ovalbumin and Colitis

Inflammatory bowel disease may be due to failed tolerance to normal gut bacteria. We demonstrate that epicutaneous immunotherapy (ET) to ovalbumin can alleviate colitis in murine models. However, most people are tolerant to or have anergy to ovalbumin. Half of Crohn's disease (CD) patients have CBir1 antibodies that can be elevated years before CD development. We determined whether ET with a CBir1 multi-epitope peptide (MEP1) could alleviate colitis.. Wild type mice (C57BL/6) were transferred with CBir1 T cell receptor (TCR) T cells followed by epicutaneous application of MEP1. Proliferating Foxp3+ T cells were measured in mesenteric lymph nodes (LNs), spleen, small intestine, and colon by flow cytometry. Lymphocytes from MEP1 epicutaneously exposed and immunized C57BL/6 mice were cultured with MEP1. Interferon (IFN)-γ production was measured. Colitis was induced by transferring CD4+CD45Rbhi T cells from CBIR1 TCR or C57BL/6 mice into RAG1-/- mice. Mice were treated with ET. Body weight, colon length, colonic cytokine production, histological inflammation, inflammatory genes, and regulatory T cells (Tregs) from lamina propria were measured.. ET with 10 μg of MEP1 induced CBir1-specific Tregs that migrated to the small intestine and colon and suppressed MEP1-specific IFN-γ production. ET alleviated colitis when the model utilized CBir1 TCR T cells in mice colonized with CBir1 or A4Fla2 positive bacteria. Treated mice had improved colon length and histological inflammation and reduced colonic IFN-γ production.. Epicutaneous immunotherapy with MEP1 induced Tregs that migrate to intestines and suppress inflammation in mice with CBir1 or A4Fla2-positive bacterial colonization. This could be a potential strategy to treat CD and warrants further study.. Epicutaneous immunotherapy with a CBir1 multi-epitope peptide, the dominant flagellin for both murine and human, can induce Tregs that migrate to intestines and suppress inflammation in mice with CBir1 or A4Fla2-positive bacterial colonization.

Topics: Animals; CD4-Positive T-Lymphocytes; Colitis; Crohn Disease; Disease Models, Animal; Immunotherapy; Inflammation; Mice; Mice, Inbred C57BL; Ovalbumin; Receptors, Antigen, T-Cell; T-Lymphocytes, Regulatory

The development and progression of colitis would detrimentally destroy the intestine barrier. However, there remains a paucity of evidence on whether ovalbumin (OVA) can be used as a nutritional food protein to repair the intestinal barrier. In this study, the repairing mechanism of OVA on intestinal barrier was thoroughly investigated by gut microbiota and untargeted metabolomics techniques. The findings demonstrated that OVA reduced intestinal permeability and restored mucin (0.75 ± 0.06) and tight junction (TJ) protein (0.67 ± 0.14) expression in colitis mice caused by 3% dextran sulfate sodium (DSS). In addition, the inflammation response and oxidative stress were also attenuated. The intake of OVA upregulated the abundance of Lactobacillaceae (7.60 ± 3.34%) and Akkermansiaceae (10.39 ± 5.97%). Furthermore, OVA upregulated the abundance of inosine (6.06 ± 0.36%), putrescine (4.14 ± 0.20%), and glycocholic acid (5.59 ± 0.23%) in colitis mice through ATP binding cassette (ABC) transporters and bile secretion pathways. In summary, our findings revealed that OVA could maintain intestinal health, which may provide crucial insights for preventing and treating intestinal diseases.

Topics: Animals; Colitis; Colon; Dextran Sulfate; Disease Models, Animal; Gastrointestinal Microbiome; Intestinal Mucosa; Intestines; Metabolomics; Mice; Mice, Inbred C57BL; Ovalbumin

The Maillard reaction (MR) is inevitable in food processing and daily cooking, but whether the MR degree would affect the biological activity of the protein

Topics: Animals; Colitis; Glycation End Products, Advanced; Maillard Reaction; Metabolomics; Mice; Ovalbumin; Proteins

Topics: Animals; Anti-Allergic Agents; Anti-Inflammatory Agents; Antioxidants; Cell Degranulation; Colitis; Enteritis; Hypersensitivity; Interleukin-10; Male; Mast Cells; Mice; Mice, Inbred C57BL; Mice, Knockout; Ovalbumin; Resveratrol

The Maillard reaction reduces the gastrointestinal digestibility of ovalbumin (OVA) in vitro. However, the regulatory effects of OVA and its Maillard reaction products (MRPs) on gut microbiota disorders remain unknown. In this study, the influence of OVA and its MRPs on the modulation of gut microbiota in mice with dextran sulfate sodium (DSS)-induced colitis was investigated. The results revealed that OVA and its MRPs intake could alleviate the symptoms of colitis and improve the richness and diversity of the gut microbiota. Moreover, the results revealed that the Maillard reaction would block the release of lysine and essential amino acids in vivo, but they variously regulated the gut microbiota and the levels of short-chain fatty acids (SCFAs) due to their indigestible properties. These findings provide a basic theory for the rational utilization of OVA and its MRPs as nutraceutical food ingredients in regulating the gut microbiota for maintaining intestinal health.

Topics: Animals; Colitis; Colon; Dextran Sulfate; Disease Models, Animal; Gastrointestinal Microbiome; Glycation End Products, Advanced; Mice; Mice, Inbred C57BL; Ovalbumin

Topics: Animals; Colitis; Diphtheria Toxin; Forkhead Transcription Factors; Immunotherapy, Adoptive; Inflammation; Inflammatory Bowel Diseases; Interleukin-10; Intestines; Mice; Mice, Inbred C57BL; Mice, Knockout; Ovalbumin; T-Lymphocytes, Regulatory; Transforming Growth Factor beta1

The gut microbiome consists of a multi-kingdom microbial community. Whilst the role of bacteria as causal contributors governing host physiological development is well established, the role of fungi remains to be determined. Here, we use germ-free mice colonized with defined species of bacteria, fungi, or both to differentiate the causal role of fungi on microbiome assembly, immune development, susceptibility to colitis, and airway inflammation. Fungal colonization promotes major shifts in bacterial microbiome ecology, and has an independent effect on innate and adaptive immune development in young mice. While exclusive fungal colonization is insufficient to elicit overt dextran sulfate sodium-induced colitis, bacterial and fungal co-colonization increase colonic inflammation. Ovalbumin-induced airway inflammation reveals that bacterial, but not fungal colonization is necessary to decrease airway inflammation, yet fungi selectively promotes macrophage infiltration in the airway. Together, our findings demonstrate a causal role for fungi in microbial ecology and host immune functionality, and therefore prompt the inclusion of fungi in therapeutic approaches aimed at modulating early life microbiomes.

Topics: Animals; Bacterial Physiological Phenomena; Colitis; Dextran Sulfate; Feces; Female; Fungi; Gastrointestinal Microbiome; Germ-Free Life; Humans; Immune System; Inflammation; Intestines; Metabolome; Mice, Inbred C57BL; Ovalbumin

Recent studies have reported an increased incidence of inflammatory bowel disease (IBD) in patients with pulmonary diseases. Despite clinical and epidemiological studies of the interplay between colitis and asthma, the diseases' related underlying mechanisms remain unclear. In this study, we evaluated the development of colitis in a model of allergic airway inflammation. We revealed that intratracheal chronic ovalbumin (OVA) exposure induces colitis and allergic airway inflammation. Interestingly, induction of colitis was largely regulated by Th1, rather than Th2 responses, whereas allergic airway inflammation was primarily mediated by Th2 responses. Experiments in

Topics: Animals; Colitis; Inflammatory Bowel Diseases; Interferon-gamma; Mice; Mice, Knockout; Ovalbumin; Signal Transduction; T-Box Domain Proteins; Th1 Cells; Th2 Cells

T lymphocytes play a pivotal role in endogenous regulation of inflammatory visceral pain. The analgesic activity of T lymphocytes is dependent on their production of opioids, a property acquired on antigen activation. Accordingly, we investigated whether an active recruitment of T lymphocytes within inflamed colon mucosa via a local vaccinal strategy may counteract inflammation-induced visceral pain in mice. Mice were immunized against ovalbumin (OVA). One month after immunization, colitis was induced by adding 3% (wt/vol) dextran sulfate sodium into drinking water containing either cognate antigen OVA or control antigen bovine serum albumin for 5 days. Noncolitis OVA-primed mice were used as controls. Visceral sensitivity was then determined by colorectal distension. Oral administration of OVA but not bovine serum albumin significantly reduced dextran sulfate sodium-induced abdominal pain without increasing colitis severity in OVA-primed mice. Analgesia was dependent on local release of enkephalins by effector anti-OVA T lymphocytes infiltrating the inflamed mucosa. The experiments were reproduced with the bacillus Calmette-Guerin vaccine as antigen. Similarly, inflammatory visceral pain was dramatically alleviated in mice vaccinated against bacillus Calmette-Guerin and then locally administered with live Mycobacterium bovis. Together, these results show that the induction of a secondary adaptive immune response against vaccine antigens in inflamed mucosa may constitute a safe noninvasive strategy to relieve from visceral inflammatory pain.

Topics: Animals; CD11 Antigens; CD4-Positive T-Lymphocytes; Colitis; Disease Models, Animal; Enkephalins; Freund's Adjuvant; Immunization; Male; Mice; Mice, Inbred C57BL; Mice, Transgenic; Mucous Membrane; Ovalbumin; Protein Precursors; Statistics, Nonparametric; Visceral Pain

In addition to conventional therapies, several new strategies have been proposed for modulating autoimmune diseases, including the adoptive transfer of immunological cells. In this context, dendritic cells (DCs) appear to be one of the most promising treatments for autoimmune disorders. The present study aimed to evaluate the effects of adoptive transfer of DCs obtained from both naïve and ovalbumin (OVA)-tolerant mice on the severity of TNBS induced colitis and analyze the eventual protective mechanisms.. To induce oral tolerance, BALB/c mice were fed 4mg/mL OVA solution for seven consecutive days. Spleen DCs were isolated from tolerant (tDC) and naïve (nDC) mice, and then adoptively transferred to syngeneic mice. Three days later, colitis was induced in DC treated mice by intrarectal instillation of 100μg2,4,6-trinitrobenzenesulfonic acid (TNBS) dissolved in 50% ethanol. Control subjects received only intrarectal instillation of either TNBS solution or a vehicle. Five days later, mice from all groups were euthanized and examined for physiological and immunological parameters. Regarding the phenotype, we observed that the frequencies of CD11+ MHC II+ and CD11+ MHCII+ CD86+ cells were significantly lower in DCs isolated from tolerant mice than in those from naive mice. However, pretreatment with both types of DCs was able to significantly reduce clinical signs of colitis such as diarrhea, rectal prolapse, bleeding, and cachexia, although only treatment with tDCs was able to prevent weight loss from instillation of TNBS. In vitro proliferation of spleen cells from mice treated with either type of DCs was significantly lower than that observed in splenic cell cultures of naïve mice. Although no significant difference was observed in the frequencies of Treg cells in the experimental groups, the frequency of Th17+CD4+cellsand the secretion of IL-17 were more reduced in the cultures of spleen cells from mice treated with either type of DCs. The levels of IL-9 and IFN-γ were lower in supernatants of cells from mice treated with nDCs.. The results allow us to conclude that the adoptive transfer of cells expressing CD11c is able to reduce the clinical and immunological signs of drug-induced colitis. Adoptive transfer of CD11c+DC isolated from both naive and tolerant mice altered the proliferative and T cell responses. To the best of our knowledge, there is no previously published data showing the protective effects of DCs from naïve or tolerant mice in the treatment of colitis.

Topics: Adoptive Transfer; Animals; B7-2 Antigen; CD11c Antigen; Cell- and Tissue-Based Therapy; Colitis; Dendritic Cells; Humans; Immune Tolerance; Mice; Ovalbumin; Spleen; T-Lymphocytes, Regulatory; Trinitrobenzenesulfonic Acid

Objective To investigate the changes of 5-HT (serotonin) signaling system in allergic diarrhea mice sensitized with ovalbumin (OVA). Methods The seven-to-eight-week-old BALB/c female mice were randomly divided into model group, sodium chromate group and negative control group. The model group and sodium chromate group were intraperitoneally injected with OVAI (50 μg per mouse) at day 0 and day 14 respectively. And starting from the 28th day, OVAII was orally administered (50 mg per mousee) every other day (8 times in total), and the sodium chromate group was given the sodium chromate (78.0 mg/kg) before the oral administration of OVA every other day (8 times in total). The allergic symptoms, including the systemic score, faeces score and body temperature were recorded following the OVA administration for sensitization. The mice were executed 43 days later. Eyeball blood sample was collected, and then serum was seperated by centrifugation, the gastric tissues was taken out. The serum OVA-specific IgE (OVA-SIgE) was detected by ELISA. The serum content of 5-HT and its related metabolites including kynurenine (KYN), tryptophan (TRP), 5-hydroxytryptophan (5-HTP), and 5-hydroxyindoleacetic acid (5-HIAA) were examined by liquid chromatography-mass spectrometry (LC-MS). The mRNA levels of tryptophan hydroxylase-1 (TPH1), indolamine-2, 3-dioxygenase 1 (IDO1), monoamine oxidase A (MAO-A), 5-hydroxytryptamine 1A receptor (HTR1A), 5-hydroxytryptamine 3 receptor (HTR3), 5-hydroxytryptamine 4 receptor (HTR4) and serotonin reuptake transporter (SERT) were determined by real-time quantitative PCR. Results OVA sensitization caused severe allergic diarrhea in mice. Serum OVA-SIgE increased significantly in mice sensitized by OVA. serum KYN increased remarkably, while 5-HT, 5-HIAA and 5-HTP decreased significantly. The mRNA levels of IDO1, HTR1A and HTR3A increased in gastric tissues, while the levels of TPH1 and MAO-A mRNA decreased. Compared with the model group, the sodium chromate group had lowed systemic score, faeces score, body temperature and OVA-SIgE as well as diarrhea rate. The mRNA levels of 5-HIAA and MAO-A increased in the gastric tissues, and IDO1, 5-HT1A and 5-HT3A mRNAs decreased in the sodium chromate group. Conclusion The serotonin signaling system in ovalbumin-sensitized allergic diarrhea mice has been activated. The administration of sodium chromate can alleviate the allergic symptoms, and change the levels of serum metabolites and the gene expressions

Topics: Animals; Colitis; Disease Models, Animal; Female; Hypersensitivity; Immunoglobulin E; Mice; Mice, Inbred BALB C; Ovalbumin; Serotonin

D-mannose, a C-2 epimer of glucose, exists naturally in many plants and fruits, and is found in human blood at concentrations less than one-fiftieth of that of glucose. However, although the roles of glucose in T cell metabolism, diabetes and obesity are well characterized, the function of D-mannose in T cell immune responses remains unknown. Here we show that supraphysiological levels of D-mannose safely achievable by drinking-water supplementation suppressed immunopathology in mouse models of autoimmune diabetes and airway inflammation, and increased the proportion of Foxp3

Topics: Adoptive Transfer; Animals; Colitis; Colon; Diabetes Mellitus, Type 1; Dietary Supplements; Disease Models, Animal; Fatty Acids; Flow Cytometry; Forkhead Transcription Factors; Humans; In Vitro Techniques; Inflammation; Integrins; Lipid Metabolism; Lung; Lung Diseases; Mannose; Mice; Mice, Inbred C57BL; Mice, Inbred NOD; Ovalbumin; Oxidation-Reduction; Pancreas; Reactive Oxygen Species; Real-Time Polymerase Chain Reaction; Respiratory Hypersensitivity; Reverse Transcriptase Polymerase Chain Reaction; Spleen; T-Lymphocytes, Regulatory; Transforming Growth Factor beta; Up-Regulation

Although inflammatory bowel disease (IBD) is a failure in maintaining tolerance to the intestinal microbiota, few studies have investigated the use of immunologic tolerance as a treatment approach for IBD. We hypothesized that induction of immune tolerance at a distal site could suppress intestinal inflammation through a process of bystander regulation.. Epicutaneous tolerance was induced by topical application of ovalbumin (OVA) using a Viaskin patch for 48 hours. In some experiments, a single feed of ovalbumin was used to drive epicutaneous tolerance-induced regulatory T cells (Tregs) to the intestine. The mechanism of tolerance induction was tested using neutralizing antibodies against TGF-β, IL-10, and Treg depletion using Foxp3-DTR mice. The capacity of skin-draining Tregs, or epicutaneous tolerance, to prevent or treat experimental IBD was tested using T-cell transfer colitis, dextran sodium sulfate (DSS) colitis, and ileitis in SAMP-YITFc mice. Weight loss, colonic inflammatory cytokines and histology were assessed.. Epicutaneous exposure to ovalbumin induced systemic immune tolerance by a TGF-β-dependent, but IL-10 and iFoxp3 Treg-independent mechanism. Skin draining Tregs suppressed the development of colitis. Epicutaneous tolerance to a model antigen prevented intestinal inflammation in the dextran sodium sulfate and SAMP-YITFc models and importantly could halt disease in mice already experiencing weight loss in the T-cell transfer model of colitis. This was accompanied by a significant accumulation of LAP and Foxp3 Tregs in the colon.. This is the first demonstration that epicutaneous tolerance to a model antigen can lead to bystander suppression of inflammation and prevention of disease progression in preclinical models of IBD.

Topics: Animals; Colitis; Dextran Sulfate; Disease Models, Animal; Forkhead Transcription Factors; Ileitis; Immune Tolerance; Inflammation; Interleukin-10; Intestinal Mucosa; Male; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Ovalbumin; T-Lymphocytes, Regulatory

The purpose of this study was to screen phytochemicals capable of inducing immune tolerance via enhanced transforming growth factor-β1 (TGF-β1) secretion and investigate their effects in a mouse model of food allergy and colitis. In a screening test using THP-1-derived dendritic cells, a significant increase in TGF-β1 levels was observed upon treatment with ferulic acid and its glycosides, among which ferulic acid rutinoside (FAR) induced the highest level of TGF-β1 secretion. Oral administration of FAR suppressed serum levels of immunoglobulin E and histamine in ovalbumin-sensitized mice and triggered the differentiation of regulatory T (Treg) cells. In comparison to the control, FAR treatment also induced stronger TGF-β1 secretion from splenic dendritic cells. FAR treatment attenuated dextran-sulfate-sodium-induced colitis in the model mice and induced Treg differentiation. These results suggest that FAR exerts potent immunomodulatory effects against allergic and intestinal inflammatory responses by inducing Treg differentiation.

Topics: Animals; Chromatography, High Pressure Liquid; Colitis; Coumaric Acids; Dendritic Cells; Dextran Sulfate; Disease Models, Animal; Female; Food Hypersensitivity; Glycosides; Histamine; Humans; Immune Tolerance; Immunoglobulin E; Lymphocyte Activation; Mice; Mice, Inbred BALB C; Ovalbumin; T-Lymphocytes, Regulatory; Transforming Growth Factor beta1; Up-Regulation

Literature data have shown that the consumption of dietary proteins may cause modulatory effects on the host immune system, process denominated oral tolerance by bystander suppression. It has been shown that the bystander suppression induced by dietary proteins can improve inflammatory diseases such as experimental arthritis. Here, we evaluated the effects of oral tolerance induced by ingestion of ovalbumin (OVA) on TNBS-induced colitis in mice, an experimental model for human Crohn's disease.. Colitis was induced in BALB/c mice by instilling a single dose of TNBS (100 mg/kg) in ethanol into the colon. Tolerized mice received OVA (4mg/mL) dissolved in the drinking water for seven consecutive days, prior to or concomitantly with the intrarectal instillation. Control groups received protein-free water and ethanol by intrarectal route. We observed that either the prior or concomitant induction of oral tolerance were able to reduce the severity of colitis as noted by recovery of body weight gain, improvement of clinical signs and reduction of histological abnormalities. The in vitro proliferation of spleen cells from tolerant colitic mice was lower than that of control mice, the same as the frequencies of CD4+ T cells secreting IL-17 and IFN-γ. The frequencies of regulatory T cells and T cells secreting IL-10 have increased significantly in mice orally treated with OVA. The levels of inflammatory cytokines (IL-17A, TNF-α, IL-6 and IFN-γ) were lower in supernatants of cells from tolerant colitic mice, whereas IL-10 levels were higher.. Our data show that the modulation of immune response induced by oral tolerance reduces the severity of experimental colitis. Such modulation may be partially attributed to the increase of Treg cells and reduction of pro-inflammatory cytokines in peripheral lymphoid organs of tolerant mice by bystander suppression.

Topics: Animals; Bystander Effect; Colitis; Female; Immune Tolerance; Interferon-gamma; Interleukin-10; Interleukin-17; Interleukin-6; Mice; Mice, Inbred BALB C; Ovalbumin; T-Lymphocytes, Regulatory; Tumor Necrosis Factor-alpha

Epithelial tissues continually undergo apoptosis. Commensal organisms that inhabit the epithelium influence tissue homeostasis, in which regulatory T cells (Treg cells) have a central role. However, the physiological importance of epithelial cell apoptosis and how the number of Treg cells is regulated are both incompletely understood. Here we found that apoptotic epithelial cells negatively regulated the commensal-stimulated proliferation of Treg cells. Gut commensals stimulated CX3CR1(+)CD103(-)CD11b(+) dendritic cells (DCs) to produce interferon-β (IFN-β), which augmented the proliferation of Treg cells in the intestine. Conversely, phosphatidylserine exposed on apoptotic epithelial cells suppressed IFN-β production by the DCs via inhibitory signaling mediated by the cell-surface glycoprotein CD300a and thus suppressed Treg cell proliferation. Our findings reveal a regulatory role for apoptotic epithelial cells in maintaining the number of Treg cell and tissue homeostasis.

Topics: Allergens; Animals; Apoptosis; Colitis; Colon; Dendritic Cells; Dermatitis, Allergic Contact; Dextran Sulfate; Epidermal Cells; Epidermis; Epithelial Cells; Flow Cytometry; Gastrointestinal Microbiome; Immunohistochemistry; Interferon-beta; Intestinal Mucosa; Langerhans Cells; Lung; Mice; Mice, Knockout; Ovalbumin; Real-Time Polymerase Chain Reaction; Receptors, Immunologic; Respiratory Mucosa; Salmonella Infections; Salmonella typhimurium; T-Lymphocytes, Regulatory

The pathogenesis of intestinal chronic inflammation is unclear. Food allergy plays an important role in the induction of intestinal inflammation. This study aims to test a hypothesis that food allergy initiates colitis. In this study, BALB/c mice were sensitized to a common food allergen, ovalbumin (OVA) with cholera toxin (CT) as an adjuvant. The colon epithelial barrier function was assessed with Ussing chamber technique. Expression of T cell immunoglobulin mucin domain molecule-4 (TIM4) in dendritic cells was evaluated by flow cytometry, RT-PCR and Western blotting. The results showed that allergen-related colitis was induced in mice as shown by heavy infiltration of inflammatory cells in the colon mucosa, loss of body weight of mice, increases in myeloperoxidase, tumor necrosis factor-α, interleukin-4, OVA-specific IgE in the colon tissue. The colon epithelial barrier function was markedly compromised in colitis group mice, which was mimicked by exposure the colon mucosa to CT in Ussing chamber. High frequency of TIM4(+) dendritic cells was detected in the colon mucosa of colitis mice. Exposure of dendritic cells to CT markedly increased the expression of TIM4. We conclude that IBD-like inflammation can be induced in the mouse colon by the food allergen-related immune response.

Topics: Animals; Cholera Toxin; Colitis; Colon; Dendritic Cells; Disease Models, Animal; Food Hypersensitivity; Inflammatory Bowel Diseases; Intestinal Mucosa; Membrane Proteins; Mice, Inbred BALB C; Ovalbumin; Th2 Cells

Increased intestinal permeability is found in noninflamed portions of the gut of inflammatory bowel disease patients and in their first-degree relatives, suggesting that it is not a consequence of inflammation. Additionally, increased small intestinal permeability precedes colonic disease in animal models of inflammatory bowel disease. However, it is not known how small intestinal permeability modulates disease in the colon. The aim of this study was to determine if increasing small intestinal permeability modulates colonic inflammation in interleukin (IL)-10 mice and if an increase in permeability is sufficient to prevent oral tolerance to a dietary antigen.. IL-10 mice were treated with the zonula occludens toxin pathway agonist AT-1002 for 8 weeks, and colitis severity was measured at 12 weeks of age. Wild-type mice were also treated with AT-1002 and fed ovalbumin (OVA) to determine the local and systemic immune response to this antigen under increased small intestinal permeability conditions.. IL-10 mice treated with AT-1002 showed exacerbated colitis at 12 weeks of age. AT-1002 also induced a significant OVA-specific humoral response compared with mice that received OVA alone. In addition, the intestinal production of IL-10 and TGF-β in response to oral OVA was prevented when OVA was given with AT-1002.. Increasing small intestinal permeability worsens colitis in IL-10 mice, and it prevents the development of oral tolerance to OVA in wild-type mice. This study suggests that small intestinal permeability is not merely a consequence of inflammation but a condition that leads to two of the main pathological features of inflammatory bowel disease.

Topics: Administration, Oral; Animals; Cell Membrane Permeability; Colitis; Disease Models, Animal; Immune Tolerance; Interleukin-10; Intestine, Small; Mice; Mice, Knockout; Oligopeptides; Ovalbumin

The interleukin-17 (IL-17) family of cytokines has emerged as a critical player in inflammatory diseases. Among them, IL-25 has been shown to be important in allergic inflammation and protection against parasitic infection. Here we have demonstrated that IL-17B, a poorly understood cytokine, functions to inhibit IL-25-driven inflammation. IL-17B and IL-25, both binding to the interleukin-17 receptor B (IL-17RB), were upregulated in their expression after acute colonic inflammation. Individual inhibition of these cytokines revealed opposing functions in colon inflammation: IL-25 was pathogenic but IL-17B was protective. Similarly opposing phenotypes were observed in Citrobacter rodentium infection and allergic asthma. Moreover, IL-25 was found to promote IL-6 production from colon epithelial cells, which was inhibited by IL-17B. Therefore, our data demonstrate that IL-17B is an anti-inflammatory cytokine in the IL-17 family.

Topics: Animals; Anti-Bacterial Agents; Asthma; Cell Line; Citrobacter rodentium; Colitis; Dysbiosis; Enterobacteriaceae Infections; Epithelial Cells; Gene Expression Regulation; Interleukin-17; Interleukin-6; Interleukins; Intestinal Mucosa; Mice; Mice, Inbred C57BL; Mice, Knockout; Ovalbumin; Protein Binding; Receptors, Interleukin-17; Signal Transduction; Sodium Dodecyl Sulfate

The pathogenesis of primary sclerosing cholangitis (PSC) remains poorly understood. Since PSC predominantly occurs in patients with inflammatory bowel disease, autoimmunity triggered by activated T cells migrating from the gut to the liver is a possible mechanism. We hypothesized that T cells primed in the gut-associated lymphoid tissue (GALT) by a specific antigen migrate to the liver and cause cholangitis when they recognize the same antigen on cholangiocytes. We induced ovalbumin-dependent colitis in mice that express ovalbumin in biliary epithelia (ASBT-OVA mice) and crossed ASBT-OVA mice with mice that express ovalbumin in enterocytes (iFABP-OVA mice). We analyzed T-cell activation in the GALT and crossreactivity to the same antigen in the liver as well as the effects of colitis per se on antigen-presentation and T-cell activation in the liver. Intrarectal application of ovalbumin followed by transfer of CD8 OT-I T cells led to antigen-dependent colitis. CD8 T cells primed in the GALT acquired effector function and the capability to migrate to the liver, where they caused cholangitis in a strictly antigen-dependent manner. Likewise, cholangitis developed in mice expressing ovalbumin simultaneously in biliary epithelia and enterocytes after transfer of OT-I T cells. Dextran sodium sulfate colitis led to increased levels of inflammatory cytokines in the portal venous blood, induced activation of resident liver dendritic cells, and promoted the induction of T-cell-dependent cholangitis.. Our data strengthen the notion that immune-mediated cholangitis is caused by T cells primed in the GALT and provide the first link between colitis and cholangitis in an antigen-dependent mouse model.

Topics: Animals; CD8-Positive T-Lymphocytes; Cell Movement; Cholangitis, Sclerosing; Colitis; Cytokines; Dextran Sulfate; Disease Models, Animal; Enterocytes; Liver; Lymphoid Tissue; Mice; Mice, Inbred C57BL; Mice, Inbred Strains; Mice, Knockout; Ovalbumin

Dendritic cells (DCs) and macrophages populate the intestinal lamina propria to initiate immune responses required for the maintenance of intestinal homeostasis. To investigate whether CX3CR1(+) phagocytes communicate with CD4 T cells during the development of transfer colitis, we established an antigen-driven colitis model induced by the adoptive transfer of DsRed OT-II cells in CX3CR1(GFP/+) × RAG(-/-) recipients challenged with Escherichia coli expressing ovalbumin (OVA) fused to a cyan fluorescent protein (CFP). After colonization of CX3CR1(GFP/+) × RAG(-/-) animals with red fluorescent E. coli pCherry-OVA, colonic CX3CR1(+) cells but not CD103(+) DCs phagocytosed E. coli pCherry-OVA. Degraded bacterial-derived antigens are transported by CD103(+) DCs to mesenteric lymph nodes (MLNs), where CD103(+) DCs prime naive T cells. In RAG(-/-) recipients reconstituted with OT II cells and gavaged with OVA-expressing E. coli, colonic CX3CR1(+) phagocytes are in close contact with CD4 T cells and presented bacterial-derived antigens to CD4 T cells to activate and expand effector T cells.

Topics: Animals; Antigens; Antigens, CD; CD4-Positive T-Lymphocytes; Colitis; CX3C Chemokine Receptor 1; Dendritic Cells; Disease Models, Animal; Escherichia coli; Female; Integrin alpha Chains; Intestinal Mucosa; Lymph Nodes; Lymphocyte Activation; Male; Mesentery; Mice; Mice, Knockout; Ovalbumin; Phagocytes; Phenotype; Receptors, Chemokine; T-Cell Antigen Receptor Specificity

CD4+ T cell responses against oral antigens can develop in inflammatory bowel disease (IBD) patients, which may modulate disease. Dextran sodium sulfate (DSS) colitis is commonly used to study IBD, however, it is not considered the best model in which to study T cell involvement in intestinal disease. Our aim was to determine if antigen-specific T cells could be induced during DSS colitis and if they could be detected after disease resolution. To induce antigen-specific T cells, the tracking antigen, ovalbumin (OVA), was administered orally during colitis initiation. Disease severity was monitored, and the antigen-reactivity of CD4+ T cells examined using CD69 expression. While OVA-directed, CD4+ Foxp3+ regulatory T cells could be detected in the spleens of both OVA-treated control and DSS mice, OVA-reactive, CD4+ Foxp3-T cells were only found in the OVA and DSS-treated mice. These results indicate that during DSS colitis T cells develop that are specific against oral antigens, and they are found systemically after colitis resolution. This gives added depth and utility to the DSS model as well as a way to track T cells that are primed against luminal antigens.

Topics: Administration, Oral; Adoptive Transfer; Animals; Antigens; CD4-Positive T-Lymphocytes; Colitis; Colon; Dextran Sulfate; Disease Models, Animal; Female; Immunologic Memory; Inflammation; Intestinal Mucosa; Mice; Mice, Inbred C57BL; Ovalbumin; Spleen

Previous studies have indicated that colitis increases intestinal permeability to food antigens. This condition also generates an immunoreactive milieu in the gut, which may exacerbate or counteract allergy reactions. This, along with the fact that both colitis and allergy are being codiagnosed more frequently, means the scientific interest on the immune relation between these pathologies is increasing. We evaluated the immune response to an internalized food antigen that was initiated during a concomitant active intestinal inflammatory response.. An ovalbumin (OVA)-induced immune response was analyzed in healthy mice and in mice suffering from colitis induced by the administration of dinitrofluorobenzene/dinitrosulfonic acid (DNFB/DNS) at the moment of OVA challenge. The OVA-induced clinical score and allergy response both in plasma and in splenocyte cultures from these animals were compared.. Although no differences were observed in the allergy clinical score, the concomitant active colitis led to an increase in the immune response to OVA antigen, as shown by increased spleen size and OVA-induced splenocyte proliferation, exacerbated expression of total and OVA-specific IgG1 levels, increased colonic IL-4 expression and OVA-induced IL-4 and IL-5 cytokine expression in spleen cells.. Our results indicate that animals with active colitis undergo an exacerbated immune response to an internalized antigen. This finding could be relevant for the allergy management of patients presenting simultaneously with chronic colitis.

Topics: Animals; Antigens; Colitis; Cytokines; Disease Models, Animal; Female; Hypersensitivity; Immunoglobulin E; Immunoglobulin G; Lymphocyte Activation; Lymphocytes; Mice; Ovalbumin; Spleen

For inflammatory bowel disease (IBD) treatment, local delivery of molecules loaded in nanoparticles to the inflamed colon could be a promising strategy. The aim of this study was to investigate how drug-loaded polymeric nanoparticles target the site of inflammation and to analyse the influence of different colon-specific delivery strategies. Three different polymeric nanoparticles were formulated using ovalbumin (OVA) as a model drug. pH-sensitive nanoparticles were made with Eudragit(®) S100. Mucoadhesive nanoparticles were created with trimethylchitosan (TMC). A mix of polymers, PLGA, PEG-PLGA and PEG-PCL, were used to obtain a sustained drug delivery. Furthermore, ligands targeting immune cells (i.e. mannose) or the inflamed colon (i.e. a specific peptide) were grafted on the PEG chain of PCL. Interaction of nanoparticles with the intestinal epithelium was explored using Caco-2 monolayers designed to mimic an inflamed epithelium and then visualized using confocal laser microscopy. TMC nanoparticles had the highest apparent permeability for OVA in the untreated model. However, in the inflamed model, there were no difference between TMC, PLGA-based and Eudragit(®) nanoparticles. The uptake of nanoparticles in the inflamed mouse colon was assessed in a horizontal diffusion chamber. Mannose-grafted PLGA nanoparticles showed the highest accumulation of OVA in inflamed colon. Based on these results, active targeting of macrophages and dendritic cells may be a promising approach for targeting the colon in IBD.

Topics: Animals; Caco-2 Cells; Chitosan; Colitis; Cytokines; Dextran Sulfate; Drug Carriers; Ethylene Oxide; Female; Humans; Inflammatory Bowel Diseases; Intestinal Absorption; Lactic Acid; Lactones; Mannose; Mice; Mice, Inbred C57BL; Nanoparticles; Ovalbumin; Polyethylene Glycols; Polyglactin 910; Polyglycolic Acid; Polylactic Acid-Polyglycolic Acid Copolymer; Polymethacrylic Acids

Repeated challenges of lipopolysaccharide (LPS) could reduce the expression of proinflammatory cytokines in vitro, and oral administration of ovalbumin (OVA) induces mucosal tolerance in vivo. However, the effect of local administration of LPS and OVA on experimental colitis in vivo remains unknown.. This study was performed to elucidate the effect of rectal administration of LPS and OVA on an acute murine colitis induced by dextran sulfate sodium (DSS).. BALB/c mice were rectally administered LPS with or without OVA followed by 3% DSS. Colitis was assessed by disease activity index (DAI) including weight loss, stool consistency and rectal bleeding, and histopathology. Primary colon epithelial cells were isolated and the expression of Toll-like receptor 4 (TLR4) was examined using the Western blot analysis. IL-6, IFN-γ and IL-10 mRNA levels in colonic tissue were assessed using real-time RT-PCR.. LPS administration significantly attenuated the severity of acute DSS-induced colitis as assessed by DAI and histopathologic scoring compared with the control group. Combined treatment of LPS and OVA restored body weight loss and further ameliorated the severity of acute DSS colitis. LPS pretreatment regardless of OVA administration decreased TLR4 expression. LPS and OVA pretreatment reduced IL-6 and IFN-γ mRNA expression and increased IL-10 mRNA expression compared with controls.. Rectal administration of LPS attenuated acute murine colitis, possibly through TLR4 down-regulation, and combined treatment of OVA additionally ameliorated colonic inflammation associated with up-regulation of IL-10.

Topics: Administration, Rectal; Animals; Colitis; Colon; Dextran Sulfate; Feces; Female; Gastrointestinal Hemorrhage; Immune Tolerance; Interferon-gamma; Interleukin-10; Interleukin-6; Lipopolysaccharides; Mice; Mice, Inbred BALB C; Ovalbumin; Rectum; Severity of Illness Index; Toll-Like Receptor 4; Weight Loss

To evaluate the concomitant effects of appendectomy and oral tolerance on colitis.. Delayed-type hypersensitivity (DTH) was investigated at a 7-d interval after ovalbumin (OVA) administration and immunization under normal and colitis conditions in appendectomized or sham-operated mice. Pathological scores for the colon were graded after ingestion of colon-extracted protein (CEP) and induction of dextran sulfate sodium (DSS) colitis in appendectomized or sham-operated mice. Thereafter, Th1 and Th2 in Peyer's patches and spleen lymphocytes were detected in CEP-treated and bovine serum albumin (BSA)-treated control mice.. In appendectomized mice, DTH was not inhibited at day 7 after OVA administration and at the initial phase of DSS colitis, whereas it was inhibited at day 14 and day 21. However, in sham-operated mice, it was inhibited during the whole procedure and the onset of DSS colitis. The protective role of CEP against DSS colitis was present in sham-operated mice, with predominant improvement of colonic pathological changes, while vanished in the appendectomized mice. A shift from Th1 to Th2 in Peyer's patches resulted from a decrease of Th1 cells with the ingestion of CEP. Compared with BSA in the sham-operated group, no predominant changes were observed in the appendectomized mice.. Appendectomy interferes with the protective role of CEP in DSS colitis via a shift from Th2 to Th1 during oral tolerance induction.

Topics: Administration, Oral; Animals; Appendectomy; Colitis; Colon; Dextran Sulfate; Disease Models, Animal; Hypersensitivity, Delayed; Immune Tolerance; Injections, Subcutaneous; Intestinal Mucosa; Male; Mice; Mice, Inbred BALB C; Ovalbumin; Peyer's Patches; Proteins; Serum Albumin, Bovine; Th1 Cells; Th2 Cells

CD103(+) gut dendritic cells (DCs) have been shown to be required for de novo conversion of adaptive T regulatory (Treg) cells. Indoleamine 2,3-dioxygenase (IDO) is an enzyme involved in tryptophan catabolism that is expressed by DCs isolated from tumour-draining lymph nodes. IDO-expressing DCs sustain and differentiate Tregs. The aim of this study was to investigate the expression and the possible physiological role of IDO in the tolerogenic properties of intestinal DCs.. The expression level of IDO in CD103(+) and CD103(-) DCs was analysed by qRT-PCR, western blot and immunofluorescence. CD103(+) and CD103(-) DCs were sorted from mesenteric lymph nodes (MLNs) and the small intestinal lamina propria, and the role of IDO in the conversion of Tregs and Th effector cell development was evaluated via specific inhibition or gene deletion. Oral tolerance, experimental colitis and T cell differentiation in vivo were assessed upon IDO inactivation.. We show that, primarily, CD103(+) but not CD103(-) gut DCs express IDO whose inhibition results in reduced CD4(+)Foxp3(+) T regulatory cell conversion and enhanced T cell proliferation. When IDO was inhibited or genetically deleted there was an increase in Th1 and Th17 differentiation both in vitro and in vivo. Finally, in vivo IDO blockade affected the development of Tregs specific for orally administered antigens, impaired oral tolerance induction and exacerbated colitis.. We identified a new IDO-dependent pathway leading to acquisition of tolerogenic functions in mucosal CD103-expressing DCs, indicating IDO as a possible therapeutic target for gut disorders.

Topics: Administration, Oral; Animals; Antigens, CD; Cell Differentiation; Cells, Cultured; Colitis; Dendritic Cells; Enzyme Inhibitors; Humans; Immune Tolerance; Immunity, Mucosal; Indoleamine-Pyrrole 2,3,-Dioxygenase; Integrin alpha Chains; Intestinal Mucosa; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, Transgenic; Ovalbumin; T-Lymphocyte Subsets; T-Lymphocytes, Regulatory

Less developed countries have a low incidence of immunological diseases like inflammatory bowel disease (IBD), perhaps prevented by the high prevalence of helminth infections in their populations. In the Rag IL-10(-/-) T cell transfer model of colitis, Heligmosomoides polygyrus, an intestinal helminth, prevents and reverses intestinal inflammation. This model of colitis was used to explore the importance of innate immunity in H. polygyrus protection from IBD. Rag mice briefly exposed to H. polygyrus before reconstitution with IL-10(-/-) colitogenic T cells are protected from colitis. Exposure to H. polygyrus before introduction of IL-10(-/-) and OT2 T cells reduced the capacity of the intestinal mucosa to make IFN-gamma and IL-17 after either anti-CD3 mAb or OVA stimulation. This depressed cytokine response was evident even in the absence of colitis, suggesting that the downmodulation in proinflammatory cytokine secretion was not just secondary to improvement in intestinal inflammation. Following H. polygyrus infection, dendritic cells (DCs) from the lamina propria of Rag mice displayed decreased expression of CD80 and CD86, and heightened expression of plasmacytoid dendritic cell Ag-1 and CD40. They were also less responsive to lamina proprias, producing less IL-12p40 and IL-10. Also diminished was their capacity to present OVA to OT2 T cells. These experiments infer that H. polygyrus does not require direct interactions with T or B cells to render animals resistant to colitis. DCs have an important role in driving both murine and human IBD. Data suggest that phenotypic alternations in mucosal DC function are part of the regulatory process.

Topics: Animals; Cells, Cultured; Colitis; Dendritic Cells; Disease Models, Animal; Immunity, Innate; Inflammatory Bowel Diseases; Interleukin-10; Mice; Mice, Inbred C57BL; Mice, Knockout; Mice, Transgenic; Mucous Membrane; Nematospiroides dubius; Ovalbumin; Strongylida Infections; T-Lymphocyte Subsets

IL-33, a member of the IL-1-related cytokines, is considered to be a proallergic cytokine that is especially involved in Th2-type immune responses. Moreover, like IL-1α, IL-33 has been suggested to act as an "alarmin" that amplifies immune responses during tissue injury. In contrast to IL-1, however, the precise roles of IL-33 in those settings are poorly understood. Using IL-1- and IL-33-deficient mice, we found that IL-1, but not IL-33, played a substantial role in induction of T cell-mediated type IV hypersensitivity such as contact and delayed-type hypersensitivity and autoimmune diseases such as experimental autoimmune encephalomyelitis. Most notably, however, IL-33 was important for innate-type mucosal immunity in the lungs and gut. That is, IL-33 was essential for manifestation of T cell-independent protease allergen-induced airway inflammation as well as OVA-induced allergic topical airway inflammation, without affecting acquisition of antigen-specific memory T cells. IL-33 was significantly involved in the development of dextran-induced colitis accompanied by T cell-independent epithelial cell damage, but not in streptozocin-induced diabetes or Con A-induced hepatitis characterized by T cell-mediated apoptotic tissue destruction. In addition, IL-33-deficient mice showed a substantially diminished LPS-induced systemic inflammatory response. These observations indicate that IL-33 is a crucial amplifier of mucosal and systemic innate, rather than acquired, immune responses.

Topics: Adaptive Immunity; Animals; Autoimmunity; Colitis; Immunity, Innate; Immunity, Mucosal; Interleukin-1; Interleukin-33; Interleukins; Lipopolysaccharides; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, Knockout; Ovalbumin; Respiratory Hypersensitivity; Shock, Septic

Several low- or non-FcR binding anti-human CD3 monoclonal antibodies have been under investigation for the treatment of autoimmune diseases. To model the mechanism of action of these anti-human CD3 mAbs in the murine system, an Fc-modified anti-mouse CD3 antibody (N297A) was generated. N297A exhibited similar biological effects as Fc-modified anti-human CD3 antibodies including rapid, reversible reduction in peripheral leukocyte numbers, differential modulation of activated versus resting T cells, and reduced levels of induced cytokine release compared to the non-Fc-modified parent antibody. In an in vivo model of colitis induced by adoptive transfer of IL-10-deficient cells, administration of N297A significantly reduced body weight loss. As N297A shared many functional characteristics of non-FcR binding anti-human CD3 mAbs both in vitro and in vivo, it provides a means to model the mechanisms of action of Fc-modified anti-human CD3 antibodies in mouse.

Topics: Adoptive Transfer; Animals; Antibodies, Monoclonal; Apoptosis; CD3 Complex; CD4-Positive T-Lymphocytes; CD8-Positive T-Lymphocytes; CHO Cells; Colitis; Colon; Cricetinae; Cricetulus; Cytokines; Humans; Lymphocyte Count; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, Transgenic; Ovalbumin; Protein Binding; Receptors, Antigen, T-Cell, alpha-beta; Receptors, IgG; Recombinant Fusion Proteins

To analyze the therapeutic effect of oral tolerance and nasal tolerance singly and in combination with mucosal adjuvant on experimental colitis in rats.. Rat models were established using trinitrobenzenesulphonic acid enemas. Ovalbumin was used as inducing antigen and lipopolysaccharide as adjuvant. Colonic scores, splenic mononuclear cell proliferation, and expressions of Toll-like receptors (TLR) and regulatory T cells were determined.. Colonic scores decreased most significantly after ovalbumin and lipopolysaccharide nasal administration (P<0.05). Colonic expression of forkhead box P3 in rats after ovalbumin and lipopolysaccharide oral (P<0.05) and nasal administration (P<0.01) were both significantly higher than untreated rats. TLR2 expression on CD4(+)CD25(+) T cells decreased most significantly after ovalbumin and lipopolysaccharide nasal therapies (P<0.01). TLR4 colonic expression decreased significantly after ovalbumin and lipopolysaccharide oral administration (P<0.05) and lipopolysaccharide oral administration (P<0.05).. Although experimental colitis prevented oral tolerance, nasal tolerance was successfully induced. The therapeutic effect of nasal tolerance combined with adjuvant produced the best results. TLR downregulation and CD4(+)CD25(+) T cells upregulation were involved in mucosal tolerance.

Topics: Adjuvants, Immunologic; Administration, Intranasal; Administration, Oral; Animals; Antigens; Colitis; Desensitization, Immunologic; Disease Models, Animal; Immune Tolerance; Immunity, Mucosal; Inflammatory Bowel Diseases; Intestinal Mucosa; Lipopolysaccharides; Male; Ovalbumin; Rats; Rats, Sprague-Dawley; T-Lymphocytes, Regulatory; Toll-Like Receptors; Trinitrobenzenesulfonic Acid

Previously, we showed that CD11c defines a novel subset of CD8(+) T cells whose in vivo activity is therapeutic for arthritis; however, the mechanisms directing their development, identity of their precursors, and basis of their effector function remain unknown. Here, we show that the novel subset develops from CD11c(surface-)CD8(+) T cells and undergoes robust expansion in an antigen- and 4-1BB (CD137)-dependent manner. CD11c(+)CD8(+) T cells exist in naïve mice (<3%) with limited suppressive activity. Once activated, they suppress CD4(+) T cells in vivo and in vitro. Suppression of CD4(+) by CD11c(+)CD8(+) T cells is related to an increase in IDO activity induced in competent cells via the general control non-derepressible-2 pathway. CD11c(+)CD8(+) T cells are refractory to the effect of IDO but constrict in a novel 1-methyl D,L-tryptophan-dependent mechanism resulting in reversal of their suppressive effects. Thus, our data uncover, for the first time, the origin, development, and basis of the suppressive function of this novel CD11c(+)CD8(+) T-cell subpopulation that has many signature features of Treg.

Topics: Animals; CD11c Antigen; CD4-Positive T-Lymphocytes; CD8-Positive T-Lymphocytes; Cell Differentiation; Cell Lineage; Colitis; Dendritic Cells; Disease Models, Animal; Immune Tolerance; Indoleamine-Pyrrole 2,3,-Dioxygenase; Lymphocyte Activation; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, Knockout; Mice, Transgenic; Ovalbumin; Peptide Fragments; Protein Serine-Threonine Kinases; Receptors, Antigen, T-Cell; Spleen; T-Lymphocyte Subsets; T-Lymphocytes, Regulatory; Transcription Factor CHOP; Tryptophan; Tumor Necrosis Factor Receptor Superfamily, Member 9

OVA-induced allergic diarrhea occurs as a consequence of over-expression of Th1 inhibitory IL-12p40 monomers and homodimers in the large intestine, establishing a dominant Th2-type environment. In this study, we demonstrate that intranasally administered murine IL-12p70 naked DNA expression plasmids resulted in the synthesis of corresponding cytokine in the large intestinal CD11c(+) dendritic cells, leading to the inhibition of Ag-specific Th2-type response for the prevention of allergic diarrhea and the suppression of clinical symptoms including OVA-specific IgE Ab synthesis. The nasal IL-12p70 DNA treatment proved effective even after the establishment of allergic diarrhea. These results suggest that the mucosal administration of naked IL-12p70 DNA plasmid should be considered as a possible preventive and therapeutic treatment for Th2 cell-mediated food allergic diseases in the intestinal tract.

Topics: Administration, Intranasal; Colitis; Cytokines; Diarrhea; Down-Regulation; Genetic Therapy; Green Fluorescent Proteins; Immunoglobulin A; Immunoglobulin G; Interleukin-12; Intestine, Large; Lymphoid Tissue; Nasopharynx; Ovalbumin; Plasmids; Protein Subunits; Spleen; Th2 Cells; Vaccines, DNA

The triggering Ag for inflammatory bowel disease and animal models of colitis is not known, but may include gut flora. Feeding OVA to DO11.10 mice with OVA-specific transgenic (Tg) TCR generates Ag-specific immunoregulatory CD4(+) T cells (Treg) cells. We examined the ability of oral Ag-induced Treg cells to suppress T cell-mediated colitis in mice. SCID-bg mice given DO11.10 CD4(+)CD45RB(high) T cells developed colitis, and cotransferring DO11.10 CD45RB(low)CD4(+) T cells prevented CD4(+)CD45RB(high) T cell-induced colitis in the absence of OVA. The induction and prevention of disease by DO11.10 CD4(+) T cell subsets were associated with an increase in endogenous TCRalpha chain expression on Tg T cells. Feeding OVA to SCID-bg mice reconstituted with DO11.10 CD4(+)CD45RB(high) attenuated the colitis in association with increased TGF-beta and IL-10 secretion, and decreased proliferative responses to both OVA and cecal bacteria Ag. OVA feeding also attenuated colitis in SCID-bg mice reconstituted with a mix of BALB/c and DO11.10 CD45RB(high) T cells, suggesting that OVA-induced Treg cells suppressed BALB/c effector cells. The expression of endogenous non-Tg TCR allowed for DO11.10-derived T cells to respond to enteric flora Ag. Furthermore, feeding OVA-induced Treg cells prevented colitis by inducing tolerance in both OVA-reactive and non-OVA-reactive T cells and by inducing Ag-nonspecific Treg cells. Such a mechanism might allow for Ag-nonspecific modulation of intestinal inflammation in inflammatory bowel disease.

Topics: Administration, Oral; Adoptive Transfer; Animals; Antigens, Bacterial; CD4-Positive T-Lymphocytes; Cecum; Cell Division; Cell Line; Colitis; Cytokines; Epitopes, T-Lymphocyte; Immune Tolerance; Immunity, Mucosal; Immunophenotyping; Intestinal Mucosa; Leukocyte Common Antigens; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, SCID; Mice, Transgenic; Ovalbumin; Receptors, Antigen, T-Cell, alpha-beta; Receptors, Interleukin-2; T-Lymphocyte Subsets

The gut mucosa is a major site of contact with antigens from food and microbiota. Usually, these daily contacts with natural antigens do not result in inflammatory reactions; instead they result in a state of systemic hyporesponsiveness named oral tolerance. Inflammatory bowel diseases (IBD) are associated with the breakdown of the immunoregulatory mechanisms that maintain oral tolerance. Several animal models of IBD/colitis are available. In mice, these include targeted disruptions of the genes encoding cytokines, T cell subsets or signaling proteins. Colitis can also be induced by intrarectal administration of chemical substances such as 2,4,6-trinitrobenzene sulfonic acid in 50% ethanol. We report here a novel model of colitis induced by intrarectal administration of 50% ethanol alone. Ethanol-treated mice develop an inflammatory reaction in the colon characterized by an intense inflammatory infiltrate in the mucosa and submucosa of the large intestine. They also present up-regulation of both interferon gamma (IFN-gamma) and interleukin-4 (IL-4) production by cecal lymph node and splenic cells. These results suggest a mixed type of inflammation as the substrate of the colitis. Interestingly, cells from mesenteric lymph nodes of ethanol-treated mice present an increase in IFN-gamma production and a decrease in IL-4 production indicating that the cytokine balance is altered throughout the gut mucosa. Moreover, induction of oral tolerance to ovalbumin is abolished in these animals, strongly suggesting that ethanol-induced colitis interferes with immunoregulatory mechanisms in the intestinal mucosa. This novel model of colitis resembles human IBD. It is easy to reproduce and may help us to understand the mechanisms involved in IBD pathogenesis.

Topics: Administration, Rectal; Animals; Colitis; Disease Models, Animal; Enzyme-Linked Immunosorbent Assay; Ethanol; Humans; Immune Tolerance; Interferon-gamma; Interleukin-4; Intestinal Mucosa; Lymph Nodes; Mesentery; Mice; Mice, Inbred BALB C; Ovalbumin

T helper type 1 (Th1) cells secreting interferon-gamma (IFN-gamma) have been closely associated with Crohn's disease (CD). Monokine-induced by IFN-gamma (MIG), IFN-gamma-inducible T cell alpha chemoattractant (I-TAC), and IFN-gamma-inducible protein-10 (IP-10), are chemokines that bind CXCR3 and mediate the chemotaxis of leukocytes. IP-10, MIG, and CXCR3 have been shown to be expressed at sites of CD. The current study stems from our recent findings that IP-10, MIG, and I-TAC significantly contribute to the development of Th1-mediated inflammatory responses. To better understand the role of CXCR3 interactions during CD, we characterized the effects of IP-10, MIG, I-TAC, and CXCR3+ T cells on mucosal immune responses. IP-10, MIG, and I-TAC significantly enhanced antigen-specific serum and mucosal antibodies through Th1-mediated events and CD28 modulation. Additionally, the adoptive transfer of naive CXCR3+ T cells and CD4+CD45RB(HI) to T cell receptor beta (TCRbeta) x delta(-/-) mice resulted in the onset of murine colitis. Taken together, these studies suggest that IP-10, MIG, I-TAC, and CXCR3 interactions are involved in mucosal immune responses required for the induction of CD.

Topics: Adjuvants, Immunologic; Adoptive Transfer; Animals; Antibody Specificity; CD28 Antigens; CD4-Positive T-Lymphocytes; Cell Division; Chemokines; Colitis; Crohn Disease; Female; Gene Deletion; Immunity, Mucosal; Interferon-gamma; Ligands; Mice; Mice, Knockout; Ovalbumin; Receptors, Antigen, T-Cell; Receptors, Chemokine; Receptors, CXCR3

Clonal expansion of T cells is associated with inflammatory bowel diseases, which indicates antigenic activation of the T cells. We investigated whether the introduction of CD4 T cells specific to a microflora would initiate colitis and assessed the cytokine requirements for colitogenic CD4 T cells.. Severe combined immunodeficiency disease (SCID) mice were reconstituted with CD4 T cells, which were either deficient in interleukin (IL)-4/interferon (IFN)-gamma production or differentiated in vitro to T-helper (Th) 1/Th 2 and bearing a transgenic T-cell receptor (TCR) specific to ovalbumin (OVA), and then inoculated with an Escherichia coli-producing OVA (ECOVA). Clinical and histologic manifestations of colitis were assessed.. Mice with ECOVA colonization and OVA-specific CD4 T cells developed colitis with histologic features of focal infiltration by mononuclear cells, destruction of crypts, and loss of goblet cells. Further, infiltration was initiated in pre-existing lymph follicles. Th1- and IL-4 deficient T cells were diffusely localized in the lamina propria and submucosa, whereas Th2- and IFN-gamma-deficient T cells were localized preferentially in lymph follicles.. A microbe-associated antigen, non-cross-reactive to colonic tissue, can drive antigen-specific CD4 T cells to cause colitis in SCID mice. Although the presence of IFN-gamma and IL-4 in the effector CD4 T cells was not an absolute requirement for the development of colitis, they seemed to regulate it in part by modulating migration of the effector T cells.

Topics: Animals; Antigens, Bacterial; CD4-Positive T-Lymphocytes; Colitis; Escherichia coli; Interferon-gamma; Interleukin-4; Mice; Mice, SCID; Ovalbumin; Th1 Cells; Th2 Cells; Wasting Syndrome

Dysregulated T cell responses to enteric bacteria have been implicated as a common mechanism underlying pathogenesis in rodent models of colitis. However, the bacterial species and T cell specificities that induce disease have been poorly defined. We have developed a model system in which target antigen, bacterial host, and corresponding T cell specificity are defined. OVA-specific T cells from DO11.RAG-2(-/-) TCR transgenic mice were transferred into RAG-2(-/-) recipients whose intestinal tracts were colonized with OVA-expressing or control Escherichia coli. Transfer of antigen-naive DO11.RAG-2(-/-) T cells into recipients colonized with OVA-E. coli resulted in enhanced intestinal recruitment and cell cycling of OVA-specific T cells; however, there was no development of disease. In contrast, transfer of polarized T helper (Th) 1 and Th2 populations resulted in severe wasting and colitis in recipients colonized with OVA-expressing but not control E. coli. The histopathologic features of disease induced by Th1 and Th2 transfers were distinct, but disease severity was comparable. Induction of disease by both Th1 and Th2 transfers was dependent on bacterially associated OVA. These results establish that a single bacterially associated antigen can drive the progression of colitis mediated by both Th1 and Th2 cells and provide a new model for understanding the immunoregulatory interactions between T cells responsive to gut floral antigens.

Topics: Adoptive Transfer; Animals; CD4-Positive T-Lymphocytes; Colitis; DNA-Binding Proteins; Escherichia coli; Mice; Mice, Transgenic; Ovalbumin; Receptors, Antigen, T-Cell, alpha-beta; Recombinant Proteins; Th1 Cells; Th2 Cells; Wasting Syndrome

Enteric bacterial and/or food antigens may be crucial in the development of colitis but little is known of the exact mechanism of antigen specific reactions in this condition. The aim of this study was to determine whether systemically primed antigen specific CD4(+) T cells containing both CD45RB(high) and CD45RB(low) populations participate as a pathogenic subset that in turn leads to inflammatory reactions selectively in the large intestine.. SCID mice were reconstituted with splenic CD4(+) CD45RB(+) T cells or CD4(+) CD45RB(low) T cells isolated from donor mice systemically primed with ovalbumin (OVA) plus CFA. The reconstituted mice were then fed OVA for several weeks.. Reconstitution of SCID mice with OVA primed splenic CD4(+) T cells, containing populations of CD45RB(high) and CD45RB(low), resulted in the development of colitis by 4-5 weeks following repeated administration of oral OVA. Histopathological study revealed thickened wall, inflammatory cell infiltration, crypt elongation, and loss of goblet cells in the large intestine. The CD4(+) CD45RB(low) population of cells extracted from the affected large intestine secreted high levels of interferon gamma (IFN-gamma) and tumour necrosis factor alpha (TNF-alpha) at the protein and mRNA levels. Administration of neutralising antibodies to TNF-alpha, but not to IFN-gamma, prevented the development of colitis. Furthermore, adoptive transfer with OVA primed splenic CD4(+) CD45RB(low) T cells evoked severe colitis.. These results demonstrate that systemically primed activated/memory CD4(+) CD45RB(low) T cells can mediate the development of specific antigen induced colitis in SCID mice, and also that TNF-alpha is critical in the induction of this type of colitis. Our results contrast with those from studies in some colitis models in which CD45RB(low) T cells appeared to prevent colitis through secretion of immunosuppressive cytokines.

Topics: Adoptive Transfer; Animals; Antigens; CD4-Positive T-Lymphocytes; Colitis; Cytokines; Disease Progression; Intestine, Large; Leukocyte Common Antigens; Lymphocyte Subsets; Mice; Mice, Inbred BALB C; Mice, SCID; Ovalbumin; Spleen; Th1 Cells; Tumor Necrosis Factor-alpha; Weight Loss

Although some animal models suggest an involvement of CD4 T cells reactive to luminal microbial antigen(s) for the pathogenesis of inflammatory bowel diseases (IBD), direct linkage between microflora-driven clonal expansion of CD4 T cells and the development of colitis has not been well studied. Here, BALB/c and SCID mice were given CD4 T cells purified from Rag-2(-/-) mice crossed to transgenic mice expressing TCR specific to ovalbumin (OVA) then administered with antibiotic-resistant Escherichia coli producing OVA (ECOVA) or LacZ (ECLacZ) via the rectum. The ECOVA-inoculated BALB/c and SCID mice developed a subacute colitis with microscopic features of distortion of crypt architecture, loss of goblet cells, and focal infiltration by mononuclear cells in the lamina propria (LP) and submucosa. Expanding OVA-specific CD4 T cells were detected in colonic follicles of mice with ECOVA. Early in colitis, OVA-specific CD4 T cells producing IFN-gamma predominate in the LP of the colon, which was followed by an emergence of OVA-specific CD4 T cells producing IL-4 and IL-10 at a later time point. Co-transfer of an IL-10-secreting OVA-specific CD4 T cell line prevented colitis. Thus, an expansion of CD4 T cells monospecific to OVA, an antigen non-cross-reactive to colonic tissue, can mediate both induction and inhibition of the colitis which was associated with hyperplasia of lymph follicles.

Topics: Administration, Rectal; Adoptive Transfer; Animals; Antigens, Bacterial; CD4-Positive T-Lymphocytes; Cell Line; Colitis; Colon; Cytokines; Disease Models, Animal; Epitopes, T-Lymphocyte; Escherichia coli; Injections, Intravenous; Interleukin-10; Intestinal Mucosa; Lac Operon; Mice; Mice, Inbred BALB C; Mice, Knockout; Mice, SCID; Mice, Transgenic; Ovalbumin; Plasmids; Wasting Syndrome

The immunoregulatory properties of primary colonic epithelial cells (CECs) have not been defined. The ability of CECs from wild-type and interleukin 2-deficient (IL-2(-/-)) mice to take up a complex protein antigen and present peptides via MHC molecules to T cells was assessed and contrasted with that of primary small intestinal epithelial cells (SIECs).. Uptake of fluorescein isothiocyanate (FITC)-labeled ovalbumin (FITC-OVA) by CECs and SIECs from wild-type and IL-2(-/-) mice was measured by flow cytometry. The effect of disrupting cytoskeleton organization and metabolic activity of CEC on antigen uptake was assessed. An OVA/I-A(b)-specific CD4(+) T-cell line transfected with an NFAT-lacZ reporter gene construct was used to evaluate the ability of CECs and SIECs as well as CECs from healthy and colitic IL-2(-/-) mice to present antigen to T cells.. Uptake of FITC-OVA by CECs is concentration dependent, is not saturated at physiologic concentrations, and requires metabolically active cells. CECs from IL-2(-/-) mice take up significantly more antigen than those from wild-type mice. CECs are more efficient APCs than SIECs, and antigen-pulsed CECs from IL-2(-/-) mice induce the highest levels of T-cell activation.. Primary CECs are efficient APCs for CD4 MHC class II-restricted T cells. Antigen uptake and presentation is up-regulated in animals prone to develop intestinal inflammation.

Topics: Animals; Antigen-Presenting Cells; Antigens; CD4-Positive T-Lymphocytes; Cell Line; Colitis; Colon; Enteritis; Female; Fluorescein-5-isothiocyanate; Fluorescent Dyes; Interleukin-2; Intestinal Mucosa; Intestine, Small; Mice; Mice, Inbred C57BL; Ovalbumin; Reference Values

We previously demonstrated that 2,4,6-trinitrophenol (TNP)-OVA immunization leads to a transmural colitis in the IL-2-/- mouse that is caused by IL-12-driven CD4+ Th1 T cells and resembles human Crohn's disease. The integrin alpha E beta 7 is highly expressed on colonic intraepithelial lymphocytes and has been suggested to function as a homing or retention molecule for intraepithelial lymphocytes. To evaluate the role of alpha E beta 7 in colitis, we administered a mAb against alpha E beta 7 to IL-2-/- mice that were immunized at the same time with TNP-OVA in CFA. To our surprise, this treatment resulted in a significantly reduced colitis severity score, 0-2 vs 3-4, that was associated with a significant reduction in CD4+ lamina propria lymphocyte subpopulation (p < 0.01). In contrast, the total number of splenic CD4+ T cells of treated animals was significantly elevated compared with that of untreated animals (3.2 +/- 0.6 x 107 vs 1.2 +/- 0.2 x 107; p < 0.05). Similarly, functional studies revealed that IFN-gamma production by lamina propria lymphocytes isolated from IL-2-/- TNP-OVA-immunized mice treated with anti-alpha E beta 7 was significantly lower than in untreated IL-2-/- TNP-OVA-immunized mice. In contrast, IFN-gamma production by splenic cells isolated from treated IL-2-/- TNP-OVA-immunized mice was significantly higher than in untreated mice. Finally, TNP-OVA-immunized IL-2-/- mice that were treated after the colitis had been established also showed a significant decrease in mucosal inflammation after alpha E beta 7 mAb administration. Thus, the above findings demonstrate that the onset and maintenance of inflammatory bowel disease depends on the colonic localization of lamina propria CD4+ lymphocytes expressing alpha E beta 7.

Topics: Animals; Antibodies, Monoclonal; CD3 Complex; CD4 Lymphocyte Count; Cell Movement; Colitis; Female; Haptens; Immunization; Injections, Intraperitoneal; Integrins; Intercellular Adhesion Molecule-1; Interferon-gamma; Interleukin-2; Intestinal Mucosa; Lymphocyte Count; Lymphocytes; Male; Mice; Mice, Knockout; Ovalbumin; Spleen; Trinitrobenzenes

Gene-targeted mice deficient for IL-2 (IL-2 -/- mice) are free of apparent disease when maintained under germfree conditions but develop colitis and autoimmunity in a conventional environment. Here we show that colitis can be reproducibly induced in IL-2 -/- mice, but not in IL-2 +/+ mice, by i.p. immunization with Ag in CFA; thus enabling the systematic study of the immunopathogenesis of the colitis. We found that TNP-KLH or TNP-OVA had the most significant effect in inducing colitis, and while TNP-KLH immunization leads to the early appearance of activated T cells in the colons of both IL-2 -/- and IL-2 +/+ mice, only lamina propria cells of IL-2 -/- mice produced high amounts of INF-gamma. Moreover, both infiltrating colon CD4+ (69%) and CD8+ (6%) T cells secrete large amounts of IFN-gamma; however, only the depletion of CD4+ T cells leads to abrogation of the inflammation. In further analysis, we showed that the high IFN-gamma production is IL-12 driven, since colonic tissues of IL-2 -/- mice but not IL-2 +/+ mice show the presence of heterodimeric IL-12 and co-administration of anti-IL-12 with TNP-KLH completely prevented colitis and significantly reduced IFN-gamma production. Finally, we demonstrate that IL-2 -/- mice are deficient in their ability to induce Th2 responses after TNP-KLH challenge and that such immunization also leads to autoimmune-like phenomena in other organs of IL-2 -/- mice. These findings suggest that in the absence of IL-2 systemic administration of Ag induces primarily Th1 cells driven by overexpression of heterodimeric IL-12.

Topics: Animals; Antigens, T-Independent; Colitis; Haptens; Hemocyanins; Immunization; Immunophenotyping; Interferon-gamma; Interleukin-12; Interleukin-2; Interleukin-4; Intestinal Mucosa; Mice; Mice, Inbred C57BL; Mice, Mutant Strains; Mutagenesis, Site-Directed; Ovalbumin; T-Lymphocytes; Trinitrobenzenes

Induction and maintenance of peripheral tolerance are important mechanisms to maintain the balance of the immune system. In addition to the deletion of T cells and their failure to respond in certain circumstances, active suppression mediated by T cells or T-cell factors has been proposed as a mechanism for maintaining peripheral tolerance. However, the inability to isolate and clone regulatory T cells involved in antigen-specific inhibition of immune responses has made it difficult to understand the mechanisms underlying such active suppression. Here we show that chronic activation of both human and murine CD4+ T cells in the presence of interleukin (IL)-10 gives rise to CD4+ T-cell clones with low proliferative capacity, producing high levels of IL-10, low levels of IL-2 and no IL-4. These antigen-specific T-cell clones suppress the proliferation of CD4+ T cells in response to antigen, and prevent colitis induced in SCID mice by pathogenic CD4+CD45RB(high) splenic T cells. Thus IL-10 drives the generation of a CD4+ T-cell subset, designated T regulatory cells 1 (Tr1), which suppresses antigen-specific immune responses and actively downregulates a pathological immune response in vivo.

Topics: Animals; CD4-Positive T-Lymphocytes; Cells, Cultured; Clone Cells; Colitis; Cytokines; Humans; Immune Tolerance; Immunosuppression Therapy; Inflammatory Bowel Diseases; Interleukin-10; Lymphocyte Activation; Mice; Mice, Inbred BALB C; Mice, SCID; Ovalbumin; Spleen; T-Lymphocyte Subsets

In previous studies we showed that a chronic colitis associated with a Th1 T cell response can be induced by the rectal administration of the haptenizing reagent 2,4,6-trinitrobenzene sulfonic acid (TNBS). We report here that oral administration of haptenized colonic proteins (HCP) before rectal administration of TNBS effectively suppresses the ability of the latter to induce colitis. This suppression (oral tolerance) appears to be due to the generation of mucosal T cells producing TGF-beta and Th2-type cytokines after oral HCP administration. Peyer's patch and lamina propria CD4+ T cells from HCP-fed animals stimulated with anti-CD3/anti-CD28 had a 5-10-fold increase in their production of TGF-beta and secreted increased amounts of IL-4 and IL-10 but lower levels of IFN-gamma in comparison to T cells from ovalbumin-fed control animals. In addition, the colons of HCP-fed mice showed strikingly increased TGF-beta but decreased IL-12 expression by immunohistochemical studies and isolated mononuclear cells from HCP-fed animals secreted less IL-12 heterodimer. Finally, and most importantly, the suppressive effect of orally administered HCP was abrogated by the concomitant systemic administration of anti-TGF-beta or rIL-12 suggesting a reciprocal relationship between IL-12 and TGF-beta on tolerance induction in TNBS-induced colitis. In parallel studies we demonstrated that TNBS-induced colitis can be transferred to naive recipient animals with purified CD4+ T cells from the colon of TNBS-treated animals and that such animals develop lethal pancolitis when exposed to very low doses of TNBS. Feeding of HCP suppressed this sensitivity to TNBS, indicating that oral feeding can suppress the response of pre-committed T cells in vivo. These studies suggest for the first time that TGF-beta production can abrogate experimental granulomatous colitis even after such colitis is established, and thus, that regulation of TGF-beta levels may have relevance to the treatment of human inflammatory bowel disease.

Topics: Animals; Antibodies; CD28 Antigens; CD3 Complex; CD4-Positive T-Lymphocytes; Colitis; Cytokines; Female; Granulomatous Disease, Chronic; Haptens; Humans; Immune Tolerance; Immunotherapy, Adoptive; Interleukin-10; Interleukin-4; Intestinal Mucosa; Mice; Mice, Inbred Strains; Ovalbumin; Peyer's Patches; T-Lymphocytes; Th1 Cells; Transforming Growth Factor beta; Trinitrobenzenesulfonic Acid

This study examined whether the immunocyte recruitment associated with a mild inflammatory state induced by acetic acid would produce detectable sulfidopeptide leukotriene (LT) levels from colonic tissues or in dialysates. Histological examination and measurements of peroxidase activities of inflamed tissues indicated edema, hyperplasia and neutrophil infiltration. Significant elevated LTB4 and prostaglandin E2(PGE2) levels were found but only slight elevations in sulfidopeptide LTs occurred. A slight elevation in eosinophil peroxidase indicated that eosinophil infiltration also occurred. The increase in sulfidopeptide LT levels appeared insufficient by itself to alter secretory responses in the distal colon. However, combined with other immunocyte products such as PGs, the sulfidopeptide LTs may influence the symptomology of inflammatory bowel disease.

Topics: Acetic Acid; Animals; Calcimycin; Calcium; Colitis; Eosinophil Peroxidase; Eosinophils; Guinea Pigs; Intestinal Mucosa; Ionophores; Leukotrienes; Male; Neutrophils; Ovalbumin; Peroxidase; Peroxidases

Experimental colitis was induced in the rat, by ethanol-oxazolone injections into the distal colon, resulting in diarrhea together with edema, ulcers, and cell infiltration in the exposed colon. Colitic rats showed an elevated urinary recovery of the permeability marker [51Cr]EDTA after intragastric feeding, 19 +/- 10%, compared to 2.9 +/- 0.7% for control rats (P < 0.001). An increased retention of [51Cr]EDTA in the intestines and a decreased discharge in feces suggested an increased intestinal transit time in colitic rats. The in vitro permeability to [51Cr]EDTA and ovalbumin was not elevated in the severely inflamed distal colon, but was in the proximal, unaffected colon to ovalbumin (P < 0.05) and in the distal small intestine, to both [51Cr]EDTA (P < 0.01) and ovalbumin (P < 0.05), indicating that an inflammation in one part of the intestine could have permeability effects in other remote parts. In conclusion, the increased [51Cr]EDTA absorption in vivo during colitis was probably due to both an increased permeability and an increased intestinal transit time.

Topics: Animals; Chromium Radioisotopes; Colitis; Colon; Edetic Acid; Ethanol; Female; In Vitro Techniques; Intestinal Absorption; Ovalbumin; Oxazolone; Rats; Rats, Sprague-Dawley

This study examined whether a mild inflammatory state induced by acetic acid would alter ovalbumin-induced motor and secretory responses of the actively sensitized colon. Short-circuit current (Isc), a measure of active transepithelial ion transport, and longitudinal contractility were measured, respectively, in mucosa-submucosa or smooth muscle sheets from guinea pig distal colon. Ovalbumin produced similar, concentration-dependent increases in Isc in noninflamed and inflamed colonic mucosa. Chlorpheniramine, an H1-histamine antagonist, produced a concentration-related decrease in antigen efficacy that was greater in noninflamed mucosa than in inflamed tissues. Lipoxygenase inhibitors (R840 and A64077) were equally effective in decreasing ovalbumin-induced secretion in both inflamed and noninflamed tissues. Ovalbumin also produced longitudinal muscle contractions that were of similar magnitude in inflamed and noninflamed strips. Moreover, chlorpheniramine and lipoxygenase inhibitors inhibited contractile responses in muscle from both inflamed and noninflamed colons. These results suggest that inflammation produces hyperresponsiveness in the colonic mucosa but not in the underlying longitudinal smooth muscle.

Topics: Animals; Antigens; Chlorpheniramine; Colitis; Cyclooxygenase Inhibitors; Disease Models, Animal; Epithelium; Guinea Pigs; In Vitro Techniques; Indomethacin; Intestinal Mucosa; Ion Transport; Lipoxygenase Inhibitors; Male; Muscle Contraction; Muscle, Smooth; Ovalbumin

Topics: Animals; Antigens; Autoimmune Diseases; Colitis; Lagomorpha; Ovalbumin; Pathology; Rabbits; Research

Topics: Antigen-Antibody Reactions; Colitis; Fluorescence; Fluorescent Antibody Technique; Hypersensitivity; Microscopy; Microscopy, Fluorescence; Ovalbumin; Rabbits; Research; Toxicology