regulatory T cells Blood, July 16, 2009; 114(3): 555 - 563. [Abstract] [Full Text] [PDF] |
||||
![]() |
F. Qian, J. Villella, P. K. Wallace, P. Mhawech-Fauceglia, J. D. Tario Jr., C. Andrews, J. Matsuzaki, D. Valmori, M. Ayyoub, P. J. Frederick, et al. Efficacy of Levo-1-Methyl Tryptophan and Dextro-1-Methyl Tryptophan in Reversing Indoleamine-2,3-Dioxygenase-Mediated Arrest of T-Cell Proliferation in Human Epithelial Ovarian Cancer Cancer Res., July 1, 2009; 69(13): 5498 - 5504. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. J. Workman, Y. Wang, K. C. El Kasmi, D. M. Pardoll, P. J. Murray, C. G. Drake, and D. A. A. Vignali LAG-3 Regulates Plasmacytoid Dendritic Cell Homeostasis J. Immunol., February 15, 2009; 182(4): 1885 - 1891. [Abstract] [Full Text] [PDF] |
||||
![]() |
Y.-I. Jeong, S. W. Kim, I. D. Jung, J. S. Lee, J. H. Chang, C.-M. Lee, S. H. Chun, M.-S. Yoon, G. T. Kim, S. W. Ryu, et al. Curcumin Suppresses the Induction of Indoleamine 2,3-Dioxygenase by Blocking the Janus-activated Kinase-Protein Kinase C{delta}-STAT1 Signaling Pathway in Interferon-{gamma}-stimulated Murine Dendritic Cells J. Biol. Chem., February 6, 2009; 284(6): 3700 - 3708. [Abstract] [Full Text] [PDF] |
||||
![]() |
W. Chen, X. Liang, A. J. Peterson, D. H. Munn, and B. R. Blazar The Indoleamine 2,3-Dioxygenase Pathway Is Essential for Human Plasmacytoid Dendritic Cell-Induced Adaptive T Regulatory Cell Generation J. Immunol., October 15, 2008; 181(8): 5396 - 5404. [Abstract] [Full Text] [PDF] |
||||
![]() |
D.-K. Shen, D. Filopon, H. Chaker, S. Boullanger, M. Derouazi, B. Polack, and B. Toussaint High-cell-density regulation of the Pseudomonas aeruginosa type III secretion system: implications for tryptophan catabolites Microbiology, August 1, 2008; 154(8): 2195 - 2208. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. J. A. M. Santegoets, S. Gibbs, K. Kroeze, R. van de Ven, R. J. Scheper, C. A. Borrebaeck, T. D. de Gruijl, and M. Lindstedt Transcriptional profiling of human skin-resident Langerhans cells and CD1a+ dermal dendritic cells: differential activation states suggest distinct functions J. Leukoc. Biol., July 1, 2008; 84(1): 143 - 151. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. Botturi, Y. Lacoeuille, P. Thomas, S. Boniface, M. Reynaud-Gaubert, and A. Magnan CTLA-4-mediated regulatory phenotype of T-cells in tolerant lung recipients Eur. Respir. J., June 1, 2008; 31(6): 1167 - 1176. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. Li, A. Meinhardt, M.-E. Roehrich, D. Golshayan, J. Dudler, M. Pagnotta, M. Trucco, and G. Vassalli Indoleamine 2,3-dioxygenase gene transfer prolongs cardiac allograft survival Am J Physiol Heart Circ Physiol, December 1, 2007; 293(6): H3415 - H3423. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. Hayashi, J.-H. Mo, X. Gong, C. Rossetto, A. Jang, L. Beck, G. I. Elliott, I. Kufareva, R. Abagyan, D. H. Broide, et al. 3-Hydroxyanthranilic acid inhibits PDK1 activation and suppresses experimental asthma by inducing T cell apoptosis PNAS, November 20, 2007; 104(47): 18619 - 18624. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. Krause, E. Singer, P. I. Darley, J. Klebensberger, M. Groettrup, and D. F. Legler Prostaglandin E2 is a key factor for monocyte-derived dendritic cell maturation: enhanced T cell stimulatory capacity despite IDO J. Leukoc. Biol., November 1, 2007; 82(5): 1106 - 1114. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. C. Cuffy, A. M. Silverio, L. Qin, Y. Wang, R. Eid, G. Brandacher, F. G. Lakkis, D. Fuchs, J. S. Pober, and G. Tellides Induction of Indoleamine 2,3-Dioxygenase in Vascular Smooth Muscle Cells by Interferon-{gamma} Contributes to Medial Immunoprivilege J. Immunol., October 15, 2007; 179(8): 5246 - 5254. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. A. Derks, E. Jankowska-Gan, Q. Xu, and W. J. Burlingham Dendritic Cell Type Determines the Mechanism of Bystander Suppression by Adaptive T Regulatory Cells Specific for the Minor Antigen HA-1 J. Immunol., September 15, 2007; 179(6): 3443 - 3451. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. Lizee, M. A. Cantu, and P. Hwu Less Yin, More Yang: Confronting the Barriers to Cancer Immunotherapy Clin. Cancer Res., September 15, 2007; 13(18): 5250 - 5255. [Abstract] [Full Text] [PDF] |
||||
![]() |
Y.-H. Ryu and J.-C. Kim Expression of Indoleamine 2,3-Dioxygenase in Human Corneal Cells as a Local Immunosuppressive Factor Invest. Ophthalmol. Vis. Sci., September 1, 2007; 48(9): 4148 - 4152. [Abstract] [Full Text] [PDF] |
||||
![]() |
Z. Fan, X.-L. Huang, P. Kalinski, S. Young, and C. R. Rinaldo Jr. Dendritic Cell Function during Chronic Hepatitis C Virus and Human Immunodeficiency Virus Type 1 Infection Clin. Vaccine Immunol., September 1, 2007; 14(9): 1127 - 1137. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. Mohib, Q. Guan, H. Diao, C. Du, and A. M. Jevnikar Proapoptotic activity of indoleamine 2,3-dioxygenase expressed in renal tubular epithelial cells Am J Physiol Renal Physiol, September 1, 2007; 293(3): F801 - F812. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. W. Tas, M. J. Vervoordeldonk, N. Hajji, J. H. N. Schuitemaker, K. F. van der Sluijs, M. J. May, S. Ghosh, M. L. Kapsenberg, P. P. Tak, and E. C. de Jong Noncanonical NF-{kappa}B signaling in dendritic cells is required for indoleamine 2,3-dioxygenase (IDO) induction and immune regulation Blood, September 1, 2007; 110(5): 1540 - 1549. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. Feunou, S. Vanwetswinkel, F. Gaudray, M. Goldman, P. Matthys, and M. Y. Braun Foxp3+CD25+ T Regulatory Cells Stimulate IFN-{gamma}-Independent CD152-Mediated Activation of Tryptophan Catabolism That Provides Dendritic Cells with Immune Regulatory Activity in Mice Unresponsive to Staphylococcal Enterotoxin B J. Immunol., July 15, 2007; 179(2): 910 - 917. [Abstract] [Full Text] [PDF] |
||||
![]() |
Z.M. Lei, M. Yang, X. Li, O. Takikawa, and C.V. Rao Upregulation of Placental Indoleamine 2,3-Dioxygenase by Human Chorionic Gonadotropin Biol Reprod, April 1, 2007; 76(4): 639 - 644. [Abstract] [Full Text] [PDF] |
||||
![]() |
D.-Y. Hou, A. J. Muller, M. D. Sharma, J. DuHadaway, T. Banerjee, M. Johnson, A. L. Mellor, G. C. Prendergast, and D. H. Munn Inhibition of Indoleamine 2,3-Dioxygenase in Dendritic Cells by Stereoisomers of 1-Methyl-Tryptophan Correlates with Antitumor Responses Cancer Res., January 15, 2007; 67(2): 792 - 801. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. D. Chiesa, S. Carlomagno, G. Frumento, M. Balsamo, C. Cantoni, R. Conte, L. Moretta, A. Moretta, and M. Vitale The tryptophan catabolite L-kynurenine inhibits the surface expression of NKp46- and NKG2D-activating receptors and regulates NK-cell function Blood, December 15, 2006; 108(13): 4118 - 4125. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. L. Seymour, V. Ganapathy, A. L. Mellor, and D. H. Munn A high-affinity, tryptophan-selective amino acid transport system in human macrophages J. Leukoc. Biol., December 1, 2006; 80(6): 1320 - 1327. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. Baas, C. R. Baskin, D. L. Diamond, A. Garcia-Sastre, H. Bielefeldt-Ohmann, T. M. Tumpey, M. J. Thomas, V. S. Carter, T. H. Teal, N. Van Hoeven, et al. Integrated Molecular Signature of Disease: Analysis of Influenza Virus-Infected Macaques through Functional Genomics and Proteomics J. Virol., November 1, 2006; 80(21): 10813 - 10828. [Abstract] [Full Text] [PDF] |
||||
![]() |
X. Zheng, J. Koropatnick, M. Li, X. Zhang, F. Ling, X. Ren, X. Hao, H. Sun, C. Vladau, J. A. Franek, et al. Reinstalling Antitumor Immunity by Inhibiting Tumor-Derived Immunosuppressive Molecule IDO through RNA Interference J. Immunol., October 15, 2006; 177(8): 5639 - 5646. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Agaugue, L. Perrin-Cocon, F. Coutant, P. Andre, and V. Lotteau 1-Methyl-Tryptophan Can Interfere with TLR Signaling in Dendritic Cells Independently of IDO Activity J. Immunol., August 15, 2006; 177(4): 2061 - 2071. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. D. Basu, T. L. Tinder, J. M. Bradley, T. Tu, C. L. Hattrup, B. A. Pockaj, and P. Mukherjee Cyclooxygenase-2 Inhibitor Enhances the Efficacy of a Breast Cancer Vaccine: Role of IDO J. Immunol., August 15, 2006; 177(4): 2391 - 2402. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. Lizee, L. G. Radvanyi, W. W. Overwijk, and P. Hwu Improving Antitumor Immune Responses by Circumventing Immunoregulatory Cells and Mechanisms. Clin. Cancer Res., August 15, 2006; 12(16): 4794 - 4803. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. J. Engelhardt, T. J. Sullivan, and J. P. Allison CTLA-4 Overexpression Inhibits T Cell Responses through a CD28-B7-Dependent Mechanism J. Immunol., July 15, 2006; 177(2): 1052 - 1061. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. S. von Bergwelt-Baildon, A. Popov, T. Saric, J. Chemnitz, S. Classen, M. S. Stoffel, F. Fiore, U. Roth, M. Beyer, S. Debey, et al. CD25 and indoleamine 2,3-dioxygenase are up-regulated by prostaglandin E2 and expressed by tumor-associated dendritic cells in vivo: additional mechanisms of T-cell inhibition Blood, July 1, 2006; 108(1): 228 - 237. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. J. Cannon and J. L. Pate Indoleamine 2,3-Dioxygenase Participates in the Interferon-gamma-Induced Cell Death Process in Cultured Bovine Luteal Cells Biol Reprod, March 1, 2006; 74(3): 552 - 559. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. J. O'Connell, X. Wang, M. Leon-Ponte, C. Griffiths, S. C. Pingle, and G. P. Ahern A novel form of immune signaling revealed by transmission of the inflammatory mediator serotonin between dendritic cells and T cells Blood, February 1, 2006; 107(3): 1010 - 1017. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Hill, V. Pereira, C. Chauveau, R. Zagani, S. Remy, L. Tesson, D. Mazal, L. Ubillos, R. Brion, K. Ashgar, et al. Heme oxygenase-1 inhibits rat and human breast cancer cell proliferation: mutual cross inhibition with indoleamine 2,3-dioxygenase FASEB J, December 1, 2005; 19(14): 1957 - 1968. [Abstract] [Full Text] [PDF] |
||||
![]() |
N. Miwa, S. Hayakawa, S. Miyazaki, S. Myojo, Y. Sasaki, M. Sakai, O. Takikawa, and S. Saito IDO expression on decidual and peripheral blood dendritic cells and monocytes/macrophages after treatment with CTLA-4 or interferon-{gamma} increase in normal pregnancy but decrease in spontaneous abortion Mol. Hum. Reprod., December 1, 2005; 11(12): 865 - 870. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. Braun, R. S. Longman, and M. L. Albert A two-step induction of indoleamine 2,3 dioxygenase (IDO) activity during dendritic-cell maturation Blood, October 1, 2005; 106(7): 2375 - 2381. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. Potula, L. Poluektova, B. Knipe, J. Chrastil, D. Heilman, H. Dou, O. Takikawa, D. H. Munn, H. E. Gendelman, and Y. Persidsky Inhibition of indoleamine 2,3-dioxygenase (IDO) enhances elimination of virus-infected macrophages in an animal model of HIV-1 encephalitis Blood, October 1, 2005; 106(7): 2382 - 2390. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. H. Munn A cautionary tale Blood, May 15, 2005; 105(10): 3761 - 3762. [Full Text] [PDF] |
||||
![]() |
U. Hainz, P. Obexer, C. Winkler, P. Sedlmayr, O. Takikawa, H. Greinix, A. Lawitschka, U. Putschger, D. Fuchs, S. Ladisch, et al. Monocyte-mediated T-cell suppression and augmented monocyte tryptophan catabolism after human hematopoietic stem-cell transplantation Blood, May 15, 2005; 105(10): 4127 - 4134. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. H. Munn, A. L. Mellor, M. Rossi, and J. W. Young Dendritic cells have the option to express IDO-mediated suppression or not Blood, March 15, 2005; 105(6): 2618 - 2618. [Full Text] [PDF] |
||||
![]() |
P. Terness, J.-J. Chuang, T. Bauer, L. Jiga, and G. Opelz Regulation of human auto- and alloreactive T cells by indoleamine 2,3-dioxygenase (IDO)-producing dendritic cells: too much ado about IDO? Blood, March 15, 2005; 105(6): 2480 - 2486. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Honig, L. Rieger, J. Dietl, and U. Kammerer Mechanisms regulating the expression of indoleamine 2,3-dioxygenase during decidualization of human endometrium Hum. Reprod., November 1, 2004; 19(11): 2683 - 2684. [Full Text] [PDF] |
||||
![]() |
A. L. Mellor, P. Chandler, B. Baban, A. M. Hansen, B. Marshall, J. Pihkala, H. Waldmann, S. Cobbold, E. Adams, and D. H. Munn Specific subsets of murine dendritic cells acquire potent T cell regulatory functions following CTLA4-mediated induction of indoleamine 2,3 dioxygenase Int. Immunol., October 1, 2004; 16(10): 1391 - 1401. [Abstract] [Full Text] [PDF] |
||||
![]() |
O. Zegarra-Moran, C. Folli, B. Manzari, R. Ravazzolo, L. Varesio, and L. J. V. Galietta Double Mechanism for Apical Tryptophan Depletion in Polarized Human Bronchial Epithelium J. Immunol., July 1, 2004; 173(1): 542 - 549. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. Meisel, A. Zibert, M. Laryea, U. Gobel, W. Daubener, and D. Dilloo Human bone marrow stromal cells inhibit allogeneic T-cell responses by indoleamine 2,3-dioxygenase-mediated tryptophan degradation Blood, June 15, 2004; 103(12): 4619 - 4621. [Abstract] [Full Text] [PDF] |
||||
![]() |
Y. Kudo, T. Hara, T. Katsuki, A. Toyofuku, Y. Katsura, O. Takikawa, T. Fujii, and K. Ohama Mechanisms regulating the expression of indoleamine 2,3-dioxygenase during decidualization of human endometrium Hum. Reprod., May 1, 2004; 19(5): 1222 - 1230. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. H. Munn, M. D. Sharma, and A. L. Mellor Ligation of B7-1/B7-2 by Human CD4+ T Cells Triggers Indoleamine 2,3-Dioxygenase Activity in Dendritic Cells J. Immunol., April 1, 2004; 172(7): 4100 - 4110. [Abstract] [Full Text] [PDF] |
||||
![]() |
O. Adams, K. Besken, C. Oberdorfer, C. R. MacKenzie, O. Takikawa, and W. Daubener Role of Indoleamine-2,3-Dioxygenase in Alpha/Beta and Gamma Interferon-Mediated Antiviral Effects against Herpes Simplex Virus Infections J. Virol., March 1, 2004; 78(5): 2632 - 2636. [Abstract] [Full Text] [PDF] |
||||
![]() |
B.-G. Xiao, X.-C. Wu, J.-S. Yang, L.-Y. Xu, X. Liu, Y.-M. Huang, B. Bjelke, and H. Link Therapeutic potential of IFN-{gamma}-modified dendritic cells in acute and chronic experimental allergic encephalomyelitis Int. Immunol., January 1, 2004; 16(1): 13 - 22. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. L. Mellor, B. Baban, P. Chandler, B. Marshall, K. Jhaver, A. Hansen, P. A. Koni, M. Iwashima, and D. H. Munn Cutting Edge: Induced Indoleamine 2,3 Dioxygenase Expression in Dendritic Cell Subsets Suppresses T Cell Clonal Expansion J. Immunol., August 15, 2003; 171(4): 1652 - 1655. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. Q. Phan, J. C. Yang, R. M. Sherry, P. Hwu, S. L. Topalian, D. J. Schwartzentruber, N. P. Restifo, L. R. Haworth, C. A. Seipp, L. J. Freezer, et al. Cancer regression and autoimmunity induced by cytotoxic T lymphocyte-associated antigen 4 blockade in patients with metastatic melanoma PNAS, July 8, 2003; 100(14): 8372 - 8377. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. L. Mellor and D. H. Munn Tryptophan Catabolism and Regulation of Adaptive Immunity J. Immunol., June 15, 2003; 170(12): 5809 - 5813. [Full Text] [PDF] |
||||
![]() |
M. van Wissen, M. Snoek, B. Smids, H. M. Jansen, and R. Lutter IFN-{gamma} Amplifies IL-6 and IL-8 Responses by Airway Epithelial-Like Cells Via Indoleamine 2,3-Dioxygenase J. Immunol., December 15, 2002; 169(12): 7039 - 7044. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. Wirleitner, D. Reider, S. Ebner, G. Bock, B. Widner, M. Jaeger, H. Schennach, N. Romani, and D. Fuchs Monocyte-derived dendritic cells release neopterin J. Leukoc. Biol., December 1, 2002; 72(6): 1148 - 1153. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. M. E. Burudi, M. C. G. Marcondes, D. D. Watry, M. Zandonatti, M. A. Taffe, and H. S. Fox Regulation of Indoleamine 2,3-Dioxygenase Expression in Simian Immunodeficiency Virus-Infected Monkey Brains J. Virol., October 25, 2002; 76(23): 12233 - 12241. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. H. Munn, M. D. Sharma, J. R. Lee, K. G. Jhaver, T. S. Johnson, D. B. Keskin, B. Marshall, P. Chandler, S. J. Antonia, R. Burgess, et al. Potential Regulatory Function of Human Dendritic Cells Expressing Indoleamine 2,3-Dioxygenase Science, September 13, 2002; 297(5588): 1867 - 1870. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. Terness, T. M. Bauer, L. Rose, C. Dufter, A. Watzlik, H. Simon, and G. Opelz Inhibition of Allogeneic T Cell Proliferation by Indoleamine 2,3-Dioxygenase-expressing Dendritic Cells: Mediation of Suppression by Tryptophan Metabolites J. Exp. Med., August 19, 2002; 196(4): 447 - 457. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. Frumento, R. Rotondo, M. Tonetti, G. Damonte, U. Benatti, and G. B. Ferrara Tryptophan-derived Catabolites Are Responsible for Inhibition of T and Natural Killer Cell Proliferation Induced by Indoleamine 2,3-Dioxygenase J. Exp. Med., August 19, 2002; 196(4): 459 - 468. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. von Bubnoff, H. Matz, C. Frahnert, M. L. Rao, D. Hanau, H. de la Salle, and T. Bieber Fc{epsilon}RI Induces the Tryptophan Degradation Pathway Involved in Regulating T Cell Responses J. Immunol., August 15, 2002; 169(4): 1810 - 1816. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. L. Mellor, D. B. Keskin, T. Johnson, P. Chandler, and D. H. Munn Cells Expressing Indoleamine 2,3-Dioxygenase Inhibit T Cell Responses J. Immunol., April 15, 2002; 168(8): 3771 - 3776. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. Sedlmayr, A. Blaschitz, R. Wintersteiger, M. Semlitsch, A. Hammer, C.R. MacKenzie, W. Walcher, O. Reich, O. Takikawa, and G. Dohr Localization of indoleamine 2,3-dioxygenase in human female reproductive organs and the placenta Mol. Hum. Reprod., April 1, 2002; 8(4): 385 - 391. [Abstract] [Full Text] [PDF] |
||||
![]() |
F. Fallarino, C. Vacca, C. Orabona, M. L. Belladonna, R. Bianchi, B. Marshall, D. B. Keskin, A. L. Mellor, M. C. Fioretti, U. Grohmann, et al. Functional expression of indoleamine 2,3-dioxygenase by murine CD8{alpha}+ dendritic cells Int. Immunol., January 1, 2002; 14(1): 65 - 68. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. Hayashi, S. P. Rao, K. Takabayashi, J. H. Van Uden, R. S. Kornbluth, S. M. Baird, M. W. Taylor, D. A. Carson, A. Catanzaro, and E. Raz Enhancement of Innate Immunity against Mycobacterium avium Infection by Immunostimulatory DNA Is Mediated by Indoleamine 2,3-Dioxygenase Infect. Immun., October 1, 2001; 69(10): 6156 - 6164. [Abstract] [Full Text] [PDF] |
||||
![]() |
Y. Kudo, C A R Boyd, I L Sargent, and C W G Redman Tryptophan degradation by human placental indoleamine 2,3-dioxygenase regulates lymphocyte proliferation J. Physiol., August 15, 2001; 535(1): 207 - 215. [Abstract] [Full Text] [PDF] |
||||
![]() |
U. Grohmann, F. Fallarino, R. Bianchi, M. L. Belladonna, C. Vacca, C. Orabona, C. Uyttenhove, M. C. Fioretti, and P. Puccetti IL-6 Inhibits the Tolerogenic Function of CD8{{alpha}}+ Dendritic Cells Expressing Indoleamine 2,3-Dioxygenase J. Immunol., July 15, 2001; 167(2): 708 - 714. [Abstract] [Full Text] [PDF] |
||||
![]() |
U. Grohmann, F. Fallarino, S. Silla, R. Bianchi, M. L. Belladonna, C. Vacca, A. Micheletti, M. C. Fioretti, and P. Puccetti CD40 Ligation Ablates the Tolerogenic Potential of Lymphoid Dendritic Cells J. Immunol., January 1, 2001; 166(1): 277 - 283. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. Apolloni, V. Bronte, A. Mazzoni, P. Serafini, A. Cabrelle, D. M. Segal, H. A. Young, and P. Zanovello Immortalized Myeloid Suppressor Cells Trigger Apoptosis in Antigen-Activated T Lymphocytes J. Immunol., December 15, 2000; 165(12): 6723 - 6730. [Abstract] [Full Text] [PDF] |
||||
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |