Individual and population-level variability in HLA-DR associated immunogenicity risk of biologics used for the treatment of rheumatoid arthritis.

Hypothesis: While conventional in silico immunogenicity risk assessments focus on measuring immunogenicity based on the potential of therapeutic proteins to be processed and presented by a global population-wide set of human leukocyte antigen (HLA) alleles to T cells, future refinements might adjust for HLA allele frequencies in different geographic regions or populations, as well for as individuals in those populations. Adjustment by HLA allele distribution may reveal risk patterns that are specific to population groups or individuals, which current methods that rely on global-population HLA prevalence may obscure. Key findings: This analysis uses HLA frequency-weighted binding predictions to define immunogenicity risk for global and sub-global populations. A comparison of assessments tuned for North American/European versus Japanese/Asian populations suggests that the potential for anti-therapeutic responses (anti-therapeutic antibodies or ATA) for several commonly prescribed Rheumatoid Arthritis (RA) therapeutic biologics may differ, significantly, between the Caucasian and Japanese populations. This appears to align with reports of differing product-related immunogenicity that is observed in different populations. Relevance to clinical practice: Further definition of population-level (regional) and individual patient-specific immunogenic risk profiles may enable prescription of the RA therapeutic with the highest probability of success to each patient, depending on their population of origin and/or their individual HLA background. Furthermore, HLA-specific immunogenicity outcomes data are limited, thus there is a need to expand HLA-association studies that examine the relationship between HLA haplotype and ATA in the clinic.

Consistency Analysis of the UF-1500 and UF-5000 Automated Urine Particle Analyzers.

BACKGROUND: The aim was to evaluate the consistency of the results between the UF-1500 and UF-5000, fully automated urine particle analyzers. METHODS: A total of 554 randomly selected inpatient and outpatient urine samples were collected for analysis using the UF-1500, the UF-5000, and by manual microscopic examination. The coincidence rate, intraday repeatability, and interday reproducibility were evaluated on the UF-1500 and UF-5000. To analyze the review flags from the UF-1500, the UF-1500 results were compared to manual microscopy as the gold standard. RESULTS: The repeatability of red blood cells (RBCs), white blood cells (WBCs), epithelial cells (ECs), casts, and bacteria using the UF-1500 and UF-5000 is expressed as the relative standard deviations of the intraday and inter-day measurements. For the UF-1500, the relative standard deviation values ranged from 5.9% to 12.6% and 4.9% to 17.2% for the low and 1.6% to 9.3% and 2.3% to 16.9% for the high samples, respectively. The correlation co-efficient for RBCs, WBCs, ECs, SECs, casts, crystals, and bacteria for the UF-1500 were 0.981, 0.993, 0.968, 0.963, 0.821, 0.783, and 0.992, respectively. Review samples from the UF-1500 were confirmed by microscopic examination. Review flags for all 554 samples included 3 samples with "DEBRIS High" and 23 samples with "RBCs/YLC Abnormal classification". CONCLUSIONS: The identification of various urine components by both instruments meets laboratory requirements. These two instruments with different performances have specific characteristics and should be used based upon the needs of each laboratory.

Sensory neurons promote immune homeostasis in the lung.

Cytokines employ downstream Janus kinases (JAKs) to promote chronic inflammatory diseases. JAK1-dependent type 2 cytokines drive allergic inflammation, and patients with JAK1 gain-of-function (GoF) variants develop atopic dermatitis (AD) and asthma. To explore tissue-specific functions, we inserted a human JAK1 GoF variant (JAK1GoF) into mice and observed the development of spontaneous AD-like skin disease but unexpected resistance to lung inflammation when JAK1GoF expression was restricted to the stroma. We identified a previously unrecognized role for JAK1 in vagal sensory neurons in suppressing airway inflammation. Additionally, expression of Calcb/CGRPß was dependent on JAK1 in the vagus nerve, and CGRPß suppressed group 2 innate lymphoid cell function and allergic airway inflammation. Our findings reveal evolutionarily conserved but distinct functions of JAK1 in sensory neurons across tissues. This biology raises the possibility that therapeutic JAK inhibitors may be further optimized for tissue-specific efficacy to enhance precision medicine in the future.

CD8+ Regulatory T Cells Induced by Lipopolysaccharide Improve Mouse Endotoxin Shock.

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.

Cost-Effectiveness Analysis of Tofacitinib Compared with Biologics in Biologic-Naïve Patients with Moderate-to-Severe Ulcerative Colitis in Japan.

OBJECTIVE: Tofacitinib is an oral Janus kinase inhibitor approved for the treatment of ulcerative colitis (UC). The objective of this study was to evaluate the long-term cost-effectiveness of tofacitinib versus current biologics, considering combinations of first-line (1L) and second-line (2L) therapies, from a Japanese payer's perspective in patients with moderate-to-severe active UC following an inadequate response to conventional therapy and in those who were naïve to biologics. METHODS: A cost-effectiveness analysis was conducted during the time horizon specified in the Markov model, which considers a patient's lifetime as 60 years and an annual discount rate of 2% on costs and effects. The model compared tofacitinib with vedolizumab, infliximab, adalimumab, golimumab, and ustekinumab. The time of active treatment was divided into induction and maintenance phases. Patients not responding to their biologic treatment after induction or during the maintenance phase were switched to a subsequent line of therapy. Treatment response and remission probabilities (for induction and maintenance phases) were obtained through a systematic literature review and a network meta-analysis that employed a multinomial analysis with fixed effects. Patient characteristics were sourced from the OCTAVE Induction trials. Mean utilities associated with UC health states and adverse events (AEs) were obtained from published sources. Direct medical costs related to drug acquisition, administration, surgery, patient management, and AEs were derived from the JMDC database analysis, which corresponded with the medical procedure fees from 2021. The drug prices were adjusted to April 2021. Further validation through all processes by clinical experts in Japan was conducted to fit the costs to real-world practices. Scenario and sensitivity analyses were also performed to confirm the accuracy and robustness of the base-case results. RESULTS: In the base-case, the treatment pattern including 1L tofacitinib was more cost-effective than vedolizumab, infliximab, golimumab, and ustekinumab for 1L therapies in terms of cost per quality-adjusted life year (QALY) gained (based on the Japanese threshold of 5,000,000 yen/QALY [38,023 United States dollars {USD}/QALY]). The base-case results demonstrated that the incremental costs would be reduced for all biologics, and decreases in incremental QALYs were observed for all biologics other than adalimumab. The incremental cost-effectiveness ratio (ICER) was found to be dominant for adalimumab; for the other biologics, it was found to be less costly and less efficacious. The efficiency frontier on the cost-effectiveness plane indicated that tofacitinib-infliximab and infliximab-tofacitinib were more cost-effective than the other treatment patterns. When infliximab-tofacitinib was compared with tofacitinib-infliximab, the ICER was 282,609,856 yen/QALY (2,149,157 USD/QALY) and the net monetary benefit (NMB) was -12,741,342 yen (-96,894 USD) with a threshold of 5,000,000 yen (38,023 USD) in Japan. Therefore, infliximab-tofacitinib was not acceptable by this threshold, and tofacitinib-infliximab was the cost-effective treatment pattern. CONCLUSION: The current analysis suggests that the treatment pattern including 1L tofacitinib is a cost-effective alternative to the biologics for patients with moderate-to-severe UC from a Japanese payer's perspective.

Incidence rates for hospitalized infections, herpes zoster, and malignancies in patients with ulcerative colitis in Japan: an administrative health claims database analysis.

BACKGROUND/AIMS: Patients with ulcerative colitis (UC) are at an increased risk of certain infections and malignancies compared with the general population. Incidence rates (IRs) of hospitalized infections, herpes zoster (HZ), and malignancies in patients with UC, stratified by treatment, in Japan were estimated. METHODS: This retrospective study identified patients with UC treated with corticosteroids, immunosuppressants, or tumor necrosis factor inhibitors (TNFi) from 2 administrative databases (Japan Medical Data Center [JMDC] and Medical Data Vision [MDV]). IRs (unique patients with events per 100 patient-years) were estimated for hospitalized infections, HZ, and malignancies, between June 2010 and May 2018. RESULTS: Among 6,033 MDV patients with UC receiving corticosteroids, immunosuppressants, or TNFi, IRs (95% confidence intervals) were: hospitalized infections, 1.73 (1.52-1.93); HZ, 1.00 (0.85-1.16), and malignancies, 1.48 (1.29-1.66). Among 958 JMDC patients with UC receiving corticosteroids, immunosuppressants, or TNFi, IRs (95% confidence intervals) were: HZ, 1.82 (1.27-2.37) and malignancies, 1.35 (0.87-1.82). In both cohorts, IRs of malignancies were generally similar among patients receiving immunosuppressants, TNFi, or combination therapy (immunosuppressants and TNFi); this was also true for IRs of hospitalized infections and HZ in the MDV cohort. IRs of hospitalized infections, HZ, and malignancies were higher in patients receiving calcineurin inhibitors compared with immunosuppressants or TNFi, in both cohorts. CONCLUSIONS: IRs of hospitalized infections, HZ, and malignancies among patients with UC were generally similar regardless of UC treatment, except for calcineurin inhibitors.

Absence of indoleamine 2,3­dioxygenase 2 promotes liver regeneration after partial hepatectomy in mice.

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 2,3­dioxygenase (Ido) 1 promotes early liver regeneration. However, the role of Ido2 in liver regeneration remains unclear. Wild­type (WT) and Ido2­deficient (Ido2­KO) 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 transcription­quantitative PCR and high­performance liquid chromatography. The activation of NF­κB 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 Ido2­KO mice compared with in WT mice. The expression of IL­6 and TNF­α in MNCs were transiently increased in Ido2­KO mice. The nuclear transport of NF­κB was significantly higher in peritoneal macrophages of Ido2­KO mice compared with WT mice. These results suggested that Ido2 deficiency resulted in transiently increased production of inflammatory cytokines through the activation of NF­kB, 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.

Safety and efficacy of long-term tofacitinib treatment in East Asian patients with ulcerative colitis in OCTAVE Open.

BACKGROUND AND AIM: Tofacitinib is an oral small molecule Janus kinase inhibitor for the treatment of ulcerative colitis (UC). We present safety and efficacy data from patients from East Asia (Japan, Korea, and Taiwan) in OCTAVE Open, an open-label, long-term extension study. METHODS: Patients in remission at OCTAVE Open baseline received tofacitinib 5 mg twice daily (BID); all others received tofacitinib 10 mg BID. Proportions and IRs (unique patients with events/100 patient-years) were calculated for adverse events (AEs) of special interest. Efficacy endpoints were evaluated up to 36 months. RESULTS: In OCTAVE Open, 105/944 patients were from East Asia (tofacitinib 5 mg BID, n = 22; tofacitinib 10 mg BID, n = 83). Overall, 87.6% and 24.8% of patients had AEs and serious AEs, respectively; IRs (95% CI) for AEs of special interest were herpes zoster (HZ; non-serious and serious), 6.07 (3.40-10.02); serious infections, 1.47 (0.40-3.76); opportunistic infections, 1.91 (0.62-4.45); major cardiovascular adverse events, 0.37 (0.01-2.04); malignancies (excluding non-melanoma skin cancer [NMSC]), 0.37 (0.01-2.04); and NMSC, 0.00 (0.00-1.35). No deaths, venous thromboembolic events, or gastrointestinal perforations occurred. At month 36, 68.2% and 54.2% of patients had a clinical response, 68.2% and 53.0% had endoscopic improvement, and 63.6% and 49.4% were in remission with tofacitinib 5 and 10 mg BID, respectively. CONCLUSIONS: The HZ IR in East Asian patients was numerically higher versus the global study population; excluding HZ, tofacitinib safety and efficacy were consistent with the global study population.

D­allose enhances the efficacy of hydroxychloroquine against Lewis lung carcinoma cell growth by inducing autophagy.

Various cancer cells require massive amounts of glucose as an energy source for their dysregulated growth. Although D­allose, a rare sugar, inhibits tumor cell growth via inhibition of glucose uptake, a few cells can survive after treatment. However, the mechanism by which D­allose­resistant cells are generated remains unclear. Here, we investigated the properties of D­allose­resistant cells and evaluated the efficacy of combined treatment with this rare sugar and antitumor drugs. To this end, we established a D­allose­resistant tumor cell line and prepared a C57BL/6J mouse tumor xenograft model using Lewis lung carcinoma (LLC) cells. Xenograft­bearing mice were treated with D­allose (9 g/kg) and/or hydroxychloroquine (HCQ, 60 mg/kg), an autophagy inhibitor, for two weeks. Although D­allose inhibited LLC cell growth in a dose­dependent manner, a few cells survived. The upregulation of LC3­II, a classical autophagy marker, and the downregulation of mTOR and its downstream molecule Beclin1 were observed in established D­allose­resistant LLC cells, which were more sensitive to cell death induced by HCQ. Similarly, in the tumor xenograft model, the tumor volume in mice co­treated with D­allose and HCQ was considerably smaller than that in untreated or HCQ­treated mice. Importantly, the administration of D­allose induced autophagy selectively at the tumor site of the xenograft­bearing mice. These results provide a new therapeutic strategy targeting autophagy which is induced in tumor cells by D­allose administration, and may be used to improve therapies for lung cancer.

Viability of diffuse large B-cell lymphoma cells is regulated by kynurenine 3-monooxygenase activity.

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.

3-Hydroxykynurenine Regulates Lipopolysaccharide-Stimulated IL-6 Production and Protects against Endotoxic Shock in Mice.

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.

Evaluation of red blood cell parameters provided by the UF-5000 urine auto-analyzer in patients with glomerulonephritis.

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.

Kynurenine 3-monooxygenase deficiency induces depression-like behavior via enhanced antagonism of α7 nicotinic acetylcholine receptors by kynurenic acid.

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 ß2nAChR 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 produced by indoleamine 2,3-dioxygenase 2 exacerbates acute liver injury by carbon tetrachloride in mice.

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.

Kynurenine plays an immunosuppressive role in 2,4,6-trinitrobenzene sulfate-induced colitis in mice.

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-ß 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.

Indoleamine 2,3-dioxygenase 2 depletion suppresses tumor growth in a mouse model of Lewis lung carcinoma.

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.

A single-nucleus RNA-sequencing pipeline to decipher the molecular anatomy and pathophysiology of human kidneys.

Defining cellular and molecular identities within the kidney is necessary to understand its organization and function in health and disease. Here we demonstrate a reproducible method with minimal artifacts for single-nucleus Droplet-based RNA sequencing (snDrop-Seq) that we use to resolve thirty distinct cell populations in human adult kidney. We define molecular transition states along more than ten nephron segments spanning two major kidney regions. We further delineate cell type-specific expression of genes associated with chronic kidney disease, diabetes and hypertension, providing insight into possible targeted therapies. This includes expression of a hypertension-associated mechano-sensory ion channel in mesangial cells, and identification of proximal tubule cell populations defined by pathogenic expression signatures. Our fully optimized, quality-controlled transcriptomic profiling pipeline constitutes a tool for the generation of healthy and diseased molecular atlases applicable to clinical samples.

Time-course analysis of cardiac and serum galectin-3 in viral myocarditis after an encephalomyocarditis virus inoculation.

Galectin-3 is a ß-galactoside-binding lectin which is important in cell proliferation and apoptotic regulation. Recently, serum galectin-3 has been shown to have prognostic value as a biomarker in heart failure. Encephalomyocarditis virus (EMCV) can cause severe myocarditis, congestive heart failure and dilated cardiomyopathy as well as encephalitis in various animals including mice. The pathophysiological role of galectin-3 in acute myocarditis following viral infection is not fully understood. The goal of this study is to determine the cardiac localization and the time-course of galectin-3 expression in heart failure after viral inoculation with EMCV. At 12, 24, 48, 96 hours, 7 and 10 days after intraperitoneal EMCV inoculation, animals were examined histologically and analyzed for the expression of galectin-3 and Iba1. Galectin-3 was up-regulated in degenerated fibrotic lesions of cardiac tissues 96 hours after viral inoculation and were followed by myocardial fibrosis. At the same time, Iba1 positive macrophages were observed within the inflammatory sites. A time-course correlation between the number of galectin-3 positive cells and the cardiac area of degenerated fibrotic lesions was detected-serum galectin-3 increased at 96 hours and correlated well with the number of cardiac galectin-3 positive cells. Our results indicate that galectin-3 expression may be a useful biomarker of cardiac fibrotic degeneration in acute myocarditis following viral infection. In addition, measuring serum galectin-3 levels might be an early diagnostic method for detecting cardiac degeneration in acute myocarditis.

Lipopolysaccharide shock reveals the immune function of indoleamine 2,3-dioxygenase 2 through the regulation of IL-6/stat3 signalling.

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.

Centrosome amplification disrupts renal development and causes cystogenesis.

Centrosome number is tightly controlled to ensure proper ciliogenesis, mitotic spindle assembly, and cellular homeostasis. Centrosome amplification (the formation of excess centrosomes) has been noted in renal cells of patients and animal models of various types of cystic kidney disease. Whether this defect plays a causal role in cystogenesis remains unknown. Here, we investigate the consequences of centrosome amplification during kidney development, homeostasis, and after injury. Increasing centrosome number in vivo perturbed proliferation and differentiation of renal progenitors, resulting in defective branching morphogenesis and renal hypoplasia. Centrosome amplification disrupted mitotic spindle morphology, ciliary assembly, and signaling pathways essential for the function of renal progenitors, highlighting the mechanisms underlying the developmental defects. Importantly, centrosome amplification was sufficient to induce rapid cystogenesis shortly after birth. Finally, we discovered that centrosome amplification sensitized kidneys in adult mice, causing cystogenesis after ischemic renal injury. Our study defines a new mechanism underlying the pathogenesis of renal cystogenesis, and identifies a potentially new cellular target for therapy.