NAC selleck chemical can react directly with reactive oxygen intermediates and acts as a precursor to glutathione synthesis [46]. In our study, we showed that the anti-oxidants NAC and GSH blocked ROS production and reduced the expression of immune/defence genes, including those encoding IL-1β, TNF-α, IL-8, CCL-20, defensins and TLRs in MS-exposed PDL

cells. These results suggest that the cellular event for enhancing cytokines, chemokines, TLRs and defensin signalling triggered by MS is oxidation-dependent. In conclusion, our data show, for the first time, that MS up-regulates immune response genes encoding cytokines, chemokines, hBDs and TLRs in non-immune PDL cells, and that the SIRT1 pathway is involved strongly in these responses. We also observed that a p38 MAPK-, ERK-, JNK-, PI3K-, PKC- and NF-κB-dependent pathway and an anti-oxidant-sensitive pathway mediate, at least in part, MS-induced immune gene expression. The possible pathways through which MS can modulate immune response are summarized in Sorafenib molecular weight Fig. 8. A detailed understanding of the mechanotransduction of tooth movement to immune activation, and the inflammatory processes that lead to bone resorption, deposition and remodelling, is required. This work was supported by the Mid-career Researcher Program through National Research Foundation

of Korea (NRF) grant funded by the (Ministry of Education, Science and Technology (MEST) (no. 2009-0078526). The authors declare no financial conflict of interest. “
“The receptor for the globular head of human C1q (gC1qR) predominantly localizes to the mitochondrial matrix. gC1qR mediates many biological responses, including growth perturbations, morphological abnormalities and the initiation of

apoptosis. The purpose of this study was to investigate the relationship between gC1qR expression, mitochondrial dysfunction and the regulation of apoptosis in human extravillous cytotrophoblast (EVCT)-derived transformed cell lines (HTR-8/SVneo and HPT-8). gC1qR expression was examined in human placental villi using real-time qPCR and Western blot analysis. The apoptotic death of HTR-8/SVneo and HPT-8 cells was assessed using flow cytometric analysis. Mitochondrial function was Thiamine-diphosphate kinase assessed via ROS generation, the amount of cytosolic Ca2+ and changes in the mitochondrial membrane potential (Δψm). The expression of the gC1qR gene was significantly increased in spontaneous abortion samples relative to induced abortion samples. HTR-8/SVneo and HPT-8 cells transfected with a gC1qR vector showed upregulation of cellular apoptosis and mitochondrial dysfunction, interestingly, which were abrogated by the addition of metformin. Metformin may protect mitochondrial function. These data support a mechanism whereby gC1qR induces apoptosis through mitochondria-dependent pathways in human EVCT-derived transformed cells.

For this purpose, a transgenic mouse was developed (MBQ mouse) where macrophages exclusively expressed the MHC class II H2-Aq (Aq) on an H2-Ap (Ap) background. Aq, but not Ap expression mediates susceptibility to CIA through presentation of type II collagen (CII) to T cells. CIA severity is enhanced PD0325901 clinical trial by a mutation in

the Ncf1 gene, impairing reactive oxygen species (ROS) production by the phagocyte NADPH oxidase (NOX2) complex. Expression of functional Ncf1 on macrophages was previously shown to protect from severe CIA. To study the effect of ROS on macrophage-mediated priming of T cells, the Ncf1 mutation was introduced in the MBQ mouse. Upon CII immunization, Ncf1-mutated MBQ mice, but not Ncf1 wild-type MBQ mice nor Ncf1-mutated Ap mice, activated autoreactive T cells and developed CIA. These findings demonstrate for the first time that macrophages can initiate arthritis and that the process is negatively regulated by ROS produced via the NOX2 complex. Mice and rats with a lower capacity to produce reactive oxygen species (ROS) due to natural

polymorphisms in Ncf1 have an impaired capacity to exert oxidative burst in vivo 1 and develop more severe arthritis upon immunization 2, 3. Ncf1 gene encodes p47phox/Ncf1 that is a cytosolic regulatory component of the phagocyte NADPH oxidase (NOX2) complex. Using adoptive transfer experiments in the rat model it was shown that the protective effect of ROS on arthritis

development was mediated via T cells 3. This demonstrated that ROS production is buy STA-9090 an important regulator of T-cell activation, a finding that was confirmed in the mouse 2, 4. However, T cells themselves only produce minute amounts of ROS and no major differences in ROS production were observed between T cells from the different Ncf1 genotypes in mice or rats, indicating that in T cells ROS production was independent of the NOX2 complex 5. This observation led to the hypothesis that APC produce ROS into the immunological synapse, oxidize the T-cell surface and thereby downregulate T-cell activation 5. Although MHC class II expressing macrophages (here defined in its broadest sense, i.e. including monocytes) and B cells can also present antigens, DC are considered to be the only APC that can prime naïve T cells and Interleukin-3 receptor initiate immune responses 6. However, DC and B cells are rather inefficient in producing ROS, whereas macrophages are much more potent 7. This led us to investigate the role of ROS produced by macrophages in T-cell activation in a mouse model for arthritis. In a transgenic mouse model where only macrophages expressed functional Ncf1 on an Ncf1-deficient background, the mice were protected from development of severe arthritis 7, indicating that in fully mutated mice the absence of macrophage derived ROS was partially mediating the severe arthritis.

Nagarkatti et al. demonstrated that CD44-deficiency triggers a Th2-biased

Th development using OVA immunization with a Th1-skewing adjuvant CFA without airway antigen challenge 12. In the present study, we used Th2-skewing adjuvant aluminum hydroxide for Derf-immunization. Before antigen challenge, the levels of Th2 cytokines, Der-specific IgE, and IgG1 in the serum of CD44KO mice were similar to those in WT mice, while IFN-γ was not detected in the serum of both CD44KO and WT mice, and the serum level of Der-specific IgG2c was similar between CD44KO and WT mice. These data suggested that the lack of CD44 did not influence the Th1- or Th2-biased Th development in the sensitization Pexidartinib research buy phase of this model. After antigen challenge, the

number of Th2 cells and the levels of Th2 cytokines in the BALF of CD44KO mice were lower than those in WT mice, while the levels of Th2 chemokine (TARC) in the BALF of CD44KO mice were similar to those in WT mice. Finally, we demonstrated that anti-CD44 mAb inhibited the infiltration of OVA-specific in vitro-differentiated Th2, but not Th1, cells into the airway after antigen challenge. These data suggested that CD44 plays a critical role in the infiltration of Th2 cells into the airway induced by antigen challenge, in large part, as an adhesion molecule. Anti-CD44 mAb significantly reduced airway accumulation of eosinophils and the concentration of eotaxin in the BALF in murine models of pulmonary eosinophilia 17, 18. Consistently, the number of eosinophil

in the BALF of CD44KO mice was marginally lower than those in WT mice, although the level of eotaxin in the BALF of CD44KO mice was selleckchem similar to that of WT mice in Derf-sensitized and challenged mouse asthmatic model in this study. Even though exact reason for such discrepancy is unclear at present, it may be caused by differences of antigen, mouse strain, and the way of antigen administration. Increased levels of both Th1 and Th2 cytokines in the serum were observed after antigen challenge. Increased levels of Th2 cytokines in the BALF reflect the elevated levels CHIR-99021 in vitro of Th2 cytokines in the serum of WT mice after antigen challenge. Higher levels of IFN-γ in the BALF and serum in CD44KO mice might be caused by lower levels of Th2 cytokines in the BALF and serum in CD44KO mice compared with WT mice after antigen challenge, because IFN-γ was not detected in the serum of both CD44KO and WT mice, while the serum levels of Th2 cytokines were similar between CD44KO and WT mice before the antigen challenge. Higher levels of IFN-γ might contribute to the higher levels of Derf-specific IgG2c in serum of CD44KO mice after antigen challenge. The number of macrophages in the BALF was not significantly different between CD44KO and WT mice at baseline, as previously described 27. In this Derf-induced asthmatic model, CD44KO mice had significantly fewer macrophages compared with WT mice 24 h after antigen challenge.

02; 95% CI 1.50–12.0; P = 0.0051). As compared with the group without early AKI, the urinary L-FABP level in early AKI group was significantly higher not only on the day of SCT

but also at the baseline. Then, ROC analysis demonstrated the urinary L-FABP level at baseline had good discriminative ability for the early AKI. Conclusion: One-quarter of allogeneic Epigenetics inhibitor SCT recipients developed the early AKI, which was linked with increased risk of their short-term mortality. Antecedent kidney damage, which can be identified by urinary L-FABP concentration, may portend the emergence of early-onset AKI. YAMASHITA TETSUSHI1, DOI KENT2, TSUKAMOTO MAKI1, NANGAKU MASAOMI1, YAHAGI NAOKI2, NOIRI EISEI3 1Department of Nephrology and Endocrinology, Graduate school of Medicine, The University of Tokyo; PLX4032 research buy 2Department of Critical Care Medicine, The University of Tokyo Hospital; 3Department of Hemodialysis and Apheresis, The University of Tokyo Hospital Introduction: Tissue inhibitor of metalloproteinases-2 (TIMP-2) has recently been reported to detect severe AKI better than new AKI biomarkers that have recently introduced to the clinical such as NGAL. Methods: This study enrolled 98 patients who were admitted to the adult mixed ICU of The University of Tokyo Hospital from July 2011 to October 2011 by consecutive sampling. Urine TIMP-2 and NAG, and plasma NGAL and IL-6 were measured

on ICU admission. This Thalidomide study was aimed to evaluate whether these biomarkers

could predict AKI and its severity, and mortality by ROC analysis. Results: AKI occurred in 42 (42.9%) patients including 27 (27.6%) severe AKI (KDIGO stage 2 or 3). The area under the ROC curve for each marker was shown in Table. Forty one (41.8%) patients was complicated with sepsis, including 19 (19.4%) severe AKI. In accordance with previous reports, plasma NGAL and IL-6 were increased by sepsis, however urine TIMP-2 and NAG was increased not by sepsis but by the presence of severe AKI (Figure). In-hospital mortality was 15.3% in this cohort and urine TIMP-2 and NAG, and plasma NGAL were significantly higher in the non-survivors than the survivors, whereas plasma IL-6 was not significantly associated with mortality. Conclusion: A new urine biomarker of TIMP-2 is increased especially in severe AKI and associated with mortality. Sepsis appeared to have a smaller impact on urine TIMP-2 and NAG compared with plasma NGAL and IL-6. This distinct feature of biomarkers will enable to evaluate the contribution of sepsis to the development of AKI. TANAKA YUKI1, KUME SHINJI1, MAEDA SHIRO2, OSHIMA ITSUKI3, ARAKI HISAZUMI1, ISSHIKI KEIJI1, ARAKI SHIN-ICHI1, UZU TAKASHI1, MAEGAWA HIROSHI1 1Department of Medicine, Shiga University of Medical Science, Japan; 2Laboratory for Endocrinology, Metabolism and Kidney diseases, RIKEN Center for Integrative Medical Science, Japan; 3Discovery Research Laboratories, Shionogi & Co., Ltd.

For example, it has been widely shown that the major lineages of T. cruzi exhibit significant differences in pathogenic potential. Trypanosoma cruzi I, generally less pathogenic for humans, has a lower acute infectious profile and progression, a more extensive chronic profile, and invades and causes pathology in different organs. Comparison of at least one T. cruzi I isolate (e.g., Silvio ×10) with the other isolates will provide an opportunity to discover the genetic basis of these phenomena. Another outstanding question

relates to the genetic basis for a variety of phenotypes (cell cycle, host range, vector selection, pathogenic and clinical manifestations, etc.) of the major groups of pathogenic Autophagy inhibitors trypanosomatids. Again, considering T. cruzi as an example, isolates of the six lineages of T. cruzi are quite divergent in many respects. Although superficially similar, their preferred hosts and vectors, method of invasion, effects on the invaded cells, levels of parasitemia, mechanisms of pathogenesis and clinical outcomes are quite different. Whereas it is quite well documented that the

differences among T. cruzi isolates are genetically programmed, it is not yet established that genes or gene networks confer these different phenotypes. The genome of Opaganib cell line trypanosomes is transcribed into long polycistronic primary transcripts (mostly by RNA polymerase II) and pre-mRNAs are processed into mature individual mRNAs through coupled trans-splicing and polyadenylation events (8). It has therefore been widely considered that trypanosomes heavily rely on post-transcriptional regulation and RNA turn-over rather than transcription initiation to regulate gene expression (28). Nonetheless, several genome-wide gene expression profiling studies have been carried out to interrogate the

differences in the distinct developmental life cycle stages in trypanosomatids. Many of the studies have revealed considerable numbers of regulated genes during trypanosome development (29–35), although some analyses noted limited and inflexible transcriptome responses across the life cycle stages (36–38). Results from multiple microarray studies were recently integrated bioinformatically Enzalutamide and co-expression clusters were used to predict putative gene functions and potential regulatory networks (38). In addition, DNA microarrays coupled with chromatin immunoprecipitation (ChIP-chip) have allowed the identification of the origins of polycistronic transcription initiation through histone acetylation profiling (39). The application of NGS technologies to transcriptome profiling (40,41) has prompted the use of alternative and more powerful approaches for analysing gene expression in trypanosomatids.

45 Androgen affects structural and functional perfection, such as NOS and PDE5 expression and activity of the corpus cavernosum and urinary tract.46,47 Reduced production of testosterone with age contributes to the occurrence of BPH/LUTS.48 Androgen receptors were expressed in the epithelial cells of the urethra and in the bladder of rabbits and in the urothelium, bladder smooth muscle, striated muscle cells of the proximal urethra and in the neurons in the autonomic ganglia of the prostatic plexus of the male rat.49,50 Testosterone and its metabolites maintain the reflex activity in the Crizotinib pelvic part of the ANS in

rats.51 NOS-NO-cGMP pathway is partially androgen-dependent in the rat urinary tract.52 It is suggested that LUTS may be related to low androgen level.21,53 Wnt drug Sleep deprivation is a significant problem among adult men who have BPH/LUTS, especially nocturia. After several days of prolonged physical and psychological stress and sleep deprivation, testosterone falls by 70–90%.53 Circulating testosterone levels increase during sleep, which start to rise on sleep onset and peak during the first episode of rapid eye movement (REM) sleep. A rise in testosterone in normal young men during continuous nocturnal sleep began at sleep onset and reached a plateau around

the time of the first REM sleep episode 90 min later.54 Sleep deprivation is a physiological stressor. Therefore, it is not surprising that serum testosterone was altered following sleep deprivation. Sleep deprivation causes secretion of serotonin. Serotonin binds to 5 HT 2 receptor resulting in production of corticotrophin-releasing hormone in Leydig cells. Corticotropin-releasing hormone inhibits cyclic adenosine monophosphate (cAMP) production and subsequent testosterone production.55 Nocturia-induced stress may be a cause of low testosterone. PDE5 mRNA is expressed in the bladder, urethra and prostate. PDE5 I inhibited the contraction of isolated bladder, urethra and prostate strips in an in vitro study.56 These results serve as a motive to attempt PDE5 I in patients with

BPH-induced LUTS. Multiple studies showed that PDE5 I improved BPH/LUTS. However, there has been debate about improvement in Qmax compared with placebo.57–70 Erastin concentration The first choice of management of ED using pharmacotherapy is PDE5 I.71 There have been many clinical studies of sildenafil in BPH/LUTS.57-63 Eryildirim et al.59 found that sildenafil has a positive effect in both LUTS and ED in men with LUTS and ED. The efficacy of tadalafil to relieve LUTS secondary to BPH has been reported in many clinical trials.64–66,70 In a recent clinical study, tadalafil was effective in treating BPH/LUTS. After 12 weeks of medication once daily, tadalafil produced great improvements over baseline in the IPSS, such as 13% for placebo versus 31% for 5 mg tadalafil, and improvement of IPSS was dose-dependent. However, the increase in peak flow rate did not reach statistical significance.

These results are consistent with Nishikawa et al. (2002), who reported that EAST1EC was isolated from 2.5% of diarrheal patients. Using virulence gene profiling, we investigated whether there

were additional virulence genes other than astA in EAST1EC strains. The properties of the 12 virulence genes targeted in this study are summarized in Table 2, and the results of virulence gene profiling of EAST1EC are summarized in Table 3. The O166 strains, designated EC12713 and EC13404, were alike in having no additional virulence genes, which suggested that serotyping of O antigens is not indicative of EAST1EC strains. In 24 of the 35 EAST1EC strains, at least one gene associated with adhesin and intestinal colonization was detected. The most frequently found gene was lpfA, a novel fimbrial gene in EHEC strain O113:H21 isolated from a patient with hemolytic uremic syndrome (Doughty Y-27632 purchase et al., 2002). buy LDK378 This gene has been shown to be widely distributed in various pathotypes of DEC (Toma et al., 2006). Wu et al. (2010) recently reported that lpfA is more prevalent in EHEC strains isolated from healthy cattle than human patients,

suggesting that lpfA in EHEC is associated only with colonization of cattle intestine. Our results indicated that lpfA is frequently detected in EAST1EC strains, supporting the suggetion that EAST1EC may be derived from farm animals and their products (Toshima et al., 2004; Veilleux & Dubreuil, 2006). The role of lpfA as a pathogenic determinant in

EAST1EC remains to be determined. The iha, pilS, pic, and aah genes were found in four, seven, two, and one strain, respectively. Similar to lpfA, iha was first identified in EHEC. It encodes an outer membrane protein similar to iron-regulated gene A protein (IrgA) of Vibrio cholerae (Goldberg et al., 1992). Tarr et al. (2000) have suggested that Iha and its homologues, rather than intimin, play roles in adherence in strains lacking eae. Harbored by seven strains, including Bacterial neuraminidase three strains that also carried iha, pilS encodes a major subunit of type IV pilus. Dudley et al. (2006) reported that pilS is associated with aggregative adherence of certain EAggEC strains. However, in a study by Abe et al. (2008), none of the uropathogenic E. coli (UPEC) strains carrying pilS exhibited an aggregative adherence phenotype. Although the adherence activity of the current strains has yet to be characterized, pilS may play a role as an accessory adhesin in particular EAST1EC strains, such as strains that also carry iha. The pic gene was detected in two strains, designated EC12935 and EC12939. Pic was originally identified in culture supernatants of EAggEC, and has been shown to have serine protease activity towards mucin (Henderson et al., 1999).

Interestingly, in

IgA nephropathy, glomerular deposition of ficolin-2 with local lectin pathway activation was associated with more severe renal disease [37]. According to our findings, pregnant women with low circulating levels of ficolin-2 or ficolin-3 have an increased risk for pre-eclampsia. Low ficolin-2 and ficolin-3 levels have already been linked to various pathological conditions, such as combined allergic and infectious respiratory disease in children [38,39], bronchiectasis [40], prematurity, low birth weight and perinatal infections [41], sarcoidosis [42], susceptibility to fever and neutropenia in pediatric cancer patients [43] and to neonatal sepsis [44]. Moreover, our research group has demonstrated recently that low ficolin-3 levels in early follow-up serum samples Talazoparib in vivo are related to the severity and unfavourable outcome of acute ischaemic stroke [45]. Genetic variations were shown to affect ligand binding or circulating levels of ficolins [46–48] and to associate with several disorders, including rheumatic fever and chronic rheumatic heart disease [49], bacterial and cytomegalovirus infections after orthotopic liver transplantation [50,51], and even immunodeficiency [52]. As pre-eclampsia is a multi-factorial disease with genetic components, the role of ficolin gene polymorphisms should be examined in Venetoclax clinical trial the

future in the risk of this pregnancy-specific disorder. In our study, the similar plasma ficolin-2 and ficolin-3 levels of pre-eclamptic patients regardless of the severity, the time of onset of the disease or the presence Histidine ammonia-lyase of fetal growth restriction might be explained by the complex aetiology of pre-eclampsia. Several genetic, behavioural and environmental factors need to interact to produce the complete picture of this pregnancy-specific disorder. We reported various genetic and soluble factors that were associated with the severity

or complications of pre-eclampsia, including HELLP syndrome and fetal growth restriction [53–56]. Nevertheless, it is also possible that the relatively small sample size of this study prevented the detection of an effect in the subgroup analyses. Although pre-eclampsia is predominantly a disease of primiparas, multiparous women, especially with advanced age or over weight, can also be affected, as in our cases. In conclusion, circulating levels of ficolin-2 are decreased in the third trimester of normal pregnancy. There is a further decrease in plasma ficolin-2 concentrations in pre-eclampsia, which might contribute to the development of the maternal syndrome of the disease through impaired removal of the trophoblast-derived material released into the maternal circulation by the hypoxic and oxidatively stressed pre-eclamptic placenta. We thank Veronika Makó, László Cervenak and Levente Lázár for measuring plasma von Willebrand factor antigen and cell-free fetal DNA concentrations.

Under the influence of these cognate signals and specific TCR triggering, all requiring close DC–T-cell interactions, the CD8+ CTL precursors will proliferate and mature to stimulate effector and memory CD8+ CTL. Most researchers

have investigated the putative role of cytokines and the various cognate interactions among CD4+ T cells, DC and CD8+ T cells with rather complex immunogens (viruses), usually at one or a few concentrations. Do these conditions really reflect what is happening during infection or do we need to dissect these events in greater detail? Should we vary the dose of virus more carefully and should we also try to dissect the different signals provided by the virus itself more carefully in order to establish synergism between different pathways of the type that was also found to occur in synergy Osimertinib order between TLR ligand activation of DC and CD40 triggering of DC

12. The current report provides interesting insights, but their general applicability under different experimental conditions certainly warrants further scrutiny. Conflict of interest: The authors declare no financial or commercial conflict of interest. See accompanying article: http://dx.doi.org/10.1002/eji.200939939 “
“Oxysterols are involved in maintaining cellular cholesterol levels. Recently, oxysterols have been demonstrated to modulate the function of immune cells and tumor growth. These effects can be dependent on the activation of the oxysterol-binding liver X receptors (LXRs) or, as recently demonstrated for Midostaurin T and B cells, DCs and neutrophils, can be independent of LXR activation. LXR-dependent Resveratrol oxysterol effects can be ascribed to the activation of LXRα, LXRβ or LXRαβ isoforms, which induces transcriptional activation or trans-repression of target genes. The prevalent activation of one isoform seems to be cell-, tissue-, or context-specific, as shown in some pathologic processes, i.e., infectious diseases, atherosclerosis, and autoimmunity. Oxysterol-LXR signaling has recently been shown

to inhibit antitumor immune responses, as well as to modulate tumor cell growth. Here, we review the mechanisms that link oxysterols to tumor growth, and discuss possible networks at the basis of LXR-dependent and -independent oxysterol effects on immune cells and tumor development. Cholesterol homeostasis is tightly regulated in mammals [1]. Cholesterol regulation is rather complex and requires the integration of different transcription factors that control synthesis, accumulation, and removal of cholesterol [1]. Considering this complexity, it is not surprising that cholesterol and its metabolites are involved in the regulation of certain functions of immune cells, as well as in the regulation of some aspects of neoplastic cell growth.

It is also a field in which Europe is recognised as a leader worldwide. Research in the field of allergen immunotherapy is extremely difficult, basically because the effects of the treatment check details are measurable only after

a relatively long period of time, usually after one year, achieving an optimal effect after three to five years. This fact hampers the possibility of undertaking large independent trials, which need a substantial economic investment. Until now, most of these trials have been conducted by allergen manufacturers. In this regard, the European Academy of Allergy and Clinical Immunology (EAACI) is actively working to increase the knowledge of this situation among relevant stakeholders in order to promote policies to support Selleck RGFP966 the knowledge and use of allergen immunotherapy and to prioritise funding of research in the field. One of the initiatives that have been undertaken is the development of the European Declaration on Immunotherapy. This document, signed by EAACI, GA2LEN and the European Federation of Allergy and Airway Diseases Patients Association (EFA), and with the support of most of the National Allergy Societies, was published

in June 2011 and is available at www.eaaci.net. The aim of this document is to illustrate the current status of the allergic epidemic in Europe, to highlight the impact of such diseases on patients’ health and overall quality of life, to provide data regarding the socioeconomic impact for society and to raise the question of awareness among the relevant governing bodies and the need to undertake proactive initiatives to fight allergies. The European Declaration on Immunotherapy has been forwarded to members of the European Parliament, and also to politicians at a

national level, in order to synergise actions in the field. Along these lines, EAACI, together with GA2LEN and EFA, would like to call upon Europe’s policy-makers to coordinate actions and improve individual and public health in allergy by: (i) Promoting immunotherapy awareness We believe that this European Declaration Allergy Immunotherapy is one of the first steps to achieving these aims. “
“Control of tryptophan metabolism by indoleamine 2,3-dioxygenase (IDO) in dendritic cells (DCs) is a highly versatile regulator of innate and adaptive immune responses. In acute reactions, Neratinib mouse the otherwise inflammatory cytokine interferon γ (IFN-γ) acts in a feedback fashion to induce IDO’s enzymatic function — and thus prevent potentially harmful, exaggerated responses — through the combined effects of tryptophan starvation and tryptophan catabolites acting via the aryl hydrocarbon receptor of T cells. IDO, however, is also involved in the maintenance of stable tolerance to self in noninflammatory contexts, thus restraining autoimmunity. Exposure, indeed, of mouse plasmacytoid DCs (pDCs) to transforming growth factor β (TGF-β) provides IDO with regulatory effects that are distinct, in nature, from its enzymic activity.