Therapeutic manipulation of immune tolerance in allergic disease

The role of regulatory B cells in immune regulation and childhood allergic asthma

BACKGROUND

As the most common chronic disease in childhood, asthma displays a major public health problem worldwide with the incidence of those affected rising. As there is currently no cure for allergic asthma, it is mandatory to get a better understanding of the underlying molecular mechanism.

MAIN BODY

By producing IgE antibodies upon allergen contact, B cells play a pivotal role in allergic asthma. Besides that, IL-10-secreting B cell subsets, namely regulatory B cells (Bregs), are reported in mice and humans to play a role in allergic asthma. In humans, several Breg subsets with distinct phenotypic and functional properties are identified among B cells at different maturational and differentiation stages that exert anti-inflammatory functions by expressing several suppressor molecules. Emerging research has focused on the role of Bregs in allergic asthma as well as their role for future diagnostic and preventive strategies.

CONCLUSION

Knowledge about the exact function of human Bregs in allergic asthma is still very limited. This review aims to summarize the current knowledge on Bregs. We discuss different human Breg subsets, several ways of Breg induction as well as the mechanisms through which they exert immunoregulatory functions, and their role in (childhood) allergic asthma.

Co-treatment with Fexofenadine and Budesonide Increases FoxP3 Gene Expression in Patients with Allergic Rhinitis

BACKGROUND

T helper type 2 (Th2), Th17, and regulatory T cells (Tregs) play essential roles in the pathogenesis and control of allergic rhinitis (AR). Fexofenadine and budesonide are first-line treatments for AR. This study aimed to investigate the effect of co-treatment with fexofenadine and budesonide on the expression of Th2, Th17, and Treg-specific transcription factors (GATA-binding protein 3 [GATA-3], RAR-related orphan receptor gamma [RORγt], and forkhead box P3 [FoxP3], respectively) in AR patients.

METHODS

In this study, 29 AR patients were co-treated with fexofenadine and budesonide for 1 month. Blood was collected from AR patients before and after 1 month of treatment. The gene expression levels of GATA-3, RORγt, and FoxP3 transcription factors in blood samples were measured. In addition, serum immunoglobulin E (IgE) levels and eosinophil percentages in blood samples were determined.

FINDINGS

The expression level of FoxP3 increased significantly after treatment compared with that before treatment (P < .001). In contrast, GATA-3 and RORγt expression levels did not show any noticeable changes. In addition, the percentage of peripheral blood eosinophils significantly decreased (P < .01). Serum IgE levels decreased compared with those before treatment, but the difference was not statistically significant. Furthermore, the clinical symptoms of the patients improved compared with those before treatment.

CONCLUSION

Our results showed that combined treatment with fexofenadine and budesonide increased the expression level of the FoxP3 gene, decreased the percentage of peripheral blood eosinophils, and improved the clinical symptoms of AR patients. This regimen appears to improve disease symptoms, at least in part by increasing the Treg population and decreasing the eosinophil population.

Single-Molecule Conductance of Intramolecular Hydrogen Bonding in Histamine on Gold

We perform single-molecule conductance measurements and DFT calculations on histamine, a biogenic amine that contains a flexible aliphatic linker and several nitrogen moieties with a potential for hydrogen bonding. Our study determines that junctions containing the free-base form of histamine can bridge through a molecular structure containing an intramolecular hydrogen bond. Conductance of this structure is higher than that through the saturated aliphatic linker. Flicker noise analysis of junction conductance confirms that transport occurs through the hydrogen bond and establishes a benchmark for noise measurements in hydrogen-bonded junctions. Overall, our work provides insights into the formation and conduction of intramolecular hydrogen bonding in single-molecule conductance measurements and into the conformations of the neurotransmitter histamine on noble metal surfaces.

Regulatory T Cell-Targeted Immunomodulatory Therapy for Long-Term Clinical Improvement of Atopic Dermatitis: Hypotheses and Perspectives

Atopic dermatitis (AD) is a chronically relapsing inflammatory skin disorder characterized by itching and eczematous lesions. It is often associated with a personal or familial history of allergic diseases. Allergic inflammation induced by immunoglobulin E and T-helper type 2 (Th2) cell responses to common environmental agents has been suggested to play an essential role in AD pathogenesis. The standard therapies for AD, including topical or systemic agents, focus on controlling skin inflammation. Recently developed monoclonal antibody to interleukin-4 receptor alpha or Janus kinase inhibitors can provide significant clinical improvements in patients with AD by inhibiting Th2 cell-mediated skin inflammation. However, the clinical efficacy of the Th2 cell-targeted therapy is transient and incomplete in patients with AD. Patients with AD are seeking a permanent cure. Therefore, the development of novel immunomodulatory strategies that can improve a long-term clinical outcome and provide a long-term treatment-free clinical remission of AD (disease-modifying therapy) is needed. Regulatory T (Treg) cells play a critical role in the maintenance of immune tolerance and suppress the development of autoimmune and allergic diseases. This review provides three working hypotheses and perspectives for the treatment of AD by Treg cell activation. (1) A decreased number or function of Treg cells is a critical event that causes the activation of Th2 cells, leading to the development and maintenance of AD. (2) Activation of Treg cells is an effective therapeutic approach for AD. (3) Many different immunomodulatory strategies activating Treg cells can provide a long-term clinical improvement of AD by induction of immune tolerance. The Treg cell-targeted immunomodulatory therapies for AD include allergen immunotherapy, microbiota, vitamin D, polyvalent human immunoglobulin G, monoclonal antibodies to the surface antigens of T cell or antigen-presenting cell, and adoptive transfer of autologous Treg cells or genetically engineered Treg cells expanded in vitro.

Identification of key genes and the pathophysiology associated with allergen-specific immunotherapy for allergic rhinitis

BACKGROUND

Allergen-specific immunotherapy (AIT) is a causative treatment in allergic rhinitis (AR), comprising long-term allergen administration and over three years of treatment. This study is carried out for revealing the mechanisms and key genes of AIT in AR.

METHODS

The present study utilized online Gene Expression Omnibus (GEO) microarray expression profiling dataset GSE37157 and GSE29521 to analyze the hub genes changes related to AIT in AR. Based on limma package, differential expression analysis for the two groups (samples of allergic patients prior to AIT and samples of allergic patients undergoing AIT) was performed to obtain differentially expressed genes (DEGs). Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis of DEGs were conducted using DAVID database. A Protein-Protein Interaction network (PPI) was built and a significant network module was acquired by using Cytoscape software (Cytoscape, 3.7.2). Utilizing the miRWalk database, we identified potential gene biomarkers, constructed interaction networks of target genes and microRNAs (miRNAs) using Cytoscape software, and explore the cell type-specific expression patterns of these genes in peripheral blood using publicly available single-cell RNA sequencing data (GSE200107). Finally, we are using PCR to detect changes in the hub genes that are screened using the above method in peripheral blood before and after AIT treatment.

RESULTS

GSE37157 and GSE29521 included 28 and 13 samples, respectively. A total of 119 significantly co-upregulated DEGs and 33 co-downregulated DEGs were obtained from two datasets. The GO and KEGG analyses demonstrated that protein transport, positive regulation of apoptotic process, Natural killer cell mediated cytotoxicity, T cell receptor signaling pathway, TNF signaling pathway, B cell receptor signaling pathway and Apoptosis may be potential candidate therapeutic targets for AIT of AR. From the PPI network, 20 hub genes were obtained. Among them, the PPI sub-networks of CASP3, FOXO3, PIK3R1, PIK3R3, ATF4, and POLD3 screened out from our study have been identified as reliable predictors of AIT in AR, especially the PIK3R1.

CONCLUSION

Our analysis has identified novel gene signatures, thereby contributing to a more comprehensive understanding of the molecular mechanisms underlying AIT in the treatment of AR.

Role of Mesenchymal Stem Cells and Short Chain Fatty Acids in Allergy: A Prophylactic Therapy for Future

Allergic diseases are broadly classified as IgE-mediated type-I hypersensitivity immune reactions due to exposure to typically harmless substances known as allergens. These allergenic substances activate antigen presenting cells, which further triggers T-helper 2 cells immune response and class switch B-cells for synthesis of allergen-specific IgE, followed by classical activation of inflammatory mast cells and eosinophils, which releases preformed mediators involved in the cascade of allergic symptoms. However, the role of Mesenchymal stem cells (MSCs) in tissue repair ability and immunomodulation, makes them as an appropriate tool for treatment of various allergic diseases. Several clinical and preclinical studies show that MSCs could be a promising alternative therapy to allergic diseases. Further, short chain fatty acids, produced from gut microbes by breaking down complex fibre-rich foods, acts through G-coupled receptor mediated activation of MSCs, and their role as key players involved in amelioration of allergic inflammation needs further investigation. Therefore, there is a need for understating the role of SCFAs on the activation of MSCs, which might shed light on the development of new therapeutic regime in allergy treatment. In summary, this review focuses on the underlying of therapeutic role of MSCs in different allergic diseases and the prospects of SCFA and MSC therapy.

Sustained antigens delivery using composite microneedles for effective epicutaneous immunotherapy

Allergen-specific immunotherapy (SIT) is a desirable way of therapy for various allergic diseases such as food allergy (FA). However, frequent visits for more than 3 years and potential adverse effects often hinder patient compliance. Recently, many researchers started focusing on microneedles (MNs) as a new method for SIT. In this study, we proposed an implantable MNs system produced by a two-step casting process, consisting of OVA (antigen)-loaded silk microneedles and a dissolvable, flexible polyvinyl alcohol (PVA) pedestal. Different from PVA, silk fibroin hydrogel has preferable vaccine release ability in vivo and in vitro. Once MNs are inserted into the skin, the PVA pedestal can dissolve in the interstitial fluid of the excised skin within 5 min and implant the OVA-loaded silk microneedle tips in dermal layer as a sustained antigen depot, thus inducing long-lasting immune response for at least 2 weeks. After receiving 3 doses of MN-based immunotherapy, the immune response in OVA-sensitized mice was successfully suppressed, with no apparent side effects. Compared to conventional subcutaneous immunotherapy (total dose of 150 [Formula: see text]g), MN immunotherapy ameliorated systemic anaphylaxis more effectively even at a lower dose (total dose of 30 [Formula: see text]g), demonstrating the antigen dose-sparing potential of the proposed MNs. Moreover, due to the prolonged release effect of silk-PVA composite MNs, the frequency of immunotherapy can be significantly reduced. To sum up, through prolonged skin exposure to antigen, this implantable designed MN may offer a new therapeutic strategy for FA treatment with significant improvements in efficacy and convenience. Schematic illustration of silk-PVA composite microneedles, consisting of OVA (antigen)-loaded silk microneedles and a dissolvable, flexible PVA pedestal. Once inserted into the skin, the PVA pedestal can dissolve in the interstitial fluid of the excised skin within 5 min. Subsequently, the OVA-loaded silk microneedle tips were implanted in the dermal layer as a sustained antigen depot and induced long-lasting immune response. This MNs-based immunotherapy can significantly modulate the Th1/Th2 imbalance of sensitized mice.

International consensus statement on allergy and rhinology: Allergic rhinitis - 2023

BACKGROUND

In the 5 years that have passed since the publication of the 2018 International Consensus Statement on Allergy and Rhinology: Allergic Rhinitis (ICAR-Allergic Rhinitis 2018), the literature has expanded substantially. The ICAR-Allergic Rhinitis 2023 update presents 144 individual topics on allergic rhinitis (AR), expanded by over 40 topics from the 2018 document. Originally presented topics from 2018 have also been reviewed and updated. The executive summary highlights key evidence-based findings and recommendation from the full document.

METHODS

ICAR-Allergic Rhinitis 2023 employed established evidence-based review with recommendation (EBRR) methodology to individually evaluate each topic. Stepwise iterative peer review and consensus was performed for each topic. The final document was then collated and includes the results of this work.

RESULTS

ICAR-Allergic Rhinitis 2023 includes 10 major content areas and 144 individual topics related to AR. For a substantial proportion of topics included, an aggregate grade of evidence is presented, which is determined by collating the levels of evidence for each available study identified in the literature. For topics in which a diagnostic or therapeutic intervention is considered, a recommendation summary is presented, which considers the aggregate grade of evidence, benefit, harm, and cost.

CONCLUSION

The ICAR-Allergic Rhinitis 2023 update provides a comprehensive evaluation of AR and the currently available evidence. It is this evidence that contributes to our current knowledge base and recommendations for patient evaluation and treatment.

PLGA-Based Micro/Nanoparticles: An Overview of Their Applications in Respiratory Diseases

Respiratory diseases, such as asthma and chronic obstructive pulmonary disease (COPD), are critical areas of medical research, as millions of people are affected worldwide. In fact, more than 9 million deaths worldwide were associated with respiratory diseases in 2016, equivalent to 15% of global deaths, and the prevalence is increasing every year as the population ages. Due to inadequate treatment options, the treatments for many respiratory diseases are limited to relieving symptoms rather than curing the disease. Therefore, new therapeutic strategies for respiratory diseases are urgently needed. Poly (lactic-co-glycolic acid) micro/nanoparticles (PLGA M/NPs) have good biocompatibility, biodegradability and unique physical and chemical properties, making them one of the most popular and effective drug delivery polymers. In this review, we summarized the synthesis and modification methods of PLGA M/NPs and their applications in the treatment of respiratory diseases (asthma, COPD, cystic fibrosis (CF), etc.) and also discussed the research progress and current research status of PLGA M/NPs in respiratory diseases. It was concluded that PLGA M/NPs are the promising drug delivery vehicles for the treatment of respiratory diseases due to their advantages of low toxicity, high bioavailability, high drug loading capacity, plasticity and modifiability. And at the end, we presented an outlook on future research directions, aiming to provide some new ideas for future research directions and hopefully to promote their widespread application in clinical treatment.

Tonsillar transcriptional profiles in atopic and non-atopic subjects

BACKGROUND

Emerging research suggests that local lymphatic tissue such as tonsils have important role in regulating the immune responses. However, allergen sensitization-induced alterations in transcriptome of tonsils are not known.

OBJECTIVES

To examine the key differences in tonsillar gene expression between atopic and non-atopic subjects and further by type of sensitization.

METHODS

RNA-sequencing was performed on 52 tonsillar samples from atopic and non-atopic tonsillectomy patients. Sensitization to common food- and aero-allergen was defined by allergen specific IgE. Following groups were studied: (1) aero- and food-allergen sensitized (AS+FS) versus non-sensitized (NS), (2) aeroallergen-sensitized (AS) versus food-allergen sensitized (FS), (3) AS versus NS, (4) FS versus NS. Bioinformatics analysis was done using DESeq2(v3.10.2), WGCNA and GATK pipeline in R software (v3.3.1). Protein-protein interaction network was made from String database.

RESULTS

We studied 13 aeroallergen-sensitized, 6 food-allergen sensitized, 4 both food-and aero-allergen-sensitized and 29 non-sensitized tonsillectomy patients. Overall, 697 unique differentially expressed genes (DEGs) were detected in all sensitized subgroups including chemokines (CXCL2, CXCL8, CXCL10, CXCL11), IL-20RA, MUC1 and MUC20. When comparing different groups, the gene expression profiles overlapped except the AS versus FS group comparison, suggesting significantly different gene expression between the two sensitization subgroups. Furthermore, aeroallergen-sensitized subjects had more prominent immune responses compared with non-sensitized and food-allergen sensitized subjects including gene expression for IL-17 pathway and Toll-like receptor signalling pathway.

CONCLUSION

Allergic sensitization is associated with extensive tonsillar transcriptomic alterations and changes in immune related genes and pathways. Distinct differences were found between aero-allergen and food-allergen sensitization.

Oral administration of Helianthus annuus leaf extract ameliorates atopic dermatitis by modulation of T cell activity in vivo

BACKGROUND

Atopic dermatitis (AD) is multifactorial disease that is highly involved in the activity of T cells from the skin lesion. Seeds of Helianthus annuus extract have been traditionally used as anti-inflammatory reagent but few studies have been reported on leaf of H. annuus that are discarded uselessly as an immunomodulator.

PURPOSE

Therefore, here, the regulatory effect of Helianthus annuus extract (HAE) on AD via suppression of T cell activity was investigated.

METHODS

The efficacy of HAE was evaluated in T cells stimulated with CD3/CD28 antibody and PMA/A23187. And demonstration of the alleviating effect of HAE on AD in the ears of Balb/c female mice stimulated with mite extract and DNCB.

RESULTS

Pre-treatment with HAE abrogates IL-2 production from activated T cells. It was also found that HAE suppresses the expression of surface molecules in activated T cells. Cell viability results demonstrated that HAE is not associated with cytotoxicity in resting and activated T cells. Besides, we exhibited that regulated phosphorylation of MAPK through TAK1-IKKα-NFκB by pre-treatment with HAE leads to the suppressive effect of HAE on T cell activation. Oral administration of HAE attenuates manifestations of AD including reduced thickness of dermis and epidermis, decreased IgE level in serum, and declined mRNA levels of atopic cytokines on ear tissues. The ameliorative effect of HAE on AD was found to be associated with suppressed activity of T cells from draining lymph nodes.

CONCLUSION

Therefore, our results provide that HAE alleviates AD symptoms via modulation of T cell activity. In addition, these results suggest the immunomodulatory effect of HAE on T-cell mediated diseases.

Virus-like Particles: Fundamentals and Biomedical Applications

Nanotechnology is a fast-evolving field focused on fabricating nanoscale objects for industrial, cosmetic, and therapeutic applications. Virus-like particles (VLPs) are self-assembled nanoparticles whose intrinsic properties, such as heterogeneity, and highly ordered structural organization are exploited to prepare vaccines; imaging agents; construct nanobioreactors; cancer treatment approaches; or deliver drugs, genes, and enzymes. However, depending upon the intrinsic features of the native virus from which they are produced, the therapeutic performance of VLPs can vary. This review compiles the recent scientific literature about the fundamentals of VLPs with biomedical applications. We consulted different databases to present a general scenario about viruses and how VLPs are produced in eukaryotic and prokaryotic cell lines to entrap therapeutic cargo. Moreover, the structural classification, morphology, and methods to functionalize the surface of VLPs are discussed. Finally, different characterization techniques required to examine the size, charge, aggregation, and composition of VLPs are described.

Majie Cataplasm Promotes Th1 Response to Fight against Asthmatic Th2 Inflammation through NKs

Background

Immune cells are tightly bound up with the pathogenesis of asthma. Besides T cells, B cells, macrophages, and mast cells, the mechanism of innate lymphoid cells (ILCs) in asthma is gradually explicit. As a kind of traditional Chinese medicine, Majie cataplasm realizes its potential in the clinical setting as an adjuvant for asthma. In our previous experiments, Majie cataplasm inhibits the increasing Th1 and Th2 in allergic asthma inflammation and reshapes a balance between Th1 and Th2. As ILCs are the reflection of Th cells in lung tissues, we will figure out whether Majie cataplasm could have similar effects on ILCs or not.

Methods

A total of 40 female C57/BL6 mice were randomly divided into the control group (n = 10), the asthma model group (n = 10), the dexamethasone group (n = 10), and the Majie cataplasm group (n = 10). Except for the control group, mice were sensitized with ovalbumin (OVA) and excited to establish mice models of asthma. Lung tissue and splenic tissue were collected at 24 h after the last challenge with OVA, and the cell suspension of the lungs and spleen was prepared. The number of ILC1s, ILC2s, ILC3s, and NKs cells in the lungs and Tregs and B10s in the spleen were detected by flow cytometry (FCM). This was followed by simultaneous quantitative detection of 40 inflammatory cytokines and chemokines in the lung by a protein microarray.

Results

The dexamethasone and Majie cataplasm could restore the number of ILC1s, ILC2s, and ILC3s in lung tissue. Compared with the control group, these cells remained unchanged in the asthma model group, while ILC1s (P < 0.001, P < 0.01), ILC2s (P < 0.001, P < 0.01), and ILC3s (P < 0.01, P < 0.05) were restored after the intervention of dexamethasone and Majie cataplasm. The number of NKs was low among the control group, the asthma model group, and the dexamethasone group, while the number of NKs rocketed in the Majie cataplasm group (P < 0.0001). For splenic Tregs and B10s, Majie cataplasm could curb the increasing numbers of them in the asthma model group (P < 0.0001, P < 0.01), while only Tregs were suppressed by the dexamethasone (P < 0.0001). For the inflammatory cytokines in the lung, the contents of TNF-α, TNFR2, CXCL-9, CCL-12, CCL-9, CCL-2, and CCL-5 in the asthma model group were higher than those in the control group, while the contents of GM-CSF and IL-1α were decreased. Comparing the asthma model group to the dexamethasone group, the levels of G-CSF, CCL-9, CCL-5, and TNFR2 in the former group were higher. The levels of TNF-α, TNFR2, and CCL-9 in the asthma model group increase, while the levels of IFN-γ, IL-1α, ICAM-1, and IL-4 increased in the Majie cataplasm group, especially IFN-γ and IL-1α.

Conclusion

Both the dexamethasone and Majie cataplasm could control the asthmatic inflammation by reducing the inflammatory factors, inhibiting the adaptive inflammation reaction in the latter stage of inflammation and furtherly reversing the inhibition of ILC2s, ILC2s, and ILC3s. In addition, Majie cataplasm can promote the quantity of NKs and the content of IL-1α and IFN-γ, induce IFN-γ⁺NKs to shut down the Th2 response, and tend to elicit the Th1 response.

Strong histamine torsion Raman spectrum enables direct, rapid, and ultrasensitive detection of allergic diseases

Allergic diseases are closely related to degranulation and release of histamine and difficult to diagnose because non-allergic diseases also exhibit the same clinical symptoms as allergy. Here, we report direct, rapid, and ultrasensitive detection of histamine using low-frequency molecular torsion Raman spectroscopy. We show that the low-frequency (<200 cm-1) Raman spectral intensities are stronger by one order of magnitude than those of the high-frequency Raman ones. Density functional theory calculation and nuclear magnetic resonance spectroscopy identify the strong spectral feature to be from torsions of carbon-carbon single bonds, which produce large variations of the polarizability densities in the imidazole ring and ethyl amino side chain. Using an omniphobic substrate and surface plasmonic effect of Au@SiO2 nanoparticles, the detection limit (signal-noise ratio >3) of histamine reaches 10-8 g/L in water and 10-6 g/L in serum. This scheme thus opens new lines of inquiry regarding the clinical diagnosis of allergic diseases.

The CD4+CD25+FoxP3+ Regulatory T Cells Regulated by MSCs Suppress Plasma Cells in a Mouse Model of Allergic Rhinitis

Background:

Allergic Rhinitis (AR) is the most common immunological disease that has been associated with inflammatory responses and is characterized by sneezing. Previous studies found that AR's allergen exposure significantly induces plasma cells and reduces regulatory T (Treg) cells, a population that contributes to control AR. Therefore, upregulating Treg expression can regulate plasma cells leading to inhibit sneezing in AR. Mesenchymal stem cells (MSCs) are multipotent stem cells that have the immunoregulatory and antiinflammation ability by secreting various cytokines including IL-10 and TGF-β which potent as a promising therapeutic modality for allergic airway diseases, including AR.

Objective:

To investigate the role of MSCs in generating CD4+, CD25+, and Foxp3+ Regulatory T cells associated with suppressing plasma cell in AR model.

Methods:

In this study, fifteen male Wistar rats (6 to 8 weeks old) were randomly divided into three groups (control group, sham group, and MSCs treatment group). OVA nasal challenge was conducted daily from day 15 to 21, and MSCs (1x10⁶) were administrated intraperitoneally to OVA-sensitized rats on day 21. Sneezing was observed from day 22 to 28. The rats were sacrificed on day 22 and day 28. The expression of CD4+ CD25+ Foxp3+ in Treg and plasma cells was analyzed by flow cytometry assay.

Results:

This study showed that the percentage of plasma cell and sneezing times significantly decreased in MSCs treatment. This finding was aligned with the significant increase of CD4+CD25+Foxp3+ Treg level.

Conclusion:

MSCs administration suppress plasma cells population and sneezing times by up regulating Treg to control AR.

Role of IL-6 in dendritic cell functions

Dendritic cells (DCs) are efficient antigen-presenting cells that serve as a link between the innate and adaptive immune systems. These cells are broadly involved in cellular and humoral immune responses by presenting antigens to initiate T cell reactions, cytokine and chemokine secretion, T cell differentiation and expansion, B cell activation and regulation, and the mediation of immune tolerance. The functions of DCs depend on their activation status, which is defined by the stages of maturation, phenotype differentiation, and migration ability, among other factors. IL-6 is a soluble mediator mainly produced by a variety of immune cells, including DCs, that exerts pleiotropic effects on immune and inflammatory responses through interaction with specific receptors expressed on the surface of target cells. Here, we review the role of IL-6, when generated in an inflammatory context or as derived from DCs, in modulating the biologic function and activation status of DCs and emphasize the importance of searching for novel strategies to target the IL-6/IL-6 signaling pathway as a means to diminish the inflammatory activity of DCs in immune response or to prime the immunogenic activity of DCs in immunosuppressive conditions.

Attenuated asthma phenotype in mice with a fetal-like antigen receptor repertoire

We hypothesized that the scarcity of N-nucleotides might contribute to the inability of the neonate to mount a robust allergic immune response. To test this, we used terminal deoxyribunucleotidyl Transferase deficient (TdT^-/-) mice, which express "fetal-like" T cell receptor and immunoglobulin repertoires with largely germline-encoded CDR3 regions. Intraperitoneal sensitization was followed by aerosol provocation with either PBS or the allergen OVA in both TdT^-/- mice and wild-type mice to develop allergic respiratory inflammation. The effects of this procedure were investigated by lung function test, immunological analysis of serum and brochoalveolar lavage. The local T_H2 cytokine milieu was significantly attenuated in TdT^-/- mice. Within this group, the induction of total IgE levels was also significantly reduced after sensitization. TdT^-/- mice showed a tendency toward reduced eosinophilic inflow into the bronchial tubes, which was associated with the elimination of respiratory hyperreactivity. In conclusion, in a murine model of allergic airway inflammation, the expression of fetal-like antigen receptors was associated with potent indications of a reduced ability to mount an asthma phenotype. This underlines the importance of somatically-generated antigen-receptor repertoire diversity in type one allergic immune responses and suggests that the fetus may be protected from allergic responses, at least in part, by controlling N addition.

A20-OVA Nanoparticles Inhibit Allergic Asthma in a Murine Model

The skewed T helper (Th) 2 response plays a critical role in the pathogenesis of allergic asthma. Regulatory T (Treg) cells and the regulatory cytokines are required in maintaining the homeostasis in the body. This study aims to determine the effects of a poly(lactic-co-glycolic) acid (PLGA)-ovalbumin (OVA)+A20 (a ubiquitin E3 ligase) nanovaccine on inhibiting allergic asthma in a murine model. In this study, A20 and OVA (a model antigen) were encapsulated into PLGA to be a nanovaccine (PLGA-OVA+A20). An allergic asthma murine model was developed with OVA as the specific antigen to test the role of PLGA-OVA+A20 nanovaccine in maintaining the immune homeostasis in the airway tissues. The results showed that PLGA-OVA+A20 nanovaccine inhibited the asthma responses in mice by suppressing Th2 inflammatory responses, promoting the generation of Treg cells in the airway tissues. We conclude that the PLGA-OVA+A20 nanovaccine has a marked inhibitory effect on the airway allergic response in sensitized mice by significantly promoting the generation of Treg cell and IL-10. The data suggest that PLGA-OVA+A20 has translational potential in the treatment of allergic asthma.

Innovative Systems to Deliver Allergen Powder for Epicutaneous Immunotherapy

Allergy is a disorder owing to hyperimmune responses to a particular kind of substance like food and the disease remains a serious healthcare burden worldwide. This unpleasant and sometimes fatal allergic disease has been tackled vigorously by allergen-specific immunotherapy over a century, but the progress made so far is far from satisfactory for some allergies. Herein, we introduce innovative, allergen powder-based epicutaneous immunotherapies (EPIT), which could potentially serve to generate a new stream of technological possibilities that embrace the features of super safety and efficacious immunotherapy by manipulating the plasticity of the skin immune system via sufficient delivery of not only allergens but also tolerogenic adjuvants. We attempt to lay a framework to help understand immune physiology of the skin, epicutaneous delivery of powdered allergy, and potentials for tolerogenic adjuvants. Preclinical and clinical data are reviewed showing that deposition of allergen powder into an array of micropores in the epidermis can confer significant advantages over intradermal or subcutaneous injection of aqueous allergens or other epicutaneous delivery systems to induce immunological responses toward tolerance at little risk of anaphylaxis. Finally, the safety, cost-effectiveness, and acceptability of these novel EPITs are discussed, which offers the perspective of future immunotherapies with all desirable features.

Preventing Atopic Diseases During Childhood - Early Exposure Matters

Atopic diseases in childhood are a major burden worldwide and there is still a lack of knowledge about treatable causes. In industrialized countries such as Germany, almost every second child is sensitized to at least one common allergen. Recent studies show that although the predisposition to allergies is inherited, the adaptive immune system of neonates and infants follows a developmental trajectory and whether an allergy actually occurs depends also on timing of allergen exposure including diet as well as environmental factors. New recommendations are far from being rigid of allergen avoidance; it is rather moving toward conditions that stand for more biodiversity. The observation that introduction of peanuts or eggs early in life significantly reduced the development of a later allergy will change our recommendations for the introduction of complementary foods. This is consistent with the hygiene hypothesis that early provocation shapes the developing immune system so that it reacts appropriately. Therefore, promoting the development of tolerance is at the heart of sensible allergy prevention - and this begins with the last trimester of pregnancy. In light of this concept, actual recommendations are discussed.

Antigen- and Epitope-Delivering Nanoparticles Targeting Liver Induce Comparable Immunotolerance in Allergic Airway Disease and Anaphylaxis as Nanoparticle-Delivering Pharmaceuticals

The targeting of natural tolerogenic liver sinusoidal endothelial cells (LSEC) by nanoparticles (NPs), decorated with a stabilin receptor ligand, is capable of generating regulatory T-cells (Tregs), which can suppress antigen-specific immune responses, including to ovalbumin (OVA), a possible food allergen. In this regard, we have previously demonstrated that OVA-encapsulating poly(lactic-co-glycolic acid) (PLGA) nanoparticles eliminate allergic airway inflammation in OVA-sensitized mice, prophylactically and therapeutically. A competing approach is a nanocarrier platform that incorporates pharmaceutical agents interfering in mTOR (rapamycin) or NF-κB (curcumin) pathways, with the ability to induce a tolerogenic state in nontargeted antigen-presenting cells system-wide. First, we compared OVA-encapsulating, LSEC-targeting tolerogenic nanoparticles (TNPs) with nontargeted NPs incorporating curcumin and rapamycin (Rapa) in a murine eosinophilic airway inflammation model, which is Treg-sensitive. This demonstrated roughly similar tolerogenic effects on allergic airway inflammation by stabilin-targeting NP^OVAversus nontargeted NPs delivering OVA plus Rapa. Reduction in eosinophilic inflammation and TH2-mediated immune responses in the lung was accompanied by increased Foxp3⁺ Treg recruitment and TGF-β production in both platforms. As OVA incorporates IgE-binding as well as non-IgE-binding epitopes, the next experiment explored the possibility of obtaining immune tolerance by non-anaphylactic T-cell epitopes. This was accomplished by incorporating OVA^323-339 and OVA^257-264 epitopes in liver-targeting NPs to assess the prophylactic and therapeutic impact on allergic inflammation in transgenic OT-II mice. Importantly, we demonstrated that the major histocompatibility complex (MHC)-II binding (former) but not the MHC-I binding (latter) epitope interfered in allergic airway inflammation, improving TNP^OVA efficacy. The epitope-specific effect was transduced by TGF-β-producing Tregs. In the final phase of experimentation, we used an OVA-induced anaphylaxis model to demonstrate that targeted delivery of OVA and its MHC-II epitope could significantly suppress the anaphylaxis symptom score, mast cell release, and the late-phase inflammatory response. In summary, these results demonstrate comparable efficacy of LSEC-targeting versus pharmaceutical PLGA nanoparticles, as well as the ability of T-cell epitopes to achieve response outcomes similar to those of the intact allergens.

Mesenchymal Stem Cells in Asthma

Asthma is one of the worldwide respiratory health problem that affect children and adult. Current treatment strategies such as conventional and allergen immunotherapy still fall behind. Mesenchymal stem cells (MSCs) have wide regenerative capacity and immunoregulatory activity with their wide range of secretions and contact dependent manner. In this review, we focus on the current treatment strategies for asthma and MSCs as a new therapeutic tool.

Asthma immunotherapy and treatment approaches with mesenchymal stem cells

Asthma is a chronic inflammatory disease of the airways where exaggerated T helper 2 immune responses and inflammatory mediators play a role. Current asthma treatment options can effectively suppress symptoms and control the inflammatory process; however, cannot modulate the dysregulated immune response. Allergen-specific immunotherapy is one of the effective treatments capable of disease modification. Injecting allergens under the skin in allergen-specific immunotherapy can reduce asthma and improve the sensitivity of the lungs, however, has a risk of severe reactions. Mesenchymal stem cells have immunoregulatory activity with their soluble mediators and contact dependent manner. In this review, we focus on the current treatment strategies with mesenchymal stem cells in asthma as a new therapeutic tool and compare those with immunotherapy.

Establishing a high microbial load maternal-offspring asthma model in adult mice

BACKGROUND

Although it is widely accepted that the "hygiene hypothesis" explains the increased incidence of asthma, the lack of suitable animal models hinders further in-depth studies of the underlying molecular immune mechanisms. Therefore, we aimed to develop a robust mouse asthma model to investigate the role of bacteria in preventing asthma.

METHODS

BALB/c female mice were fed a mixture of eight common bacterial lysates (BL; Broncho-Vaxom®) and a commercial probiotic (Bifidobacterium tetravaccine tablets) at different concentrations before and during pregnancy to simulate different microbial load levels. Faeces from the mother mice were subjected to bacterial 16S rRNA sequencing to quantify the maternal microbial load. TLR2/4 expression and the proportion of regulatory T cells (Tregs) in the intestinal tract of female mice were determined, and the safety of the microbial load was evaluated. An asthma model was established in the offspring mice after weaning, and the extent of pulmonary pathological changes and Treg proportion were evaluated.

RESULTS

A BL concentration of 1 mg/kg enriched the intestinal flora, increased the proportion of Tregs, and increased the expression of TLR2/4 in the maternal mice. The proportion of peripheral blood Tregs was increased, whereas the risk of asthma decreased only in the offspring from mothers with a high microbial load relative to control mice.

CONCLUSION

This study established a safe and stable high microbial load maternal-offspring mouse asthma model, laying the foundation for a study on the molecular mechanism underlying the protective effects of a high microbial load against asthma.

Mesenchymal stem cells in allergic diseases: Current status

Allergic diseases, which include asthma, allergic skin diseases, allergic rhinitis and allergic conjunctivitis, have already garnered worldwide public health attention over recent decades. Mesenchymal stem cells (MSCs) have gradually emerged as a potential method for treating allergic diseases due to their immunosuppressive characteristics, tissue repair ability and secretion of various biological factors. This potential of MSC-based therapy has been confirmed in clinical and preclinical studies, which report the therapeutic benefits of MSCs for various allergic diseases and explore the antiallergic mechanisms. In this review, we focus on the discoveries and biological mechanisms of MSCs as a therapeutic tool in allergic diseases. We discuss the challenges of conducting MSC studies as well as future directions.

Expression of FOXP3 and GATA3 Transcription Factors Among Bronchial Asthmatics in Northern Population

Asthma is a common chronic airways inflammatory disorder in which the expression of genes for the transcription factors FoxP3 and GATA3 plays crucial roles in activation of specific T cells population and pathogenesis of asthma. Recent data have shown that Hb, Eosinophils, total leucocytes count (TLC), absolute eosinophil count (AEC), and IgE, may be involved in adversely influencing the status of several chronic diseases including asthma. In this communication, we have carried out a case control study in order to evaluate the expression of FoxP3, GATA-3 genes in 80 bronchial asthmatic patients using real time polymerase chain reaction technique, and also to analyse and compare the values of Hb, TLC, AEC, and IgE in asthmatics with 80 control subjects. The numbers of eosinophils and total leucocytes and the level of serum IgE were higher in asthmatics compared to healthy subjects. The relative expressions of FoxP3 and GATA-3 genes in control versus asthmatics were 12.42 ± 1.413 versus 5.79 ± 0.260 (P value = < 0.0001) and 4.731 ± 0.350 versus 8.415 ± 0.359 (P value = 0.0043), respectively. The asthmatics displayed comparatively decreased level of FoxP3 expression and higher level of GATA-3 expression. There was a positive and significant correlation between the level of IgE and expression of GATA-3 in asthmatics. Relatively lower level of FoxP3 mRNA expression in bronchial asthmatics may be linked with the sustained inflammatory process and decreased immune tolerance by asthmatics. A positive correlation of GATA-3 expression with the increase in IgE level shows it to be a characteristic of asthma. However, extensive work is required to delineate the targets involved in the pathogenesis of asthma for adequate therapeutic interventions.

Schistosoma japonicum peptide SJMHE1 suppresses airway inflammation of allergic asthma in mice

Helminths and their products can shape immune responses by modulating immune cells, which are dysfunctional in inflammatory diseases such as asthma. We previously identified SJMHE1, a small molecule peptide from the HSP60 protein of Schistosoma japonicum. SJMHE1 can inhibit delayed-type hypersensitivity and collagen-induced arthritis in mice. In the present study, we evaluated this peptide's potential intervention effect and mechanism on ovalbumin-induced asthma in mice. SJMHE1 treatment suppressed airway inflammation in allergic mice, decreased the infiltrating inflammatory cells in the lungs and bronchoalveolar lavage fluid, modulated the production of pro-inflammatory and anti-inflammatory cytokines in the splenocytes and lungs of allergic mice, reduced the percentage of Th2 cells and increased the proportion of Th1 and regulatory T cells (Tregs). At the same time, Foxp3 and T-bet expression increased, and GATA3 and RORγt decreased in the lungs of allergic mice. We proved that SJMHE1 can interrupt the development of asthma by diminishing airway inflammation in mice. The down-regulation of Th2 response and the up-regulation of Th1 and Tregs response may contribute to the protection induced by SJMHE1 in allergic mice. SJMHE1 can serve as a novel therapy for asthma and other allergic or inflammatory diseases.

Der p 1-specific regulatory T-cell response during house dust mite allergen immunotherapy

BACKGROUND

Allergen-specific immunotherapy (AIT) is the only available treatment for allergic diseases that can induce specific immune tolerance to allergens. The key mechanisms involved in this process include changes in allergen-specific regulatory T (Treg) cells.

METHODS

We studied 25 allergic rhinitis patients undergoing subcutaneous house dust mite-specific immunotherapy. Peripheral blood mononuclear cells were studied before and after 10, 30 weeks, and 3 years of AIT. Der p 1-specific T regulatory cell responses were investigated by characterization of Der p 1-MHC class II tetramer-positive cells and correlated with nasal symptom score.

RESULTS

Twelve of 25 AIT patients matched with their MHC class II expression to the Der p 1 peptide-MHC class II tetramers. A significant increase in the numbers of Der p 1-specific FOXP3⁺ Helios⁺ CD25⁺ CD127^- Treg cells after 30 weeks was observed, which slightly decreased after 3 years of AIT. In contrast, Der p 1-specific immunoglobulin-like transcript 3 (ILT3)⁺ CD25⁺ Treg cells decreased substantially from baseline after 3 years of AIT. ILT3⁺ Treg cells displayed compromised suppressive function and low FOXP3 expression. In addition, Der p 1-specific IL-10 and IL-22 responses have increased after 30 weeks, but only IL-10⁺ Der p 1-specific Treg cells remained present at high frequency after 3 years of AIT. Increased number of FOXP3⁺ Helios⁺ and IL-10⁺ and decreased ILT3⁺ Treg cell responses correlated with improved allergic symptoms.

CONCLUSION

The results indicate that AIT involves upregulation of the activated allergen-specific Treg cells and downregulation of dysfunctional allergen-specific Treg cell subset. Correction of dysregulated Treg cells responses during AIT is associated with improved clinical response.

The role of regulatory T cells in the acquisition of tolerance to food allergens in children

Food allergy is a pathological immune reaction that identifies certain harmless food proteins, usually tolerated by the majority of the people, as a threat. The prevalence of these food allergies is increasing worldwide and currently affects 8% of children. Exacerbated reactions to milk, egg and peanut are the most frequent in the pediatric population. It is well known that allergic diseases are a type 2 T-helper (Th2) immune response, characterized by the elevated production of IgE antibodies. However, little is known about the immune mechanisms responsible for the development of clinical tolerance toward food allergens. Recent studies have suggested the key role of regulatory T cells (Tregs) in controlling allergic inflammation. In this review, we discuss the importance of Tregs in the pathogenesis of food allergy and the acquisition of oral tolerance in children. Further investigation in this area will be crucial for the identification of predictive markers and the development of new therapies, which will represent a clinical and social benefit for these allergic diseases.

Integrative Analysis of lncRNAs, miRNAs, and mRNA-Associated ceRNA Network in an Atopic Dermatitis Recurrence Model

Atopic dermatitis (AD) is a prevalent inflammatory skin disease characterized by its chronic nature and relapse. Ample evidence suggests that non-coding RNAs play a major role in AD pathogenesis. However, the mechanism remains unknown, particularly in AD recurrence. Dynamic morphological and cytokine changes were measured throughout the whole course of an FITC-induced AD recurrence murine model. Microarray assay and integrative analysis were performed to comprehensively explore long non-coding RNA (lncRNA), messenger RNA (mRNA), and microRNA (miRNA) networks. Our results showed that an AD recurrence model was established. Overall, 5766 lncRNAs, 4025 mRNAs, and 202 miRNAs changed after elicitation, whereas, 419 lncRNAs, 349 mRNAs, and more notably, only 23 miRNAs, were dysregulated in the remission phase. Gene ontology (GO) and KEGG pathway enrichment analyses were used to investigate the potential functions of the dysregulated genes. The altered regulation of seven miRNAs and seven lncRNAs were validated in different stages of the model. The competing endogenous RNA (ceRNA) network inferred that lncRNA humanlincRNA0490+ could compete for miR-155-5p binding, through which it might affect Pkiα expression. Altogether, our findings have provided a novel perspective on the potential roles of non-coding RNAs in AD, and suggest that specific non-coding RNAs could be new therapeutic targets against AD recurrence.

A Hypoallergenic Polygalacturonase Isoform from Olive Pollen Is Implicated in Pollen-Pollen Cross-Reactivity

BACKGROUND

Cross-reactivity reactions between allergenic polygalacturonases (PGs) from different biological sources, especially foods and pollens from the Oleaceae family, have been described using Salsola kali PG (Sal k 6). No PG from olive pollen has been characterized to date, hampering further knowledge about cross-reactions through PGs.

OBJECTIVES

The aim of this work was to determine the potential allergenicity of the PG from olive pollen and clarify its role in cross-reactivity.

METHODS

A cDNA-encoding olive pollen PG sequence was subcloned into the pET41b vector and used to transform BL21(DE3) Escherichia coli cells to produce a His-tag fusion recombinant protein. The allergenic properties of olive pollen PG were determined by immunoblotting and ELISA in comparison to Sal k 6. The cross-reactivity potential of the protein with other pollen sources was analyzed by inhibition immunoassays.

RESULTS

The existence of other isoforms of Ole e 14 with different allergenicity was confirmed by proteomics and a meta-analysis of the recently reported olive genome. Sal k 6 showed a higher IgE recognition than Ole e 14 regardless of patient sensitization, suggesting the existence of more allergenic Ole e 14 isoforms in olive pollen. IgG and IgE inhibition assays supported the existence of cross-reactions between them and with other PGs from Oleaceae and Poaceae plant families.

CONCLUSIONS

A new allergen from olive pollen, Ole e 14, has been identified, produced as a recombinant isoform, and structurally and immunologically characterized. Its role in cross-reactivity has been confirmed and, due to its smaller IgE binding capacity, it could have an important role for therapeutic purposes.

Decorating and loading ghosts with allergens for allergen immunotherapy

More than 25% of the global population has IgE mediated allergic diseases. Allergen immunotherapy (AIT) is the only available form of treatment that alters the underlying mechanism of IgE-mediated allergic diseases. AIT is aimed at desensitizing allergic individuals by repeatedly administering disease-causing allergens over a long period of time. Despite its proven efficacy in numerous clinical trials, the effectiveness of AIT still suffers some drawbacks due to the quality of allergens used and in particular the unavailability of efficient allergen delivery systems. Several studies have demonstrated that bacterial ghosts (BG) systems can be used to display and deliver antigens to their targets for the management of diseases. However, there is no report documenting the use of BG systems for immunotherapy of IgE-mediated diseases so far. Thus, in this review, we intend to discuss the potentialities of BG systems for displaying and delivering allergens for future management of IgE-mediated diseases.

Helminth-induced regulatory T cells and suppression of allergic responses

Infection with helminths has been associated with lower rates of asthma and other allergic diseases. This has been attributed, in part, to the ability of helminths to induce regulatory T cells that suppress inappropriate immune responses to allergens. Recent compelling evidence suggests that helminths may promote regulatory T cell expansion or effector functions through either direct (secretion of excretory/secretory molecules) or indirect mechanisms (regulation of the microbiome). This review will discuss key findings from human immunoepidemiological observations, studies using animal models of disease, and clinical trials with live worm infections, discussing the therapeutic potential for worms and their secreted products for treating allergic inflammation.

International Consensus Statement on Allergy and Rhinology: Allergic Rhinitis

BACKGROUND

Critical examination of the quality and validity of available allergic rhinitis (AR) literature is necessary to improve understanding and to appropriately translate this knowledge to clinical care of the AR patient. To evaluate the existing AR literature, international multidisciplinary experts with an interest in AR have produced the International Consensus statement on Allergy and Rhinology: Allergic Rhinitis (ICAR:AR).

METHODS

Using previously described methodology, specific topics were developed relating to AR. Each topic was assigned a literature review, evidence-based review (EBR), or evidence-based review with recommendations (EBRR) format as dictated by available evidence and purpose within the ICAR:AR document. Following iterative reviews of each topic, the ICAR:AR document was synthesized and reviewed by all authors for consensus.

RESULTS

The ICAR:AR document addresses over 100 individual topics related to AR, including diagnosis, pathophysiology, epidemiology, disease burden, risk factors for the development of AR, allergy testing modalities, treatment, and other conditions/comorbidities associated with AR.

CONCLUSION

This critical review of the AR literature has identified several strengths; providers can be confident that treatment decisions are supported by rigorous studies. However, there are also substantial gaps in the AR literature. These knowledge gaps should be viewed as opportunities for improvement, as often the things that we teach and the medicine that we practice are not based on the best quality evidence. This document aims to highlight the strengths and weaknesses of the AR literature to identify areas for future AR research and improved understanding.

The Origin of Skin Dendritic Cell Network and Its Role in Psoriasis

Dendritic cells (DCs) are heterogeneous groups of innate immune cells, which orchestrate immune responses by presenting antigens to cognate T cells and stimulating other types of immune cells. Although the term ‘DCs’ generally represent highly mixed subsets with functional heterogeneity, the classical definition of DCs usually denotes conventional DCs (cDCs). Skin contains a unique DC network mainly composed of embryo precursor-derived epidermal Langerhans cells (LCs) and bone marrow-derived dermal cDCs, which can be further classified into type 1 (cDC1) and type 2 (cDC2) subsets. Psoriasis is a chronic inflammatory skin disease, which is principally mediated by IL-23/IL-17 cytokine axis. In the psoriatic skins, DCs are prominent cellular sources for TNF-α and IL-23, and the use of blocking antibodies against TNF-α and IL-23 leads to a significant clinical improvement in psoriatic patients. Recent elegant human and mouse studies have shown that inflammation-induced inflammatory DCs, LCs, dermal cDC2, and monocyte-derived DCs are pivotal DC subsets in psoriatic inflammation. Thus, targeting specific pathogenic DC subsets would be a potential strategy for alleviating and preventing DC-derived IL-23-dependent psoriatic inflammation and other inflammatory dermatoses in the future.

Safety and pharmacodynamics of intranasal GSK2245035, a TLR7 agonist for allergic rhinitis: A randomized trial

BACKGROUND

Toll-like receptor 7 (TLR7) stimulation in the airways may reduce responses to aeroallergens by induction of type 1 interferons (IFNs). GSK2245035 is a novel selective TLR7 agonist in pharmaceutical development.

OBJECTIVE

Assessment of safety, pharmacodynamics and nasal allergic reactivity following repeated weekly intranasal (i.n.) GSK2245035.

METHODS

This randomized, double-blind, placebo-controlled study (TL7116958) was conducted over two pollen seasons (2013-2014) and follow-up study (204509) conducted 1 year later. Participants with allergic rhinitis (n=42) were randomized to receive eight weekly doses of i.n. GSK2245035 (20 ng [2014 Cohort; n=14] or 80 ng [2013 Cohort; n=14]) or placebo (n=14). Adverse events (AEs) including cytokine release syndrome AEs (CytoRS-AEs) and nasal symptoms were assessed. Nasal and serum IFN-inducible protein 10 (IP-10) were measured after doses 1 and 8, then 1 (follow-up visit [FUV] 1) and 3 (FUV2) weeks after final dose. Nasal allergen challenges (NACs) and allergic biomarker assessment (nasal, serum) were conducted at baseline, FUV1, FUV2 and at a FUV 1 year after final dose (FUV3; 2014 Cohort only). A Bayesian framework enabled probability statements for mean effect sizes.

RESULTS

GSK2245035 induced CytoRS-AEs (most commonly headache, median duration <1 day) in 93% of participants at 80 ng, while AE incidence at 20 ng was similar to placebo. There was no evidence of nasal inflammation. Dose-related increases in nasal and serum IP-10 were observed 24 hours after doses 1 and 8 (>95% certainty). Both doses showed a trend in reducing total nasal symptom score 15 minutes post-NAC at FUV1 and FUV2, but there was no reduction evident at FUV3. Nasal levels of selected allergic biomarkers demonstrated trends for reductions at FUV1, FUV2 and FUV3.

CONCLUSIONS AND CLINICAL RELEVANCE

Weekly i.n. GSK2245035 20 ng was well tolerated and reduced allergic reactivity to nasal challenge for 3 weeks post-treatment.

Psychoneuroimmunoendocrinology: clinical implications

Psychoneuroimmunoendocrinology, which was first described in 1936, is the study of the interactions between the psyche, neural and endocrine functions and immune responses. The aim of psychoneuroimmunoendocrinology is to apply medical knowledge to the treatment of different allergic, immune, autoimmune, rheumatic, neoplastic, endocrine, cardiovascular and dental pathologies, among other disorders. Epigenetic factors and major stresses from different types of stimuli acting through distinct pathways and neurotransmitters are highly involved in altering the psychoneuroimmunoendocrine axis, resulting in the emergence of disease. The main purpose of this report is to expand the understanding of psychoneuroimmunoendocrinology and to demonstrate the importance of the above-mentioned interactions in the etiology of multiple pathologies. In this review, a search of the medical literature using PubMed (free access search engine for the Medline database of the National Library of Medicine of the United States) over the years 1936 to 2016 was conducted, and descriptive and experimental studies and reviews of the scientific literature were included.

Oral tolerance inhibits atopic dermatitis-like type 2 inflammation in mice by modulating immune microenvironments

BACKGROUND

Oral tolerance is immune unresponsiveness induced by oral administration of innocuous antigens. Oral administration of allergens has been shown to be effective for suppressing IgE production in allergic responses. However, whether oral tolerance has a role in protection from allergic skin inflammation has not been fully investigated. Here, we evaluated the potential protective role of oral tolerance in a murine model of atopic dermatitis (AD) and investigated the underlying immunologic mechanisms.

METHODS

Mice were fed with ovalbumin (OVA) in drinking water then epicutaneously sensitized by repeated application of OVA to tape-stripped skin. Skin biopsies were analyzed for immunohistopathologic features. Levels of antibodies in sera and intestinal washes were measured by ELISA. Flow cytometry and real-time PCR analysis of the skin and mesenteric lymph nodes (MLN) were performed to investigate the immunologic effects of oral tolerance in epicutaneous (EC) sensitization-induced allergic responses.

RESULTS

Induction of oral tolerance effectively inhibited inflammatory responses provoked by EC sensitization. Tolerogenic immune mediators were significantly increased in the skin and MLN of EC-sensitized mice following induction of oral tolerance. A marked increase in Il5 and Il13 expression and infiltration of eosinophils and type 2 innate lymphoid cells (ILC2) in the skin of EC-sensitized mice were significantly inhibited by oral tolerance.

CONCLUSIONS

Oral tolerance plays a protective role in the development of AD in a murine model by modulating immune microenvironments to be more favorable for immune regulation. This modulation involves inhibition of ILC2 infiltration in skin lesions.

T Cell Epitope-Containing Domains of Ragweed Amb a 1 and Mugwort Art v 6 Modulate Immunologic Responses in Humans and Mice

BACKGROUND

Ragweed (Ambrosia artemisiifolia) and mugwort (Artemisia vulgaris) are the major cause of pollen allergy in late summer. Allergen-specific lymphocytes are crucial for immune modulation during immunotherapy. We sought to generate and pre-clinically characterise highly immunogenic domains of the homologous pectate lyases in ragweed (Amb a 1) and mugwort pollen (Art v 6) for immunotherapy.

METHODS

Domains of Amb a 1 (Amb a 1α) and Art v 6 (Art v 6α) and a hybrid molecule, consisting of both domains, were designed, expressed in E. coli and purified. Human IgE reactivity and allergenicity were assessed by ELISA and mediator release experiments using ragweed and mugwort allergic patients. Moreover, T cell proliferation was determined. Blocking IgG antibodies and cytokine production in BALB/c mice were studied by ELISA and ELISPOT.

RESULTS

The IgE binding capacity and in vitro allergenic activity of the Amb a 1 and Art v 6 domains and the hybrid were either greatly reduced or abolished. The recombinant proteins induced T cell proliferative responses comparable to those of the natural allergens, indicative of retained allergen-specific T cell response. Mice immunisation with the hypoallergens induced IL-4, IL-5, IL-13 and IFN-γ production after antigen-specific in vitro re-stimulation of splenocytes. Moreover, murine IgG antibodies that inhibited specific IgE binding of ragweed and mugwort pollen allergic patients were detected.

CONCLUSION

Accumulation of T cell epitopes and deletion of IgE reactive areas of Amb a 1 and Art v 6, modulated the immunologic properties of the allergen immuno-domains, leading to promising novel candidates for therapeutic approach.

Allergen-specific immunotherapy: is it vaccination against toxins after all?

IgE-mediated allergies, in particular allergic rhinoconjunctivitis and asthma, have reached epidemic proportions, affecting about one-third of the population in developed countries. The most effective treatment for allergies is specific immunotherapy (SIT), which involves the injection of increasing doses of an allergen extract to allergic individuals. The current form of SIT was first introduced in 1911 and recently celebrated its 100th birthday for the treatment of hay fever. The concept of this therapy at the time was straightforward, as it was believed that pollen contained toxins against which the patient could be vaccinated. However, the understanding became blurred with the discovery that IgE antibodies were the effector molecules of the allergic response. Subsequent research focused on the idea that SIT should induce tolerance keeping the IgE antibodies at bay. In this review, we will discuss the various hypotheses for the mechanism of SIT and we will put forward the concept that allergens may be viewed as 'protoxins' which need to be activated by IgE antibodies. Within this framework, protoxin-neutralizing antibodies are the key effector molecules while a shift to Th1 or Treg cells mainly contributes to the efficacy of SIT by helping B cells to produce neutralizing IgG antibodies.

Novel Delivery Routes for Allergy Immunotherapy: Intralymphatic, Epicutaneous, and Intradermal

Current allergy immunotherapy protocols suffer from two main problems: long treatment duration and systemic allergic side effects of the allergen administrations. The immunologic effects of allergen administration could be enhanced and the number of allergen administrations and treatment duration reduced by choosing a tissue for administration that contains a high density of antigen-presenting cells. Local side effects could be reduced by choosing a route characterized by a low density of mast cells, and systemic side effects could be reduced by administration to nonvascularized tissues, so that inadvertent systemic distribution of the allergen and consequent systemic allergic side effects are minimized.

Bifidobacterium longum BBMN68-specific modulated dendritic cells alleviate allergic responses to bovine β-lactoglobulin in mice

AIMS

This study was designed to demonstrate the protective effects of Bifidobacterium longum BBMN68-specific modulated dendritic cells (DCs) on allergic inflammation in β-lactoglobulin (BLG)-sensitized mice.

METHODS AND RESULTS

BALB/c mice were sensitized to BLG in accordance with a model of food allergy protocol and given oral BBMN68 daily. BBMN68 was found to significantly reduce BLG-specific hypersensitivity reactions by suppressing the aberrant balance of Th1/Th2 responses with increasing the number of CD4+CD25+Foxp3+ Treg cells in mesenteric lymph nodes (MLN) by 48·1%. The level of CD103+DCs was up-regulated by 136·7 and 56·2% in payer's patches and MLN, respectively, in response to the lower expression levels of cell-surface molecules (CD86 and MHC-II) induced by BBMN68 supplementation. The CD11c+DCs isolated from BBMN68 mice showed 45·6% more Foxp3+ expression in vitro.

CONCLUSIONS

These data suggest that BBMN68-specific induction of CD11c+CD103+DCs and semi-mature DCs reduce BLG allergic reactions.

SIGNIFICANCE AND IMPACT OF THE STUDY

These data confirm that BBMN68 may be a suitable therapeutic approach to the alleviation of food allergies, and BBMN68-specific induction of CD11c+CD103+DCs and semi-mature DCs are associated with this protection.

microRNA and Allergy

Allergy is a common hypersensitivity disorder of the immune system, which, along with other factors, is also subjected to regulation by microRNAs. The most common allergic diseases are allergic rhinitis, asthma, atopic dermatitis, and food allergy, which all are multifactorial and very heterogeneous conditions, highlighting the need for more individualized treatment techniques. More particular key questions in relation to allergic diseases are how microRNAs influence the differentiation, polarization, plasticity and functions of T helper and other immune cells, as well as the development of immune tolerance. In addition, microRNAs can affect allergic inflammation and tissue remodeling through their functions in epithelial and other tissue cells. Among immune system-related microRNAs, miR-21, miR-146a, and miR-155 are the most intensively studied and have convincingly been demonstrated to regulate immune responses and tissue inflammation in allergic diseases. Further characterization of microRNA functions is important, as similar to other conditions, the modulation of microRNA expression could potentially be used for therapeutic purposes in allergic diseases in the future. In addition, miRNAs could be implemented as biomarkers for endotyping complex allergic conditions.