Tetsuro Takayama

Imbalance of NKp44+NKp46− and NKp44−NKp46+ Natural Killer Cells in the Intestinal Mucosa of Patients With Crohn's Disease

BACKGROUND & AIMS Mucosal natural killer (NK) cells that produce interleukin (IL)-22 mediate intestinal homeostasis and inflammation in mice. However, their role in the pathogenesis of human inflammatory bowel diseases (IBDs) is not known. We investigated intestinal NK cells in intestinal mucosa samples of patients with Crohns disease (CD). METHODS We isolated lamina propria NK cells from intestinal mucosal samples of patients with IBD and subjects without IBD (controls) and analyzed expression patterns of cell surface molecules and cytokine production. Interactions between lamina propria NK cells and intestinal macrophages were examined. RESULTS In intestinal mucosa samples from controls, NKp44 and NKp46 were expressed differentially on CD3(-)CD56(+) NK cells, NKp44(+)NKp46(-) (NKp44(+)) NK cells expressed CD127 and the transcription factor retinoic acid-related orphan receptor C (RORC) and produced IL-22 whereas NKp44(-)NKp46(+) (NKp46(+)) NK cells did not express CD127 or RORC and produced interferon (IFN)-gamma. NKp46(+) NK cells were predominant in intestinal mucosa of patients with CD compared with controls or patients with ulcerative colitis. Upon interaction with intestinal inflammatory macrophages NKp46(+), NK cells from patients with CD were activated via IL-23 and produced IFN-gamma; this activation required cell-to-cell contact. CONCLUSIONS The balance of NKp44(+)/NKp46(+) NK cells is disrupted in intestinal mucosa of patients with CD. NKp46(+) NK cells might mediate the pathogenesis of CD by producing IFN-gamma.

TL1A produced by lamina propria macrophages induces Th1 and Th17 immune responses in cooperation with IL-23 in patients with Crohn's disease

Background: Tumor necrosis factor (TNF)‐like protein 1A (TL1A) is a member of the TNF superfamily and contributes to the pathogenesis of Crohns disease (CD) by stimulating T‐helper (Th) 1 cells. In addition to Th1, recent studies have focused on the role of Th17 cells in the pathogenesis of CD. Here we tried to clarify the role of TL1A in Th1 and Th17 immunity in CD. Methods: TL1A expression was assessed by quantitative reverse‐transcription polymerase chain reaction (RT‐PCR) in lamina propria (LP) macrophages (LP‐M&PHgr;s) from normal controls (NC) and patients with CD or ulcerative colitis (UC). Purified LP CD4+ T cells were stimulated with TL1A and/or IL‐23 and interferon gamma (IFN‐&ggr;) and interleukin (IL)‐17 levels were analyzed. We also examined the effect of TL1A on naïve CD4+ T‐cell differentiation. Results: We found that LP‐M&PHgr;s are a major producer of TL1A. TL1A expression was markedly enhanced in LP‐M&PHgr;s from CD patients compared with NC or UC patients. IL‐23, in addition to TL1A, was induced in LP‐M&PHgr;s by commensal bacteria stimulation. TL1A and IL‐23 synergistically promoted the production of IFN‐&ggr; and IL‐17 by LP T cells, while TL1A alone did not induce cytokine production. Furthermore, TL1A promoted Th17 differentiation from naïve T cells by LP‐M&PHgr;s; however, IL‐23 did not show any synergistic effects on Th17 differentiation. Conclusions: TL1A expressed in LP‐M&PHgr;s might play an important role in the pathogenesis of CD by inducing Th1 and Th17 immunity. IL‐23 differentially regulated these functions of TL1A on memory and naïve T cells. Inflamm Bowel Dis 2009

Human CD14+ Macrophages in Intestinal Lamina Propria Exhibit Potent Antigen-Presenting Ability

Intestinal APCs are considered critical in maintaining the balance between the response against harmful pathogens and the induction of tolerance to commensal bacteria and food Ags. Recently, several studies indicated the presence of gut-specific APC subsets, which possess both macrophage and dendritic cell (DC) markers. These unique APC subsets play important roles in gut immunity, especially for immune regulation against commensal bacteria. Herein, we examined a unique macrophage subset, which coexpressed the macrophage (Mφ) marker CD14 and the DC marker CD209 in human intestinal lamina propria (LP). The LP Mφ subset in both normal control subjects or Crohn’s disease (CD) patients induced proliferation of naive CD4+ T cells as well as monocyte-derived DCs, and it expressed retinoic acid synthetic enzyme retinaldehyde dehydrogenase 2 and retinol dehydrogenase 10, which induced expression of gut homing receptors on T cells in a retinoic acid-dependent manner. Moreover, the LP Mφ subset strongly evoked differentiation of Th1 cells and slightly induced Th17 cells in both normal control subjects and CD patients; the inducing potential was highest in CD patients. In CD patients, Th17, but not Th1, induction by the LP Mφ subset was enhanced in the presence of commensal bacteria Ags. This enhancement was not observed in normal control subjects. The Th17 induction by the LP Mφ subset was inhibited by neutralization of IL-6 and IL-1β, but it was enhanced by blockade of retinoic acid signaling. These observations highlight a role for LP Mφ in the enhanced Th1, and potentially in Th17 differentiation, at the inflammatory site of inflammatory bowel diseases.

Monocyte Chemoattractant Protein-1 Contributes to Gut Homeostasis and Intestinal Inflammation by Composition of IL-10-Producing Regulatory Macrophage Subset

Lamina propria macrophages (LPMϕs) spontaneously produce large amounts of anti-inflammatory IL-10 and play a central role in regulation of immune responses against commensal bacteria. MCP-1 is a chemokine that plays an important role in recruitment of monocytes and macrophages to inflamed tissues. We demonstrated that, in addition to IL-10, LPMϕs produced large amounts of MCP-1, even in a steady state. MCP-1 deficiency caused impaired IL-10 production by LPMϕs and led to exacerbation of dextran sulfate sodium-induced acute colitis. As an explanation of this impaired IL-10 production by LPMϕs, we found that LPMϕs could be separated into two subsets with distinct side-scattered properties, namely LPMϕ1 (CD11b+F4/80+CD11c–SSChi) and LPMϕ2 (CD11b+F4/80+CD11c–SSClo). Unlike LPMϕ1, the LPMϕ2 subset migrated in response to MCP-1 and produced a larger amount of IL-10 in response to commensal bacteria. LPMϕs isolated from MCP-1–deficient mice produced less IL-10 as a consequence of the lack of the MCP-1–dependent LPMϕ2 population. This imbalanced composition in LPMϕ population may be involved in the susceptibility to DSS-induced colitis in MCP-1–deficient mice. Our results suggest that endogenous MCP-1 contributes to the composition of resident LPMϕ subsets in the intestine. Moreover, MCP-1–dependent LPMϕ2 subset may play an important role in maintenance of gut homeostasis in the steady state, and in the termination of excess inflammatory responses in the intestine, by producing IL-10.

Bile acids induce monocyte differentiation toward interleukin-12 hypo-producing dendritic cells via a TGR5-dependent pathway

Dendritic cells (DCs) are known as antigen‐presenting cells and play a central role in both innate and acquired immunity. Peripheral blood monocytes give rise to resident and recruited DCs in lymph nodes and non‐lymphoid tissues. The ligands of nuclear hormone receptors can modulate DC differentiation and so influence various biological functions of DCs. The role of bile acids (BAs) as signalling molecules has recently become apparent, but the functional role of BAs in DC differentiation has not yet been elucidated. We show that DCs derived from human peripheral blood monocytes cultured with a BA produce lower levels of interleukin‐12 (IL‐12) and tumour necrosis factor‐α in response to stimulation with commensal bacterial antigens. Stimulation through the nuclear receptor farnesoid X (FXR) did not affect the differentiation of DCs. However, DCs differentiated with the specific agonist for TGR5, a transmembrane BA receptor, showed an IL‐12 hypo‐producing phenotype. Expression of TGR5 could only be identified in monocytes and was rapidly down‐regulated during monocyte differentiation to DCs. Stimulation with 8‐bromoadenosine‐cyclic AMP (8‐Br‐cAMP), which acts downstream of TGR5 signalling, also promoted differentiation into IL‐12 hypo‐producing DCs. These results indicate that BAs induce the differentiation of IL‐12 hypo‐producing DCs from monocytes via the TGR5‐cAMP pathway.

Prediction of metabolic syndrome using artificial neural network system based on clinical data including insulin resistance index and serum adiponectin

OBJECTIVE This study aimed to predict the 6-year incidence of metabolic syndrome (MetS) using an artificial neural network (ANN) system and multiple logistic regression (MLR) analysis based on clinical factors, including the insulin resistance index calculated by homeostasis model assessment (HOMA-IR). DESIGN Subjects were recruited from participants in annual health check-ups in both 2000 and 2006. A total of 410 Japanese male teachers and other workers at Keio University, 30-59 years of age at baseline, participated in this retrospective cohort study. MEASUREMENTS Clinical parameters were randomly divided into a training dataset and a validation dataset, and the ANN system and MLR analysis were applied to predict individual incidences. The leave some out cross validation method was used for validation. RESULTS The sensitivity of the prediction was 0.27 for the MLR model and 0.93 for the ANN system, while specificities were 0.95 and 0.91, respectively. Sensitivity analysis employing the ANN system identified BMI, age, diastolic blood pressure, HDL-cholesterol, LDL-cholesterol and HOMA-IR as important predictors, suggesting these factors to be non-linearly related to the outcome. CONCLUSION We successfully predicted the 6-year incidence of MetS using an ANN system based on clinical data, including HOMA-IR and serum adiponectin, in Japanese male subjects.

In vivo visualization of trophozoites in patients with amoebic colitis by using a newly developed endocytoscope

BACKGROUND The endocytoscopy system (ECS) is a new method to provide real-time super-magnifying microscopic imaging in vivo. Routine diagnosis of amebic colitis requires multiple tests that are both time consuming and costly. OBJECTIVE To determine the feasibility of ECS to directly detect the amebic parasites in vivo. DESIGN Prospective, single-center, pilot study. SETTING Tertiary-care university hospital. PATIENTS This study involved 5 patients who were suspected to have amebic colitis by conventional colonoscopy in our institute. INTERVENTIONS A super-magnifying ECS with 450 x magnification. MAIN OUTCOME MEASUREMENTS We compared ECS findings with those of conventional methods-serum antibody tests and histology of colon biopsy specimens. RESULTS We successfully visualized the amebic trophozoites in all 5 cases. In contrast, 3 specimens had positive results on serology, and 3 had positive histology results on hematoxylin and eosin staining. LIMITATIONS Pilot study with a limited number of patients. Findings were compared only with serology and histology findings. CONCLUSIONS ECS would be a useful tool for the prompt diagnosis of amebic colitis via the real-time in vivo visualization of amebic trophozoites.

Prediction of survival and complications after percutaneous endoscopic gastrostomy in an individual by using clinical factors with an artificial neural network system

Background The demand for percutaneous endoscopic gastrostomy (PEG) has increased because it is safe and a technically easy method, but it has risks of severe complications including death and a high mortality rate within 30 days. At present, we cannot predict survival or the incidence of complications before tube placement in an individual. Earlier studies have used traditional statistical analysis by assuming a linear relationship between clinical features, but most phenomena in the clinical situation are not linearly related. Aims We predicted the survival and complications before PEG placement in an individual by using artificial neural network (ANN) system, which can assess the nonlinear relationship. Methods We studied 100 patients who underwent PEG at the Kitasato Medical Institute Hospital from 1997 to 2005. Clinical data and laboratory data were used as input data. Complications related to PEG placement and survival dates were historically and prospectively measured. From the clinical data and laboratory data, we examined the prediction of outcome in individual patients using multiple logistic regression analysis and an ANN. Results The correct answer rate of survival by multiple logistic regression analysis was 67.9%. In contrast, using the ANN, we correctly predicted the survival date and aspiration pneumonia in 75 and 89% of patients, respectively. There was a nonlinear relationship among input factors and survival and complications. Conclusion We correctly predicted the outcome and complications of individual patients with PEG with a high correct answer rate. Our data show the potential of an ANN as a powerful tool in daily clinical use to individualize treatment (‘tailor-made medicine’) for PEG and reduce costs.

Long-term prognosis of patients with ulcerative colitis treated with cytapheresis therapy.

BACKGROUND Although accumulating studies in Japan show that cytapheresis (CAP) therapy is safe and effective for the induction of remission of moderate or severe ulcerative colitis (UC), the long-term prognosis of UC patients treated with CAP is unknown. The aim of this study was to determine the long-term prognosis of UC patients treated with CAP. METHODS Ninety patients treated previously with CAP and followed for more than 3 years were evaluated. The rates of operation, readmission, and use or dose-up of corticosteroid were analyzed as long-term prognosis. RESULTS Following the first course of CAP treatment, 64% of patients showed clinical improvement (> 4-point decrease in the clinical activity index (CAI)), and 49% of patients achieved clinical remission (CAI ≤ 4). Longer disease duration and lower age at the first CAP treatment correlated significantly with the therapeutic effects of CAP (p = 0.003 and 0.035, respectively). The rates of operation and readmission were significantly lower in patients who showed previous clinical effects of CAP than in those who did not respond to CAP. The rates of operation and readmission were also significantly lower in patients whose treatment was combined with immunomodulators after the initiation of CAP than in patients who did not use immunomodulators. Importantly, the second course of CAP was also effective in most of the patients who showed a clinical response to the first CAP. CONCLUSIONS Patients who achieve remission after the first CAP therapy may have a good long-term prognosis and a good response to a second CAP therapy even after relapse.

Computer-Aided Prediction of Long-Term Prognosis of Patients with Ulcerative Colitis after Cytoapheresis Therapy

Cytoapheresis (CAP) therapy is widely used in ulcerative colitis (UC) patients with moderate to severe activity in Japan. The aim of this study is to predict the need of operation after CAP therapy of UC patients on an individual level using an artificial neural network system (ANN). Ninety UC patients with moderate to severe activity were treated with CAP. Data on the patients’ demographics, medication, clinical activity index (CAI) and efficacy of CAP were collected. Clinical data were divided into training data group and validation data group and analyzed using ANN to predict individual outcomes. The sensitivity and specificity of predictive expression by ANN were 0.96 and 0.97, respectively. Events of admission, operation, and use of immunomodulator, and efficacy of CAP were significantly correlated to the outcome. Requirement of operation after CAP therapy was successfully predicted by using ANN. This newly established ANN strategy would be used as powerful support of physicians in the clinical practice.