Beyond immediate hypersensitivity: evolving roles for IgE antibodies in immune homeostasis and allergic diseases

Isolation of holostane-type saponins from the black sea cucumber Holothuria atra and evaluating their anti-allergic activity: in vitro and in silico study

Sea cucumbers are both versatile marine organisms and an Asian marine food known to have several medicinal effects. We evaluated the anti-allergic potential of some major purified holostane-type saponins from the body wall of the black sea cucumber, Holothuria atra. Six saponin compounds were isolated, holothurin B (1), holothurin A (2), 24-dehydro echinoside A (3), desholothurin A1 (4), desholothurin A (5), and des 24-dehydro echinoside A (6). The structures were identified based on spectroscopic methods and by comparison with the literature. Each compound's inhibitory activity toward the release of β-hexosaminidase was evaluated. Among the six compounds, holothurin B (1) showed the strongest inhibition of the degranulation at all tested concentrations in a dose-dependent manner, compared to the positive control, quercetin. We also observed that holothurin B (1) was able to alleviate the inflammatory mediators interleukin (IL)-6, IL-13, and tumor necrosis factor-alpha (TNF-α). Holothurin B (1) also inhibited the Ca2+ influx stimulated by the calcium ionophore A23187, by suppressing the expression of inositol-1,4,5-triphosphate receptor (IP3R) mRNA. These results suggest that (i) holothurin B (1) has good anti-allergy activity without cytotoxicity at effective concentrations, and (ii) this compound could be a lead compound for the treatment of allergic diseases and associated inflammation. We also performed a molecular docking study for the tested compounds to correlate their binding modes and affinity for the IP3R with the in vitro results. The results concluded that the holostane-type saponins could be used as anti-allergy agents, which may be attributed to their holostane group.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10616-024-00649-8.

Therapeutic monoclonal antibodies in allergy: Targeting IgE, cytokine, and alarmin pathways

The etiology of allergy is closely linked to type 2 inflammatory responses ultimately leading to the production of allergen-specific immunoglobulin E (IgE), a key driver of many allergic conditions. At a high level, initial allergen exposure disrupts epithelial integrity, triggering local inflammation via alarmins including IL-25, IL-33, and TSLP, which activate type 2 innate lymphoid cells as well as other immune cells to secrete type 2 cytokines IL-4, IL-5 and IL-13, promoting Th2 cell development and eosinophil recruitment. Th2 cell dependent B cell activation promotes the production of allergen-specific IgE, which stably binds to basophils and mast cells. Rapid degranulation of these cells upon allergen re-exposure leads to allergic symptoms. Recent advances in our understanding of the molecular and cellular mechanisms underlying allergic pathophysiology have significantly shaped the development of therapeutic intervention strategies. In this review, we highlight key therapeutic targets within the allergic cascade with a particular focus on past, current and future treatment approaches using monoclonal antibodies. Specific targeting of alarmins, type 2 cytokines and IgE has shown varying degrees of clinical benefit in different allergic indications including asthma, chronic spontaneous urticaria, atopic dermatitis, chronic rhinosinusitis with nasal polyps, food allergies and eosinophilic esophagitis. While multiple therapeutic antibodies have been approved for clinical use, scientists are still working on ways to improve on current treatment approaches. Here, we provide context to understand therapeutic targeting strategies and their limitations, discussing both knowledge gaps and promising future directions to enhancing clinical efficacy in allergic disease management.

The Association of Nasal and Blood Eosinophils with Serum IgE Level in Allergic Rhinitis and Asthma: A Case-Control Study

Background and Aims

Allergic rhinitis and asthma are two common respiratory diseases with allergic etiology in the world's population. Eosinophils and serum IgE levels have been known as inflammatory allergy markers for many years. This study aimed to evaluate the correlation of nasal and blood eosinophils with serum IgE levels in allergic rhinitis and asthma patients.

Methods

This prospective study was done on patients (n = 78) diagnosed with asthma (n = 20), allergic rhinitis (n = 49), and chronic rhinosinusitis with nasal polyposis (CRSwNP) (n = 9) at our hospital in Ahvaz City, Iran. The age of participants in our study ranged from 3 to 73 years, and all of them were subjected to a complete blood count (CBC) test, nasal smear, and determination of serum IgE levels after their consent.

Results

There was no correlation between serum IgE level and nasal eosinophil count (p = 0.728) or between serum IgE level and blood eosinophil count (p = 0.657); however, a positive correlation was detected between blood and nasal eosinophil levels (p = 0.003).

Conclusion

There is no significant relationship between serum IgE level and eosinophil count in the blood and nasal secretions. Serum IgE level and blood or nasal eosinophil count are both useful biomarkers for monitoring allergic rhinitis and asthma individually, but no diagnostic conclusion can be drawn from their correlation.

Whence and wherefore IgE?

Despite the near ubiquitous presence of Ig-based antibodies in vertebrates, IgE is unique to mammals. How and why it emerged remains mysterious. IgE expression is greatly constrained compared to other IgH isotypes. While other IgH isotypes are relatively abundant, soluble IgE has a truncated half-life, and IgE plasma cells are mostly short-lived. Despite its rarity, IgE is consequential and can trigger life-threatening anaphylaxis. IgE production reflects a dynamic steady state with IgG memory B cells feeding short-lived IgE production. Emerging evidence suggests that IgE may also potentially be produced in longer-lived plasma cells as well, perhaps as an aberrancy stemming from its evolutionary roots from an antibody isotype that likely functioned more like IgG. As a late derivative of an ancient systemic antibody system, the benefits of IgE in mammals likely stems from the antibody system's adaptive recognition and response capability. However, the tendency for massive, systemic, and long-lived production, common to IgH isotypes like IgG, were likely not a good fit for IgE. The evolutionary derivation of IgE from an antibody system that for millions of years was good at antigen de-sensitization to now functioning as a highly specialized antigen-sensitization function required heavy restrictions on antibody production-insufficiency of which may contribute to allergic disease.

Optical Label-Free Aptasensor Based on Weak Value Amplification for Real-Time and Ultrasensitive Detection of IgE

Allergy is a prevalent disease, and the potential allergic population is expanding with industrialization and changes in people's living standards. Serum immunoglobulin E (IgE) level is one of the critical indicators for determining allergy. Here, we proposed a simple, real-time monitoring, low chip cost, label-free aptamer biosensing strategy based on weak value amplification (WVA) for the quantitative detection of IgE in serum samples, enabling early and accurate diagnosis of allergic or hypersensitive patients. The aptasensor combined an imaging weak measurement system with the high specificity of the aptamer for the marker IgE. By modifying the amino group at the 3-terminal end, the anti-IgE aptamers can attach to a dopamine-modified prism's surface and selectively recognize IgE in human serum. In the presence of IgE, a specific binding reaction occurred, resulting in a change in the refractive index of the reactive region's surface, manifested as a change in the light intensity of the camera acquired experimental images. As the concentration of IgE increased, the relative light intensity advanced sequentially. The WVA-aptasensing strategy achieved a wide detection range of 0.01 ng/mL to 2 μg/mL in phosphate buffered saline buffer, with the resolution as low as 4.3 pg/mL. IgE testing experiments in human serum have proved the feasibility of our methods in detecting complex samples. In addition, the method specifically recognized IgE without interference from other proteins. We believe that our proposed sensing strategy opens up new possibilities for ultrahigh sensitivity screening of IgE and can be expanded to detecting other biomolecules.

A Comparison of Natural and Therapeutic Anti-IgE Antibodies

Immunoglobulin E (IgE) plays a critical role for the immune system, fighting against parasites, toxins, and cancer. However, when it reacts to allergens without proper regulation, it can cause allergic reactions, including anaphylaxis, through a process initiated by effector cells such as basophils and mast cells. These cells display IgE on their surface, bound to the high-affinity IgE receptor FcεRI. A cross-linking antigen then triggers degranulation and the release of inflammatory mediators from the cells. Therapeutic monoclonal anti-IgE antibodies such as omalizumab, disrupt this process and are used to manage IgE-related conditions such as severe allergic asthma and chronic spontaneous urticaria. Interestingly, naturally occurring anti-IgE autoantibodies circulate at surprisingly high levels in healthy humans and mice and may thus be instrumental in regulating IgE activity. Although many open questions remain, recent studies have shed new light on their role as IgE regulators and their mechanism of action. Here, we summarize the latest insights on natural anti-IgE autoantibodies, and we compare their functional features to therapeutic monoclonal anti-IgE autoantibodies.

Effects of house-cultivated edible bird's nest on immunoglobulin and cytokine release in vitro

Background and Aim

Edible bird's nest (EBN) is known as the "Caviar of the East" because of its high nutritional and medicinal values. Nevertheless, its effect on human immunity is yet to be explored. This study examined the effects of EBN's aqueous extract (EBNE) on human immunity through the modular immune in vitro construct (MIMIC) model consisting of peripheral tissue equivalent (PTE) and lymphoid tissue equivalent (LTE) modules.

Materials and Methods

One hundred twenty mL of full blood was obtained from four healthy human volunteers. The human immune system was simulated using an in vitro model, called MIMIC. Under EBNE treatment, monocyte transendothelial migration through reversed endothelial layers was observed. Using PTE and LTE modules, monocytes were differentiated into dendritic cells with lipopolysaccharide, then co-cultured with T- and B-cells for cytokine and immunoglobulin (Ig) production. The human cytokine array G2000 and quantitative human Ig isotyping array were used to identify the cytokine profile and Ig isotypes, respectively.

Results

IgE, IgA, and IgG3 levels were significantly raised by EBNE. These cytokines, including brain-derived neurotrophic factor, ciliary neurotrophic factor, glial cell line-derivative neurotrophic factor, insulin-like growth factor 1, and insulin-like growth factor binding protein 4, were generated.

Conclusion

For the first time, this work uses a MIMIC model to illustrate the impact of EBNE on human immune response. This new understanding of EBN's immunoregulatory effect allows for further exploration of how EBN interacts with the human immune system.

Therapeutic potential of ginseng leaf extract in inhibiting mast cell-mediated allergic inflammation and atopic dermatitis-like skin inflammation in DNCB-treated mice

Ginseng leaves are known to contain high concentrations of bioactive compounds, such as ginsenosides, and have potential as a treatment for various conditions, including fungal infections, cancer, obesity, oxidative stress, and age-related diseases. This study assessed the impact of ginseng leaf extract (GLE) on mast cell-mediated allergic inflammation and atopic dermatitis (AD) in DNCB-treated mice. GLE reduced skin thickness and lymph node nodules and suppressed the expression and secretion of histamine and pro-inflammatory cytokines. It also significantly lowered the production of inflammatory response mediators including ROS, leukotriene C4 (LTC4), prostaglandin E2 (PGE2), cyclooxygenase-2 (COX-2), and inducible nitric oxide synthase (iNOS). GLE inhibited the phosphorylation of MAPKs (ERK, P38, JNK) and the activation of NF-κB, which are both linked to inflammatory cytokine expression. We demonstrated that GLE's inhibitory effect on mast cell-mediated allergic inflammation is due to the blockade of the NF-κB and inflammasome pathways. Our findings suggest that GLE can be an effective therapeutic agent for mast-cell mediated and allergic inflammatory conditions.

Unanswered questions on the use of biologics in pediatric asthma

The emergence of biologic therapies for the management of asthma has been a revolutionary change in our capacity to manage this disease. Since the launch of omalizumab, several other biologics have been marketed or are close to being marketed, suggesting that a plethora of monoclonal antibodies can be expected in the coming years. This will facilitate the transition to the paradigm of personalized medicine, but on the other hand will decisively further complicate the choice of the most appropriate treatment, in the absence of reliable enough biological markers. For these reasons, along with the relatively short time of use with these treatments, there are recurrently arising questions for which there are not even moderately documented answers, and for which the only solution must be based, with all reservations, on the combination of indirect evidence and expertise. In this paper, we attempt to address such questions, providing relevant commentaries and considering the whole width of the evidence base.

Gene Therapy for Immunoglobulin E, Complement-Mediated, and Eosinophilic Disorders

Immunoglobulin E, complement, and eosinophils play an important role in host defense, but dysfunction of each of these components can lead to a variety of human disorders. In this review, we summarize how investigators have adapted gene therapy and antisense technology to modulate immunoglobulin E, complement, and/or eosinophil levels to treat these disorders.

Mast cell-mediated immune regulation in health and disease

Mast cells are important components of the immune system, and they perform pro-inflammatory as well as anti-inflammatory roles in the complex process of immune regulation in health and disease. Because of their strategic perivascular localization, sensitivity and adaptability to the microenvironment, and ability to release a variety of preformed and newly synthesized effector molecules, mast cells perform unique functions in almost all organs. Additionally, Mast cells express a wide range of surface and cytoplasmic receptors which enable them to respond to a variety of cytokines, chemicals, and pathogens. The mast cell's role as a cellular interface between external and internal environments as well as between vasculature and tissues is critical for protection and repair. Mast cell interactions with different immune and nonimmune cells through secreted inflammatory mediators may also turn in favor of disease promoting agents. First and forefront, mast cells are well recognized for their multifaceted functions in allergic diseases. Reciprocal communication between mast cells and endothelial cells in the presence of bacterial toxins in chronic/sub-clinical infections induce persistent vascular inflammation. We have shown that mast cell proteases and histamine induce endothelial inflammatory responses that are synergistically amplified by bacterial toxins. Mast cells have been shown to exacerbate vascular changes in normal states as well as in chronic or subclinical infections, particularly among cigarette smokers. Furthermore, a potential role of mast cells in SARS-CoV-2-induced dysfunction of the capillary-alveolar interface adds to the growing understanding of mast cells in viral infections. The interaction between mast cells and microglial cells in the brain further highlights their significance in neuroinflammation. This review highlights the significant role of mast cells as the interface that acts as sensor and early responder through interactions with cells in systemic organs and the nervous system.

The potential of dietary nanoparticles to enhance allergenicity of milk proteins: an in vitro investigation

In recent years, the popularity of dietary nanoparticles (NPs) in the food industry as additives has raised concerns because of the lack of knowledge about potential adverse health outcomes ensuing from the interactions of NPs with components of the food matrix and gastrointestinal system. In this study, we used a transwell culture system that consisted of human colorectal adenocarcinoma (Caco-2) cells in the apical insert and Laboratory of Allergic Diseases 2 mast cells in the basal compartment to study the effect of NPs on milk allergen delivery across the epithelial layer, mast cell responses and signaling between epithelial and mast cells in allergenic inflammation. A library of dietary particles (silicon dioxide NPs, titanium dioxide NPs and silver NPs) that varied in particle size, surface chemistry and crystal structures with or without pre-exposure to milk was used in this investigation. Milk-interacted particles were found to acquire surface corona and increased the bioavailability of milk allergens (casein and β-lactoglobulin) across the intestinal epithelial layer. The signaling between epithelial cells and mast cells resulted in significant changes in the early phase and late-phase activation of the mast cells. This study suggested that antigen challenge in mast cells with the presence of dietary NPs may cause the transition of allergic responses from an immunoglobulin E (IgE)-dependent mechanism to a mixed mechanism (both IgE-dependent and IgE-independent mechanisms).

Associations between endometriosis and allergy-related diseases as well as different specific immunoglobulin E allergy: A cross-sectional study

AIM

To explore the associations between endometriosis and different kinds of allergy-related diseases as well as different specific immunoglobulin E (IgE) allergy.

METHODS

This cross-sectional study included 1332 female participants ≥20 years and divided them into the endometriosis group (n = 97) and the nonendometriosis group (n = 1235). The confounders were obtained by comparing the differences of variables in groups. Univariate and multivariate logistic regression analyses were performed to analyze the associations between endometriosis and allergy-related diseases as well as different specific IgE allergy. Subgroup analysis were performed in age, body mass index (BMI), and pregnancy history.

RESULTS

After adjusting for confounders, increased risk of allergy (odd ratios [OR] = 2.13, 95% confidence interval [CI]: 1.31-3.47), hay fever (OR = 2.31, 95%CI: 1.32-4.06), and dog-specific IgE (OR = 2.13, 95%CI: 1.03-4.41) were observed in females with endometriosis. Among females aged between 30 and 39 years, the risk of allergy (OR = 3.51, 95%CI: 1.07-11.56), hay fever (OR = 3.26, 95%CI: 1.08-9.83), and dog-specific IgE (OR = 4.39, 95%CI: 1.02-18.88) was increased in patients with endometriosis compared with those without. In terms of females aged 40 to 49 years, the risk of hay fever was increased in patients with endometriosis. For females with BMI of 25-30 kg/m² , the risk of allergy was increased in patients with endometriosis. Increased risk of allergy, hay fever, and dog-specific IgE was observed in females with a history of pregnancy.

CONCLUSION

Endometriosis was associated with higher risk of allergy, hay fever, and dog dander. Special care should be provided for patients with endometriosis for the potential risk of allergy.

Treating allergies via skin - Recent advances in cutaneous allergen immunotherapy

Subcutaneous allergen immunotherapy has been practiced clinically for decades to treat airborne allergies. Recently, the cutaneous route, which exploits the immunocompetence of the skin has received attention, which is evident from attempts to use it to treat peanut allergy. Delivery of allergens into the skin is inherently impeded by the barrier imposed by stratum corneum, the top layer of the skin. While the stratum corneum barrier must be overcome for efficient allergen delivery, excessive disruption of this layer can predispose to development of allergic inflammation. Thus, the most desirable allergen delivery approach must provide a balance between the level of skin disruption and the amount of allergen delivered. Such an approach should aim to achieve high allergen delivery efficiency across various skin types independent of age and ethnicity, and optimize variables such as safety profile, allergen dosage, treatment frequency, application time and patient compliance. The ability to precisely quantify the amount of allergen being delivered into the skin is crucial since it can allow for allergen dose optimization and can promote consistency and reproducibility in treatment response. In this work we review prominent cutaneous delivery approaches, and offer a perspective on further improvisation in cutaneous allergen-specific immunotherapy.

Bradykinin-induced angioedema in the emergency department

Background

Acute airway angioedema commonly occurs through two distinct mechanisms: histamine- and bradykinin-dependent. Although they respond to distinct treatments, these two potentially life-threatening states present similarly. Poor recognition of the bradykinin-dependent pathway leads to treatment errors in the emergency department (ED), despite the availability of multiple pharmacologic options for hereditary angioedema (HAE) and other forms of bradykinin-induced angioedema. Here, we consider the pathophysiology and clinical features of bradykinin-induced angioedema, and we present a systematic literature review exploring the effectiveness of the available therapies for managing such cases.

Methods

PubMed searches using ‘emergency’, ‘bradykinin’ and various therapeutic product names identified studies reporting the efficacy of treatments for bradykinin-induced angioedema in the ED setting. In all, 22 studies met prespecified criteria and are analysed here.

Findings

Whereas histamine-induced angioedema has a faster onset and often presents with urticaria, bradykinin-induced angioedema is slower in onset, with greater incidence of abdominal symptoms. Acute airway angioedema in the ED should initially be treated with anaphylactic protocols, focusing on airway management and treatment with epinephrine, antihistamine and systemic steroids. Bradykinin-induced angioedema should be considered if this standard treatment is not effective, despite proper dosing and regard of beta-adrenergic blockade. Therapeutics currently approved for HAE appear as promising options for this and other forms of bradykinin-induced angioedema encountered in the ED.

Conclusion

Diagnostic algorithms of bradykinin-induced angioedema should be followed in the ED, with early use of approved therapies to improve patient outcomes.

FcεRI: A Master Regulator of Mast Cell Functions

Mast cells (MCs) perform multiple functions thought to underlie different manifestations of allergies. Various aspects of antigens (Ags) and their interactions with immunoglobulin E (IgE) cause diverse responses in MCs. FcεRI, a high-affinity IgE receptor, deciphers the Ag–IgE interaction and drives allergic responses. FcεRI clustering is essential for signal transduction and, therefore, determines the quality of MC responses. Ag properties precisely regulate FcεRI dynamics, which consequently initiates differential outcomes by switching the intracellular-signaling pathway, suggesting that Ag properties can control MC responses, both qualitatively and quantitatively. Thus, the therapeutic benefits of FcεRI-targeting strategies have long been examined. Disrupting IgE–FcεRI interactions is a potential therapeutic strategy because the binding affinity between IgE and FcεRI is extremely high. Specifically, FcεRI desensitization, due to internalization, is also a potential therapeutic target that is involved in the mechanisms of allergen-specific immunotherapy. Several recent findings have suggested that silent internalization is strongly associated with FcεRI dynamics. A comprehensive understanding of the role of FcεRI may lead to the development of novel therapies for allergies. Here, we review the qualitatively diverse responses of MCs that impact the attenuation/development of allergies with a focus on the role of FcεRI toward Ag exposure.

Synergistic effect of Korean red ginseng extract and GABA mixture on the IgE production in mice via Th1/Th2 cell balance

It has been recently reported that the immune system has been linked to the nervous system. This study was conducted to investigate the effect of administration of two components, gamma-aminobutyric acid (GABA) and Panax ginseng Meyer (GIN), on the production of IgE and Th1-Th2 dominant cytokines. Antibody and inflammatory mediator levels in serum, and the cytokines secreted to spleen cells of ovalbumin (OVA) immunized mice were analyzed. The group of GABA and GIN mixture significantly reduced IgE level and dramatically increased OVA-IgG2a antibody production. In addition, rising effect on IFN-gamma and GM-CSF levels related to Th1 cytokine was observed only in the group of GABA + GIN. The mixture alleviated allergic symptoms by reducing the level of histamine and prostaglandin. These studies suggest that GIN + GABA administration in the allergen-induced mouse model may regulate the Th1-Th2 balance by strongly acting on the immune response associated with Th1.

Hypersensitivity in the lungs is responsible for acute respiratory failure in COVID-19 patients: Case series of patients who received high-dose/short-term methylprednisolone

Background

COVID‐19 is a highly contagious respiratory disease caused by the SARS‐CoV‐2 virus. Patients with severe disease have a high fatality rate and face a huge medical burden due to the need for invasive mechanical ventilation. Hypoxic respiratory failure is the major cause of death in these patients. There are currently no specific anti‐SARS‐CoV‐2 drugs, and the effect of corticosteroids is still controversial.

Methods

The clinical data of 102 COVID‐19 patients, including 27 patients with severe disease, were analyzed. The serum levels of total IgE and anti‐SARS‐CoV‐2 specific IgE were compared in healthy controls and COVID‐19 patients, changes in the level of anti‐SARS‐CoV‐2 specific IgE and clinical response to methylprednisolone (MP) treatment were analyzed, and the effect of high‐dose/short‐term MP therapy for patients with critical illness and respiratory failure was determined.

Results

COVID‐19 patients had elevated serum levels of anti‐SARS‐CoV‐2 specific IgE, and patients with severe disease, especially critical illness, had even higher levels. Application of short‐term/high‐dose MP significantly reduced the level of these IgE antibodies and also blocked the progression of hypoxic respiratory failure. Hypoxic respiratory failure in patients with COVID‐19 is related to pulmonary hypersensitivity.

Conclusions

Hypersensitivity in the lungs is responsible for acute respiratory failure in COVID‐19 patients. Application of high‐dose/short‐term MP appears to be an effective life‐saving method for COVID‐19 patients who have hypoxic respiratory failure.

Pediococcus Pentosaceus from the Sweet Potato Fermented Ger-Minated Brown Rice Can Inhibit Type I Hypersensitivity in RBL-2H3 Cell and BALB/c Mice Models

In this study, the effect of GBR fermented with the Pediococcus pentosaceus SP024 strain on IgE/Ag mediated passive cutaneous anaphylaxis (PCA) was investigated. Protocatechuic acid and trans-ferulic acid levels in GBR-SP024 increased more than those in unfermented GBR, respec-tively. The inhibitory activity of GBR-SP024 on β-hexosaminidase release and the level of proin-flammatory cytokine mRNA expression (tumor necrosis factor-α (TNF-α) and interleukin 4 (IL-4)) was observed in IgE/Ag-stimulated RBL-2H3 cells. Western blot analysis showed that GBR-SP024 significantly inhibited the phosphorylation of the linker for activation of T cell (LAT) and nuclear factor-κB (NF-κB) in IgE/Ag-stimulated RBL-2H3 cells. Further, we investigated the anti-allergic effect of GBR-SP024 using PCA murine model. The number of infiltrated immune cells and degranulated mast cells in GBR-SP024 treated dermis was lower than that in the GBR-treated mice. In addition, mRNA expression of 5-lipoxygenase (5-LOX) in the dermis of ear tissue declined in the GBR-SP024–treated group, compared to that in the GBR group. GBR-SP024 was also more effective than GBR at reducing the levels of IL-33 protein expression in IgE/Ag-stimulated BALB/c mice. Our study suggests the potential usage of GBR-SP024 as a dietary supplement or an adjuvant for treating IgE-dependent-allergic diseases.

Pharmacological Benefits of Triphala: A Perspective for Allergic Rhinitis

Allergic rhinitis (AR) is considered a major nasal condition impacting a large number of people around the world, and it is now becoming a global health problem. Because the underlying mechanisms of AR are complex, the development of single-drug treatment might not be enough to treat a wide spectrum of the disease. Although the standard guidelines classify and provide suitable diagnosis and treatment, the vast majority of people with AR are still without any means of controlling it. Moreover, the benefits of AR drugs are sometimes accompanied by undesirable side effects. Thus, it is becoming a significant challenge to find effective therapies with limited undesirable side effects for a majority of patients suffering from uncontrolled AR. Aller-7/NR-A2, a polyherbal formulation, has revealed promising results in patients by reducing nasal symptoms and eosinophil counts without serious adverse effects. Interestingly, three out of seven of the herbals in the Aller-7/NR-A2 formulation are also found in an Ayurvedic polyherbal formulation known as “Triphala,” which is a potential candidate for the treatment of AR. However, there are no current studies that have examined the effects of Triphala on the disease. This review aims to describe the complexity of AR pathophysiology, currently available treatments, and the effects of Triphala on AR in order to help develop it as a promising alternative treatment in the future.

Oral Mucosa as a Potential Site for Diagnosis and Treatment of Allergic and Autoimmune Diseases

Most prevalent food allergies during early childhood are caused by foods with a high allergenic protein content, such as milk, egg, nuts, or fish. In older subjects, some respiratory allergies progressively lead to food-induced allergic reactions, which can be severe, such as urticaria or asthma. Oral mucosa remodeling has been recently proven to be a feature of severe allergic phenotypes and autoimmune diseases. This remodeling process includes epithelial barrier disruption and the release of inflammatory signals. Although little is known about the immune processes taking place in the oral mucosa, there are a few reports describing the oral mucosa-associated immune system. In this review, we will provide an overview of the recent knowledge about the role of the oral mucosa in food-induced allergic reactions, as well as in severe respiratory allergies or food-induced autoimmune diseases, such as celiac disease.

Immunoglobulin levels in systemic lupus erythematosus: A narrative review

Immunoglobulins play a fundamental role in the protection of the human body against internal and external threats. They also contribute to the immune system homeostasis and maintenance of self-tolerance. Hypogammaglobulinemia is occasionally encountered in routine clinical practice by rheumatologists. Low levels of immunoglobulins can occur as primary or secondary issues and may predispose patients to various forms of infection. However, the impact of the low immunoglobulin level abnormality varies with the underlying condition. In this narrative review, we shed light on the overall types and functions of immunoglobulins for clinicians. We discuss important principles of immunoglobulin measurements. We then consider the primary and secondary causes of low immunoglobulins with a special focus on hypogammaglobulinemia in patients with systemic lupus erythematosus (SLE).

bbeaR: an R package and framework for epitope-specific antibody profiling

SUMMARY

Analysis of epitope-specific antibody repertoires has provided novel insights into the pathogenesis of inflammatory disorders, especially allergies. A novel multiplex immunoassay, termed Bead-Based Epitope Assay (BBEA), was developed to quantify levels of epitope-specific immunoglobulins, including IgE, IgG, IgA and IgD isotypes. bbeaR is an open-source R package, developed for the BBEA, provides a framework to import, process and normalize .csv data files exported from the Luminex reader, evaluate various quality control metrics, analyze differential epitope-binding antibodies with linear modelling, visualize results, and map epitopes' amino acid sequences to their respective primary protein structures. bbeaR enables streamlined and reproducible analysis of epitope-specific antibody profiles.

AVAILABILITY AND IMPLEMENTATION

bbeaR is open-source and freely available from GitHub as an R package: https://github.com/msuprun/bbeaR; vignettes included.

SUPPLEMENTARY INFORMATION

Supplementary data are available at Bioinformatics online.

Does exposure to parasites modify relationships between diurnal cortisol and leukocytes among Honduran women?

BACKGROUND

Altered hypothalamic-pituitary-adrenal (HPA) function and related changes in circulating glucocorticoids have been implicated in the pathogenesis of numerous diseases that involve dysregulated immune function. Glucocorticoid hormones have both direct and indirect modulatory effects on both pro- and anti-inflammatory aspects of the immune system, including granulocytic and lymphocytic leukocyte subsets. However, past findings are complicated by inconsistencies across studies in how glucocorticoids and immune markers interact and relate to disease risk. Some incongruencies are likely due to an overreliance on single-unit (e.g., HPA or one immune marker) measures, and a failure to consider ecological exposures that may shape the base levels or correspondence between these systems. Here, we test single-unit and diurnal measures of HPA axis and immune system interactions in a less-industrial ecological setting with relatively high parasite loads.

METHODS

In a sample of 114 Honduran women (mean age = 36 years), morning and evening blood samples were analyzed to quantify granulocytes, lymphocytes, and immunoglobulin-E (IgE). Saliva was collected over 2 days (8 samples per woman) to measure peak cortisol, cumulative cortisol, and slope of decline. These repeated measures of saliva and venous blood were used to investigate associations between single-point and diurnal salivary cortisol and leukocytes, under variable levels of past parasite exposure (proxied by IgE).

RESULTS

Individuals with less of a decline in cortisol (i.e., "flatter" decline) show less of an increase in lymphocytes (2.27% increase in cells/μL/hr; 95% CI: 0.91-7.29; p = .01) across the day compared to those with steeper cortisol decline (7.5% increase in lymphocytes; 95% CI: 5.79-9.34; p < .001). IgE levels did not modify this association. Interestingly, IgE did moderate relationships between measures of cortisol and granulocytes: diurnal cortisol was positively associated with granulocytes, only in individuals with high previous exposure to parasites. There were no consistent relationships between single-unit measures of cortisol, lymphocytes or granulocytes, regardless of past parasite exposure.

DISCUSSION

Results demonstrate that the relationship between HPA function and immune modulation cannot be fully understood without an understanding of local disease ecology. These results highlight the importance of research that seeks to identify etiologies of disease across environmental contexts.

Preventing asthma in high risk kids (PARK) with omalizumab: Design, rationale, methods, lessons learned and adaptation

Asthma remains one of the most important challenges to pediatric public health in the US. A large majority of children with persistent and chronic asthma demonstrate aeroallergen sensitization, which remains a pivotal risk factor associated with the development of persistent, progressive asthma throughout life. In individuals with a tendency toward Type 2 inflammation, sensitization and exposure to high concentrations of offending allergens is associated with increased risk for development of, and impairment from, asthma. The cascade of biological responses to allergens is primarily mediated through IgE antibodies and their production is further stimulated by IgE responses to antigen exposure. In addition, circulating IgE impairs innate anti-viral immune responses. The latter effect could magnify the effects of another early life exposure associated with increased risk of the development of asthma - viral infections. Omalizumab binds to circulating IgE and thus ablates antigen signaling through IgE-related mechanisms. Further, it has been shown restore IFN-α response to rhinovirus and to reduce asthma exacerbations during the viral season. We therefore hypothesized that early blockade of IgE and IgE mediated responses with omalizumab would prevent the development and reduce the severity of asthma in those at high risk for developing asthma. Herein, we describe a double-blind, placebo-controlled trial of omalizumab in 2-3 year old children at high risk for development of asthma to prevent the development and reduce the severity of asthma. We describe the rationale, methods, and lessons learned in implementing this potentially transformative trial aimed at prevention of asthma.

A review on the effect of COVID-19 in type 2 asthma and its management

Background

COVID-19 is considered the most critical health pandemic of 21st century. Due to extremely high transmission rate, people are more susceptible to viral infection. COVID-19 patients having chronic type-2 asthma prevails a major risk as it may aggravate the disease and morbidities.

Objective

The present review mainly focuses on correlating the influence of COVID-19 in type-2 asthmatic patients. Besides, it delineates the treatment measures and drugs that can be used to manage mild, moderate, and severe symptoms of COVID-19 in asthmatic patients, thus preventing any exacerbation.

Methods

An in-depth research was carried out from different peer-reviewed articles till September 2020 from several renowned databases like PubMed, Frontier, MEDLINE, and related websites like WHO, CDC, MOHFW, and the information was analysed and written in a simplified manner.

Results

The progressive results were quite conflicting as severe cases of COVID-19 shows an increase in the level of several cytokines that can augment inflammation to the bronchial tracts, worsening the asthma attacks. Contradicting to this, certain findings reveal the decrease in the severity of COVID-19 due to the elevation of T-cells in type-2 asthmatic patients, as prominent reduction of T-cell is seen in most of the COVID-19 positive patients. This helps to counteract the balance of immune responses and hence ameliorate the disease progression.

Conclusion

Asthmatic patients must remain cautious during the COVID-19 pandemic by maintaining all the precautions to stay safe due to limited research data. Future strategies should include a better understanding of asthmatic exacerbation and its relation to COVID-19.

IgE and mast cells: The endogenous adjuvant

Mast cells and IgE are most familiar as the effectors of type I hypersensitivity reactions including anaphylaxis. It is becoming clear however that this pair has important immunomodulatory effects on innate and adaptive cells of the immune system. In this purview, they act as endogenous adjuvants to ignite evolving immune responses, promote the transition of allergic disease into chronic illness and disrupt the development of active mechanisms of tolerance to ingested foods. Suppression of IgE-mediated mast cell activation can be exerted by molecules targeting IgE, FcɛRI or signaling kinases including Syk, or by IgG antibodies acting via inhibitory Fcγ receptors. In 2015 we reviewed the evidence for the adjuvant functions of mast cells. This update includes the original text, incorporates some important developments in the field over the past five years and discusses how interventions targeting these pathways might have promise in the development of strategies to treat allergic disease.

Total dose defines the incidence of percutaneous IgE/IgG1 mediated immediate-type hypersensitivity caused by papain

Assessment of human health risk requires an understanding of antigen dose metrics associated with toxicity. Whereas assessment of the human health risk for delayed-type hypersensitivity is understood, the metrics remain unclear for percutaneous immediate-type hypersensitivity (ITH) mediated by IgE/IgG1. In this work, we aimed to investigate the dose metric for percutaneous ITH mediated by IgE/IgG1 responses. Papain, which causes ITH via percutaneous sensitization in humans, was used to sensitize guinea pigs and mice. The total dose per animal or dose per unit area was adjusted to understand the drivers of sensitization. Passive cutaneous anaphylaxis (PCA) and enzyme-linked immunosorbent assay (ELISA) for papain-specific IgG1 enabled quantification of the response in guinea pigs. In mice, the number of antigen-bearing B cells in the draining lymph nodes (DLN) was calculated using flow cytometry papain-specific IgG1 and IgE levels were quantified by ELISA. PCA positive test rates and the amounts of antigen-specific antibody corresponded with total dose per animal, not dose per unit area. Furthermore, the number of B cells taking up antigen within DLN also correlated with total dose. These findings indicate that the total antigen dose is the important metric for percutaneous IgE/IgG1-mediated ITH.

Development of a protein microarray-based diagnostic chip mimicking the skin prick test for allergy diagnosis

Protein microarrays have been successfully used for detection of allergen-specific IgE in patient sera. Here, we demonstrate proof-of-concept of a solid-phase technique coupling the high-throughput potential of protein microarrays with the biologically relevant readout provided by IgE reporter cells, creating a novel allergic sensitization detection system. Three proteins (κ-casein, timothy grass pollen extract, polyclonal anti-human IgE) were printed onto three different polymer-coated surfaces (aldehyde-, epoxy- and NHS ester-coated). ToF-SIMs analysis was performed to assess printed protein stability and retention during washing steps. NFAT-DsRed rat basophil leukemia cell attachment and retention during washing steps was assessed after treatment with various extracellular matrix proteins. NFAT-DsRed IgE reporter cells were sensitized with serum of an allergic donor, incubated on the printed slides, and cell activation determined using a microarray laser scanner. NFAT DsRed IgE reporter cell binding was significantly increased on all polymer surfaces after incubation with fibronectin and vitronectin, but not collagen or laminin. All surfaces supported printed protein stability during washing procedure, with epoxy- and NHS ester-coated surfaces showing best protein retention. Cell activation was significantly higher in NHS ester-coated slides after timothy grass pollen extract stimulation appearing a suitable substrate for further development of an automated allergy diagnosis system.

A Snapshot on Food Allergies: A Case Study on Edible Flowers

This perspective study addresses the main causes of adverse reactions to foods in humans, by taking into account the main allergic reactions that may occur as a result of food ingestion, as well the main allergens present in food and how their allergenicity change as a result of food preparation. In addition, European legislation on food labeling and novel foods was taken into account. The case study of this perspective is on the potential allergenicity of edible flowers as well as evidence of phytochemistry and toxic compounds and the risk associated with their ingestion. Regarding edible flowers, a key issue to address is if they are safe to consume or not. In the framework of the project “Innovative activities for the development of the cross-border supply chain of the edible flower” (ANTEA), we considered 62 different species and varieties of edible flowers. The results obtained by consulting two databases on allergens, COMPRISE and Allergen Nomenclature, marked two alerts for two species of edible flowers selected in the project. Moreover, based on edible flower consumption, about ten grams per serving, and on their protein content, we can also state that the risk of allergic reactions due to edible flower ingestion is very low.

Exosomal MicroRNAs in Pregnancy Provides Insight into a Possible Cure for Cancer

The biological links between cancer and pregnancy are of recent interest due to parallel proliferative, immunosuppressive and invasive mechanisms between tumour and trophoblast development. Therefore, understanding “cancer-like” mechanisms in pregnancy could lead to the development of novel cancer therapeutics, however, little is understood on how tumour and trophoblast cells recapitulate similar molecular mechanisms. Based on our observations from a previous study, it was not only evident that exosomal miRNAs are involved in the pathophysiology of preeclampsia but also contained cancer-specific miRNAs, which suggested that “pseudo-malignant-like” exosomal-mediated mechanisms exist in pregnancy. The presented study therefore aimed to identify exosomal miRNAs (exomiR) in pregnancy which can be repurposed towards preventing tumour metastasis and immunosuppression. It was identified that exomiR-302d-3p, exomiR-223-3p and exomiR-451a, commonly associated with cancer metastasis, were found to be highly expressed in pregnancy. Furthermore, computational merging and meta-analytical pathway analysis (DIANA miRPath) of significantly expressed exomiRs between 38 ± 1.9 vs. 30 ± 1.11 weeks of gestation indicated controlled regulation of biological pathways associated with cancer metastasis and immunosuppression. Therefore, the observations made in this study provide the experimental framework for the repurposing of exosomal miRNA molecular mechanisms in pregnancy towards treating and preventing cancer.

Harnessing Therapeutic IgE Antibodies to Re-educate Macrophages against Cancer

Currently, IgG is the only class of antibodies employed for cancer therapy. However, harnessing the unique biological properties of a different class ( e.g., IgE) could engender potent effector cell activation, and unleash previously untapped immune mechanisms against cancer. IgE antibodies are best known for pathogenic roles in allergic diseases and for protective effector functions against parasitic infestation, often mediated by IgE Fc receptor-expressing macrophages. Notably, IgE possess a very high affinity for cognate Fc receptors expressed by tumor-associated macrophages (TAMs). This paper reviews pre-clinical studies, which indicate control of cancer growth by tumor antigen-specific IgE that recruit and re-educate TAMs towards activated profiles. The clinical development harnessing the antitumor potential of recombinant IgE antibodies in cancer patients is also discussed.

Long noncoding RNA atlas of the inflammation caused by asthma in mice

There is little evidence regarding the roles of long noncoding RNAs (lncRNAs) in inflammation caused by asthma. In this study, we successfully generated an asthma mouse model that was induced by ovalbumin (OVA). The effects of dexamethasone (Dex) treatment on lung tissue were investigated using pathological and biochemical methods, including Diff-Quik staining, enzyme-linked immunosorbent assay (ELISA), hematoxylin-eosin (H&E) staining, and western blotting (WB). The inflammation was effectively relieved with Dex treatment. High-throughput sequencing revealed that a total of 1490 lncRNAs were detected in lung tissue samples. Differential expression analysis revealed that the Dex group had 20 upregulated and 15 downregulated lncRNAs compared with those in the Model group. Moreover, nine differentially expressed and inflammation-related lncRNAs were verified by quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR). Furthermore, the regulation networks of these nine lncRNAs, their potential binding microRNA (miRNAs), and the putative target genes showed that these lncRNAs play important roles in the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling pathway. We further identified the expression levels of three potential binding miRNAs by qRT-PCR. The results of this study contribute to a better understanding of the functions of lncRNAs in inflammation caused by asthma.

Antigen-Antibody Complexes

In vertebrates, immunoglobulins (Igs), commonly known as antibodies, play an integral role in the armamentarium of immune defense against various pathogens. After an antigenic challenge, antibodies are secreted by differentiated B cells called plasma cells. Antibodies have two predominant roles that involve specific binding to antigens to launch an immune response, along with activation of other components of the immune system to fight pathogens. The ability of immunoglobulins to fight against innumerable and diverse pathogens lies in their intrinsic ability to discriminate between different antigens. Due to this specificity and high affinity for their antigens, antibodies have been a valuable and indispensable tool in research, diagnostics and therapy. Although seemingly a simple maneuver, the association between an antibody and its antigen, to make an antigen-antibody complex, is comprised of myriads of non-covalent interactions. Amino acid residues on the antigen binding site, the epitope, and on the antibody binding site, the paratope, intimately contribute to the energetics needed for the antigen-antibody complex stability. Structural biology methods to study antigen-antibody complexes are extremely valuable tools to visualize antigen-antibody interactions in detail; this helps to elucidate the basis of molecular recognition between an antibody and its specific antigen. The main scope of this chapter is to discuss the structure and function of different classes of antibodies and the various aspects of antigen-antibody interactions including antigen-antibody interfaces-with a special focus on paratopes, complementarity determining regions (CDRs) and other non-CDR residues important for antigen binding and recognition. Herein, we also discuss methods used to study antigen-antibody complexes, antigen recognition by antibodies, types of antigens in complexes, and how antigen-antibody complexes play a role in modern day medicine and human health. Understanding the molecular basis of antigen binding and recognition by antibodies helps to facilitate the production of better and more potent antibodies for immunotherapy, vaccines and various other applications.

Aberrant Th2 Immune Responses Are Associated With a Reduced Frequency of IL-35-Induced Regulatory T Cells After Allergen Exposure in Patients With Allergic Asthma

PURPOSE

Allergen exposure induces aberrant T helper (Th) 2 immune responses in patients with allergic asthma, but not in sensitized asymptomatic and nonallergic subjects. Interleukin (IL)-35-induced regulatory T (iTr35) cells are a new subset of regulatory T cells with immunoregulatory properties. These cells can significantly suppress Th2 responses in seasonal allergic rhinitis. However, it remains unknown whether iTr35 cells are involved in the immunoregulation of allergic asthmatic individuals after specific allergen exposure.

METHODS

The iTr35 cell frequency in peripheral blood mononuclear cells (PBMCs) was measured in patients with allergic asthma as well as in asymptomatic and healthy subjects. The difference in naïve CD4⁺ T cell conversion to iTr35 cells in vitro during allergen stimulation was also investigated. The effects of iTr35 cells on naïve CD4⁺ T cell differentiation into Th2 cells, CD4⁺CD25^- T (Teff) cell proliferation and Th2 cytokine production in vitro were assessed.

RESULTS

Significantly reduced iTr35 cell frequencies and IL-35 expression levels were found in asthmatic patients with Derp1 allergy compared with asymptomatic and healthy subjects. Moreover, the circulating iTr35 cell proportion and IL-35 expression level in asthmatic patients gradually decreased with disease severity. Patients with allergic asthma had reduced transformation of naïve CD4⁺ T cells into iTr35 cells and IL-35 production after allergen exposure compared with asymptomatic and healthy subjects. Most importantly, iTr35 cells inhibited allergen-driven differentiation of naïve CD4⁺ T cells into Th2 cells, Teff cell proliferation and Th2 cytokine production in an IL-35-dependent manner.

CONCLUSIONS

The results of our study suggest that iTr35 cells may play an important role in preventing Th2 responses to allergens by secreting IL-35 and that iTr35 cells may be a potential new immune regulator of allergic asthma.

Phellinus linteus Grown on Germinated Brown Rice Inhibits IgE-Mediated Allergic Activity through the Suppression of FcεRI-Dependent Signaling Pathway In Vitro and In Vivo

Phellinus linteus (PL) has been used as a traditional herbal medicine owing to its immune regulatory activity. Previous studies reported that PL grown on germinated brown rice (PBR) exerted immunomodulatory, anticancer, and anti-inflammatory activities. However, role of PBR on type I hypersensitive reactions has not been studied yet. We found that PBR contained more polyphenolic compounds than PL extract. Among fractions, PBR butanol fraction (PBR-BuOH) significantly contained the most amounts of total polyphenolic contents compared with all extracts or fractions. In this study, anti-allergic activity of PBR-BuOH was examined using in vitro and in vivo models of immunoglobulin E/antigen- (IgE/Ag-) stimulated allergy. The inhibitory activity of degranulation was higher in PBR-BuOH (IC₅₀ 41.31 ± 0.14 μg/mL) than in PL-BuOH (IC₅₀ 108.07 ± 8.98 μg/mL). We observed that PBR-BuOH suppressed calcium influx and the level of TNF-α and IL-4 mRNA expression in a dose-dependent manner. The phosphorylation of Fyn, Gab2, PI3K, Syk, and IκB protein is reduced by PBR-BuOH. Oral administration of PBR-BuOH inhibited allergic reactions including the extravasation of Evans blue dye, ear swelling, and infiltration of immune cells in mice with passive cutaneous anaphylaxis (PCA). These findings suggest that PBR-BuOH might be used as a functional food, a health supplement, or a drug for preventing type I hypersensitive allergic disease.

Key role of the epithelium in chronic upper airways diseases

The respiratory epithelium of the upper airways is a first-line defence against inhaled irritants, pathogens and allergens. It ensures a physical barrier provided by apical junctions and mucociliary clearance to avoid excessive activation of the immune system. The epithelium also forms a chemical and immunological barrier, extensively equipped to protect the airways against external aggressions before the adaptive immune system is required. Under normal circumstances, the epithelium is capable of recovering rapidly after damage. This manuscript reviews these main properties of the upper airway epithelium as well as its reported impairments in chronic inflammatory diseases. The knowledge on normal epithelial functions and their dysregulation in upper airway diseases should help to design new epithelial-targeted treatments.

Allergenicity reduction and rheology property of Lactobacillus-fermented soymilk

BACKGROUND

This study aimed to investigate the reduction in the potential allergenicity of soymilk, and its rheological properties, after fermentation with Lactobacillus. Soymilk (SM) was fermented with Lactobacillus brevis and Lactobacillus sp. The molecular weight of fermented soymilk (FSM) was characterized using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and the potential allergenicity of FSM was analyzed using enzyme-linked immunosorbent assay in vitro and the BALB/c mouse model to detect changes in histamine, mouse mast cell protease-1 (mMCP-1), allergen-specific IgG/IgE, and cytokine levels and histomorphology of jejunum in vivo.

RESULTS

The SDS-PAGE and enzyme linked immunosorbent assay (ELISA) showed that allergens of soybean (β-conglycinin and acidic subunit of glycinin) were almost degraded, and their immunoreactivity was decreased. In the BALB/c mouse model, the FSM group did not show anaphylactic shock symptoms compared with the SM group. Moreover, a tendency toward decreased serum allergen-specific IgG/IgE levels, plasma histamine levels, and mMCP-1 concentrations was observed in the FSM group. Furthermore, Th2-related cytokines were decreased, while IFN-γ production increased in spleen cell cultures. The intestinal villus was slightly damaged after the challenge. All these findings indicated that the Th1/Th2 balance in the FSM group shifted toward a Th1 response, ultimately reducing the potential allergenicity of FSM. Rheological assessment suggested that FSM has good viscous and pseudoplastic properties.

CONCLUSION

Fermentation might be a promising method for producing tasty, hypoallergenic soybean products. © 2019 Society of Chemical Industry.

Silkworm dropping extract regulates food allergy symptoms via inhibition of Th2-related responses in an ovalbumin-induced food allergy model

BACKGROUND

Silkworm droppings have long been used in traditional medicine to remedy allergic itching, palsy, blood circulation problems, and arthritis in Asian countries. To investigate the anti-allergic effect of silkworm dropping extract (SDE) and its mechanism, we used a mouse model of food allergy induced by ovalbumin (OVA).

RESULTS

SDE ameliorated the symptoms of OVA-induced food allergies, and the levels of T helper 2 (Th2)-related cytokines [such as interleukin (IL)-4, IL-5, IL-10, and IL-13] were found to be significantly decreased in both the spleen and mesenteric lymph nodes by SDE. Furthermore, SDE treatment directly inhibited OVA permeation, IL-4 production, and degranulation of mast cells; in contrast, immunoglobulin E (IgE) production from B cells was not affected.

CONCLUSION

These results suggest that SDE has potential anti-allergic activities, and SDE may be useful in the treatment/prevention of allergic disorders such as food allergies, serving as therapeutic agents. © 2019 Society of Chemical Industry.

Allergen-specific IgE levels and the ability of IgE-allergen complexes to cross-link determine the extent of CD23-mediated T-cell activation

Background

CD23 mediates IgE-facilitated allergen presentation and subsequent allergen-specific T-cell activation in allergic patients.

Objective

We sought to investigate key factors regulating IgE-facilitated allergen presentation through CD23 and subsequent T-cell activation.

Methods

To study T-cell activation by free allergens and different types of IgE–Bet v 1 complexes, we used a molecular model based on monoclonal human Bet v 1–specific IgE, monomeric and oligomeric Bet v 1 allergen, an MHC-matched CD23-expressing B-cell line, and a T-cell line expressing a human Bet v 1–specific T-cell receptor. The ability to cross-link Fcε receptors of complexes consisting of either IgE and monomeric Bet v 1 or IgE and oligomeric Bet v 1 was studied in human FcεRI-expressing basophils. T-cell proliferation by monomeric or oligomeric Bet v 1, which cross-links Fcε receptors to a different extent, was studied in allergic patients’ PBMCs with and without CD23-expressing B cells.

Results

In our model non–cross-linking IgE–Bet v 1 monomer complexes, as well as cross-linking IgE–Bet v 1 oligomer complexes, induced T-cell activation, which was dependent on the concentration of specific IgE. However, T-cell activation by cross-linking IgE–Bet v 1 oligomer complexes was approximately 125-fold more efficient. Relevant T-cell proliferation occurred in allergic patients’ PBMCs only in the presence of B cells, and its magnitude depended on the ability of IgE–Bet v 1 complexes to cross-link CD23.

Conclusion

The extent of CD23-mediated T-cell activation depends on the concentration of allergen-specific IgE and the cross-linking ability of IgE-allergen complexes.

Grifola frondosa extract and ergosterol reduce allergic reactions in an allergy mouse model by suppressing the degranulation of mast cells

The increasing number of patients suffering from allergic diseases is a global health problem. Grifola frondosa is an edible mushroom consumed as a health food in Asia, and has recently been reported to have anti-allergic effects. We previously reported that G. frondosa extract (GFE) and its active components, ergosterol and its derivatives, inhibited the antigen-induced activation of RBL-2H3 cells. Here, we demonstrated that GFE and ergosterol also had an inhibitory effect on the degranulation of bone marrow-derived mast cells (BMMCs) and alleviated anaphylactic cutaneous responses in mice. Using an air pouch-type allergic inflammation mouse model, we confirmed that oral administration of GFE and ergosterol suppressed the degranulation of mast cells in vivo. Our findings suggest that G. frondosa, including ergosterol as its active component, reduces type I allergic reactions by suppressing mast cell degranulation in mice, and might be a novel functional food that prevents allergic diseases.

Function and dysfunction of plasma cells in intestine

As the main player in humoral immunity, antibodies play indispensable roles in the body's immune system. Plasma cells (PCs), as antibody factories, are important contributors to humoral immunity. PCs, recognized by their unique marker CD138, are always discovered in the medullary cords of spleen and lymph nodes and in bone marrow and mucosal lymphoid tissue. This article will review the origin and differentiation of PCs, characteristics of short- and long-lived PCs, and the secretion of antibodies, such as IgA, IgM, and IgG. PCs play a crucial role in the maintenance of intestinal homeostasis using immunomodulation though complex mechanisms. Clearly, PCs play functional roles in maintaining intestinal health, but more details are needed to fully understand all the other effects of intestinal PCs.

Allergic Airway-Induced Hypersensitivity Is Attenuated by Bergapten in Murine Models of Inflammation

Bergapten (5-methoxypsoralen, 5-MOP) is a plant-derived furocoumarin with demonstrated anti-inflammatory action. The present study investigated its effects on allergic inflammation in two related pathways of mast cell degranulation. Compound 48/80 and lipopolysaccharide (LPS) were used to activate the IgE-independent pathway while bovine serum albumin (BSA) was used as allergen for the IgE-dependent pathway. The modulatory effect of bergapten on mast cell degranulation, neutrophil extravasation, protein concentration, lung histopathology, and oxidative stress was assessed. Bergapten at 10, 30, and 100 μg/ml for 15 min stabilized mast cells in rat mesenteric tissue from disruption in vitro and when administered in vivo at 3, 10, and 30 mg kg⁻¹ for 1 h protected mice from fatal anaphylaxis induced by compound 48/80. Similarly, treatment of LPS-challenged mice with bergapten (3, 10, and 30 mg kg⁻¹) for 24 h significantly decreased neutrophil infiltration into bronchoalveolar lavage fluid, mean protein concentration, and inflammatory cell infiltration of pulmonary tissues when compared to the saline-treated LPS-challenged control. In addition, lung histology of the bergapten-treated LPS-challenged mice showed significantly less oedema, congestion, and alveolar septa thickening when compared to the saline-treated LPS-challenged disease control. LPS-induced oxidative stress was significantly reduced through increased tissue activities of catalase and superoxide dismutase and reduced malondialdehyde levels on treatment with bergapten. In the triple antigen-induced active anaphylaxis, daily administration of bergapten at 3, 10, and 30 mg kg⁻¹ for 10 days, respectively, protected previously sensitized and challenged mice against anaphylactic shock. Overall, our study demonstrates the ability of bergapten to attenuate allergic airway-induced hypersensitivity in murine models of inflammation, suggesting its possible therapeutic benefit in this condition.

Ergosterol and its derivatives from Grifola frondosa inhibit antigen-induced degranulation of RBL-2H3 cells by suppressing the aggregation of high affinity IgE receptors

Grifola frondosa is an edible mushroom consumed as a health food and/or traditional medicine in Asia. However, the anti-allergic effects of G. frondosa are not yet understood. In this study, we demonstrated the effects of G. frondosa extract (GFE) on IgE-mediated allergic responses, using antigen-stimulated RBL-2H3 cells. Three active compounds: ergosterol, 6β-methoxyergosta-7,22-dien-3β,5α-diol (MEDD), and 6-oxoergosta-7,22-dien-3β-ol (6-OXO) were isolated from GFE and shown to inhibit the antigen-induced release of β-hexosaminidase and histamine. Among the three active components, we focused on ergosterol because of its high content in GFE. Ergosterol inhibited the aggregation of high-affinity IgE receptor (FcεRI), which is the first step in the activation of mast cells and antigen-induced tyrosine phosphorylation. Furthermore, ergosterol suppressed antigen-increased IL-4 and TNF-α mRNA. Taken together, our findings suggest that G. frondosa, including ergosterol and its derivatives as active components, has the potential to be a novel functional food that prevents type I allergies.

Gut Mucosal Antibody Responses and Implications for Food Allergy

The gastrointestinal mucosa is a critical environmental interface where plasma cells and B cells are exposed to orally-ingested antigens such as food allergen proteins. It is unclear how the development of B cells and plasma cells in the gastrointestinal mucosa differs between healthy humans and those with food allergy, and how B cells contribute to, or are affected by, the breakdown of oral tolerance. In particular, the antibody gene repertoires associated with symptomatic allergy have only begun to be characterized in full molecular detail. Here, we review literature concerning B cells and plasma cells in the gastrointestinal system in the context of food allergy, with a focus on human studies.

IL-13 is produced by tumor cells in breast implant-associated anaplastic large cell lymphoma: implications for pathogenesis

More than 500 women worldwide have developed a CD30+ T-cell lymphoma around breast implants, strongly suggesting a cause-and-effect relationship, and designated as breast implant-associated anaplastic large cell lymphoma (BIA-ALCL). The mechanism of lymphomagenesis is unknown. Recently, a bacterial biofilm containing gram-negative bacilli was discovered on the surface of breast implants associated with ALCL. We and others have described overexpression of the proto-oncogene JUNB and mutations of JAK1/2, TP53 and STAT3 in BIA-ALCL. Here we report that BIA-ALCL cell lines and anaplastic lymphoma cells in clinical specimens produce IL-13, the signature cytokine of allergic inflammation. Supporting the link of BIA-ALCL to allergic inflammation, lymphoma cells were often surrounded by eosinophils and mast cells, features typically absent in systemic ALCL. Because of the link of IL-13 to allergy, we looked for IgE and found it decorating the surface of mast cells and antigen-presenting follicular dendritic cells in capsules and lymph nodes infiltrated by anaplastic lymphoma cells, but not uninvolved capsules. Plasma cells within capsules and regional lymph nodes were identified as a possible source of IgE. Together, these findings suggest the hypothesis that an amplified immune response with features of a chronic allergic reaction in a susceptible patient underlies the pathogenesis of BIA-ALCL.

Approaches to target IgE antibodies in allergic diseases

IgE is the antibody isotype found at the lowest concentration in the circulation. However IgE can undeniably play an important role in mediating allergic reactions; best exemplified by the clinical benefits of anti-IgE monoclonal antibody (omalizumab) therapy for some allergic diseases. This review will describe our current understanding of the interactions between IgE and its main receptors FcεRI and CD23 (FcεRII). We will review the known and potential functions of IgE in health and disease: in particular, its detrimental roles in allergic diseases and chronic spontaneous urticaria, and its protective functions in host defense against parasites and venoms. Finally, we will present an overview of the drugs that are in clinical development or have therapeutic potential for IgE-mediated allergic diseases.

THE JEREMIAH METZGER LECTURE NOVEL THERAPEUTIC STRATEGIES OF ALLERGIC AND IMMUNOLOGIC DISORDERS

Advances in understanding the immunological basis and mechanisms underlying allergic and immunologic disorders have led to effective but costly long-term and repetitive biologic therapies. Gene therapy is a rapidly advancing technology, in which a single administration of an adeno-associated virus encoding the therapeutic protein or monoclonal antibody may provide effective long-term therapy for allergic and immunologic disorders. In this review, we summarize the recent studies from our laboratory developing gene therapy strategies to treat hereditary angioedema and peanut allergy. The unraveling of the pathogenesis of immune-based disorders, including hereditary deficiencies of components of the immune system and allergic disorders, has led to the development of therapies using parenteral administration of recombinant proteins or monoclonal antibodies (1). While many of these therapies are highly effective, they are limited by the half-life of the therapeutic protein or antibody, requiring repetitive administration of days to weeks (2-15). The focus of recent work in our laboratory has been to solve this problem by substituting protein/monoclonal antibody administration with gene therapy, where current technology allows for a single administration of the gene coding for a protein or antibody to provide persistent expression of effective levels of the therapeutic protein or antibody. Gene therapy is a drug delivery platform which uses genetic material, usually in the form of coding exons of the therapeutic gene, to correct, compensate for, or prevent the development of an abnormal phenotype (16). Originally conceptualized as a strategy to treat rare hereditary disorders, gene therapy is being developed for a wide range of human disorders, including common acquired conditions (17-20). In this review, we will describe how we have adopted gene therapy technology to develop therapies for immune-related disorders, using as examples hereditary angioedema, an inherited autosomal dominant disorder, and peanut allergy, a common acquired allergic disorder.