Antiallergic effect of anti-Siglec-F through reduction of eosinophilic inflammation in murine allergic rhinitis

Undaria pinnatifida ameliorates nasal inflammation by inhibiting eosinophil and mast cell activation and modulating the NF-κB/MAPKs signaling pathway

BACKGROUND

Allergic rhinitis (AR) is the most prevalent form of atopic disease. Undaria pinnatifida has potent antioxidative, antidiabetic, and anti-inflammatory properties.

AIMS

We investigated the immunomodulatory effect of Undaria pinnatifida extract (UPE) on allergic inflammation in an AR mouse model.

MATERIALS & METHODS

Mice were sensitized and intranasally challenged with ovalbumin (OVA), and the Th1/Th2 and Th17/Treg-related cytokines and histopathology were exanimated after UPE treatments. Enzyme-linked immunosorbent assay was performed using serum samples and NALF to detect OVA-specific immunoglobulins and inflammatory cytokines. Mitogen-activated protein kinases (MAPKs) were measured by western blotting analysis, and an in vitro study measured mast cell activation induced by compound 48/80.

RESULTS

After UPE treatment, nasal and lung allergy symptoms, nasal mucosal swelling, and goblet cell hyperplasia were ameliorated. Oral UPE regulated the balance of Th1/Th2 and Th17/Treg cell differentiation in AR mice in a dose-dependent manner. In addition, UPE attenuated the migration of eosinophils and mast cells to the nasal mucosa by suppressing nuclear factor kappa B (NF-κB)/MAPKs. The levels of anti-OVA IgE and IgG1 were also decreased.

DISCUSSION

UPE inhibited inflammation by regulating the NF-κB/MAPKs signaling pathway and supressing the activation of critical immune cells such as eosinophils and mast cells.

CONCLUSION

UPE may have therapeutic potential for AR.

Vectorized Human Antibody-Mediated Anti-Eosinophil Gene Therapy

Chronic hypereosinophilia, defined as persistent elevated blood levels of eosinophils ≥1,500/μL, is associated with tissue infiltration of eosinophils and consequent organ damage by eosinophil release of toxic mediators. The current therapies for chronic hypereosinophilia have limited success, require repetitive administration, and are associated with a variety of adverse effects. As a novel approach to treat chronic hypereosinophilia, we hypothesized that adeno-associated virus (AAV)-mediated delivery of an anti-human eosinophil antibody would provide one-time therapy that would mediate persistent suppression of blood eosinophil levels. To assess this hypothesis, we first generated a human monoclonal antibody (mAb) directed against Siglec8, a sialic-acid binding immunoglobulin-like lectin, expressed at high levels on the cell surface of human eosinophils. Transgenic mice with a human immunoglobulin repertoire were immunized with human Siglec8 protein or DNA encoding human Siglec8. Based on target binding assessments, the 08C07 mAb was chosen for further study. The human variable regions of 08C07 were joined to the human Ig constant region, creating H08C07 (hAntiEos), a fully human anti-human eosinophil mAb. Using the gene sequence of hAntiEos, we created AAVrh.10hAntiEos, an AAVrh.10-based vector expressing the heavy and light chains of H08C07. Intravenous administration of AAVrh.10hAntiEos (1011 genome copies or gc) to C57Bl/6 mice resulted in persistent elevated serum levels of hAntiEos. In vivo gene therapy generated hAntiEos bound to recombinant human Siglec8 protein in a dose-dependent manner and to human eosinophils, mediated apoptosis of human eosinophils, and antibody-dependent cellular cytotoxicity activity against human eosinophils. Consistent with these data, administration of AAVrh.10hAntiEos to human CD34+ transplanted NSG-SGM3 immunodeficient mice suppressed levels of human eosinophils in vivo. AAVrh.10hAntiEos holds the potential to offer therapeutic benefit to patients with chronic hypereosinophilia.

Recent Progress in Traditional Chinese Medicines and Their Mechanism in the Treatment of Allergic Rhinitis

Objective

To conduct a systematic review on the mechanism of action and use of traditional Chinese medicines (TCM) in allergic rhinitis treatment.

Background

Allergic rhinitis (AR) is a type I allergic disease of the immune system induced by immunoglobulin E mediated inflammation and is characterized by sneezing, nasal itching, paroxysmal nasal obstruction, mucosal edema, cough, and rhinorrhea. More than 500 million people have been affected by rhinitis worldwide in the past 20 years, leading to negative effects on health, quality of life, and social relationships. Currently, the trending medicines used in the case of AR include intranasal corticosteroids and oral H1 antihistamines, which are given as combinatorial medicines supplemented with immune therapy. These medications have been found to be very effective in either the short term or long term; however, they have been found to possess some serious side effects. Search Methodology. The information in this article on classical and traditional Chinese medications used to treat AR was derived from original papers and reviews published in Chinese and English language journals. Two Chinese databases (Wanfang and CNKI) and three English databases (Cochrane Library, PubMed, and Embase) were utilized for data gathering.

Results

Traditional Chinese remedies have been identified to influence the production of cytokines such as IL-5 and IL-6, which are key mediators of eosinophilic inflammation, TNF-α, which stimulates TH2 cells at the site of inflammation, and NF-кB, which is required for cytokine and IgE antibody production. TCM has also been shown to be successful in lowering histamine levels, preserving histological changes by decreasing the thickness of the lamina propria, and downregulating the expression of Orai1, STIM1, and TRYC1, showing low expression of Ca⁺² channel proteins.

Conclusion

In this review, we discussed a series of classical, traditional Chinese medications, including Centipeda minima, Scutellaria baicalensis, licorice root (Glycyrrhiza uralensis), and others, as potential antiallergic agents and investigate their in vivo effect upon the production of cytokines and release of histamines for allergic rhinitis treatment.

Embelin Alleviates Severe Airway Inflammation in OVA-LPS-Induced Rat Model of Allergic Asthma

BACKGROUND

Asthma is a chronic lung disease, which causes wheezing, tightness in the chest, shortness of breath and coughing. In the wake of coronavirus disease 2019 (COVID-19), which affect the lungs, asthma patients are at high risk. Embelin, a natural benzoquinone obtained mainly from Embelia ribes Burm, has excellent biological properties, including protection against acute asthma. However, since asthma is a chronic and multi-factorial inflammatory disease, asthma conferred by a single allergen in an animal may not be clinically significant. Therefore, the purpose of the current study was to evaluate the effectiveness of embelin against ovalbumin (OVA)-lipopolysaccharide (LPS)-induced severe airway inflammation in experimental animals and to investigate the plausible mechanism of action.

METHODS

Rats (n=36) were divided into six groups. Group I served as a normal control. Groups II-VI were sensitised with severe allergens (OVA and LPS) on day 7, 14 and 21, followed by OVA and LPS challenge for 30 min three times/week for 3 weeks. Group II acted as an asthmatic disease control and received only vehicle. On the other hand, groups III-V received embelin (12.5, 25 and 50 mg/kg, P.O. respectively) while group VI received a standard dexamethasone (2.5 mg/kg, P.O.) for 15 days from day 27. Lung function parameters, including the respiratory rate, tidal volume and airflow rate were measured at the end of the experiment (day 42). The total and differential counts of leukocytes in the blood and bronchoalveolar fluid (BALF) were calculated. Th2-mediated serum pro-inflammatory cytokines such as interleukin (IL)-4, IL-5 and IL-13 levels were analyzed. At the end of the study protocol, the lung tissues were removed for a histopathology study. Additionally, a molecular docking simulation on embelin and standard dexamethasone was applied to support the in vivo findings.

RESULTS

Significant inhibition of eosinophils, neutrophils, lymphocytes and monocytes in the blood and the BALF was seen in the groups, which received embelin (25 and 50 mg/kg) and dexamethasone (2.5 mg/kg). Moreover, the lung function parameters were normalised by embelin (25 and 50 mg/kg) treatment significantly. The lung histopathological changes confirmed the protective effect of embelin against severe airway inflammation. The docking findings indicated good binding efficacy of embelin to IL-13.

CONCLUSION

Overall, our findings indicate that embelin can alleviate severe airway inflammation in OVA-LPS-induced model of allergic asthma occurring by suppression of Th2-mediated immune response. Due to its promising anti-asthmatic effect, it is recommended that embelin should be investigated in clinical trials against asthma. It should also be further explored against COVID-19 or COVID-like diseases due to its ameliorative effects on cytokines and immune cell infiltration.

Chlorogenic Acid Alleviates Allergic Inflammatory Responses Through Regulating Th1/Th2 Balance in Ovalbumin-Induced Allergic Rhinitis Mice

BACKGROUND Allergic rhinitis (AR) is a prevalent atopic disorder caused by immune imbalance. Chlorogenic acid (CGA) has antibacterial, antiviral, antioxidative and immunoregulatory effects, but its role in anaphylactic disease remains unclear. The current study aimed to investigate the function of CGA in AR. MATERIAL AND METHODS AR mice models were induced with ovalbumin (OVA) by orally administrating the mice with 50 mg/kg (L-CGA), 100 mg/kg (M-CGA), or 200 mg/kg (H-CGA) of CGA. The number of nasal rubbings and sneezes was recorded. Afterward, the mice were sacrificed for the collection of blood, nasal lavage fluid (NALF), and nasal tissues. The cells in NALF were counted by hemocytometer and stained by Diff-Quick. Nasal mucosa was observed by H&E staining. ELISA testing was conducted for detecting the levels of anti-OVA antibodies and Th1/Th2-related cytokine. Quantitative real-time polymerase chain reaction experiments were conducted to determine mRNA expressions of Th1/Th2-related cytokines. RESULTS In the OVA-induced AR mice, CGA treatment reduced nasal rubbing and sneezing, and also suppressed the number of total cells, eosinophils, neutrophils, lymphocytes, macrophages, and epithelial cells in NALF. OVA-induced up-regulation of nasal mucosa thickness was inhibited by CGA, and the effects of OVA on IgE, IgG1, and IgG2a were reversed by CGA. The regulatory effects of OVA on mRNA expressions and levels of Th1/Th2-related cytokines were abolished by CGA treatment in AR mice. CONCLUSIONS CGA can alleviate allergic inflammatory responses through regulating Th1/Th2 balance in OVA-induced allergic rhinitis mice.

Preventive Effect of Bupleurum chinense on Nasal Inflammation via Suppressing T Helper Type 2, Eosinophil and Mast Cell Activation

Bupleurum chinense is distributed in East Asia and has been used as a traditional herbal medicine for more than a thousand years. Though B. chinense has been reported to have immunomodulatory, anti-inflammatory, anti-oxidant, hepato-protective, antipyretic, analgesic and antifibrotic effects, its specific effect on allergic rhinitis disease has not been clarified. In this study, we investigated the anti-allergic and anti-inflammation effects of B. chinense extract (BCE) in an ovalbumin (OVA)-induced allergic rhinitis (AR) mouse model. Oral administration of BCE in a dose-independent manner regulated the balance of Th1/Th2/Treg cell differentiation in AR mice. Accordingly, BCE attenuated the expression of Th2-related cytokines such as IL-4, IL-5 and IL-13 in nasal lavage fluid (NALF) and nasal tissue and up-regulated the secretion of Th1/Treg cells including IL-10, IL-12 and IFN-[Formula: see text]. Also, BCE inhibited the formation and migration of eosinophils to the nasal mucosa and NALF, as well as suppressed CCL24, an eosinophil-specific chemoattractant in NALF. The levels of anti-OVA specific IgE and anti-OVA specific IgG1 were decreased, and as a result, the allergic response was attenuated by BCE via inhibiting mast cells accumulation in nasal mucosa and serum histamine release. The nasal allergy symptoms, nasal mucosal swelling, epithelial barrier disruption and mucus hyperplasia were obviously ameliorated. These results suggest that BCE may have therapeutic potential for treating allergic rhinitis through modulating the accumulation and activation of important leukocytes in the immune system such as Th1, Th2, Treg, eosinophils and mast cells.

Gallic acid alleviates nasal inflammation via activation of Th1 and inhibition of Th2 and Th17 in a mouse model of allergic rhinitis

Allergic rhinitis (AR) is an allergic nasal disease characterized by nasal obstruction, rhinorrhea, sneezing, and itching. Type 1 helper T cells (Th1)/type 2 helper T cells (Th2) imbalance has been identified as an important immunological mechanism of AR. In addition, up-regulation of type 17 helper T cells (Th17) also increase the risk of developing AR. Gallic acid (3, 4, 5-trihydroxybenzoic acid, GA), a polyphenol natural product, is obtained from various herbs, red wine, and green tea. It is known to have diverse biological effects such as anti-oxidation, anti-inflammation, anti-microbial and anti-cancer. In the present study, the effect of GA on airway inflammation and expression of Th1, Th2 and Th17 cytokines in an ovalbumin (OVA)-induced AR mouse model were investigated. GA alleviated the nasal allergic symptoms, reduced the thickness of nasal mucosa, attenuated goblet cell hyperplasia and eosinophil cell infiltration in the nasal mucosa, decreased the levels of interleukin (IL)-4, IL-5, IL-13 and IL-17 in nasal lavage fluid (NALF), and diminished the levels of OVA-specific IgE, OVA-specific IgG1 and OVA-specific IgG2a in serum. However, GA increased the expression of interferon-gamma and IL-12 in NALF. Taken together, it suggests that GA may be used as a therapeutic agent for AR.

Rosae multiflorae fructus extract and its four active components alleviate ovalbumin-induced allergic inflammatory responses via regulation of Th1/Th2 imbalance in BALB/c rhinitis mice

BACKGROUND

Rosae Multiflorae fructus has potent antioxidative, analgesic, and anti-inflammatory properties.

PURPOSE

We investigated the immunomodulatory effect of Rosae Multiflorae fructus extract (RMFE) on allergic inflammation in an allergic rhinitis (AR) mouse model.

METHODS

Mice were sensitized and intranasally challenged with ovalbumin (OVA), the Th1/Th2-related cytokines and histopathology were examinated after RMFE treatments. Primary cell culture from spleen and NALT was performed to evaluate RMFE effect on Th1/Th2 responses. Four active components of RMFE were determined using HPLC and then tested the inhibition on Th2 response.

RESULTS

Oral administration of RMFE inhibited the accumulation of eosinophils in nasal lavage fluid (NALF) and the nasal mucosa, goblet cells in the nasal epithelium, and mast cells in the respiratory region of the nasal cavity. Thus, the swelling of the nasal epithelium, nasal-associated lymphoid tissue (NALT), and lung tissue were ameliorated. Furthermore, the RMFE suppressed Th2-related cytokines, such as IL-4, IL-5, and IL-13 in NALF, NALT, and splenocytes, whereas the Th1-associated cytokine IL-12 was up-regulated by RMFE. We also revealed the active components of RMFE, such as ellagic acid, hyperoside, isoquercitrin, and miquelianin. They may inhibit IL-4 secretion in allergic responses.

CONCLUSION

RMFE may have therapeutic potential for treating AR by modulating the relationships between Th1/Th2 responses.

Bupleurum chinense extract ameliorates an OVA-induced murine allergic asthma through the reduction of the Th2 and Th17 cytokines production by inactivation of NFκB pathway

Bupleurum chinense belongs to the Bupleurum spp. family that has been used in traditional herbal medicine for over thousand years. It has been reported to have anti-inflammatory, anti-oxidant, hepato-protective, antipyretic, analgesic, anti-fibrotic and immunomodulatory effect. However, the effect of B. Chinense on allergic asthma remains unclear. This study investigated the immunomodulatory effects of B. Chinense extracts (BCE) on airway inflammation in asthmatic mice model. In the ovalbumin (OVA)-induced allergic asthma model, we evaluated the number of total cells, differential inflammatory cells and the production of proinflammatory cytokines in bronchoalveolar lavage fluid (BALF) and lung homogenate as well as histological structure. The levels of NFκB p65, IκBα, p-NFκB p65, p-IκBα and the total immunoglobulin (Ig) E, anti-OVA IgE, anti-OVA IgG were also examined. The oral administration of 200mg/kg BCE inhibited the accumulation of inflammatory cells especially eosinophils in BALF. Also, BCE regulated the imbalance of Th1, Th2 and Th17-related production, with attenuated the expression of GATA3, IL-1β, IL-4, IL-5, IL-6, TNF-α and RORγt, IL-17A in BALF and lung homogenate, meanwhile, up-regulated the secretion of INF-γ in lung homogenate. The levels of IgE, anti-OVA IgE, anti-OVA IgG1 and anti-OVA IgG2a were also suppressed by BCE treatment in serum. Futhermore, BCE inhibited the proinflammatory cytokines via inactivation of NFκB p65 phosphorylation and IκBα degradation in cytoplasm. The histological analysis showed that the infiltration of inflammatory cells, mucus hypersecretion and collagen fiber deposits were ameliorated in BCE treated mice. In addition, BCE induced the functional differentiation of naive CD4+ T cells forward to Th1 and Tr1 through producing INF-γ and IL-10. These results suggest that BCE may have therapeutic potential for treating allergic asthma through inhibiting Th2/Th17 cytokines production by inactivation of NFκB pathway.

Xanthii Fructus inhibits allergic response in the ovalbumin-sensitized mouse allergic rhinitis model

Background:

Xanthii Fructus (XF) is widely used in traditional anti-bacterial and anti-inflammatory Asian medicine. Allergic rhinitis is a common inflammatory disease characterized by markedly increased levels of anti-inflammatory factors and the recruitment of inflammatory cells into the nasal mucosa. We investigated the effects of XF in the allergen-induced rhinitis model.

Materials and Methods:

Following ovalbumin (OVA)/alum intraperitoneal injection on days 0, 7 and 14, the BALB/c mice (albino, laboratory-bred strain of the house mice) were challenged intranasally with OVA for 10 days a week after the last sensitization. The number of sneezes was recorded for 10 days; additionally, the levels of cytokines, histamine, immunoglobulin E (IgE) and OVA-specific serum IgE were estimated. Eosinophil infiltration, thickness of nasal mucosa and expression of caspase-1 were determined by immunohistochemistry. We also evaluated the effect of XF on the phosphorylation of nuclear factor kappa-B (NF-κB) and inhibitor of nuclear factor kappa B-alpha (IκB-α) in human mast cell-1 (HMC-1), by Western blotting.

Results:

The administration of XF significantly decreased sneezing and the serum levels of histamine, IgE, OVA-specific IgE, and cytokines such as tumor necrosis factor-alpha (TNF-α), interleukine-1 beta (IL-1β), IL-5, IL-6, monocyte chemoattractant protein-1 (MCP-1) and macrophage inflammatory protein-2 (MIP-2). XF inhibited the changes in thickness of the nasal septum, influx of eosinophils and expression of capase-1. In addition, XF inhibited the phosphorylation of IκB-α and NF-κB in phorbol-myristate-acetate plus calcium ionophore A23187 (A23187) stimulated HMC-1.

Conclusion:

This study suggests that XF acts a potent anti-allergic drug which alleviates the allergic responses in ovalbumin-sensitized mouse allergic rhinitis model.

Additive anti-allergic effects of anti-interleukin-33 and anti-Siglec-F treatments in a murine model of allergic asthma

Background

Anti-interleukin-33 (anti-IL-33) and anti-Siglec-F antibodies have potent anti-allergic effects on murine allergic asthma and rhinitis and induce eosinophil apoptosis.

Objective

We aimed to determine whether post-sensitization with anti-IL-33/anti-Siglec-F treatments exhibited more potent effects compared to individual treatments in a murine allergic asthma model.

Material and methods

Twenty-five BALB/c mice were separated into five groups (n = 5): Group A (control), Group B (ovalbumin [OVA] challenge), Group C (OVA + anti-IL-33), Group D (OVA + anti-Siglec-F), and Group E (OVA + anti-IL-33 + anti-Siglec-F). Serum total/ OVA-specific IgE, bronchoalveolar lavage (BAL) inflammatory cells and cytokines (IL-4 and IL-5), histopathological lung properties, and airway hyperreactivity were compared.

Results

Ovalbumin challenge induced strong immune and inflammatory responses with > 6-fold IgE level increases; 10- to 25-fold BAL eosinophil, neutrophil, and lymphocyte count increases; and > 1.5-fold IL-4 and IL-5 level increases (p < 0.05). Whereas anti-IL-33 reduced neutrophil counts, anti-Siglec-F and anti-IL-33/anti-Siglec-F reduced both eosinophil and neutrophil counts (p < 0.05). Individual treatments reduced OVA-mediated bronchiolar infiltration by 50% (p <0.05). Ovalbumin challenge increased airway hyperreactivity by 4-fold (Group B; 2000.0 ±671.8% increase in Penh) compared to controls (Group A; 445.7 ±33.5% increase in Penh) (p = 0.016). The anti-IL-33 (Group C: 1579.4 ±973.6% increase in Penh) and anti-Siglec-F (Group D: 930.4 ±236.5%) groups demonstrated significantly reduced hyperreactivity (p = 0.029). Anti-IL-33/anti-Siglec-F therapy showed synergism towards neutrophil counts, IL-5 concentrations, bronchial infiltration, and hyperreactivity (p < 0.05).

Conclusions

Combination treatment with anti-IL-33/anti-Siglec-F had more potent anti-allergic effects, reducing eosinophilic infiltration through their additive effects in a murine allergic asthma model.

Siglec-mediated regulation of immune cell function in disease

All mammalian cells display a diverse array of glycan structures that differ from those that are found on microbial pathogens. Siglecs are a family of sialic acid-binding immunoglobulin-like receptors that participate in the discrimination between self and non-self, and that regulate the function of cells in the innate and adaptive immune systems through the recognition of their glycan ligands. In this Review, we describe the recent advances in our understanding of the roles of Siglecs in the regulation of immune cell function in infectious diseases, inflammation, neurodegeneration, autoimmune diseases and cancer.

Benzaldehyde suppresses murine allergic asthma and rhinitis

To evaluate the antiallergic effects of oral benzaldehyde in a murine model of allergic asthma and rhinitis, we divided 20 female BALB/c mice aged 8-10 weeks into nonallergic (intraperitoneally sensitized and intranasally challenged to normal saline), allergic (intraperitoneally sensitized and intranasally challenged to ovalbumin), and 200- and 400-mg/kg benzaldehyde (allergic but treated) groups. The number of nose-scratching events in 10 min, levels of total and ovalbumin-specific IgE in serum, differential counts of inflammatory cells in bronchoalveolar lavage (BAL) fluid, titers of Th2 cytokines (IL-4, IL-5, IL-13) in BAL fluid, histopathologic findings of lung and nasal tissues, and expressions of proteins involved in apoptosis (Bcl-2, Bax, caspase-3), inflammation (COX-2), antioxidation (extracellular SOD, HO-1), and hypoxia (HIF-1α, VEGF) in lung tissue were evaluated. The treated mice had significantly fewer nose-scratching events, less inflammatory cell infiltration in lung and nasal tissues, and lower HIF-1α and VEGF expressions in lung tissue than the allergic group. The number of eosinophils and neutrophils and Th2 cytokine titers in BAL fluid significantly decreased after the treatment (P<0.05). These results imply that oral benzaldehyde exerts antiallergic effects in murine allergic asthma and rhinitis, possibly through inhibition of HIF-1α and VEGF.