星 雅人

Sepsis is a systemic inflammatory disease caused by a bacterial infection that leads to severe mortality, especially in elderly patients, because of an excessive immune response and impaired regulatory functions. Antibiotic treatment is widely accepted as the first-line therapy for sepsis; however, its excessive use has led to the emergence of multidrug-resistant bacteria in patients with sepsis. Therefore, immunotherapy may be effective in treating sepsis. Although CD8+ regulatory T cells (Tregs) are known to have immunomodulatory effects in various inflammatory diseases, their role during sepsis remains unclear. In this study, we investigated the role of CD8+ Tregs in an LPS-induced endotoxic shock model in young (8-12 wk old) and aged (18-20 mo old) mice. The adoptive transfer of CD8+ Tregs into LPS-treated young mice improved the survival rate of LPS-induced endotoxic shock. Moreover, the number of CD8+ Tregs in LPS-treated young mice increased through the induction of IL-15 produced by CD11c+ cells. In contrast, LPS-treated aged mice showed a reduced induction of CD8+ Tregs owing to the limited production of IL-15. Furthermore, CD8+ Tregs induced by treatment with the rIL-15/IL-15Rα complex prevented LPS-induced body wight loss and tissue injury in aged mice. In this study, to our knowledge, the induction of CD8+ Tregs as novel immunotherapy or adjuvant therapy for endotoxic shock might reduce the uncontrolled immune response and ultimately improve the outcomes of endotoxic shock.

The partial loss of liver due to liver transplantation or acute liver failure induces rapid liver regeneration. Recently, we reported that the selective inhibition of indoleamine 2,3‑dioxygenase (Ido) 1 promotes early liver regeneration. However, the role of Ido2 in liver regeneration remains unclear. Wild‑type (WT) and Ido2‑deficient (Ido2‑KO) mice were subjected to 70% partial hepatectomy (PHx). Hepatocyte growth was measured using immunostaining. The mRNA expression of inflammatory cytokines and production of kynurenine in intrahepatic mononuclear cells (MNCs) were analyzed using reverse transcription‑quantitative PCR and high‑performance liquid chromatography. The activation of NF‑κB was determined by both immunocytochemistry and western blotting analysis. The ratio of liver to body weight and the frequency of proliferation cells after PHx were significantly higher in Ido2‑KO mice compared with in WT mice. The expression of IL‑6 and TNF‑α in MNCs were transiently increased in Ido2‑KO mice. The nuclear transport of NF‑κB was significantly higher in peritoneal macrophages of Ido2‑KO mice compared with WT mice. These results suggested that Ido2 deficiency resulted in transiently increased production of inflammatory cytokines through the activation of NF‑kB, thereby promoting liver regeneration. Therefore, the regulation of Ido2 expression in MNCs may play a therapeutic role in liver regeneration under injury and disease conditions.

Various cancer cells require massive amounts of glucose as an energy source for their dysregulated growth. Although D‑allose, a rare sugar, inhibits tumor cell growth via inhibition of glucose uptake, a few cells can survive after treatment. However, the mechanism by which D‑allose‑resistant cells are generated remains unclear. Here, we investigated the properties of D‑allose‑resistant cells and evaluated the efficacy of combined treatment with this rare sugar and antitumor drugs. To this end, we established a D‑allose‑resistant tumor cell line and prepared a C57BL/6J mouse tumor xenograft model using Lewis lung carcinoma (LLC) cells. Xenograft‑bearing mice were treated with D‑allose (9 g/kg) and/or hydroxychloroquine (HCQ, 60 mg/kg), an autophagy inhibitor, for two weeks. Although D‑allose inhibited LLC cell growth in a dose‑dependent manner, a few cells survived. The upregulation of LC3‑II, a classical autophagy marker, and the downregulation of mTOR and its downstream molecule Beclin1 were observed in established D‑allose‑resistant LLC cells, which were more sensitive to cell death induced by HCQ. Similarly, in the tumor xenograft model, the tumor volume in mice co‑treated with D‑allose and HCQ was considerably smaller than that in untreated or HCQ‑treated mice. Importantly, the administration of D‑allose induced autophagy selectively at the tumor site of the xenograft‑bearing mice. These results provide a new therapeutic strategy targeting autophagy which is induced in tumor cells by D‑allose administration, and may be used to improve therapies for lung cancer.

Diffuse large B-cell lymphoma (DLBCL) is a clinically heterogeneous lymphoid malignancy that is the most common type of lymphoma in Japan. Previous studies have demonstrated that patients with DLBCL have a poor prognosis due to increased levels of indoleamine 2,3-dioxygnase and kynurenine (KYN). However, the roles of metabolites acting downstream of KYN and associated enzymes are not fully understood. The present study investigated the role of kynurenine 3-monooxygenase (KMO), which catalyzes the conversion of KYN to 3-hydroxykynurenine (3-HK), using serum samples from patients with DLBCL and human DLBCL cell lines with different KMO expression [STR-428 cells with high levels of KMO expression (KMOhigh) and KML-1 cells with low levels of KMO expression (KMOlow)]. Serum samples from 28 patients with DLBCL and 34 healthy volunteers were used to investigate the association between prognosis and KMO activity or 3-HK levels. Furthermore, to investigate the roles of KMO and its related metabolites, STR-428 and KML-1 cell lines, and the lymph nodes of patients with DLBCL were analyzed by reverse transcription-quantitative PCR for KMO, KYNU, 3-hydroxyanthranilate-3,4-dioxygenase and quinolinate phosphoribosyltransferase, by western blotting, and immunohistochemical or immunofluorescence staining for KMO, and by cell viability and NAD+/NADH assays. KYN pathway metabolites in serum samples were measured by HPLC. Serum 3-HK levels were regulated independently of serum KYN levels, and increased serum 3-HK levels and KMO activity were found to be associated with worse disease progression. Notably, the addition of KMO inhibitors and 3-HK negatively and positively regulated the viability of DLBCL cells, respectively. Furthermore, NAD+ levels in KMOhigh STR-428 cells were significantly higher than those in KMOlow KML-1 cells. These results suggested that 3-HK generated by KMO activity may be involved in the regulation of DLBCL cell viability via NAD+ synthesis.

OBJECTIVES: The microscopic examination of hematuria, a cardinal symptom of glomerulonephritis (GN), is time-consuming and labor-intensive. As an alternative, the fully automated urine particle analyzer UF-5000 can interpret the morphological information of the glomerular red blood cells (RBCs) using parameters such as UF-5000 small RBCs (UF-%sRBCs) and Lysed-RBCs. METHODS: Hematuria samples from 203 patients were analyzed using the UF-5000 and blood and urine chemistries to determine the cut-off values of RBC parameters for GN and non-glomerulonephritis (NGN) classification and confirm their sensitivity to the IgA nephropathy and non-IgA nephropathy groups. RESULTS: The UF-%sRBCs and Lysed-RBCs values differed significantly between the GN and NGN groups. The cut-off value of UF-%sRBCs was >56.8% (area under the curve, 0.649; sensitivity, 94.1%; specificity, 38.1%; positive predictive value, 68.3%; and negative predictive value, 82.1%), while that for Lysed-RBC was >4.6/μL (area under the curve, 0.708; sensitivity, 82.4%; specificity, 56.0%; positive predictive value, 72.6%; and negative predictive value, 69.1%). Moreover, there was no significant difference in the sensitivity between the IgA nephropathy and non-IgA nephropathy groups (87.1 and 89.8% for UF-%sRBCs and 83.9 and 78.4% for Lysed-RBCs, respectively). In the NGN group, the cut-off values showed low sensitivity (56.0% for UF-%sRBCs and 44.0% for Lysed-RBCs). CONCLUSIONS: The RBC parameters of the UF-5000, specifically UF-%sRBCs and Lysed-RBCs, showed good cut-off values for the diagnosis of GN.

Despite advances in our understanding of endotoxic shock, novel therapeutic interventions that can reduce the burden of sepsis remain elusive. Current treatment options are limited, and it is only through refinements in the ways that we deliver supportive care that mortality has fallen over the years. In this study, the role of kynurenine 3-monooxygenase (KMO) in immune regulation was examined in LPS-induced endotoxemia using KMO-/- and KMO+/+ mice treated with the KMO inhibitor Ro61-8048. We showed that LPS-induced or cecal ligation and puncture-induced mortality and hepatic IL-6 production increased in the absence of KMO, possibly involving increased activating transcription factor 4 (ATF4) signaling in hepatic macrophages. Moreover, treatment of septic mice with 3-hydroxykynurenine reduced mortality rates and inflammatory responses regardless of the presence or absence of KMO. According to our results, the administration of 3-hydroxykynurenine as part of the treatment approach for sepsis or as an adjuvant therapy might reduce the overproduction of IL-6, which is responsible for severe endotoxemia, and ultimately improve the survival rates of patients with sepsis.

Tryptophan (TRP) is metabolized via the kynurenine (KYN) pathway, which is related to the pathogenesis of major depressive disorder (MDD). Kynurenine 3-monooxygenase (KMO) is a pivotal enzyme in the metabolism of KYN to 3-hydroxykynurenine. In rodents, KMO deficiency induces a depression-like behavior and increases the levels of kynurenic acid (KA), a KYN metabolite formed by kynurenine aminotransferases (KATs). KA antagonizes α7 nicotinic acetylcholine receptor (α7nAChR). Here, we investigated the involvement of KA in depression-like behavior in KMO knockout (KO) mice. KYN, KA, and anthranilic acid but not TRP or 3-hydroxyanthranilic acid were elevated in the prefrontal cortex of KMO KO mice. The mRNA levels of KAT1 and α7nAChR but not KAT2-4, α4nAChR, or β2nAChR were elevated in the prefrontal cortex of KMO KO mice. Nicotine blocked increase in locomotor activity, decrease in social interaction time, and prolonged immobility in a forced swimming test, but it did not decrease sucrose preference in the KMO KO mice. Methyllycaconitine (an α7nAChR antagonist) antagonized the effect of nicotine on decreased social interaction time and prolonged immobility in the forced swimming test, but not increased locomotor activity. Galantamine (an α7nAChR allosteric agonist) blocked the increased locomotor activity and prolonged immobility in the forced swimming test, but not the decreased social interaction time in the KMO KO mice. In conclusion, elevation of KA levels contributes to depression-like behaviors in KMO KO mice by α7nAChR antagonism. The ameliorating effects of nicotine and galantamine on depression-like behaviors in KMO KO mice are associated with the activation of α7nAChR.

Kynurenine (Kyn) plays an important role as an immune check-point molecule and regulates various immune responses through its aryl hydrocarbon receptor (Ahr). Kyn is synthesized by indoleamine 2,3-dioxygenase (Ido) and tryptophan 2,3-dioxygenase (Tdo). Ido contributes approximately 90% of tryptophan catabolism. Although Kyn is increased in various liver disorders, the roles of Kyn in liver injury are complicated because Ido1, Ido2, and Tdo are activated in different cell types. In this study, the roles of Ido2 in carbon tetrachloride (CCl4; 1 ml/kg, i.p.)-induced acute liver injury were examined using Ido2 knockout mice and Ido2 inhibitor. After CCl4 treatment, the ratio of Kyn to tryptophan and levels of Kyn in the liver were increased, accompanied by activation of Ahr-mediated signaling, as revealed by increased nuclear Ahr and Cyp1a1 mRNA. Knockout of Ido2 (Ido2-/-) and treatment with Ido2 inhibitor 1-methyl-D-tryptophan (D-1MT; 100 mg/kg, i.p.) attenuated CCl4-induced liver injury, with decreased induction of Ahr-mediated signaling. Administration of D-Kyn (100 mg/kg, i.p.) to Ido2-/- mice canceled the effect of Ido2 deficiency and exacerbated acute liver damage by CCl4 treatment. In addition, liver fibrosis induced by repeated CCl4 administration was suppressed in Ido2-/- mice. In conclusion, the action of Ido2 and Kyn in the liver may prevent severe hepatocellular damage and liver fibrosis.

BACKGROUND: Inflammatory bowel disease, such as Crohn's disease and ulcerative colitis, is characterized by chronic intestinal inflammation leading to intestinal mucosal damage. Inflammatory bowel disease causes dysregulation of mucosal T cell responses, especially the responses of CD4+ T cells. Previously, we demonstrated that indoleamine-2,3-dioxygenase plays an immunosuppressive role in 2,4,6-trinitrobenzene sulfate (TNBS)-induced colitis. Although indoleamine-2,3-dioxygenase exerts immunosuppressive effects by altering the local concentration of tryptophan (Trp) and immunomodulatory Trp metabolites, the specific changes in immune regulation during colitis caused by Trp metabolites and its related enzymes remain unclear. AIM: To investigate role of kynurenine 3-monooxygenase (KMO) in TNBS-induced colitis and involvement of Trp metabolites in maintenance of intestinal homeostasis. METHODS: Colitis was induced in eight-week-old male KMO+/+ or KMO-/- mice of C57BL/6N background using TNBS. Three days later, the colon was used for hematoxylin-eosin staining for histological grading, immunohistochemical or immunofluorescence staining for KMO, cytokines, and immune cells. Inflammatory and anti-inflammatory cytokines were measured using quantitative RT-PCR, and kynurenine (Kyn) pathway metabolites were measured by high-performance liquid chromatography. The cell proportions of colonic lamina propria and mesenteric lymph nodes were analyzed by flow cytometry. RESULTS: KMO expression levels in the colonic mononuclear phagocytes, including dendritic cells and macrophages increased upon TNBS induction. Notably, KMO deficiency reduced TNBS-induced colitis, resulting in an increased frequency of Foxp3+ regulatory T cells and increased mRNA and protein levels of anti-inflammatory cytokines, including transforming growth factor-β and interleukin-10. CONCLUSION: Absence of KMO reduced TNBS-induced colitis via generation of Foxp3+ regulatory T cells by producing Kyn. Thus, Kyn may play a therapeutic role in colon protection during colitis.

Tryptophan metabolism is important to induce immune tolerance in tumors. To date, 3 types of tryptophan-metabolizing enzymes have been identified: indoleamine 2,3-dioxygenase 1 and 2 (IDO1 and IDO2) and tryptophan 2,3-dioxygenase 2. Numerous studies have focused on IDO1 as its expression is enhanced in various cancers. Recently, IDO2 has been identified as a tryptophan-metabolizing enzyme that is involved in several immune functions and expressed in cancers such as pancreatic cancer. However, the biological role of IDO2 in the induction of immune tolerance in tumors has not yet been reported. In the present study, we examined the effects of Ido2 depletion on tumor growth in a mouse model of Lewis lung carcinoma by using Ido2-knockout mice. Ido2-knockout mice had reduced tumor volumes compared to WT mice. Furthermore, Ido2 depletion altered the tumor microenvironment, such as tryptophan accumulation and kynurenine reduction, leading to enhancement of immune cell invasion. Finally, enzyme-linked immunospot assay revealed that Ido2 depletion enhanced γ-interferon secretion in the tumor. In conclusion, Ido2 is an important immune regulator in the tumor microenvironment. Our data indicate that IDO2 is a potential target for cancer treatment and drug development.

Quinolinic acid (QA) is a neurotoxic and implicated in the neurological disorders. QA is metabolized by quinolinic acid phosphoribosyltransferase (QPRT). However, the physiological roles of QPRT in central nervous system are still unclear. To investigate the roles of QPRT in emotional and cognitive functions, QPRT KO mice were subjected to several types of neurobehavioral tests. The KO mice decreased locomotor activity in novel environment, prolonged escape latency in Barns maze test, and decreased alternation behavior in Y-maze test. In the KO mice, the contents of homovanillic acid (HVA) and 3,4-Dihydroxyphenylacetic acid (DOPAC), and the ratios of HVA/ dopamine (DA) in the nucleus accumbens and DOPAC/DA in the prefrontal cortex were decrease. In the immunohistochemistry, the number of tyrosine hydroxylase (TH)-positive neuron was less compared with wild mice. Taken together, the present findings suggest a novel role of QPRT in hypolocomotion and cognitive impairment in relation to impairment of dopaminergic functions in the nucleus accumbens and prefrontal cortex, respectively.

Indoleamine 2,3-dioxygenase 2 (Ido2) is a recently identified catalytic enzyme in the tryptophan-kynurenine pathway that is expressed primarily in monocytes and dendritic cells. To elucidate the biological role of Ido2 in immune function, we introduced lipopolysaccharide (LPS) endotoxin shock to Ido2 knockout (Ido2 KO) mice, which led to higher mortality than that in the wild type (WT) mice. LPS-treated Ido2 KO mice had increased production of inflammatory cytokines (including interleukin-6; IL-6) in serum and signal transducer and activator of transcription 3 (stat3) phosphorylation in the spleen. Moreover, the peritoneal macrophages of LPS-treated Ido2 KO mice produced more cytokines than did the WT mice. By contrast, the overexpression of Ido2 in the murine macrophage cell line (RAW) suppressed cytokine production and decreased stat3 expression. Finally, RAW cells overexpressing Ido2 did not alter nuclear factor κB (NF-κB) or stat1 expression, but IL-6 and stat3 expression decreased relative to the control cell line. These results reveal that Ido2 modulates IL-6/stat3 signalling and is induced by LPS, providing novel options for the treatment of immune disorders.

UNLABELLED: Indoleamine 2,3-dioxygenase (IDO), an enzyme that is ubiquitously distributed in mammalian tissues and cells, converts tryptophan to kynurenine, and is also known as a key molecule that promotes apoptosis in lymphocytes and neurons. In this study, we established hepatitis B virus (HBV)-transgenic (Tg)/IDO-knockout (KO) mice and examined the influence of IDO in a murine fulminant hepatitis model induced by HBV-specific cytotoxic T lymphocytes (CTL). An increase of IDO expression in the livers of HBV-Tg/IDO-wild-type (WT) mice administered HBV-specific CTL was confirmed by real-time polymerase chain reaction, western blotting, and evaluating IDO activity. Plasma alanine aminotransferase (ALT) levels in HBV-Tg/IDO-KO mice after HBV-specific CTL injection significantly decreased compared with those in HBV-Tg/IDO-WT mice. An inhibitor of IDO, 1-methyl-d-tryptophan (1-MT), could also attenuated the observed liver injury induced by this HBV-specific CTL. The expression levels of cytokine and chemokine mRNAs in the livers of HBV-Tg/IDO-WT mice were higher than those in the livers of HBV-Tg/IDO-KO mice. The administration of kynurenine aggravated the liver injury in HBV-Tg/IDO-KO mice injected with HBV-specific CTL. Simultaneous injection of recombinant murine interferon (IFN-γ) and kynurenine also increased the ALT levels in HBV-Tg/IDO-KO mice. The liver injury induced by IFN-γ and kynurenine was improved in HBV-Tg/tumor necrosis factor-α-KO mice. CONCLUSION: Kynurenine and IFN-γ induced by the administration with HBV-specific CTL are cooperatively involved in the progression of liver injury in acute hepatitis model. Our results may lead to a new therapy for the acute liver injury caused by HBV infection.

IDO, an enzyme that degrades the essential amino acid l-tryptophan to N-formylkynurenine, is known to exert immunomodulatory effects in a number of diseases and disorders. IDO expression is increased in tumors, where it is thought to be involved in tumor evasion by suppressing the immune response. A competitive inhibitor of IDO is currently being tested in clinical trials for relapsed or refractory solid tumors; however, there remains a concern that attenuation of the immunosuppressive function of IDO might exacerbate inflammatory responses. In this study, we investigated the role of IDO in 2,4,6-trinitrobenzene sulfate (TNBS)-induced colitis in mice by gene deletion and pharmacological inhibition. TNBS treatment induced significantly more severe colitis in Ido1 gene-deficient (Ido1(-/-)) mice than in Ido1 wild-type (Ido1(+/+)) mice, indicating a role for IDO1 in suppression of acute colitis. Consistent with this, the expression of Ido1 was increased in the colonic interstitial tissues of TNBS-treated Ido1(+/+) mice. Furthermore, transplantation of Ido1(+/+) bone marrow cells into Ido1(-/-) mice reduced the pathological damage associated with colitis, altered the expression of cyto

The escape of preneoplastic cells from the immune system, which is caused by immune tolerance, occurs during the development of several types of tumors. Indoleamine 2,3-dioxygenase (IDO) plays a critical role in the induction of immune tolerance. In the present study we investigated the effects of 1-methyltryptophan (1-MT), an IDO inhibitor, and (-)-epigallocatechin gallate (EGCG), the major catechin ingreen tea, on the development of azoxymethane (AOM)-induced colonic preneoplastic lesions by focusing on the inhibition of IDO. To induce colonic premalignant lesions, male F344 rats were injected with AOM (20 mg/kg body weight, s.c.) once a week for 2 weeks. They also received 0.2% 1-MT or 0.1% EGCG in their drinking water for 4 weeks, starting 1 week before the first dose of AOM. Both 1-MT and EGCG significantly decreased the total number of aberrant crypt foci and β-catenin-accumulated crypts, which overexpressed IDO protein. Treatment with EGCG decreased IDO mRNA expression in both the colonic epithelium and stroma of rats induced by AOM. The AOM-induced increasein cyclooxygenase-2 mRNA expression in the colonic stroma was significantly decreased by EGCG. Furthermore, AOM-induce

The activity of IDO that catalyzes the degradation of tryptophan (Trp) into kynurenine (Kyn) increases after diseases caused by different infectious agents. Previously, we demonstrated that IDO has an important immunomodulatory function in immune-related diseases. However, the pathophysiological role of IDO following acute viral infection is not fully understood. To investigate the role of IDO in the l-Trp-Kyn pathway during acute viral myocarditis, mice were infected with encephalomyocarditis virus, which induces acute myocarditis. We used IDO-deficient (IDO(-/-)) mice and mice treated with 1-methyl-d,l-Trp (1-MT), an inhibitor of IDO, to study the importance of Trp-Kyn pathway metabolites. Postinfection with encephalomyocarditis virus infection, the serum levels of Kyn increased, whereas those of Trp decreased, and IDO activity increased in the spleen and heart. The survival rate of IDO(-/-) or 1-MT-treated mice was significantly greater than that of IDO(+/+) mice. Indeed, the viral load was suppressed in the IDO(-/-) or 1-MT-treated mice. Furthermore, the levels of type I IFNs in IDO(-/-) mice and IDO(-/-) bone marrow-transplanted IDO(+/+) mice were significantly higher than tho

Indoleamine 2,3-dioxygenase (IDO) exerts immunomodulatory effects due to enzymatic activities catalyzing the essential amino acid L-tryptophan. IDO activity might play an important role in regulating immune responses exerted by antigen-presenting cells as a potent tool to help escape from assault by the immune system. In this study, we performed immunohistochemical analysis for IDO expression using mouse anti-human IDO monoclonal antibody in 119 tissue samples of diffuse large B-cell lymphoma (DLBCL) obtained before treatment with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP). Not only the lymphoma cells themselves but also dendritic cells (DCs) expressed IDO. Positive IDO expression in lymphoma cells was found in 38 cases (32%). Complete remission rates in patients with IDO-positive DLBCL and IDO-negative DLBCL were 55.3% and 79.0% (p=0.008), while 3-year overall survival rates were 49.8% and 78.8%, respectively (p=0.0003). IDO activity might thus play an important role in DLBCL and cells that express IDO appear important for determining outcomes after R-CHOP treatment. IDO might represent a candidate therapeutic target for DLBCL patients who show

IDO converts tryptophan to l-kynurenine, and it isnoted as a relevant molecule in promoting tolerance and suppressing adaptive immunity. In this study, we examined the effect of IDOin α-galactosylceramide (α-GalCer)-induced hepatitis. The increase in IDO expression in the liver of wild-type (WT) mice administered α-GalCer was confirmed by real-time PCR, Western blotting, and IDO immunohistochemical analysis. The serum alanine aminotransferase levels in IDO-knockout (KO) mice after α-GalCer injection significantly increased compared with those in WT mice. 1-Methyl-D-tryptophan also exacerbated liver injury in this murine hepatitis model. In α-GalCer-induced hepatitis models, TNF-α is critical in the development of liver injury. The mRNA expression and protein level of TNF-α in the liver from IDO-KO mice were more enhanced compared with those in WT mice. The phenotypes of intrahepatic lymphocytes from WT mice and IDO-KO mice treated with α-GalCer were analyzed by flow cytometry, and the numbers of CD49b(+) and CD11b(+) cells were found to have increased in IDO-KO mice. Moreover, as a result of the increase in the number of NK cells and macrophages in the liver of IDO-KO mice

Indoleamine 2,3-dioxygenase, the L-tryptophan-degrading enzyme, plays a key role in the powerful immunomodulatory effects on several different types of cells. Because modulation of IDO activities after viral infection may have great impact on disease progression, we investigated the role of IDO following infection with LP-BM5 murine leukemia virus. We found suppressed BM5 provirus copies and increased type I IFNs in the spleen from IDO knockout (IDO(-/-)) and 1-methyl-D-L-tryptophan-treated mice compared with those from wild-type (WT) mice. Additionally, the number of plasmacytoid dendritic cells in IDO(-/-) mice was higher in the former than in the WT mice. In addition, neutralization of type I IFNs in IDO(-/-) mice resulted in an increase in LP-BM5 viral replication. Moreover, the survival rate of IDO(-/-) mice or 1-methyl-D-L-tryptophan-treated mice infected with LP-BM5 alone or with both Toxoplasma gondii and LP-BM5 was clearly greater than the survival rate of WT mice. To our knowledge, the present study is the first report to observe suppressed virus replication with upregulated type I IFN in IDO(-/-) mice, suggesting that modulation of the IDO pathway may be an effective str

Introduction of rituximab has largely improved the prognosis of patients with diffuse large B-cell lymphoma(DLBCL). Such change in therapeutic outcome necessitates the identification of additional prognostic factors to conventional indexes that have been validated for CHOP without rituximab. Indoleamine 2,3-dioxygenase (IDO) exerts intense immunomodulatory effects because of enzymatic activities that catalyze the breakdown of the essential amino acid L-tryptophan. The activity of IDO can be estimated by measuring the serum concentration of L-kynurenine. Here, we investigated the role of L-kynurenine as a prognostic marker in R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisolone) therapy. Experimental design: Data from 73 consecutive patients treated with eight cycles of R-CHOP or R-THP (tetrahydropyranyl adriamycin)-COP between December 2002 and March 2007 were analyzed. L-kynurenine concentrations in serum samples obtained at admission were measured by high-performance liquid chromatography. Results: The median serum L-kynurenine level was 1.575 microm (range 0.537-9.588). The complete response (CR) rates of patients with L-kynurenine<1.5 and>or =1.5 microm w

Autoantibodies against cyclic citrullinated peptide (anti-CCP) are sensitive and highly specific markers for rheumatoid arthritis (RA). We evaluated the analytical and diagnostic accuracy of chemiluminescenceenzyme immunoassay (CLEIA) for anti-CCP antibodies, and compared it with that of ELISA.Ninety-nine RA patients who were diagnosed according to the American College of Rheumatology criteria, 16 patients with osteoarthritis, and 94 healthy subjects were included. Sera were used to assess the precision, functional sensitivity, and linearity of anti-CCP antibody determination by CLEIA and the correlation of anti-CCP antibody values between CLEIA and ELISA.For anti-CCP antibodies by CLEIA, the total CV was 4.0 and 5.3% at 21.17 and 90 U/ml, respectively, and the lower limit of detection was 0.1 U/ml. The correlation of CLEIA (x) with ELISA (y) for anti-CCP was: y=1.08x+4.171, r=0.9178 (p<0.0001). No difference was observed in the sensitivity and specificity between CLEIA and ELISA.The automated CLEIA processing system for determining anti-CCP antibodies showed a good analytical performance, and suggested that the CLEIA system has a potential to provide clinically useful data within

In thisstudy, we demonstrated that lipopolysaccharide (LPS) markedly increased nitric oxide (NO) production and indoleamine 2,3-dioxygenase (IDO) activity in mouse peritoneal cells in the presence of activated Valpha14 natural killer T cells. Moreover, LPS-induced NO production in peritoneal cells from IDO-knockout (KO) mice was more increasedthan that from wild-type mice. However, there was no significant difference in the expression of inducible nitric oxide synthase (iNOS) mRNA and protein between the wild-type and IDO-KO mice. No significant difference was also observed in the ratio of CD3- and DX5-positive cells and F4/80- and TLR4-positive cells in peritoneal cells between the wild-type and IDO-KO mice. Since the IDO activity was enhanced by an NO inhibitor, NO may be post-translationally consumed by inhibiting the IDO activity. IDO is well known to play an important role in immunosuppression during inflammatory disease. Therefore, the inhibition of IDO by NO may exacerbate inflammation in the peritoneal cavity.