Serum OVA-specific IgE Research Articles

Mannose targeting of poly(lactic-co-glycolic acid): a promising approach for improving sublingual allergen-specific immunotherapy

Objective One of the most effective treatments for allergic respiratory diseases is allergen-specific sublingual immunotherapy (SLIT). While, mannose targeting has been applied in various immunostimulatory approaches, but it has not been investigated in sublingual allergen-specific immunosuppressive treatment. This study assesses mannose targeting for the ovalbumin (Ova) loaded poly(lactic-co-glycolic acid) (PLGA) nanoparticles(NPs). Methods The emulsion-solvent evaporation method was employed for the synthesis of PLGA NPs containing Ova, and subsequently they attached to D-mannose. Ova-sensitized mice underwent treatment in different ways: subcutaneous administration of 10 µg Ova, sublingual administration of 5 and 10 µg Ova loaded in PLGA NPs, 5 and 10 µg Ova loaded in mannose-targeted PLGA NPs, 10 µg Ova, and 10 µg Ova loaded in dendritic cell-specific aptamer-attached PLGA NPs. Serum Ova-specific IgE and IgG2a levels, as well as IFN-γ, IL-4, IL-10, and IL-17a levels in the supernatant of Ova-stimulated splenocytes were measured. Splenocyte proliferation was assessed using an MTT assay, and also lung histological examinations, and nasal lavage fluid cell counting were performed. Results Ova-specific IgE, IL-4, IL-17a levels, eosinophil cell count, and splenocyte proliferation were remarkably reduced in the mice treated with mannose or aptamer targeted NPs compared to other groups. Also, IL-10 and IFN-γ levels were remarkably increased in the targeted NPs groups. Conclusion Our findings indicated that mannose targeting of PLGA NPs could decrease allergen dose and improve immunomodulatory effects of SLIT. However, this approach suggests an effective formulation for SLIT in the mice model, further studies with common allergens are needed for application in humans.

The function and mechanism of Human nasal mucosa-derived mesenchymal stem cells in allergic rhinitis in mice.

To investigate the immunomodulatory effects and potential mechanisms of human nasal mucosa-derived mesenchymal stem cells(hNMSCs) on mouse allergic rhinitis, and to compare them with human umbilical cord-derived mesenchymal stem cells (hUCMSCs). hNMSCs and hUCMSCs were isolated and cultured for identification from human nasal mucosa and umbilical cord tissues. A co-culture system of LPS-stimulated RAW264.7 cells/mouse peritoneal macrophages and MSCs was employed.Changes in inflammatory factors in RAW264.7 cells and the culture medium as well as the expression of NF-κB signaling pathway in RAW264.7 cells were detected. Forty-eight BALB/c mice were randomly divided into control, OVA, hNMSCs, and hUCMSCs groups. An allergic rhinitis (AR) model was established through ovalbumin (OVA) stimulation and treated with hNMSCs and hUCMSCs. Subsequent assessments included related symptoms, biological changes, and the expression of the NF-κB signaling pathway in the nasal mucosa of mice. MSCs can be successfully isolated from human nasal mucosa. Both hNMSCs and hUCMSCs interventions significantly reverseed the inflammation induced by LPS and suppressed the upregulation of the NF-κB signaling pathway in RAW264.7 cells. Treatment with hNMSCs and hUCMSCs alleviated mouse allergic symptoms, reduced levels of total IgE, OVA-specific IgE and IgG1 in mouse serum, TH2-type cytokines and chemokines in mouse nasal mucosa, and TH2-type cytokines in mouse spleen culture medium, while also inhibiting the expression of the NF-κB signaling pathway in the nasal mucosa of mice. moreover, the hNMSCs group showed a more significant reduction in OVA-specific IgG1 in serum and IL-4 expression levels in mouse spleen culture medium compared to the hUCMSCs group. Our findings suggest that hNMSCs can ameliorate allergic rhinitis in mice, with a certain advantage in anti-inflammatory effects compared to hUCMSCs. The NF-κB pathway is likely involved in the anti-inflammatory regulation process by hNMSCs.Therefore, hNMSCs might represent a novel therapeutic approach for allergic rhinitis.

Rosuvastatin attenuates airway inflammation and remodeling in a chronic allergic asthma model through modulation of the AMPKα signaling pathway.

The efficacy of rosuvastatin in reducing allergic inflammation has been established. However, its potential to reduce airway remodeling has yet to be explored. This study aimed to evaluate the efficacy of rosuvastatin in reducing airway inflammation and remodeling in a mouse model of chronic allergic asthma induced by sensitization and challenge with OVA. Histology of the lung tissue and the number of inflammatory cells in bronchoalveolar lavage fluid (BALF) showed a marked decrease in airway inflammation and remodeling in mice treated with rosuvastatin, as evidenced by a decrease in goblet cell hyperplasia, collagen deposition, and smooth muscle hypertrophy. Furthermore, levels of inflammatory cytokines, angiogenesis-related factors, and OVA-specific IgE in BALF, plasma, and serum were all reduced upon treatment with rosuvastatin. Western blotting was employed to detect AMPK expression, while immunohistochemistry staining was used to observe the expression of remodeling signaling proteins such as α-SMA, TGF-β, MMP-9, and p-AMPKα in the lungs. It was found that the activity of 5'-adenosine monophosphate-activated protein kinase alpha (AMPKα) was significantly lower in the lungs of OVA-induced asthmatic mice compared to Control mice. However, the administration of rosuvastatin increased the ratio of phosphorylated AMPK to total AMPKα, thus inhibiting the formation of new blood vessels, as indicated by CD31-positive staining mainly in the sub-epithelial region. These results indicate that rosuvastatin can effectively reduce airway inflammation and remodeling in mice with chronic allergic asthma caused by OVA, likely due to the reactivation of AMPKα and a decrease in angiogenesis.

The effect of Bruton’s tyrosine kinase (BTK) inhibitor in the eosinophilic asthma model of mouse

Bruton’s Tyrosine kinase (BTK) plays a pivotal role as the key mediator in B cell signaling. Recent research has revealed that it is also expressed in cells critical to asthma development, such as T cells, and eosinophils. This study aims to investigate the potential of BTK inhibitor in eosinophilic asthma mouse model. BALB/c mice were sensitized with ovalbumin (OVA) via intraperitoneal injections and followed by OVA nebulizations. The mice were treated with 250 µg/ml or 500 µg/ml of ibrutinib before the second intraperitoneal injection and the first nebulization. Two days after the last OVA challenge, airway hyperresponsiveness (AHR) was assessed with methacholine, and differential cell count in bronchoalveolar lavage fluid (BALF) was performed. The cytokines were measured in BALF, and serum OVA-specific IgE and IgG antibody levels were evaluated by ELISA. The inhibitory effect of ibrutinib was also evaluated in splenic mononuclear cells, mast cells, eosinophils, and T cells in vitro. Treatment with ibrutinib significantly attenuated AHR and airway inflammation, compared to the OVA-induced positive control. The treatment also reduced IL-4, IL-5, IL-13 and IFN-γ cytokine levels and suppressed OVA-specific IgE and IgG production compared to the OVA-induced positive control. Additionally, ibrutinib decreased beta-hexosaminidase release from mast cells, type 2 cytokine productions from mononuclear cells and T cells, and eosinophilic activation markers in vitro. The results of this study suggest that ibrutinib treatment could exert anti-allergic effects by inactivating B cells and other BTK-expressing cells. Further studies are needed to investigate the potential therapeutic effect of ibrutinib on allergic diseases.

Monotropein Alleviates Ovalbumin-Induced Asthma in Mouse Model by Inhibiting AKT/NF-κB Pathway

Introduction: Clinical management of asthma remains as a prevalent challenge. Monotropein (MON) is a naturally occurring cyclic enol ether terpene glycoside with medical application potential. This study aims to evaluate the potential therapeutic effects of MON in the mouse model of chronic asthma. Methods: An ovalbumin (OVA)-induced asthmatic mouse model was established to evaluate the therapeutic effect of MON at different doses (20, 40, and 80 mg/kg). The potential involvement of protein kinase B (AKT)/nuclear factor kappa B (NF-κB) pathway in the effect of MON was investigated by the administration of an AKT activator SC79. Histological changes in pulmonary tissues were examined by hematoxylin and eosin staining. The profiles of inflammatory cytokines (interleukin [IL]-4, IL-5, IL-13, and tumor necrosis factor [TNF]-α) in bronchoalveolar lavage fluid (BALF), and OVA-specific IgE in blood samples were analyzed by enzyme-linked immunosorbent assay (ELISA). The oxidative stress in the lung tissues was determined by measuring malondialdehyde level. The phosphorylation activation of AKT and NF-κB was examined by immunoblotting in the lung tissues. Results: MON treatment suppressed the infiltration of inflammatory cells in the airways of OVA-induced asthma mice and reduced the thickness of the bronchial wall and smooth muscle layer in a dose-dependent manner. MON treatment also reduced the levels of OVA-specific IgE in serum and cytokines in BALF in asthma-induced mice, and attenuated the oxidative stress in the lung tissues. OVA induced the phosphorylation of AKT and NF-κB proteins in the lung tissues of asthmatic mice, which was significantly suppressed by MON treatment. The co-administration of AKT activator SC79 impaired the therapeutic effect of MON on asthma-induced mice. Conclusion: Our data demonstrated the potential therapeutic effect of MON on asthmatic mouse model, suggesting that MON attenuated the inflammatory and oxidative damages in ling tissues by dampening the AKT/NF-κB signaling pathway.

Morita-Baylis-Hillman adduct 2-(3-hydroxy-1-methyl-2-oxoindolin-3-il) acrylonitrile (CISACN) ameliorates the pulmonary allergic inflammation in CARAS model by increasing IFN-γ/IL-4 ratio towards the Th1 immune response

Combined allergic rhinitis and asthma syndrome (CARAS) is an airway-type 2 immune response with a profuse inflammatory process widely affecting the world population. Due to the compromise of quality of life and the lack of specific pharmacotherapy, the search for new molecules becomes relevant. This study aimed to evaluate the effectiveness of the Morita-Bailys-Hillman adduct (CISACN) treatment in the CARAS experimental model. Female BALB/c mice were ovalbumin (OVA) -sensitized and -challenged and treated with CISACN. The treatment decreased the eosinophil migration to the nasal and lung cavities and tissues and the goblet cell hyperplasia/hypertrophy, attenuated airway hyperactivity by reducing the hyperplasia/hypertrophy of the smooth muscle and the extracellular matrix's thickness. Also, the treatment reduced the clinical signs of rhinitis as nasal rubbing and sneezing in a histamine-induced nasal hyperreactivity assay. The immunomodulatory effect of CISACN was by reducing OVA-specific IgE serum level, and IL-33, IL-4, IL-13, and TGF-β production, dependent on IFN-γ increase. Furthermore, the effect of CISACN on lung granulocytes was by decreasing the p-p38MAPK/p65NF-κB signaling pathway. Indeed, CISACN reduced the p38MAPK and p65NF-κB activation. These data demonstrated the anti-inflammatory and immunomodulatory effects of the CISACN with scientific support to become a pharmacological tool to treat airway inflammatory diseases.

Kechuanning Gel Plaster Exerts Anti-inflammatory and Immunomodulatory Effects on Ovalbumin-induced Asthma Model Rats via ERK Pathway.

We aimed to evaluate the therapeutic effects of Kechuanning gel plaster on ovalbumin (OVA)-induced rat model of asthma. Rats were injected with OVA to induce asthma, and Kechuanning gel plaster was administered after the OVA challenge. The immune cell counts in the bronchial alveolar lavage fluid (BALF) were calculated after Kechuanning gel plaster administration. The levels of immune factors in BALF and serum OVA-specific IgE levels were analyzed. Western blot analysis and immunohistochemistry were carried out to analyze the following proteins: C-FOS, C-JUN, RAS p21 protein activator 1 (RASA1), matrix metalloproteinase 9 (MMP9), RAF1, p-MEK1, tissue inhibitor of metalloproteinase-1 (TIMP1), and p-extracellular signal-regulated kinase 1 (ERK1). Administration of Kechuanning gel plaster led to decreased immune cell counts, inflammatory cytokines (interleukin (IL)-1β, IL13, and IL17), and OVA-specific IgE expression. Compared to the normal group, the C-FOS, C-JUN, RASA1, MMP9, RAF1, MEK1, TIMP1, and p- ERK1 expressions in the model group were significantly increased, whereas Kechuanning gel plaster administration decreased C-JUN, MMP9, TIMP1, RAF1, MEK1, p-ERK1, C-FOS, and RASA1 protein levels. Kechuanning gel plaster exerted its therapeutic effects on OVA-induced asthma model rats through the ERK signaling pathway. Kechuanning gel plaster could be considered as a potential alternative therapeutic agent for the management of asthma.

Study the involvement of Langerin in mediating epicutaneous sensitization of atopic dermatitis-like mouse model

Objective: To explore the role of Langerin in mediating epicutaneous sensitization of atopic dermatitis (AD) in mouse model. Methods: Mice were topically treated with calcipotriol (MC903) plus ovalbumin (OVA) on the ears to establish AD mouse models, and mice were divided into wild-type control group, wild-type AD group, Langerin knockout control group, and Langerin knockout AD group. Changes of lesion were daily observed. Infiltration of inflammatory cells, mRNA expression of Tslp, Il4, Il13, Il17a, and Il22, levels of serum total IgE, OVA-specific IgE (sIgE), OVA sIgG1 and OVA sIgG2a, proportion of regulatory T (Treg) cells in cervical draining lymph nodes were evaluated at the end of model preparation. Results: Skin tumidness and thickness, dermal inflammatory cells infiltration, the mRNA expression levels of Tslp, Il4, Il13, Il17a and Il22 in wild-type AD groups were higher than those in wild-type control groups, with (1.80±0.66, 1.64±0.25, 1.71±0.54, 2.41±0.23, 2.49±0.32) and (0.53±0.45, 0.85±0.29, 0.73±0.50, 0.72±0.25, 0.56±0.29), respectively (all P<0.05). In addition, the levels of serum total IgE, OVA sIgE and OVA sIgG1 in wild-type AD groups were higher than those in wild-type control groups, with [(1 216.00±572.70) ng/ml, (597.00±538.30) ng/ml, 1.59±0.09] and [(24.22±35.04) ng/ml, (20.01±41.71) ng/ml, 1.16±0.03], respectively (all P<0.05). In Langerin knockout mice, compared to wild-type mice, skin erythema, skin tumidness, epidermal thickening, inflammatory cell infiltration were more obvious; the mRNA expression levels of Tslp, Il4, Il13, Il17a and Il22 were upregulated with (8.19±6.44, 2.53±0.69, 2.82±0.73, 3.94±1.32, 3.80±1.43) (all P<0.05); the levels of serum total IgE, OVA sIgE and OVA sIgG1 were significantly increased with (2 508.00±657.10) ng/ml, (1 808.00±470.70) ng/ml, (1.73±0.09) (all P<0.05); the number of CD4+CD25+CD127-Treg cells were decreased significantly with (13.25±0.96)% and (15.31±1.47)%, respectively (P<0.05). Conclusion: Langerin is involved in mediating epicutaneous sensitization of the AD mouse model and plays a negative immunoregulatory role.

Qufeng Xuanbi Formula inhibited benzo[a]pyrene-induced aggravated asthma airway mucus secretion by AhR/ROS/ERK pathway

Ethnopharmacological relevanceExcessive secretion of airway mucus may be an important pathological factor of air pollution-induced acute asthma attacks. Treatment of airway mucus hypersecretion improves asthma aggravated by air pollutants. Qufeng Xuanbi Formula (QFXBF) has been used to treat asthma for more than 30 years. However, whether QFXBF inhibits asthmatic mucus secretion exacerbated by air pollutants has not yet been established. Aim of the studyThis study aimed to evaluate the effect of QFXBF on airway mucus secretion and the mechanism of action in an air pollutant benzo[a]pyrene (BaP)-induced mouse model of aggravated asthma. Materials and methodsOvalbumin (OVA) and BaP co-exposure were used to establish the aggravated asthma model. The average enhanced pause (Penh), serum OVA-specific IgE, and changes in lung histopathology were determined. 16HBE cells exposed to BaP, treatment with QFXBF, arylhydrocarbon receptor (AhR) signal antagonist SR1, reactive oxygen species (ROS) antagonist NAC, or extracellular signal-regulated kinase (ERK1/2) signal antagonist U0126 were established to investigate the effect of QFXBF on BaP-induced mucus secretion and its target. The mRNA and protein expression levels of MUC5AC in the lung tissue and 16HBE cells were examined. We also studied the effect of QFXBF on ROS production. Finally, the protein expression of AhR, phospho-extracellular signal-regulated kinases (p-ERK1/2), and ERK1/2 in 16HBE cells and lung tissues was determined by western blotting. ResultsAdministration of QFXBF significantly alleviated the pathological symptoms, including Penh, serum OVA-specific IgE, and changes in lung histopathology in a BaP-induced mouse model of aggravated asthma. QFXBF inhibited MUC5AC expression in asthmatic mice and 16HBE cells exposed to BaP. ROS production, AhR expression, and ERK1/2 phosphorylation were significantly increased in BaP-induced asthmatic mice and 16HBE cells. Signaling pathway inhibitors StemRegenin 1 (SR1), NAC, and U0126 significantly inhibitedBaP-induced MUC5AC expression in 16HBE cells. SR1 reversed Bap-induced ROS production and ERK activation, and NAC inhibited Bap-induced ERK activation. In addition, QFXBF regulated AhR signaling, inhibited ROS production, reversed ERK activation, and downregulated mucus secretion to improve asthma aggravated by air pollutant BaP. ConclusionsQFXBF can ameliorate mucus secretion in BaP-induced aggravated asthmatic mice and 16HBE cells, and the specific mechanism may be related to the inhibition of the AhR/ROS/ERK signaling pathway.

Chemical constituents from the flowers of Inula japonica and their anti-inflammatory activity

Ethnopharmacological relevanceThe flowers of Inula japonica (Inulae Flos) can be used to treat cough and asthma and remove phlegm in traditional Chinese medicine (TCM). Aim of the studyOur research aimed to obtain active components with the inhibition of inflammation and MUC5AC production to alleviate asthma symptoms from I. japonica. Materials and methodsThese compounds were separated from the MeOH extract of Inulae Flos by column chromatography over silica gel, AB-8 macroporous resin column, MPLC, and semipreparative HPLC. Their structures were elucidated by detailed spectroscopic data analysis, ECD calculations, and chemical methods. NO production was determined to evaluate anti-inflammatory activity in RAW 264.7 cells. The expression of MUC5AC, IL-1β, and IL-4 were measured in NCI–H292 cells by qRT-PCR. The anti-asthma activity assessments in vivo were performed through H & E and PAS staining, pulmonary function analysis, and cytokines determination by qRT-PCR or ELISA. The expression levels of PI3K, p-PI3K, AKT, p-AKT, MEK, p-MKE, ERK, p-MEK, and IL-1β were analyzed through western blotting. ResultsOne undescribed 1,10-seco-eudesmanolide derivative (1), two previously unreported 1,10-seco-eudesmanolide glycosides (2 and 3), and thirty-two known compounds (4–35) were obtained from Inulae Flos. Compound 11 had the most inhibitory effect against LPS-induced NO production in RAW 264.7 murine macrophages. Meanwhile, compound 11 also attenuated the increase in MUC5AC, IL-1β, and IL-4 mRNA expression in NCI–H292 cells. The results of the animal experiment confirmed that compound 11 significantly ameliorated OVA-induced asthma in a murine model of allergic asthma demonstrated by elevated pulmonary function, reduced inflammatory cell infiltration and mucus production. In addition, compound 11 significantly inhibited the levels of OVA-specific IgE in serum, of IL-4 and IL-6 in BALF, and of MUC5AC, IL-1β , IL-4, IL-5, IL-6 and IL-13 in lung tissue. Finally, compound 11 suppressed PI3K/AKT/MEK/ERK signaling pathway in lung tissue of mice. ConclusionThis study indicated that compound 11 might be a potential therapeutic candidate ameliorating airway inflammation and mucus hypersecretion via PI3K/AKT/MEK/ERK signaling pathway in allergic asthma.

Blocking Th2 Signaling Pathway Alleviates the Clinical Symptoms and Inflammation in Allergic Conjunctivitis.

To explore the role of Th2 signaling pathway in allergic conjunctivitis (AC). Serum Th2 cytokines IL-4 or IL-13 of patients with AC were detected using the Meso scale discovery assay to verify the correlation of Th2 immunity and AC pathogenesis. Wistar Han rats were intraperitoneally and subcutaneously injected with ovalbumin (OVA) to establish an experimental AC model and the Th2 signaling pathway was blocked by an investigational neutralizing antibody (CM310). Serum IgE and OVA-specific IgE were detected by ELISA. Conjunctivitis inflammation, infiltration of eosinophils, and mast cell degranulation were detected by histological examination. Immortalized human conjunctival epithelial cells, a conjunctival epithelial cell line, and peripheral blood mononuclear cells of patients with AC were used as the target cells to study the impact of IL-4 or IL-13 on AC progression. Finally, a STAT6 reporter gene system was constructed using immortalized human conjunctival epithelial cells to confirm whether the downstream signaling pathway activated by IL-4 or IL-13. Serum IL-4 or IL-13 were increased in patients with AC versus healthy individuals. In an OVA-induced rat experimental AC model, blocking the Th2 signaling pathway with CM310, an investigational neutralizing antibody, alleviated the conjunctival symptoms, and decreased serum IgE, suppressed infiltration of eosinophils and mast cell degranulation. Further, an in vitro model showed CM310 suppressed the secretion of inflammatory cytokine from both immune cells and epithelial cells in both patients peripheral blood mononuclear cells and cell line. Blocking Th2 signaling pathway alleviates the clinical symptoms and inflammation in AC.

Effects of total alkaloids from Alstonia scholaris (L.) R. Br. on ovalbumin-induced asthma mice

Ethnopharmacological relevanceMore than 300 million people worldwide suffer from asthma, a chronic respiratory inflammatory disease. Total alkaloids (TA) were extracted from the ethnic medicinal plant Alstonia solaris (L.) R.Br., which is used to treat respiratory diseases. They may be effective drugs for treating asthma, but research is still needed to determine their effectiveness and mechanism in treating asthma. Aim of the studyTo further understand TA's role in the treatment of asthma and to support the phase II trial of the drug. Materials and methodsIn this study, we investigated the effects of TA in a mouse asthma model produced by Ovalbumin (OVA). H&E and PAS staining were used to observe the histopathological features of lung. airway hyperresponsiveness (AHR) was detected by ventilator; The expression of interleukin (IL)-33, suppression of tumorigenicity 2 (ST2) and E-cadherin in the lungs was evaluated by IHC. The concentrations of Mucin5AC (MUC5AC), eotaxin, IL-4, IL-5, IL-9, IL-13, interferon (IFN)-γ, IL-6, IL-8, IL-17A, IL-33, IL-25, thymic stromal lymphopoietin (TSLP), monocyte chemoattractant protein 1 (MCP-1), leukotriene (LT) B4, LTC4, LTD4, LTE4 in bronchoalveolar lavage fluid (BALF) and total IgE (tIgE), OVA-Specific IgE (OVA-IgE) in serum were measured by ELISA. ILC2s and eosinophils were detected in lung tissue by flow cytometry. The gene expression levels of IL-33 and ST2 were detected by RT-qPCR. ResultsAdministration of TA reduced pulmonary inflammatory symptoms, MUC5AC production in the BALF, and AHR. At the same time, TA inhibited eotaxin production and eosinophil recruitment. Moreover, TA significantly decreased Th2 and Th17 cytokines and increased Th1 cytokines, contributing to restore the balance between Th1 and Th2 and Th17 cytokines. TA may reduce ILC2s numbers by inhibiting IL-33, IL-25, and TSLP levels in BALF and IL-33/ST2 signaling in lung tissue. Finally, TA decreased tIgE, OVA-IgE, and MCP-1 levels and subsequently inhibited mast cell activation and leukotriene release. ConclusionsThese findings imply that TA may be an effective immunoregulatory medication for the management and prevention of asthma.

Deficiency of leukotriene B4 receptor type 1 ameliorates ovalbumin-induced allergic enteritis in mice.

Leukotriene B4 receptor type 1 (BLT1), a high-affinity receptor for leukotriene B4 (LTB4), plays an important role in inflammatory responses, including allergic airway inflammation. In this study, we examined the effect of genetic BLT1 deletion (BLT1KO) on ovalbumin (OVA)-induced allergic enteritis in mice to determine the pathogenic role of LTB4/BLT1 in allergic enteritis, a gastrointestinal form of food allergy. Repeated oral OVA challenges after sensitization with OVA and aluminium potassium sulphate induced allergic enteritis, characterized by systemic allergic symptoms (scratching, immobility and swelling), diarrhoea, colonic oedema and colonic goblet cell hyperplasia, accompanied by increased colonic peroxidase activity, colonic inflammatory cytokine expression and increased serum OVA-specific IgE levels. The severity of enteritis was significantly attenuated in BLT1KO mice compared with wild-type (WT) mice, without an increase in serum OVA-specific IgE levels. The accumulation of neutrophils, eosinophils, M2-macrophages, dendritic cells, CD4+ T cells and mast cells was observed in the colonic mucosa of allergic enteritis, and such accumulation was significantly lower in BLT1KO mice than in WT mice. BLT1 expression was upregulated and colocalized mostly in neutrophils and partly in eosinophils and dendritic cells in the colonic mucosa of allergic enteritis. These findings indicate that BLT1 deficiency ameliorates OVA-induced allergic enteritis in mice and that LTB4/BLT1 contributes to neutrophil and eosinophil accumulation in the allergic colonic mucosa. Therefore, BLT1 is a promising drug target for treating food allergies.

Sublingual prophylactic administration of OVA-loaded MSC-derived exosomes to prevent allergic sensitization

AimThis study evaluated the immunomodulatory and delivery potential of adipose tissue-isolated MSC-derived exosomes as a prophylactic regimen through a sublingual route in the ovalbumin (OVA)-induced allergic asthma murine model. Material and methodsBalb/c mice received 10 μg/dose of OVA-enriched MSC-derived exosomes as a prophylactic regimen in six doses during three weeks, and then OVA sensitization was conducted through intraperitoneal and aerosol administration of allergen. The total cells and eosinophils counted in nasal lavage fluid (NALF) and lung tissues were assessed for histopathological analysis. In addition, the secretion of IFN-γ, IL-4, and TGF-β by spleen cells and serum OVA-specific IgE levels were measured via ELISA. ResultsSignificant reduction in the IgE levels and IL-4 production, along with elevated TGF-β levels, were observed. Also, limited cellular infiltrations and perivascular and peribronchiolar inflammation in the lung tissues and normal total numbers of cells and eosinophils in the NALF were reported. ConclusionProphylactic regimen using OVA-enriched MSC-derived exosomes modulated immune responses and inhibited allergic OVA sensitization.

PM2.5 exposure regulates Th1/Th2/Th17 cytokine production through NF-κB signaling in combined allergic rhinitis and asthma syndrome

Particulate matter (PM) is a major component of air pollution from emissions from anthropogenic and natural sources and is a serious problem worldwide due to its adverse effects on human health. Increased particulate air pollution increases respiratory disease-related mortality and morbidity. However, the impact of PM with an aerodynamic diameter of≤2.5μm (PM2.5) on combined allergic rhinitis and asthma syndrome (CARAS) remains to be elucidated. Accordingly, in the present study, we investigated the effect of PM2.5 in an ovalbumin (OVA)-induced CARAS mouse model with a focus on NF-κB signaling. We established an OVA-induced mouse model of CARAS to determine the effects of exposure to PM2.5. BALB/c mice were randomly divided into four groups: (1) naive, (2) PM2.5, (3) CARAS, and (4) CARAS/PM2.5. Mice were systemically sensitized with OVA and challenged with inhalation of ultrasonically nebulized 5% OVA three times by intranasal instillation of OVA in each nostril for 7 consecutive days. Mice in the PM2.5 and CARAS/PM2.5 groups were then exposed to PM2.5 by intranasal instillation of PM2.5 for several days. We then examined the impacts of PM2.5 exposure on histopathology and NF-κB signaling in our OVA-induced CARAS mouse model. PM2.5 increased infiltration of eosinophils in bronchoalveolar lavage fluid (BALF) samples and inflammatory cells in lung tissue. It also increased production of GATA3, RORγ, IL-4, IL-5, IL-13, and IL-17 in nasal lavage fluid (NALF) and BALF samples in the CARAS mouse model, but secretion of IL-12 and IFN-γ was suppressed. Exposure to PM2.5 increased OVA-specific IgE and IgG1 levels in serum, inflammatory cell infiltration in the airways, and fibrosis in lung tissue. It also activated the NF-κB signaling pathway, increasing Th2/Th17 cytokine levels while decreasing Th1 cytokine expression, thereby inducing an inflammatory response and promoting inflammatory cell infiltration in nasal and lung tissue. Our results demonstrate that PM2.5 can aggravate OVA-induced CARAS.

A non-invasive strategy for suppressing asthmatic airway inflammation and remodeling: Inhalation of nebulized hypoxic hUCMSC-derived extracellular vesicles.

Mesenchymal stromal cell-derived extracellular vesicles (MSC-EVs) are extremely promising nanoscale cell-free therapeutic agents. We previously identified that intravenous administration (IV) of human umbilical cord MSC-EVs (hUCMSC-EVs), especially hypoxic hUCMSC-EVs (Hypo-EVs), could suppress allergic airway inflammation and remodeling. Here, we further investigated the therapeutic effects of Hypo-EVs administration by atomizing inhalation (INH), which is a non-invasive and efficient drug delivery method for lung diseases. We found that nebulized Hypo-EVs produced by the atomization system (medical/household air compressor and nebulizer) maintained excellent structural integrity. Nebulized Dir-labeled Hypo-EVs inhaled by mice were mainly restricted to lungs. INH administration of Hypo-EVs significantly reduced the airway inflammatory infiltration, decreased the levels of IL-4, IL-5 and IL-13 in bronchoalveolar lavage fluid (BALF), declined the content of OVA-specific IgE in serum, attenuated the goblet cell metaplasia, and the expressions of subepithelial collagen-1 and α-smooth muscle actin (α-SMA). Notably, Hypo-EV INH administration was generally more potent than Hypo-EV IV in suppressing IL-13 levels and collagen-1 and α-SMA expressions. RNA sequencing revealed that various biological processes, such as cell adhesion, innate immune response, B cell activation, and extracellular space, were associated with the activity of Hypo-EV INH against asthma mice. In addition, Hypo-EVs could load exogenous miR-146a-5p (miR-146a-5p-EVs). Furthermore, INH administration of miR-146a-5p-EVs resulted in a significantly increased expression of miR-146a-5p mostly in lungs, and offered greater protection against the OVA-induced increase in airway inflammation, subepithelial collagen accumulation and myofibroblast compared with nebulized Hypo-EVs. Overall, nebulized Hypo-EVs effectively attenuated allergic airway inflammation and remodeling, potentially creating a non-invasive route for the use of MSC-EVs in asthma treatment.

Topical Administration of Gardenia jasminoides Extract Regulates Th2 Immunity in OVA-Induced Mice.

A key feature of an allergic immune response is a T helper type 2 (Th2)-mediated response with production of allergen-specific IgE antibodies. Gardenia jasminoides extract with the crocin removed (GJExCR) has been shown to inhibit IgE-mediated allergic disease. To evaluate the efficacy and mechanism-of-action of this inhibition, GJExCR was used in an ovalbumin (OVA)-induced allergy model in BALB/C mice. Sensitization of BALB/C mice with OVA and aluminum hydroxide was performed on days 1 and 14 by intraperitoneal injection, followed by OVA challenge to the dorsal skin for 2 weeks before removal. Seven days post-challenge, mice were treated with GJExCR topically every day for 11 days. Enzyme-linked immunosorbent assay, flow cytometry analysis, real-time PCR, and western blot were performed to determine IgE and Th2 cytokine levels. Following OVA challenge, Th2 cytokine expression and both total and OVA-specific serum IgE levels increased, of which OVA-specific IgE and Th2 cytokine levels decreased after GJExCR treatment. Flow cytometry analysis revealed that GJExCR treatment decreased CD4+ and CD8+ T cell populations in the spleen and lymph nodes. In addition, treatment with GJExCR downregulated signal transducer and activator of transcription 1 (STAT1) activation and Th2 cytokine levels as compared to control. GJExCR containing geniposide downregulated STAT1 activation in HaCaT cells. These findings demonstrate that GJExCR exerts its anti-allergy effect via inhibition of STAT1 activation, thus regulating the immune response via modulation of Th2 cytokine release and IgE levels. Therefore, we propose GJExCR as a potential treatment for allergic hypersensitivity reactions.

Immune response modulation by allergen loaded into mesenchymal stem cell-derived exosomes as an effective carrier through sublingual immunotherapy

BackgroundAllergen-specific sublingual immunotherapy (SLIT) was considered an interesting needle-free alternative for subcutaneous immunotherapy (SCIT). Mesenchymal stem cell (MSC)-derived exosomes were introduced as potent nanoscale delivery systems with immunomodulatory potentials. The current study investigated the therapeutic efficacy of SLIT using ovalbumin (OVA)-enriched MSC-derived exosomes formulation in a murine model of allergic asthma. Material and methodsMSCs were harvested from mice adipose tissues. Then, exosomes were isolated, and OVA-loaded exosomes were prepared. Following sensitization, Balb/c mice received therapeutic formulation (10 μg/dose OVA-containing MSC-derived exosomes) twice a week for two months. Serum OVA-specific IgE levels as well as IFN-γ, IL-4, and TGF-β secretions by cultured splenocytes were measured by ELISA. Also, lung tissue underwent histopathologic analysis, and the numbers of inflammatory cells and eosinophils in nasopharyngeal lavage fluid (NALF) were examined. ResultsSLIT using OVA-enriched exosomes significantly reduced IgE levels and IL-4 production, while the secretion of IFN-γ and TGF-β were significantly elevated. Also, a decrease was observed in the numbers of total cells and eosinophils in the NALF, and lower levels of perivascular and peribronchiolar inflammation and cellular infiltrations were observed in the lung tissue. ConclusionSLIT using OVA-loaded exosomes improved immunomodulatory responses and efficiently alleviated allergic inflammation.

Bufotalin ameliorates ovalbumin-induced allergic rhinitis by restoring the Tregs.

Allergic rhinitis (AR) is one of the most common inflammatory diseases. IgE, inflammatory cytokine production and Th17/Tregs imbalance have been implicated in AR pathogenesis. Bufotalin, a component extracted from toad venom skin secretions and auricular glands, has anti-inflammatory activity and regulates Th17/Tregs balance. Here, the effects of bufotalin on AR were explored. The AR mice model was established using ovalbumin (OVA). AR mice were treated with bufotalin started on Day 22 with various doses (1, 10, 100μg or 1mg per mouse) every day to Day 30. The sneezing and rubbing frequencies were counted. Serum levels of IL-1β, IL-10 and OVA-specific IgE were measured. The superficial cervical lymph nodes were harvested and the percentage of Tregs in lymph node was determined using CD4 and Foxp3 markers. OVA treatment successfully induced AR model in mice with significantly increased sneezing and rubbing frequency, elevated levels of serum histamine, IL-1β, IL-10 and OVA-specific IgE. Bufotalin treatment significantly ameliorated AR symptoms, with reduced histamine, IgE and IL-1β levels, as well as sneezing and rubbing frequency. Moreover, bufotalin treatment decreased the serum levels of IL-1β, IL-10 and OVA-specific IgE in AR mice. Bufotalin ameliorated allergic rhinitis symptoms in AR mice by restoring Tregs in lymph node.

A retro-inverso modified peptide alleviated ovalbumin-induced asthma model by affecting glycerophospholipid and purine metabolism of immune cells

Allergic asthma is a heterogeneous disease involving a variety of inflammatory cells. Immune imbalance or changes in the immune microenvironment are the essential causes that promote inflammation in allergic asthma. Tetraspanin CD81 can be used as a platform for receptor clustering and signal transmission owing to its special transmembrane structure and is known to participate in the physiological processes of cell proliferation, differentiation, adhesion, and migration. Previous studies have shown that CD81-targeting peptidomimetics exhibit anti-allergic lung inflammation. However, due to the low metabolic stability of peptide drugs, their druggability is limited. Here, we aimed to generate a metabolically stable anti-CD81 peptide, evaluate its anti-inflammatory action and establish its mechanism of action. Based on previous reports, we applied retro-inverse peptide modification to obtain a new compound, PD00 (NH2-D-Gly-D-Ser-D-Thr-D-Tyr-D-Thr-D-Gln-D-Gly-COOH), with high metabolic stability. Enhanced ultraperformance liquid chromatography–tandem mass spectrometry was used to investigate the in vitro and in vivo metabolic stabilities of PD00. The affinities of PD00 and CD81 were studied using molecular docking and surface plasmon resonance techniques. An ovalbumin (OVA)-induced asthma model was used to evaluate the effects of PD00 in vivo. Mice were treated with different concentrations of PD00 (175 and 350 μg/kg) for 10 days. Airway hyperresponsiveness (AHR) to acetyl-β-methacholine (Mch), inflammatory cell counts in the bronchoalveolar lavage fluid, and serum OVA-specific IgE levels were detected in the mice at the end of the experiment. Lung tissues were collected for haematoxylin and eosin staining, untargeted metabolomic analysis, and single-cell transcriptome sequencing. PD00 has a high affinity for CD81; therefore, administration of PD00 markedly ameliorated AHR and airway inflammation in mice after OVA sensitisation and exposure. Serum OVA-specific IgE levels decreased considerably. In addition, PD00 treatment increased glycerophospholipid and purine metabolism in immune cells. Collectively, PD00 may regulate the glycerophospholipid and purine metabolism pathways to ameliorate the pathophysiological features of asthma. These findings suggest that PD00 is a potential compound for the treatment of asthma.