OVA-specific IgE Levels Research Articles

Synergic Effects of CD40 and CD86 Silencing in Dendritic Cells on the Control of Allergic Diseases

Background: We previously reported that siRNA-induced CD40-silenced dendritic cells (DCs) inhibit allergic responses and symptoms. However, more potent therapies are needed. To our knowledge, synergic effects of gene silencing in DCs by ≥2 siRNAs have not been reported to control allergic diseases. Therefore, we investigated the synergistic effects of the silencing of CD40 and CD86 in DCs on allergic responses. Methods: Mice were treated with CD40/CD86-silenced DCs, which were transfected with CD40/CD86 siRNAs and pulsed with ovalbumin (OVA) antigen. The effects of these DCs on allergic symptoms and allergic responses were estimated. Results: The administration of CD40/CD86-silenced OVA-pulsed DCs significantly inhibited the number of sneezes and nasal rubbing movements, the number of eosinophils in the nasal mucosa, and the level of OVA-specific IgE when compared with those for CD40- or CD86-silenced OVA-pulsed DCs alone (p < 0.01). These inhibitory effects were detected before sensitization as well as after the establishment of allergic rhinitis. CD40/CD86-silenced OVA-pulsed DCs did not inhibit KLH-induced allergies. Foxp3 gene expression was significantly upregulated in CD40-silenced DCs compared to in CD86-silenced DCs (p < 0.01). IL-4 production by T cells was suppressed more substantially when using CD86-silenced DCs than with CD40-silenced DCs (p < 0.01). Conclusions: These results indicate, for the first time, that siRNA-induced CD40/CD86-silenced antigen-specific DCs have greater inhibitory effects against allergic responses than those of CD40- or CD86-silenced antigen-specific DCs alone. This study also suggests that the synergic effects of gene silencing in DCs by ≥2 siRNAs are useful for the control of allergic diseases. Thus, owing to the synergistic effects, CD40 and CD86 silencing has the potential to substantially improve the treatment of allergic diseases.

Phenotype analyses of IL-10-producing Foxp3− CD4+ T cells increased by subcutaneous immunotherapy in allergic airway inflammation

IntroductionThe mechanisms of allergen immunotherapy are not fully elucidated. Here, we sought to develop a murine model to demonstrate the effectiveness of subcutaneous immunotherapy (SCIT) for allergic responses. As excessive antigen dosages may induce immune tolerance in sensitized mice, the effects of SCIT were assessed by varying the antigen dosage. The mechanisms of SCIT were analyzed by focusing on the induction of Foxp3+ Treg cells and IL-10-producing Foxp3− CD4+ T cells, as well as on the phenotype of the latter cells. MethodsOvalbumin (OVA) + Al(OH)3-sensitized mice received subcutaneous dosages of OVA at 0.01, 0.1 or 1 mg/animal for SCIT, followed by intratracheal challenges with OVA at 5, 50 or 500 μg/animal. ResultsThe maximum effects of SCIT were observed with 1 mg/animal of OVA for airway inflammation induced by 5 μg/animal of OVA, in which airway eosinophilia and Th2 cytokine production were markedly suppressed. The increase in the OVA-specific IgE level was significantly suppressed by SCIT. The development of bronchial epithelial thickening and mucus accumulation were also suppressed by SCIT. Concomitantly, IL-10-producing Foxp3− CD4+ T cells were increased in the lungs by SCIT, but Foxp3+ Treg cells were not. Most of the induced IL-10-producing Foxp3− CD4+ T cells were negative for either IL-5 or LAG-3, but positive for CD49b. ConclusionWe successfully developed an airway allergic model for SCIT. It was suggested that most of IL-10-producing Foxp3− CD4+ regulatory T cells increased by SCIT in the lungs were CD49b+ CD4+ regulatory T cells, but neither Th2 cells nor Tr1 cells.

Maternal and early-life vitamin D deficiency enhances allergic reaction in an ovalbumin-sensitized BALB/c mouse model.

BackgroundRecent studies have shown that vitamin D deficiency may contribute to the high prevalence of food allergy but the underlying mechanisms are far from clear.ObjectiveThe present study was designed to investigate the effect of maternal and early-life vitamin D deficiency in the development of food allergy.DesignBALB/c mice were treated with ovalbumin (OVA) to trigger allergic reactions, under vitamin D-deficient (by maternal and early-life feeding of vitamin D deprived chow diet) or vitamin D-sufficient conditions.ResultsIncreased occurrence and severity of allergic diarrhea as well as decreased rectal temperature were observed after OVA sensitization. For vitamin D deficiency groups, OVA-specific IgE and IL-4 levels were significantly increased, while IFN-γ levels were unchanged. Vitamin D deficiency also attenuated the structure of small intestinal villi and decreased the expression of the tight junction protein between adjacent epithelial cells and the percentages of CD4+CD25+Foxp3+Treg cell in spleen and mesenteric lymph nodes.ConclusionsMaternal and early-life vitamin D deficiency have notable influence on the susceptibility to food allergy, which may relate with the reduced population of Treg cell and the dysfunction of intestinal epithelial barrier.

SIRT1 attenuates murine allergic rhinitis by downregulated HMGB 1/TLR4 pathway.

Conventional allergic rhinitis (AR) treatments have limitations due to the lack of safety and complete cure strategy. We evaluated the effects of silent information regulator 1 (SIRT1), a multifunctional molecule involved in a variety of inflammatory pathways, on murine AR model. Ovalbumin (OVA)-induced murine model was constructed, and recombinant SIRT1 was administered into the nostril continuously. The expression of SIRT1 was measured at mRNA and protein levels, and the allergic symptoms were evaluated. Protein levels of OVA-specific IgE, leukotriene C4 (LTC4), eosinophil cation protein (ECP), prostaglandin D2 (PGD2), as well as different inflammatory cytokine mediators in the serum and nasal lavage fluid (NLF), were assessed by ELISA. The effects of SIRT1 on human primary nasal epithelial cells challenged with tumour necrosis factor (TNF)-α were also evaluated by investigating the HMGB1/TLR4 signalling pathway. Administration of SIRT1 significantly alleviated OVA-induced AR symptoms with lower numbers of sneezing and nasal rubbing events, decreased levels of OVA-specific IgE, LTC4, ECP, PGD2, less inflammatory cells and downregulated levels of Th2 type cytokines. SIRT1 also reduced the genes of HMGB1/TLR4 signalling pathway in the murine model and cultured human nasal epithelial cells. Expression of SIRT1 is impaired in OVA-induced AR model. The administration of SIRT1 alleviates the allergic symptoms of mice, regulates the production of pro-inflammatory mediators predominantly produced by Th2 cells in AR and attenuates expressions of proteins relevant to HMGB1/TLR4 signalling pathway. All the results showed that SIRT1 is promising as a therapeutic agent of AR.

IL-21 alleviates allergic asthma in DOCK8-knockout mice

Patients with DOCK8 deficiency are at increased susceptibility to develop allergic diseases such as food allergy and asthma. Here, we aimed to analyze the pathogenesis of asthma in DOCK8-deficient patients. In our mouse model, DOCK8-knockout (KO) mice sensitized with low-dose OVA were challenged with 1.5% OVA to induce allergic asthma. As compared to that in WT mice, remarkable airway hyperresponsiveness was observed in KO mice. Increased inflammatory cells and eosinophils infiltrated in airway lumen in KO mice especially around bronchi. KO mice showed higher levels of serum IgE and OVA-specific IgE and significantly elevated IgE-producing B cells in blood and in spleen. Surprisingly, nasal administration with rmIL-21 significantly reduced the airway hyperresponsiveness, inflammatory infiltration, as well as the serum IgE and IgE-producing B cells. DOCK8-knockout mice are susceptible to low-dose OVA induced allergic airway inflammation and airway hyperresponsiveness. Supplementary nasal administration of rmIL-21 alleviates allergic asthma in this mouse model.

Oral Intake of Lactobacillus helveticus NS8 Alleviates Ovalbumin-Induced Atopic Dermatitis in SKH-1 Hairless Mice.

Atopic dermatitis (AD) is the most common chronic inflammatory skin disease and is driven by strong type 2 immune responses. Lactobacillus helveticus NS8 (NS8), a probiotic strain isolated from Mongolian koumiss, has anti-inflammatory activities. Here, we evaluated the therapeutic potential of NS8 on AD-like skin lesions by using SKH-1 hairless mice that underwent three cycles of epicutaneous sensitization (EC) with ovalbumin (OVA). NS8 (5 × 108 CFU/day) was orally administered to mice from 2weeks before the first sensitization until the end of the study. NS8 attenuated the symptoms and pathological changes in the skin of AD mice. For example, NS8 reduced epidermal and dermal thickening and significantly restrained the infiltration of mast cells, eosinophils, and CD4+ T cells into the dermis. By analysing the Th1/Th2 cytokines produced in skin lesions, we found that NS8 significantly suppressed the expression of IL-4, IL-5, and IL-13 (P < 0.05), while it had no discernible effect on the expression of IFN-γ. Systemically, NS-8 reduced the total IgE and OVA-specific IgE levels in serum (P < 0.05). Our study demonstrates that oral administration of L. helveticus NS8 effectively alleviates AD severity in mice by suppressing the Th2 immune response. NS8 may be a promising candidate for prophylactic and therapeutic treatments of allergic diseases, such as AD.

Deficiency of Leukocyte‐Specific Protein 1 (LSP1) Alleviates Asthma in a Mouse Model

Asthma is one of the most serious forms of respiratory disease, causing economic losses, high mortality, and morbidity globally. However, its etiology is still ambiguous. Many inflammatory cells, including T lymphocytes, eosinophils, mast cells, macrophages, and neutrophils, are recruited into the airway of asthma lung patients. In the previous study, we reported that LSP1 deficiency reduces neutrophil migration and acute lung inflammation, but its role in asthma remains unknown. Therefore, in this study, we developed an asthma‐like disease in LSP1‐deficient (Lsp1−/−) and wild‐type (WT) 129/SvJ mice (n=6 each treatment group) through two intraperitoneal (IP) injections of 2μg OVA/2mg alum two weeks apart, followed by three aerosol challenges with 1% OVA two days apart after two weeks of the last IP injection. We hypothesized that the absence of LSP1 inhibited airway inflammation in this OVA‐induced asthma mouse model due to inhibition of immune cell migration.Immunohistochemistry staining and western blot data showed that the level of LSP1 increased in asthma mouse lungs, compared with normal healthy lungs. Results from immuno‐gold as well as immunofluorescent staining illustrated that LSP1 was expressed on endothelium, bronchiolar epithelium, neutrophils, eosinophils, lymphocytes, alveolar macrophages, and pulmonary intravascular macrophages. There was no significant difference in peripheral leukocyte numbers between normal and asthmatic WT and Lsp1−/− mice. However, compared to Lsp1−/− asthma mice, WT asthma mice had higher levels leukocytes in broncho‐alveolar lavage fluid, higher myeloperoxidase, a marker of neutrophils, and eosiperoxidase levels in lungs (P&lt;0.05). The level of OVA‐specific IgE, but not IgA and IgG1, in the serum of WT asthma mice was higher than that of Lsp1−/− asthma mice (P&lt;0.05). Other research reported that IL‐4, IL‐5, IL‐6, IL‐13, and KC are associated with eosinophilia and neutrophil migration. We found that the absence of the LSP1 gene significantly reduced the levels of IL‐4, IL‐5, IL‐6, IL‐13, and KC (P&lt;0.05) but not the levels of IL‐17, eotaxin, IFN‐gamma, and total protein in broncho‐alveolar lavage fluid. The airway hyper‐responsiveness response to methacholine in Lsp1−/− asthma mice was ameliorated compared to WT asthma mice (P&lt;0.05). Histopathology evaluation findings showed more recruited inflammatory cells, as well as airway and blood vessel wall thickening, in the lungs of WT mice than in those of Lsp1−/− mice. These data indicate that LSP1 promotes airway inflammation associated with asthma in this mouse model. LSP1 may be a potential target for therapeutic intervention in allergic lung disease or asthma in humans.Support or Funding InformationWe thank to the Natural Science and Engineering Research Council (NSERC), Graduate Student Scholarship from Integrated Training Program in Infectious Disease, Food Safety and Public Policy (ITraP), Devolved Graduate Scholarship from Department of Veterinary Biomedical Sciences, and Graduate Student Scholarship from Western College of Veterinary Medicine, University of Saskatchewan, Canada for supporting this research. We thank Ms. LaRhonda Sobchishin for the technical support provided for the electron microscope technique and Ms. Eiko Kawamura for technical support in using a confocal microscope.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

FcγRIIIA Negatively Impacts Humoral Immune Responses but Not Overall Lung Inflammation in an Ovalbumin-Induced Allergic Asthma Mouse Model

Background: Fcγ receptors (FcγR) play substantial immune regulatory roles both positively and negatively in pathophysiological processes including allergy and asthma. Compared with FcγRIIB which is classically defined as an inhibitory receptor, mouse FcγRIIIA and its functional human homologue FcγRIIA have been assumed to be activating receptors. However, evidence demonstrating inhibitory regulation by mouse FcγRIIIA has recently been emerging. Objective: To dissect the contributory roles of mouse FcγRIIIA (human FcγRIIA) in parallel with FcγRIIB in an ovalbumin (OVA)-induced mouse model of asthma and to preliminarily assess the correlation of the respective FcγR with circulating IgE levels in human asthma patients. Methods: Wild-type, FcγRIIB^–/–, and FcγRIIIA^–/– mice were used in an OVA-induced asthma model followed by assessment of the allergic pathology focused on the lung tissues. Expression levels of FcγRIIB, FcγRIIA, and FcγRIIIA on peripheral blood mononuclear cells (PBMC) together with the circulating IgE levels in the serum from patients with allergic asthma were analysed. Results: Although enhanced humoral immune responses typically represented by augmented OVA-specific IgG and IgE levels in serum were observed in the absence of FcγRIIIA in the mouse asthma model, no overall regulation by FcγRIIIA, especially in terms of those parameters measuring lung tissue inflammation, was recorded. As expected, in the absence of FcγRIIB, augmented immune responses measured as serum antibody levels as well as those in various regulatory pathways in this mouse asthma model were observed. The expression levels of human FcγRIIB but not FcγRIIA were negatively correlated with serum levels of IgE in human asthma patients. Conclusion: We did not find major evidence demonstrating an immune inhibitory role of mouse FcγRIIIA in this OVA-induced mouse asthma model. As asthma is a complex disease and the immune regulatory responses involve sophisticated components and pathways, the exact roles of FcγRIIIA as well as its human functional homologue FcγRIIA in asthma still await further clarification using other mouse asthma models as well as clinical studies.

Investigation of the effects of probiotics on allergy

Objectives: To investigate the effects of a probiotic mixture thatwas isolated from human gut flora, and a standard probiotic strainLactobacillus GG (LGG) on allergic immune responses in ananimal model.Materials and Methods: Three Enterococcus faecalis, 8Lactobacillus plantarum, and 2 Lactobacillus rhamnosus strainswere included in the mixture. Balb-c mice in the study groupswere given the probiotic mixture, and standard strain LGG, andanimals in the control groups were given skimmed milk for 28days. The mice in the study groups and the positive control groupwere immunized with an intraperitoneal injection of ovalbumin(OVA) on days 14 and 21. An enzyme-linked immunosorbentassay was used to study the OVA-specific IgE levels in the miceserums.Results: The most remarkable results were that OVAspecificIgE levels were significantly higher (P&amp;lt;0.001) inthe positive control group compared with the nonimmunizednegative control group, and OVA-specific IgE levels in thestudy groups were significantly lower than the positive controlgroup (P&amp;lt;0.001).Conclusion: The data of the present study suggest thatoral administration of probiotics prevents IgE-mediated OVAhypersensitivity;however, the immunoregulatory effects ofstrains must be described in detail while preparing probioticmixtures.

Skin inflammation exacerbates food allergy symptoms in epicutaneously sensitized mice.

Cutaneous exposure to food antigen through impaired skin barrier has been shown to induce epicutaneous sensitization, thereby causing IgE-mediated food allergies. We examined whether skin barrier impairment following epicutaneous sensitization exacerbates food allergies. BALB/c mice were epicutaneously sensitized by repeated application of ovalbumin (OVA) to MC903-pretreated ear skin for 48hours weekly and then intragastrically challenged with OVA. After the first oral challenge, the skin barrier was disrupted with topical application of MC903 or by tape-stripping. Mice were monitored for changes in body temperature and the occurrence of diarrhea after undergoing the second oral challenge. Serum levels of mouse mast cell protease-1 (mmcp1) and OVA-specific IgE, IgG1, IgG2a antibodies and OVA-specific IgA levels in intestinal lavage fluid were measured by ELISA. Tissue accumulation of eosinophils was determined histologically. Epicutaneously sensitized mice developed anaphylaxis after intragastric challenge, as evidenced by diarrhea, decreased body temperature, and increased serum mmcp1 levels. Skin barrier disruption by MC903 treatment or tape-stripping exacerbated allergic reactions induced by oral challenge. MC903 treatment increased serum baseline and postchallenge mmcp1 levels. Topical pretreatment with dexamethasone alleviated allergic reactions that were exacerbated by MC903 treatment. Even after eliminating exposure to the antigen, inflammation from skin barrier disruption can exacerbate the severity of food allergy symptoms. Serum baseline mmcp1 levels might be an effective marker for predicting the severity of antigen-induced allergic symptoms.

Therapeutic Role for TSP-2 Antibody in a Murine Asthma Model

Background: Specific immunotherapy, including agonists for Toll-like receptor 2 (TLR2), have been shown to protect from allergies and to have a high immunomodulatory capacity. Methods: A new antibody, TSP-2, reactive against an epitope of the extracellular domain of TLR2, was identified. The effect of the antibody on dendritic cells was assessed by immunohistochemistry, Western blot, and flow cytometric analysis. The effect of TSP-2 in a murine asthma model induced with ovalbumin (OVA) was assessed. The model is a form of airway hyperresponsiveness (AHR) and was analyzed by whole-body plethysmography, the measurement of Th1/Th2 cytokines in bronchial alveolar lavage fluid (BALF) and serum by ELISA, and the CCK-8 assay for lymphocyte proliferation. The effect of TSP-2 on the maturation of bone marrow-derived dendritic cells (BMDCs) was assessed by flow cytometric analysis. Results: TSP-2 promoted the maturation of dendritic cells and the proliferation of lymphocyte in vitro and in vivo. The effect of TSP-2 on T helper 1 (Th1)/Th2 cytokine secretion was slightly more powerful than that of Pam₃CSK₄. TSP-2 antibody reduced AHR and OVA-specific IgE levels in allergic asthma. TSP-2 antibody also reduced lung inflammation and decreased leukocyte numbers in an OVA-sensitized and challenged asthma model. TSP-2 antibody increased OVA-stimulated I-A, CD80, CD86, and MHC-II levels on BMDCs. Conclusions: This study identifies a novel therapeutic strategy for AHR, which uses antibodies reactive against TLR2. It also provides theoretical evidence for the control of allergic asthma by targeting TLR2.

Dose dependence and durability of the therapeutic effects of Asparagus cochinchinensis fermented extract in an ovalbumin-challenged asthma model

The butanol extract of Asparagus cochinchinensis roots fermented with Weissella cibaria (BAfW) significantly suppressed the inflammatory response induced by lipopolysaccharide (LPS) treatment in RAW264.7 cells. To investigate the dose dependence and durability of BAfW on the anti-asthma effects, alterations in key parameters were measured in ovalbumin (OVA)-challenged Balb/c mice treated with the different doses of BAfW at three different time points. The number of immune cells, OVA-specific IgE level, thickness of respiratory epithelium and mucus score decreased significantly in a dose-dependent manner in response to treatment with 125 to 500 mg/kg BAfW (P<0.05), although the highest level was detected in the 500 mg/kg treated group. Moreover, the decrease in these parameters was maintained from 24 to 48 h in the 500 mg/kg of BAfW treated group. At 72 h, the effects of BAfW on the number of immune cells, OVA-specific IgE level and thickness of respiratory epithelium partially disappeared. Overall, this study provides the first evidence that the anti-asthma effect of BAfW may reach the maximum level in OVA-challenged Balb/c mice treated with 500 mg/kg and that these effects can last for 48 h.

A novel allergen-specific therapy with regulatory T cells induced by CD40-silenced dendritic cells.

We previously reported that dendritic cells (DCs) transfected with CD40 siRNA and pulsed by ovalbumin (OVA) (CD40-silenced OVA DCs) inhibited allergic responses through facilitation of regulatory T cells (Tregs). However, to our knowledge, no prior study has examined allergen-specific therapy by administration of siRNA-induced Tregs for the control of allergy. We aimed to investigate the effect of Tregs induced in vitro on allergic responses and symptoms in vivo. Mice were treated with Tregs (OVA DCs-induced Tregs) induced by CD40-silenced OVA DCs or Tregs (nonantigen DCs-induced Tregs) induced by DCs transfected with CD40 siRNA and pulsed with no antigen, and the effects of these Tregs on allergic responses were estimated. Administration of nonantigen DCs-induced Tregs prevented not only OVA-induced allergy but also keyhole limpet hemocyanin-induced allergy. Administration of OVA DCs-induced Tregs significantly reduced the number of sneezes and nasal rubbing movements, eosinophilia in the nasal mucosa, and the level of OVA-specific IgE in mice with OVA-induced allergy, compared with CD40-silenced nonantigen DC-induced Tregs in numbers 20 times greater, even in mice with established allergic rhinitis. Furthermore, Tregs induced by CD40-silneced DCs pulsed with Cry j 1, a major allergen of Japanese cedar pollen, inhibited Japanese cedar-induced allergy. This study shows for the first time that both antigen-independent Tregs and antigen-specific Tregs can be induced by siRNA, and that therapy with siRNA-induced Tregs inhibits allergic responses and symptoms. It also shows that antigen-specific Tregs have more potent effects in inhibiting allergic responses than antigen-nonspecific Tregs.

March1 E3 Ubiquitin Ligase Modulates Features of Allergic Asthma in an Ovalbumin-Induced Mouse Model of Lung Inflammation.

Membrane-associated RING-CH-1 (March1) is a member of the March family of E3 ubiquitin ligases. March1 downregulates cell surface expression of MHC II and CD86 by targeting them to lysosomal degradation. Given the key roles of MHC class II and CD86 in T cell activation and to get further insights into the development of allergic inflammation, we asked whether March1 deficiency exacerbates or attenuates features of allergic asthma in mice. Herein, we used an acute model of allergy to compare the asthmatic phenotype of March1-deficient and -sufficient mice immunized with ovalbumin (OVA) and later challenged by intranasal instillation of OVA in the lungs. We found that eosinophilic inflammation in airways and lung tissue was similar between WT and March1−/− allergic mice, whereas neutrophilic inflammation was significant only in March1−/− mice. Airway hyperresponsiveness as well as levels of IFN-γ, IL-13, IL-6, and IL-10 was lower in the lungs of asthmatic March1−/− mice compared to WT, whereas lung levels of TNF-α, IL-4, and IL-5 were not significantly different. Interestingly, in the serum, levels of total and ova-specific IgE were reduced in March1-deficient mice as compared to WT mice. Taken together, our results demonstrate a role of March1 E3 ubiquitin ligase in modulating allergic responses.

고려엉겅퀴 에탄올 추출물의 대식세포에서의 항염효능과 정상 및 ovalbumin 감작 Balb/c에서 혈청 면역글로불린에 대한 효능

This study evaluated the anti-inflammatory effects of Cirsium setidens ethanol extract on raw 264.7 cells and effect on serum immunoglobulins in normal and ovalbumin-sensitized Balb/c mouse. In animal experiments, the Balb/c mice were randomly divided into four to five groups, which may or may not be ovalbumin-sensitized. Mice were administered AIN-93G basal diet (for control groups, NC or SC) or AIN-93G diet mixed with 2.5%(G-2.5), 5%(G-5), and 10%(G-10) Cirsium setidens extracts (treated groups) for 7 weeks. The serum IgE and IgG1 levels and the degree of oxidative DNA damage were evaluated. The results showed that the NO release from raw cell was not significantly changed by the Cirsium setidens ethanol extract, whereas the levels of TNF-α and IL-1β were significantly decreased from 500 and 250 μg/mL, respectively. In non-sensitized animal experiments, the serum IgE concentration of the experimental groups was dose-dependently reduced compared with the control group (P0.05). The tail length and moment resulting from DNA fragmentation of blood white cells decreased significantly in G-5 and G-10 groups. In the OVA-sensitized animal experiment, the serum OVA-specific IgE levels were significantly decreased in groups fed with Cirsium setidens extract. The tail DNA and tail moment in all the experimental groups decreased compared with the SC group. Cirsium setidens is a vegetable with antioxidant, anti-inflammatory and immunomodulating properties, which warrant additional research.

Luteolin attenuates airway inflammation by inducing the transition of CD4+CD25– to CD4+CD25+ regulatory T cells

Regulatory T cells play an important role in autoimmunity and have been shown to exert anti-inflammatory effects in allergic asthma. Mouse model of airway inflammation was used to examine the suppressive activity of luteolin-induced CD4+CD25+ regulatory T cells (Tregs) in vivo. In this study, BALB/c mice were sensitized with ovalbumin antigen (OVA) by aerosol challenge. Then, various biological processes were examined, including airway eosinophilia; mucus hypersecretion; elevation of OVA-specific IgE, expression of Th2 cytokines and chemokine levels; expression of eotaxin 2 and CCR3; and airway hyper responsiveness (AHR). Luteolin significantly inhibited OVA-induced increase in immune cell and eosinophil counts as well as IL-4, IL-5, IL-13, and eotaxin levels in bronchoalveolar lavage fluid (BAL Fluid). Luteolin and cyclosporine A (CsA) which was a positive control also substantially reduced OVA-specific IgE levels, eotaxin 2 levels, and CCR3 expression in BAL Fluid. In contrast, luteolin significantly increased IL-10 and IFN-γ protein levels, as well as IL-10 and TGF-β1 mRNA expression in the lung. In vitro studies showed that the number of luteolin-induced CD4+CD25+ Treg (iTreg) cells was higher, with elevated levels of TGF-β1 and foxp3 mRNA expression in lungs tissue. Transfer of iTreg cells into OVA-sensitized mice reduced AHR, eosinophil recruitment, eotaxin, IgE, and Th2 cytokine expressions, and increased IFN-γ production in BAL Fluid after allergen challenge. Furthermore, adoptive transfer of iTreg cells prevented disease in a CD25-depleted mouse asthma model. Luteolin via induction of foxp3 and CD4+CD25+ Treg cells may represent a new strategy in the development of therapies for managing asthma.

Intranasal immunization with phosphorylcholine suppresses allergic rhinitis in mice.

Intranasal immunization with phosphorylcholine (PC) is known to reduce immunoglobulin (Ig)E production. However, its effects on the occurrence of allergic rhinitis (AR) are unknown. This study was performed to evaluate the effects of PC-keyhole limpet hemocyanin (PC-KLH) and to examine the effects on the occurrence of AR in a murine model of AR. In vivo study using an animal model. Forty-five female BALB/c mice were divided into three groups; those pretreated with intranasal administration of PC-KLH followed by intraperitoneal sensitization and nasal challenge with ovalbumin (OVA) (group A), those untreated with PC-KLH followed by sensitization and nasal challenge with OVA (group B), and those untreated with PC-KLH or OVA as controls (group C). Nasal symptoms, allergic inflammation in the nasal mucosa, OVA specific IgE production, and cytokine profile were compared among those three groups. Dendritic cells (DCs) were isolated from splenic cells and PC-KLH-stimulated interleukin (IL)-12p40 production was measured. The mice pretreated with PC-KLH showed lower allergic nasal symptoms and inflammation compared to untreated mice. The levels of total IgE and OVA-specific IgE in serum, and IL-4 production by nasal and splenic CD4+ T cells were significantly reduced by PC-KLH pretreatment. Furthermore, IL-12p40 production by DCs was induced by PC-KLH in a dose-dependent manner. Intranasal administration of PC-KLH suppressed allergic inflammation in nasal mucosa and antigen-specific IgE production by downregulating Th2-type immune response. Intranasal immunization with PC might be useful to prevent AR and upper airway bacterial infection. NA. Laryngoscope, 128:E234-E240, 2018.

Exogenous murine antimicrobial peptide CRAMP significantly exacerbates Ovalbumin-induced airway inflammation but ameliorates oxazolone-induced intestinal colitis in BALB/c mice

ABSTRACTCathelicidin has been reported to be multifunctional. The current study aimed to investigate the influences of exogenous cathelicidin-related antimicrobial peptide (CRAMP) on inflammatory responses in different disease models. In OVA-induced allergic airway inflammation, CRAMP significantly enhanced the infiltration of inflammatory cells and accumulation of proinflammatory Th2 cytokine IL-13 and IL-33 in bronchial alveolar lavage fluid (BALF), exacerbated lung tissue inflammation and airway goblet cell hyperplasia, and elevated OVA-specific IgE level in serum. In oxazolone-induced intestinal colitis, the expression levels of CRAMP and its receptor FPR2 significantly increased in comparison with those of TNBS-induced mice, vesicle and normal controls. Exogenous CRAMP significantly prevented the development of ulcerative colitis, evidenced by improved body weight regain, decreased colons weight/length ratio, elevated epithelial integrity, and ameliorated colon tissue inflammation. In addition, pro-inflammatory cytokines TNF-α, IL-1β, IL-4 and IL-13, as well as chemokines CXCL2 and CXCL5 for neutrophils recruitment were significantly decreased in CRAMP-treated mice, and epithelial repair-related factors MUC2 and Claudin1 were increased, determined by real time-PCR and ELISAs. The results indicated that although CRAMP has pro-inflammatory effects in airway, local application of exogenous CRAMP might be a potential approach for the treatment of ulcerative colitis.

Effects of ovalbumin exposure during pregnancy of mice on the ovalbumin re-exposure in adult progeny

Objective: To observe the immunoreaction of offspring mice by ovalbumin (OVA) re-exposure after their mothers exposed to OVA during pregnancy. Method: A prospective controlled study was conducted to observe mice after repeated OVA exposures at 6-8 weeks.Their mothers were exposed to OVA during different stages of pregnancy.The symptoms were recorded and scored.The levels of OVA-specific IgE in serum, interferon-γ(IFN-γ) and interleukin-4(IL-4) in supernatant of spleen primary lymphocytes in vitro were measured by ELISA.The results were analyzed by single factor analysis of variance or rank sum test. Result: All the mice in each group had acute diarrhea.The diarrhea happened earliest (2 days) and most severe in the late pregnancy group (early pregnancy group 7.0±1.0; middle pregnancy group: 7.1±1.1; late pregnancy group: 9.9±2.2, P<0.01). The levels of absorbance of OVA-specific IgE in the pregnancy groups were higher than those of the control group.The absorbance of OVA-specific IgE in late pregnancy group was the highest (control: 0.27±0.06; early pregnancy group: 0.51±0.13; middle pregnancy group: 0.50±0.09; late pregnancy group: 0.63±0.13, P<0.01). There was no significant change in IFN-γ expression in cultured supernatant of spleen lymphocytes in each group (control: (133±7) pg/ml; early pregnancy group: (133±4) pg/ml; middle pregnancy group: (134±6) pg/ml; late pregnancy group: (132±4) pg/ml, all P value >0.05). The expression of IL-4 in the experimental groups was higher than that in the control group, especially in late pregnancy group(control: (25.3±2.4) pg/ml; early pregnancy group: (32.4±4.4) pg/ml; middle pregnancy group: (35.0±5.4) pg/ml; late pregnancy group: (47.1±5.8) pg/ml; P value all<0.01). Conclusion: The allergic reaction of the OVA re-exposure progeny whose mothers were exposed to OVA in the late pregnancy period was most severe, suggesting that late pregnancy period might be the high risk stage of intrauterine sensitization, or"window period".

Ferulic acid supresses Th2 immune response and prevents remodeling in ovalbumin-induced pulmonary allergy associated with inhibition of epithelial-derived cytokines

Asthma is characterized by intermittent airway obstruction and chronic inflammation, orchestrated primarily by Th2 cytokines. There is a strong rationale for developing new asthma therapies, since current treatment protocols present side effects and may not be effective in cases of difficult-to-control asthma. The purpose of this study was to evaluate the effect of ferulic acid, a phenolic acid commonly present in plants, in the ovalbumin-induced pulmonary allergy murine model. MethodsBALB/c mice were sensitized and challenged with ovalbumin, and treatments were provided by gavage. Six groups of mice (n = 6) were studied, labeled as: control, pulmonary allergy, dexamethasone, and 3 receiving ferulic acid (at 25, 50, and 100 mg/kg). Lung tissue, bronchoalveolar lavage fluid and serum were collected for analysis. ResultsFerulic acid treatment inhibited an established allergic Th2-response by decreasing the key features of pulmonary allergy, including lung and airway inflammation, eosinophil infiltration, mucus production and serum levels of OVA-specific IgE. These results were associated with lower levels of CCL20, CCL11 and CCL5 chemokines and IL-4, IL-5, IL-13, TSLP, IL-25 and IL-33 cytokines in lung tissue homogenate. ConclusionsIn this study it was demonstrated for the first time that ferulic acid treatment is able to suppress one of the main features of the airway remodeling, indicated by reduction of mucus production, besides the Th2 pathogenic response on ovalbumin-induced pulmonary allergy. Taken together, results shows that the immunopathological mechanism underlying these effects is linked to a reduction of the epithelial-derived chemokines and cytokines, suggesting that ferulic acid may be useful as a potential therapeutic agent for asthma.