Epithelial cell-intrinsic Notch signaling plays an essential role in the maintenance of gut immune homeostasis

Intestinal epithelial cells (IECs) have important functions as the first line of defense against diverse microorganisms on the luminal surface. Impaired integrity of IEC has been implicated in increasing the risk for inflammatory disorders in the gut. Notch signaling plays a critical role in the maintenance of epithelial integrity by regulating the balance of secretory and absorptive cell lineages, and also by facilitating epithelial cell proliferation. We show in this article that mice harboring IEC-specific deletion of Rbpj (RBP-J(ΔIEC)), a transcription factor that mediates signaling through Notch receptors, spontaneously develop chronic colitis characterized by the accumulation of Th17 cells in colonic lamina propria. Intestinal bacteria are responsible for the development of colitis, because their depletion with antibiotics prevented the development of colitis in RBP-J(ΔIEC) mice. Furthermore, bacterial translocation was evident in the colonic mucosa of RBP-J(ΔIEC) mice before the onset of colitis, suggesting attenuated epithelial barrier functions in these mice. Indeed, RBP-J(ΔIEC) mice displayed increase in intestinal permeability after rectal administration of FITC-dextran. In addition to the defect in physical barrier, loss of Notch signaling led to arrest of epithelial cell turnover caused by downregulation of Hes1, a transcriptional repressor of p27(Kip1) and p57(Kip2). Thus, epithelial cell-intrinsic Notch signaling ensures integrity and homeostasis of IEC, and this mechanism is required for containment of intestinal inflammation.

Estimation of direction of attention using EEG and out-of-head sound localization

Brain-Machine Interfaces (BMIs) are being researched controlling external devices such as robots and computers by measuring the cranial nerve activity of the operator. The brain activities evoked by visual stimuli have been studied intensively. However, few studies have considered a BMI that uses the brain activities evoked by auditory stimuli. This study investigated whether a person's direction of attention can be estimated using an event-related potential (ERP) generated by selective attention to an auditory stimulus. An auditory stimulus and an out-of-head sound localization system that can create an audio image outside the head that is presented through an earphone were used instead of a loudspeaker system. This system was experimentally evaluated by presenting the subject auditory cues from one of six directions while the subject directed his attention in one direction. An EEG response similar to an ERP was observed. The direction of attention was estimated using support vector machine with an accuracy of 89.2[%] on average for the three subjects. This suggests that a BMI system based on the estimated direction of attention can be developed by using out-of-head sound localization.

Pathological classification of canine mammary tumor based on quantifying mRNA levels of hormonal receptors, SATB1, and Snail in tissue and fine needle biopsy samples

Cytological diagnosis is not generally conclusive enough to identify histopathological malignancy in canine mammary tumors (CMTs). To establish cytological examination using fine needle biopsy (FNB) samples, gene expressions of hormonal receptors, human epidermal growth factor receptor 2 (HER2), and transcription regulators (Special AT-rich binding protein 1: SATB1 and Snail) were investigated in both tissue and FNB samples of CMTs. In tissue samples of malignant CMTs, especially invasive ones, low expressions of hormonal receptors and high expressions of SATB1 and Snail were detected. On discriminant analysis of tissue samples, 73.2% of CMTs were correctly classified according to histopathological examinations. In FNB samples of malignant CMTs, low expressions of hormonal receptors were detected. On discriminant analysis of FNB samples, 74.2% of CMTs were correctly classified according to histopathological examination. In conclusion, FNB gene expressions had a utility for diagnosis of CMTs malignancy in some degree. By researching more sensitive genes for malignant CMTs, the gene examination of FNB samples from CMTs will become a useful diagnostic tool that can be performed easily without anesthesia and could predict tumor malignancy and invasion prior to surgical removal.

Prevalence and impact of rhinitis in asthma. SACRA, a cross-sectional nation-wide study in Japan

BACKGROUND

Asthma and rhinitis are common co-morbidities everywhere in the world but nation-wide studies assessing rhinitis in asthmatics using questionnaires based on guidelines are not available.

OBJECTIVE

To assess the prevalence, classification, and severity of rhinitis using the Allergic Rhinitis and its Impact on Asthma (ARIA) criteria in Japanese patients with diagnosed and treated asthma.

METHODS

The study was performed from March to August 2009. Patients in physicians' waiting rooms, or physicians themselves, filled out questionnaires on rhinitis and asthma based on ARIA and Global Initiative for Asthma (GINA) diagnostic guides. The patients answered questions on the severity of the diseases and a Visual Analog Scale. Their physicians made the diagnosis of rhinitis.

RESULTS

In this study, 1910 physicians enrolled 29,518 asthmatics; 15,051 (51.0%) questionnaires were administered by physician, and 26,680 (90.4%) patients were evaluable. Self- and physician-administered questionnaires gave similar results. Rhinitis was diagnosed in 68.5% of patients with self-administered questionnaires and 66.2% with physician-administered questionnaires. In this study, 994 (7.6%) patients with self-administered and 561 (5.2%) patients with physician-administered questionnaires indicated rhinitis symptoms on the questionnaires without a physician's diagnosis of rhinitis. Most patients with the physician's diagnosis of rhinitis had moderate/severe rhinitis. Asthma control was significantly impaired in patients with a physician's diagnosis of rhinitis for all GINA clinical criteria except exacerbations. There were significantly more patients with uncontrolled asthma as defined by GINA in those with a physician's diagnosis of rhinitis (25.4% and 29.7%) by comparison with those without rhinitis (18.0% and 22.8%).

CONCLUSION

Rhinitis is common in asthma and impairs asthma control.

Chemerin activates fibroblast-like synoviocytes in patients with rheumatoid arthritis

Introduction

Chemerin is a chemotactic agonist identified as a ligand for ChemR23 that is expressed on macrophages and dendritic cells (DCs). In this study, we analyzed the expression of chemerin and ChemR23 in the synovium of rheumatoid arthritis (RA) patients and the stimulatory effects of chemerin on fibroblast-like synoviocytes (FLSs) from RA patients.

Methods

Chemerin and ChemR23 expression in the RA synovium was ascertained by immunohistochemistry and Western blot analysis. Chemerin expression on cultured FLSs was analyzed by ELISA. ChemR23 expression on FLSs was determined by immunocytochemistry and Western blot analysis. Cytokine production from FLSs was measured by ELISA. FLS cell motility was evaluated by utilizing a scrape motility assay. We also examined the stimulating effect of chemerin on the phosphorylation of mitogen-activated protein kinase (MAPK), p44/42 mitogen-activated protein kinase (ERK1/2), p38MAPK, c-Jun N-terminal kinase (JNK)1/2 and Akt, as well as on the degradation of regulator of NF-κB (IκBα) in FLSs, by Western blot analysis.

Results

Chemerin was expressed on endothelial cells and synovial lining and sublining cells. ChemR23 was expressed on macrophages, immature DCs and FLSs and a few mature DCs in the RA synovium. Chemerin and ChemR23 were highly expressed in the RA synovium compared with osteoarthritis. Chemerin and ChemR23 were expressed on unstimulated FLSs. TNF-α and IFN-γ upregulated chemerin production. Chemerin enhanced the production of IL-6, chemokine (C-C motif) ligand 2 and matrix metalloproteinase 3 by FLSs, as well as increasing FLS motility. The stimulatory effects of chemerin on FLSs were mediated by activation of ERK1/2, p38MAPK and Akt, but not by JNK1/2. Degradation of IκB in FLSs was not promoted by chemerin stimulation. Inhibition of the ERK1/2, p38MAPK and Akt signaling pathways significantly suppressed chemerin-induced IL-6 production. Moreover, blockade of the p38MAPK and Akt pathways, but not the ERK1/2 pathway, inhibited chemerin-enhanced cell motility.

Conclusions

The interaction of chemerin and ChemR23 may play an important role in the pathogenesis of RA through the activation of FLSs.

The epithelia-specific membrane trafficking factor AP-1B controls gut immune homeostasis in mice

BACKGROUND & AIMS

Epithelial cells that cover the intestinal mucosal surface maintain immune homeostasis and tolerance in the gastrointestinal tract. However, little is known about the molecular mechanisms that regulate epithelial immune functions. Epithelial cells are distinct in that they are highly polarized; this polarity is, at least in part, established by the epithelium-specific polarized sorting factor adaptor protein (AP)-1B. We investigated the role of AP-1B-mediated protein sorting in the maintenance of gastrointestinal immune homeostasis.

METHODS

The role of AP-1B in intestinal immunity was examined in AP-1B-deficient mice (Ap1m2(-/-)) by monitoring their phenotypes, intestinal morphology, and epithelial barrier functions. AP-1B-mediated protein sorting was examined in polarized epithelial cells from AP-1B knockdown and Ap1m2(-/-) mice.

RESULTS

Ap1m2(-/-) mice developed spontaneous chronic colitis, characterized by accumulation of interleukin-17A-producing, T-helper 17 cells. Deficiency of AP-1B caused epithelial immune dysfunction, such as reduced expression of antimicrobial proteins and impaired secretion of immunoglobulin A. These defects promoted intestinal dysbiosis and increased bacterial translocation within the mucosa. Importantly, AP-1B deficiency led to mistargeting of a subset of basolateral cytokine receptors to the apical plasma membrane in a polarized epithelial cell line and in colonic epithelial cells from mice. AP1M2 expression was reduced significantly in colonic epithelium samples from patients with Crohn's disease.

CONCLUSIONS

AP-1B is required for proper localization of a subset of cytokine receptors in polarized epithelial cells, which allows them to respond to cytokine signals from underlying lamina propria cells. The AP-1B-mediated protein sorting machinery is required for maintenance of immune homeostasis and prevention of excessive inflammation.

CCR6hiCD11c(int) B cells promote M-cell differentiation in Peyer's patch

M cells are responsible for uptake of mucosal antigens in Peyer's patches (PPs). Differentiation of M cells is thought to be induced by interactions between follicle-associated epithelium and PP cells; however, it remains elusive what types of immune cells function as M-cell inducers. Here, we attempted to identify the cells that serve as an M-cell inducer in PP. We found that a unique B-cell subset characterized by CCR6(hi)CD11c(int) resided in the subepithelial dome (SED) in mouse PP. CCR6(hi)CD11c(int) B cells showed chemotactic migration in response to CCL20. Furthermore, this unique B-cell subset substantially decreased in PP of CCR6-deficient mice, indicating that the SED localization of CCR6(hi)CD11c(int) B cells is most likely regulated by the CCL20-CCR6 system. Concomitantly, CCR6 deficiency caused remarkable decrement of M cells. Moreover, adoptive transfer of CCR6(hi)CD11c(int) B cells from wild-type mice restored the M-cell decrement in CCR6-deficient mice. Collectively, the spatial regulation of CCR6(hi)CD11c(int) B cells via the CCL20-CCR6 system may play a vital role in M-cell differentiation in mice.

Uptake through glycoprotein 2 of FimH(+) bacteria by M cells initiates mucosal immune response

The mucosal immune system forms the largest part of the entire immune system, containing about three-quarters of all lymphocytes and producing grams of secretory IgA daily to protect the mucosal surface from pathogens. To evoke the mucosal immune response, antigens on the mucosal surface must be transported across the epithelial barrier into organized lymphoid structures such as Peyer's patches. This function, called antigen transcytosis, is mediated by specialized epithelial M cells. The molecular mechanisms promoting this antigen uptake, however, are largely unknown. Here we report that glycoprotein 2 (GP2), specifically expressed on the apical plasma membrane of M cells among enterocytes, serves as a transcytotic receptor for mucosal antigens. Recombinant GP2 protein selectively bound a subset of commensal and pathogenic enterobacteria, including Escherichia coli and Salmonella enterica serovar Typhimurium (S. Typhimurium), by recognizing FimH, a component of type I pili on the bacterial outer membrane. Consistently, these bacteria were colocalized with endogenous GP2 on the apical plasma membrane as well as in cytoplasmic vesicles in M cells. Moreover, deficiency of bacterial FimH or host GP2 led to defects in transcytosis of type-I-piliated bacteria through M cells, resulting in an attenuation of antigen-specific immune responses in Peyer's patches. GP2 is therefore a previously unrecognized transcytotic receptor on M cells for type-I-piliated bacteria and is a prerequisite for the mucosal immune response to these bacteria. Given that M cells are considered a promising target for oral vaccination against various infectious diseases, the GP2-dependent transcytotic pathway could provide a new target for the development of M-cell-targeted mucosal vaccines.

Activation-induced cytidine deaminase deficiency causes organ-specific autoimmune disease

Activation-induced cytidine deaminase (AID) expressed by germinal center B cells is a central regulator of somatic hypermutation (SHM) and class switch recombination (CSR). Humans with AID mutations develop not only the autosomal recessive form of hyper-IgM syndrome (HIGM2) associated with B cell hyperplasia, but also autoimmune disorders by unknown mechanisms. We report here that AID-/- mice spontaneously develop tertiary lymphoid organs (TLOs) in non-lymphoid tissues including the stomach at around 6 months of age. At a later stage, AID-/- mice develop a severe gastritis characterized by loss of gastric glands and epithelial hyperplasia. The disease development was not attenuated even under germ-free (GF) conditions. Gastric autoantigen -specific serum IgM was elevated in AID-/- mice, and the serum levels correlated with the gastritis pathological score. Adoptive transfer experiments suggest that autoimmune CD4+ T cells mediate gastritis development as terminal effector cells. These results suggest that abnormal B-cell expansion due to AID deficiency can drive B-cell autoimmunity, and in turn promote TLO formation, which ultimately leads to the propagation of organ-specific autoimmune effector CD4+ T cells. Thus, AID plays an important role in the containment of autoimmune diseases by negative regulation of autoreactive B cells.

A survey of patients with self-reported severe food allergies in Japan

Food allergies have increased in recent years in Japan. Details of causative foods, places where anaphylaxis developed, and other allergic factors remain unknown, and we investigated them. A'questionnaire survey for the prevention of food allergies' was conducted using a nationwide group of patients with food allergies. A total of 1383 patients from 878 families (including 319 patients who experienced anaphylaxis) provided valid answers to the questionnaire. The average age of the first anaphylactic attack was 3.20 +/- 6.327 yr. The most common allergens causing anaphylaxis were in order milk, eggs, wheat, peanuts, and soybeans, followed by sesame and buckwheat. The most common place where anaphylaxis developed was the patient's own home, followed by fast food restaurants, places visited, restaurants, and schools. In patients' own homes, fast food restaurants (buffet), places visited and schools, the most common allergens were milk, eggs, and wheat. In restaurants and accommodation facilities, eggs were the most common allergen followed by milk. As possible food allergies can cause anaphylaxis, it is necessary to provide precise information for consumers regarding packaged and processed foods.

Psg18 is specifically expressed in follicle-associated epithelium

Pregnancy-specific glycoproteins (Psgs) secreted by the placenta regulate the immune system to ensure the survival of the fetal allograft by inducing IL-10, an anti-inflammatory cytokine. However, it is unknown whether Psgs are involved in more general aspects of immune response other than maternal immunity. Here, we report that Psg18 is highly expressed in the follicle-associated epithelium (FAE) overlaying Peyer's patches (PPs). Bioinformatics analysis with Reference Database for Immune Cells (RefDIC) as well as RT-PCR data demonstrated that Psg18 is exclusively expressed in FAE in adult mice, in contrast to other Psg family members that are either not expressed or only slightly expressed in FAE. Psg18 expression was observed in FAE of germ-free-conditioned mice, and was slightly upregulated after bacterial inoculation. In situ hybridization analysis revealed that Psg18 is widely expressed throughout FAE. Furthermore, Psg18 protein is deposited on the extracellular matrix in the subepithelial dome beneath FAE, where antigen-presenting cells accumulate. These results suggest that Psg18 is an FAE-specific marker protein that could promote interplay between FAE and immune cells in mucosa-associated lymphoid tissues.

Transforming growth factor-beta(2) polymorphisms are associated with childhood atopic asthma

BACKGROUND

Transforming growth factor (TGF)-beta plays an important role in the regulation of airway inflammation and remodelling in asthma. Recent studies suggest that TGF-beta(2) is a predominant isoform expressed in severe asthma and it is also associated with airway remodelling.

OBJECTIVE

To determine whether the polymorphisms in TGF-beta(2) are associated with childhood atopic bronchial asthma in a Japanese population.

METHODS

We identified a total of eight polymorphisms and characterized the linkage disequilibrium (LD) mapping of the gene. Three variants in the promoter and 3'UTR were genotyped, and we conducted an association study of TGF-beta(2) (childhood atopic asthma n=297, normal controls n=555). An association analysis of these variants and an expression and functional analysis were performed.

RESULTS

3'UTR 94862T >A was found to be significantly associated with the risk of childhood atopic asthma (P=0.00041). The -109-->ACAA ins promoter variant was also associated with the risk of childhood atopic asthma (P=0.0037). TGF-beta(2) expression was observed in both the normal and asthmatic bronchial epithelium, and both real-time PCR and an ELISA showed a significant basal and TGF-beta(1)-induced TGF-beta(2) expression in the bronchial epithelial cell line BEAS2B. Furthermore, the promoter variant -109-->ACAA ins increased the TGF-beta(2) promoter-reporter activity in BEAS2B cells.

CONCLUSIONS

Our data suggest that TGF-beta(2) may therefore be involved in the development of childhood atopic asthma by means of functional genetic polymorphism. The polymorphisms in TGF-beta(2) may become important information for asthma susceptibility in children.

Influence of histological type, smoking history and chemotherapy after 1st line on treatment outcome in advanced non-small cell lung cancer

17118

Background: Primary endpoint of clinical trials of 1st line chemotherapy in advanced non-small cell lung cancer (NSCLC) is usually used over all survival. However, we know that 2nd line chemotherapy is prolonged survival time. Especially, Asian ethnicity, non-smokier and adenocarcinoma (Ad) were possible to be associated with survival in EGFR TKI such as gefitinib. Thus, we undertook this analysis to identify the prognostic factors of the progression free survival (PFS) and overall survival (OS) and to examine the effect of chemotherapy after 1st line in advanced NSCLC patients. Methods: We selected the patients who were received 1st line chemotherapy in the Shizuoka Cancer Center between October, 2002 and September 2005 and fullfilled following criteria: 1. stage IIIB or IV NSCLC, 2. no prior therapy for lung cancer, 3. chemotherapy regimen was CBDCA AUC 6 + Paclitaxel 200 mg/m2, 4. PS 0 or 1. Univariate and multivariate analyses were performed on possible porgnostic factors such as gender, PS, smoking history, histology (adenocarcinoma or other), and stage. Results: A total of 98 patients (35 females, median age 61 years [range 340–78], 74 adenocarcinomas, 73 smokers, 56 PS 0) fullfilled above selection criteria. 71 (78%) in these patients received 2nd line chemothrapy (gefitinib 44%, erlotinib 4%, and docetaxel 48%). Median-PFS and MST was 4.9 months(m) and 16.1m. PFS was not significant difference in smoking history (M-PFS: smoker 5.0m, non-smoker 4.4m) and histlogical type (Ad 4.9m, others 4.7m). However, OS was significant diference in each factor(2 yr survival rate: smoker 61%, non-smoker 17%, p = .0001, Ad 39%, others 8%, P = .0001). Multivariate analysis in 71 patients received 2nd line chemotheraoy revealed that treatment of EGFR TKI was only independent predictors of OS. Conclusions: OS of non-smoker or adenocarcinoma patients was very excellent. the usage of EGFR TKI was associate with prolongation of these OS.

No significant financial relationships to disclose.

Retrospective analysis of gefitinib versus docetaxel in never-smoking patients with previously treated non-small-cell lung cancer (NSCLC)

17154

Background: Docetaxel has been standard for second line treatment of NSCLC. In ISEL study, subgroup analyses showed significantly longer survival in the gefitinib group than the placebo group for never-smokers and Asians. It is not clear whether gefitinib has the clinical advantage in these selected patients with NSCLC. We aimed to compare the clinical benefit of gefitinib with that of docetaxel in never smoker previously treated with chemotherapy, retrospectively. Methods: We reviewed patients from August 2002 to September 2005 in Shizuoka Cancer Center. Patients with following conditions were analyzed: NSCLC, received gefitinib or docetaxel, never-smoker, not chemo-naived. We assessed the response rate, progression free survival (PFS) and over all survival for gefitinib and docetaxel respectively. Survival curves were calculated using the Kaplan Meier-method. Prognostic factors were estimated using multivariate analysis. Results: 108 patinets were selected. 69 patients were treated with gefitinib and 39 patients were treated with docetaxel. 28 patients overlapped each other. The patients treated with gefitinib following docetaxel and those with docetaxel following gefitinib were 17 and 13, respectively. 69 patients with gefitinib: the median age, 62 years (31–79); stage IIIB/IV, 14/55; ad/sq/ others, 61/3/5; PS 0/1/2/3, 19/35/13/2; prior therapy containing platinum regimen, 58. The response rate was 36%. 39 patients with docetaxel: the median age, 63 years (31–76); stage IIIB/IV, 8/31; ad/sq/others, 29/7/3; PS 0/1/2/3, 18/19/1/1; prior therapy containing platinum regimen, 34. The response rate was 10%. Gefitinib was superior in longer median PFS (148 days vs 43 days, p = 0.0002). Over all survivals were not significant between two arms. In multivariate analysis for PFS, following factors were significant: gefitinib therapy (hazard ratio 0.375, p = 0.0002); male (hazard ratio 1.854, p = 0.0011); good performance status (hazard ratio 0.450, p = 0.0057). Conclusions: Our results suggested that gefitinib therapy is very attractive for never smoker in the point of PFS. Many patients received cross-over therapies made difficult to analyze over all survival.

No significant financial relationships to disclose.

Evaluation of cytomegalovirus-specific cytotoxic T-lymphocytes in patients with the HLA-A*02 or HLA-A*24 phenotype undergoing hematopoietic stem cell transplantation

Cytomegalovirus-specific cytotoxic T-lymphocytes (CMV-CTL) are essential for the control of CMV reactivation. To monitor the quantity and function of CMV-CTL after hematopoietic stem cell transplantation (HSCT), two CMV epitopes that bind to HLA-A*0201 NLVPMVATV (A*02NLV) and HLA-A*2402 QYDPVAALF (A*24QYD) were evaluated for their immunological potential. Samples from patients with the HLA-A*02 or HLA-A*24 serotype were analyzed by tetramer, intracellular cytokine staining and enzyme-linked immunospot (ELISPOT) assay. There were significantly more A*02NLV-specific CMV-CTL than A*24QYD (23 x 10(6) vs 0.4 x 10(6)/l). The frequency of IFN-gamma-producing cells was also higher upon stimulation with A*02NLV than with A*24QYD (2.5 vs 0.1%/CD8). Furthermore, the magnitude of CMV-CTL expansion was two- to 50-fold when cells were cultured with A*02NLV, while only an insignificant increase was observed in culture with A*24QYD. Although the number of A*24QYD-specific CMV-CTL was very low in most of the HLA-A*24 patients, the incidence of CMV reactivation did not differ between those with HLA-A*02 and HLA-A*24 serotype alone. These results suggest that an epitope other than A*24QYD plays a major role in patients with HLA-A*24. Our study also showed that A*02NLV may be a useful epitope for monitoring CMV-CTL not only in patients with HLA-A*0201 but also in those with the A*0206 genotype.