New targets for allergic rhinitis — a disease of civilization

Immunoglobulin E Detection Method Based on Cascade Enzymatic Reaction Utilizing Portable Personal Glucose Meter

We herein describe a cascade enzymatic reaction (CER)-based IgE detection method utilizing a personal glucose meter (PGM), which relies on alkaline phosphatase (ALP) activity that regulates the amount of adenosine triphosphate (ATP). The amount of sandwich assay complex is determined according to the presence or absence of the target IgE. Additionally, the ALP in the sandwich assay catalyzes the dephosphorylation of ATP, a substrate of CER, which results in the changes in glucose level. By employing this principle, IgE was reliably detected at a concentration as low as ca. 29.6 ng/mL with high specificity toward various proteins. Importantly, the limit of detection (LOD) of this portable PGM-based approach was comparable to currently commercialized ELISA kit without expensive and bulky analysis equipment as well as complexed washing step. Finally, the diagnostic capability of this method was also successfully verified by reliably detecting IgE present in a real human serum sample with an excellent recovery ratio within 100 ± 6%.

Flos magnoliae constituent fargesin has an anti-allergic effect via ORAI1 channel inhibition

Flos magnoliae (FM), the dry flower buds of Magnolia officinalis or its related species, is a traditional herbal medicine commonly used in Asia for symptomatic relief of and treating allergic rhinitis, headache, and sinusitis. Although several studies have reported the effects of FM on store-operated calcium entry (SOCE) via the ORAI1 channel, which is essential during intracellular calcium signaling cascade generation for T cell activation and mast cell degranulation, the effects of its isolated constituents on SOCE remain unidentified. Therefore, we investigated which of the five major constituents of 30% ethanoic FM (vanillic acid, tiliroside, eudesmin, magnolin, and fargesin) inhibit SOCE and their physiological effects on immune cells. The conventional whole-cell patch clamp results showed that fargesin, magnolin, and eudesmin significantly inhibited SOCE and thus human primary CD4⁺ T lymphocyte proliferation, as well as allergen-induced histamine release in mast cells. Among them, fargesin demonstrated the most potent inhibitory effects not only on ORAI1 (IC50 = 12.46 ± 1.300 μM) but also on T-cell proliferation (by 87.74% ± 1.835%) and mast cell degranulation (by 20.11% ± 5.366%) at 100 μM. Our findings suggest that fargesin can be a promising candidate for the development of therapeutic drugs to treat allergic diseases.

The efficacy and safety of acupoint application combined with western medicine for allergic rhinitis: A protocol for systematic review and meta-analysis

BACKGROUND

Acupoint application combined with western medicine has been used for treating allergic rhinitis widely. However, the efficacy and safety of acupoint application combined with western medicine for allergic rhinitis are unclear. This study aims to evaluate the efficacy and safety of acupoint application combined with western medicine for allergic rhinitis.

METHODS

Randomized controlled trials of acupoint application combined with western medicine for allergic rhinitis will be searched in PubMed, EMbase, Cochrane Library, Web of Science, China National Knowledge Infrastructure, WanFang, the Chongqing VIP Chinese Science and Technology Periodical Database, and China biomedical literature database from inception to July, 2020. And Baidu Scholar, Google Scholar, International Clinical Trials Registry Platform, and Chinese Clinical Trials Registry will be searched to obtain more relevant studies comprehensively. Two researchers will perform data extraction and risk of bias assessment independently. Statistical analysis will be conducted in RevMan 5.3.

RESULTS

This study will summarize the present evidence by exploring the efficacy and safety of acupoint application combined with western medicine for the treatment of allergic rhinitis.

CONCLUSIONS

The findings of the study will provide helpful evidence for the efficacy and safety of acupoint application combined with western medicine in the treatment of allergic rhinitis, facilitating clinical practice and further scientific studies.

ETHICS AND DISSEMINATION

The private information from individuals will not publish. This systematic review also will not involve endangering participant rights. Ethical approval is not required. The results may be published in a peer-reviewed journal or disseminated in relevant conferences.

OSF REGISTRATION NUMBER

DOI 10.17605/OSF.IO/NSGJH.

Prostaglandin D2 receptor antagonists in allergic disorders: safety, efficacy, and future perspectives

INTRODUCTION

Prostaglandin D₂ (PGD₂) is a major cyclooxygenase mediator that is synthesized by activated human mast cells and other immune cells. The biological effects of PGD₂ are mediated by D-prostanoid (DP₁), DP₂ (CRTH2) and thromboxane prostanoid (TP) receptors that are expressed on several immune and non-immune cells involved in allergic inflammation. PGD₂ exerts various proinflammatory effects relevant to the pathophysiology of allergic disorders. Several selective, orally active, DP₂ receptor antagonists and a small number of DP₁ receptor antagonists are being developed for the treatment of allergic disorders.

AREAS COVERED

The role of DP₂ and DP₁ receptor antagonists in the treatment of asthma and allergic rhinitis.

EXPERT OPINION

Head-to-head studies that compare DP₁ antagonists with the standard treatment for allergic rhinitis are necessary to verify the role of these novel drugs as mono- or combination therapies. Further clinical trials are necessary to verify whether DP₂ antagonists as monotherapies or, more likely, as add-on therapies, will be effective for the treatment of different phenotypes of adult and childhood asthma. Long-term studies are necessary to evaluate the safety of targeted anti-PGD₂ treatments.

JAK/STAT inhibitors and other small molecule cytokine antagonists for the treatment of allergic disease

OBJECTIVE

To provide an overview of janus kinase (JAK), chemoattractant receptor homologous molecule expressed on T_H2 cells (CRTH2), and phosphodiesterase 4 (PDE4) inhibitors in allergic disorders.

DATA SOURCES

PubMed literature review.

STUDY SELECTIONS

Articles included in this review discuss the emerging mechanism of action of small molecule inhibitors and their use in the treatment of atopic dermatitis (AD), asthma, and allergic rhinitis (AR).

RESULTS

Allergic diseases represent a spectrum of diseases, including AD, asthma, and AR. For decades, these diseases have been primarily characterized by increased T_H2 signaling and downstream inflammation. In recent years, additional research has identified disease phenotypes and subsets of patients with non-Th2 mediated inflammation. The increasing heterogeneity of disease has prompted investigators to move away from wide-ranging treatment approaches with immunosuppressive agents, such as corticosteroids, to consider more targeted immunomodulatory approaches focused on specific pathways. In the past decade, inhibitors that target JAK signaling, PDE4, and CRTH2 have been explored for their potential activity in models of allergic disease and therapeutic benefit in clinical trials. Interestingly, although JAK inhibitors provide an opportunity to interfere with cytokine signaling and could be beneficial in a broad range of allergic diseases, current clinical trials are focused on the treatment of AD. Conversely, both PDE4 and CRTH2 inhibitors have been evaluated in a spectrum of allergic diseases. This review summarizes the varying degrees of success that these small molecules have demonstrated across allergic diseases.

CONCLUSION

Emerging therapies currently in development may provide more consistent benefit to patients with allergic diseases by specifically targeting inflammatory pathways important for disease pathogenesis.

A 2-year step-down withdrawal from inhaled corticosteroids in asthmatic children receiving immunotherapy

BACKGROUND

Inhaled corticosteroids (ICSs) for treating asthma are controversial because of their negative effects on the growth of asthmatic children and without clearly defined withdrawal strategy. A 2-year ICS step-down and withdrawal strategy has been developed for asthmatic children receiving 3-year subcutaneous immunotherapy (SCIT).

METHODS

Eleven children were included into the SCIT group and 13 children into the ICS group. ICSs were discontinued when children met the following criteria: requiring only 1 puffper day, with good control, for at least 6 months; having a forced expiratory volume in 1 second (FEV₁)/forced vital capacity ≥80%; and SCIT discontinued for ≥24 months. The main endpoints were the results of both the childhood asthma control test (C-CAT) and the methacholine bronchial provocation test.

RESULTS

In the SCIT group, all the 11 children had ICS discontinued, with one child developed asthma attack after pneumonia and received ICS again after completion of SCIT. In the ICS group, five children discontinued ICS and developed asthma attacks later and received ICS again; the other eight children developed severe symptoms during ICS step-down. Thus, the discontinuation of ICS was only achieved in the SCIT group. The dose of methacholine that caused a decrease of 20% in FEV₁ continued to improve after discontinuation of ICS for the SCIT group and presented better results than the ICS group (P=0.050). After completion of SCIT, the C-CAT had improved significantly after 30 months of treatment compared with the ICS group (P<0.05).

CONCLUSIONS

In the present study, we developed a 2-year step-down and withdrawal strategy from ICSs strategy for allergic asthma children receiving SCIT; the strategy was efficacious and safe.

Treatment of allergic rhinitis with acupoint herbal plaster: an oligonucleotide chip analysis

Background

Allergic rhinitis is regarded as an imbalanced Th1/Th2 cell-mediated response. The present study used microarray analysis to compare gene expression levels between allergic rhinitis patients before and after a series of acupoint herbal plaster applications.

Methods

In this experimental pilot study, volunteers experiencing sneezing, runny nose, and congestion for more than 9 months in the year following initial diagnoses were included after diagnostic confirmation by otolaryngologists to exclude patients with sinusitis and nasal polyps. Patients with persistent allergic rhinitis each received four acupoint herbal plaster treatments applied using the moxibustion technique. Clinical outcomes were evaluated using the Rhinitis Quality of Life Questionnaire (RQLQ). Peripheral blood samples were analyzed using an ImmunoCAP Phadiatop test, and patients were classified as phadiatop (Ph)-positive or -negative. Microarray results were analyzed for genes that were differentially expressed between (1) Ph-positive and -negative patients treated with herbal plaster; and (2) before and after herbal plaster treatment in the Ph-positive patient group. Unsupervised and supervised methods were used for gene-expression data analysis.

Results

Nineteen Ph-positive and four Ph-negative participants with persistent allergic rhinitis were included in the study. RQLQ results indicated that the 19 Ph-positive volunteers experienced improvement in six of seven categories following acupoint herbal plaster treatments, whereas the four Ph-negative participants reported improvement in only two categories. Hierarchical clustering and principle component analysis of the gene expression profiles of Ph-positive and –negative participants indicated the groups exhibited distinct physiological responses to acupoint herbal treatment. Evaluation of gene networks using MetaCore identified that the “Immune response_IL-13 signaling via JAK-STAT” and the “Inflammation_Interferon signaling” were down- and up-regulated, respectively, among Ph-positive subjects.

Conclusions

In this preliminary study, we find that the IL-13 immune response via JAK-STAT signaling and interferon inflammation signaling were down- and upregulated, respectively, in the Ph-positive group. Further studies are required to verify these pathways in Ph-positive patients, and to determine the mechanism of such pathway dysregulation.

Trial registration

ClinicalTrials.gov: NCT02486159. Registered 30 Jun 2015.

Hydroxytyrosol modulates Par j 1-induced IL-10 production by PBMCs in healthy subjects

Several papers have demonstrated the importance of substances from natural sources which can exert powerful anti-inflammatory effects. In this respect, hydroxytyrosol, one of the major elements of the phenolic components of olive oil, has been extensively studied for its anti-inflammatory activities and safety profile. In this report, we demonstrate that the co-stimulation of human PBMCs from healthy subjects with the Par j 1 allergen and hydroxytyrosol induced a statistically significant increase in the amount of Par j 1-induced IL-10, demonstrating that hydroxytyrosol can modulate an allergen-specific immune response potentiating a suppressive immune response towards an allergen. Our work opens the way to further studies to elaborate the possibility of using hydroxytyrosol as a nutrient for allergy prevention.

Mouse Models Applied to the Research of Pharmacological Treatments in Asthma

Models developed for the study of asthma mechanisms can be used to investigate new compounds with pharmacological activity against this disease. The increasing number of compounds requires a preclinical evaluation before starting the application in humans. Preclinical evaluation in animal models reduces the number of clinical trials positively impacting in the cost and in safety. In this chapter, three protocols for the study of drugs are shown: a model to investigate corticoids as a classical treatment of asthma; a protocol to test the effects of retinoic acid (RA) on asthma; and a mouse model to test new therapies in asthma as monoclonal antibodies.

Macrophage Infiltrate Is Elevated in CRSwNP Sinonasal Tissue Regardless of Atopic Status

Objective

Macrophages are major producers of inflammatory cytokines; however, their role in chronic rhinosinusitis (CRS) has not been clearly defined. The aim of this study was to quantify macrophages in sinus tissue of patients with various subtypes of CRS and determine the impact of atopic status on macrophage infiltrate.

Study Design

Prospective immunohistochemical study of human sinonasal tissue.

Setting

Academic medical center.

Subjects and Methods

Human sinonasal tissue was taken from patients with CRS with nasal polyposis (CRSwNP, n = 8), CRS without nasal polyposis (CRSsNP, n = 8), and controls (n = 8) undergoing surgery for CSF leak repair or endoscopic excision of non-secreting pituitary tumor. Samples were immunohistochemically stained for macrophage/monocyte markers Mac387 and CD68.

Results

CRSwNP patients had significantly increased numbers of Mac387 and CD68 cells compared to control patients ( P < .05) or CRSsNP patients ( P < .01). CRSsNP had significantly increased number of cells staining for CD68 compared to controls ( P < .05). The increased presence of macrophages measured by either marker in CRSwNP was independent of atopic status.

Conclusion

Macrophages are increased in CSRwNP patients regardless of atopic status and may contribute to the immunopathology of CRS.

Molecular mechanism of action of K(D)PT as an IL-1RI antagonist for the treatment of rhinitis

K(D)PT curing allergic rhinitis through keeping IL-1RI in close status.

The major allergen of the Parietaria pollen contains an LPS-binding region with immuno-modulatory activity

BACKGROUND

The major allergens in Parietaria pollen, Par j 1 and Par j 2, have been identified as lipid transfer proteins. The family of the Par j 1 allergens is composed of two isoforms, which differ by the presence of a 37 amino acid peptide (Par37) exclusive to the Par j 1.0101 isoform. The goal of this study was to elucidate the biological properties of the Par37 peptide.

METHODS

In silico analysis, spectrofluorimetric experiments and in vitro cell culture assays were used to identify the biological properties of Par37. In addition, a mouse model of sensitization was used to study the influence of Par37 in the murine immune response.

RESULTS

In silico analysis predicted that Par37 displays characteristics of a host defence peptide. Spectrofluorimetric analysis, real-time PCR and ELISA assays demonstrated that Par37 possesses an LPS-binding activity influencing cell signalling in vitro. In RAW264.7 cells, LPS-induced IL-6 and TNF-α transcription and translation were inhibited after preincubation with Par37. Consistent with these data, inhibition of IFN-γ secretion was observed in murine spleen cells and in human PBMC. Finally, mice immunized with the two Par j 1 isoforms differing in the presence or absence of the Par37 peptide showed different immunological behaviours in vivo.

CONCLUSIONS

This study demonstrates that the Par j 1.0101 allergen displays LPS-binding activity due to the presence of a 37 amino acid COOH-terminal region and that this region is capable of influencing cytokine and antibody responses in vitro and in vivo.

Climate change and its impact on allergic rhinitis and other allergic respiratory diseases

PURPOSE OF REVIEW

To discuss current evidence of global climate change and its implications for allergic rhinitis and other allergic respiratory diseases.

RECENT FINDINGS

Global climate change is evidenced by increasing average earth temperature, increasing anthropogenic greenhouse gas levels, and elevated pollen levels. Pollutants of interest include carbon dioxide (CO2), ozone (O3), and nitrous oxide (NO2) because they can enhance the allergic response and lead to increased symptoms of allergic respiratory diseases. Heightened CO2 levels stimulate pollen production via photosynthesis and increased growth in multiple plant species investigated. Although worsened air quality appears to increase prevalence of allergic rhinitis, the effects of increased temperature are less certain. The findings of increased aeroallergen levels likely contribute to increases in presentation of allergic diseases, although more healthcare impact studies are necessary.

SUMMARY

Although recent literature indicates and strongly supports changes in temperature, pollution levels, and aeroallergen levels, more longitudinal epidemiologic surveillance of allergic diseases in relation to climate change as well as pathophysiologic studies on changing aeroallergen effects on allergic diseases are needed.

Innate and adaptive immune responses to the major Parietaria allergen Par j 1 in healthy subjects

In this study we wanted to analyse the pattern of the immune response to the Parietaria major allergen Par j 1 in freshly purified peripheral blood mononuclear cell (PBMC) from healthy subjects. We observed that Par j 1 was capable of inducing IFN-γ production by CD3⁻ and CD16⁺/CD56⁺ cells exclusively in healthy individuals. Furthermore, a multiparametric analysis allowed us a better definition of two IFN-γ-Par j 1 specific populations (IFN-γ(dim) and IFN-γ(high)) characterized by the presence of different proportions of NKT and NK cells. We also identified the concomitant presence of a subset of IL-10⁺ NK cells. Moreover, CFSE staining showed that the Par j 1 preferentially induced the proliferation of CD3⁻/CD56⁺/CD335⁺ cells. Finally, a subset of CD4⁺/CD25⁺/FoxP3⁺/IL-10⁻ T cells was identified. The result of this pilot study suggest that during a tolerogenic response, the major allergen of the Parietaria pollen works as an activator of both the innate and the adaptive human immune system.

Luminal decoration of blood vessels by activated perivasal mast cells in allergic rhinitis

BACKGROUND

In allergic diseases, like in rhinitis, antigen challenge induces rapid degranulation of tissue resident mast cells and subsequent recruitment of leukocytes in response to soluble immunmodulators. The fate of mast cell-derived, membrane associated factors in inflamed tissue remained however unresolved.

METHODS

Components of the mast cell granular membrane, including the unique marker CD63var, were examined by FACS and by confocal laser scanning microscopy in cell culture and in diseased human tissue.

RESULTS

We discovered that selected mast cell membrane components appeared on the surface of distinct bystander cells. Acceptor cells did not acquire these molecules simply by uptake of soluble material or in the form of exosomes. Instead, physically stable cell-to-cell contact was required for transfer, in which a Notch2-Jagged1 interaction played a decisive role. This process is activation-dependent, unidirectional, and involves a unique membrane topology. Endothelial cells were particularly efficient acceptors. In organotypic 3D in vitro cultures we found that transferred mast cell molecules traversed an endothelial monolayer, and reappeared focally compacted on its distal surface, away from the actual contact zone. Moreover, we observed that such mast cell-derived membrane patches decorate microcapillaries in the nasal mucosa of allergic rhinitis patients.

CONCLUSION

Direct membrane transfer from perivasal mast cells into nearby blood vessels constitutes a novel mechanism to modulate endothelial surface features with apparent significance in allergic diseases.

Lipid nanoparticles as delivery vehicles for the Parietaria judaica major allergen Par j 2

Parietaria pollen is one of the major causes of allergic reaction in southern Europe, affecting about 30% of all allergic patients in this area. Specific immunotherapy is the only treatment able to modify the natural outcome of the disease by restoring a normal immunity against allergens. The preparation of allergen-solid lipid nanoparticles as delivery vehicles for therapeutic proteins, P. judaica major allergen Par j 2, was investigated. The Par j 2 allergen was expressed in a large amount in Escherichia coli and purified to homogeneity. Its immunological properties were studied by western blotting and enzyme-linked immunosorbent assay inhibition. Solid lipid nanoparticles were obtained by water-in-oil-in-water multiple emulsion method and characterized in terms of mean size and surface charge. These systems (approximately 250 nm diameter and negative surface charge) incorporated recombinant Par j 2 with 40% or greater efficiency. Moreover, the endotoxin level and anaphylactic activity of the empty solid lipid nanoparticles and recombinant Par j 2-loaded solid lipid nanoparticles were evaluated by looking at the overexpression of CD203c marker on human basophils. These results demonstrate that recombinant Par j 2-nanoparticles could be proposed as safe compositions for the development of new therapeutic dosage forms to cure allergic reactions.

Novel Strategies for the Development of a Vaccine for Parietaria Allergy

Specific immunotherapy is a well established and clinically proved strategy to cure allergic reactions. The impressive boost of knowledge derived from DNA recombinant technology applied to this field allowed the identification, cloning and expression of several clinically relevant allergens. Recombinant allergens can be easily produced in a pure and reproducible way with immunological properties comparable to natural allergens and matching the requirements of pharmaceutical companies. Parietaria pollinosis is a major health problem in the Mediterranean basin with prolonged symptoms. In this review we will discuss the rational approaches to design hypoallergenic derivatives of the major allergens of this pollen, their immunological properties and possible clinical future implications.

Allergic rhinitis: epidemiological aspects, diagnosis and treatment

This study was a review of the literature on the epidemiological, clinical, diagnostic and therapeutic aspects of allergic rhinitis. Bibliographic searches were based on the information contained within the Medline, Latin American and Caribbean Health Sciences Literature and HighWire databases, covering the last thirty years and using the following search terms: 'allergic rhinitis', 'epidemiology', 'diagnosis' and 'treatment'. Sixty articles were selected. This study describes the increase in the prevalence of allergic rhinitis, its relationship with asthma, the diagnostic criteria and the treatment. The classification of allergic rhinitis and strategies for its treatment are presented. Therapeutic modalities presented and discussed include the administration of antihistamines, corticosteroids, immunotherapy, anti-leukotrienes, sodium cromoglycate and anti-IgE antibodies, as well as minimizing exposure to inhaled allergens. Finally, the importance of the management of allergic rhinitis in public health is emphasized.

Soy isoflavone intake is not associated with the development of cedar pollinosis in adults

Although soy isoflavone has been suggested to have both immune-enhancing and immune-suppressive effects, the effects of soy isoflavone intake on allergic disorders are unclear. A cross-sectional study indicated that a high intake of soy isoflavone is associated with a decreased risk of allergic rhinitis. We aimed to prospectively examine the relationship between soy isoflavone intake and risk of cedar pollinosis, the most common seasonal allergic rhinitis in Japan. The study was conducted in a population-based cohort of Japanese men and women. Each subject's usual diet, including soy isoflavone intake, was determined with the use of a validated FFQ in 1992. In 2002, a total of 11,229 persons who were 35-69 y old and had no history of cancer or allergic diseases at the baseline responded to a follow-up questionnaire asking about 4 symptoms related to cedar pollinosis. Cox hazard regression model was used to determine the association between soy isoflavone intake and the risk of cedar pollinosis. During the 10-y follow-up, 931 of these subjects reported that they had cedar pollinosis. There was no significant association between soy isoflavone intake and risk of cedar pollinosis in men and women after controlling for covariates. For the highest compared with the lowest quartile of soy isoflavone intake, hazard ratios were 1.07 (95% CI: 0.81-1.42) in men and 0.89 (95% CI: 0.68-1.15) in women. These data did not support an association between soy isoflavone intake and risk of cedar pollinosis.

Fungal proteases induce Th2 polarization through limited dendritic cell maturation and reduced production of IL-12

Allergens are capable of polarizing the T cell immune response toward a Th2 cytokine profile in a process that is mediated by dendritic cells (DCs). Proteases derived from Aspergillus species (Aspergillus proteases; AP) have been shown to induce a Th2-like immune response when administered directly to the airway and without adjuvant or prior priming immunizations at sites remote from the lung in models of allergic airway disease. To explore mechanisms that underlie the Th2 immune response, we have investigated the effect of AP on DC function. We found that human DCs derived from CD14(+) monocytes from healthy donors underwent partial maturation when incubated with AP. Naive allogeneic T cells primed with AP-activated DCs proliferated and displayed enhanced production of IL-4 and reduced expression of IFN-gamma as compared with naive T cells primed with LPS-activated DCs. Global gene expression analysis of DCs revealed relatively low expression of IL-12p40 in AP-activated DCs as compared with those activated by LPS, and this was confirmed at the protein level by ELISA. Exogenous IL-12p70 added to cocultures of DCs and T cells resulted in reduced IL-4 and increased IFN-gamma expression when DCs were activated with AP. When the proteolytic activity of AP was neutralized by chemical inactivation it failed to up-regulate costimulatory molecules on DCs, and these DCs did not prime a Th2 response in naive T cells. These findings provide a mechanism for explaining how proteolytically active allergens could preferentially induce Th2 responses through limited maturation of DCs with reduced production of IL-12.

Biotechnology-based allergy diagnosis and vaccination

The diagnosis and immunotherapy currently applied to allergic diseases involve the use of crude extracts of the allergen source without defining the allergy-eliciting molecule(s). Advances in recombinant DNA technology have made identification, cloning, expression and epitope mapping of clinically significant allergens possible. Recombinant allergens that retain the immunological features of natural allergens form the basis of accurate protein-chip-based methods for diagnosing allergic conditions. The ability to produce rationally designed hypoallergenic forms of allergens is leading to the development of novel and safe forms of allergy vaccines with improved efficacy. The initial clinical tests on recombinant-allergen-based vaccine preparations have provided positive results, and ongoing developments in areas such as alternative routes of vaccine delivery will enhance patient compliance.

Syk inhibitors as treatment for allergic rhinitis

Allergic rhinitis is characterized by a hypersensitive immune response in the upper airways to seasonal or perennial allergens leading to episodes of sneezing, itching, runny nose and nasal congestion. These symptoms are mainly the manifestations of a large number of mediators released by mast cells and basophils localized in the nasal mucosa, following their activation via allergen-specific immunoglobulin E (IgE) receptors. Current medications antagonize the action of distinct mediators such as histamine and leukotrienes for symptom relief, or block the production of pro-inflammatory cytokines to suppress allergic inflammation. Notably, rather than neutralizing individual mediators, Syk kinase inhibitors can block the allergen-induced release of all mast cell mediators and the production of most eicosanoids and cytokines. Thus, Syk kinase represents an attractive therapeutic target for acute and chronic allergic inflammation. Syk kinase inhibitors are now entering clinical trials. Using cell-based structure-activity relationships with primary human mast cells, a series of 2,4-diaminopyrimidine Syk kinase inhibitors was developed. One of these compounds, referred to as R112, exhibited suitable characteristics for intranasal delivery and was tested for safety and efficacy in allergic rhinitis patients. In a park environment, R112 showed remarkable amelioration of acute allergic rhinitis symptoms with rapid onset of action. These results demonstrate the clinical significance of inhibiting Syk in allergic upper airway disorders.

Anti-asthmatic potential of a D-galactose-binding lectin from Synadenium carinatum latex

Extracts from the plant Synadenium carinatum latex are widely and indiscriminately used in popular medicine to treat a great number of inflammatory disorders and although the mechanisms underlying these effects remain undefined, the lectin isolated from S. carinatum latex (ScLL) is thought to be in part responsible for these anti-inflammatory effects. In order to elucidate possible immunoregulatory activities of ScLL, we investigated the effects of ScLL administration in models of acute and chronic inflammation. Oral administration of ScLL significantly inhibited neutrophil and eosinophil extravasation in models of acute and chronic inflammation and reduced eosinophil and mononuclear blood counts during chronic inflammation. ScLL administration reduced IL(interleukin)-4 and IL-5 levels but increased interferon-gamma and IL-10 in an asthma inflammatory model, which suggested that it might induce a TH2 to TH1 shift in the adaptive immune response. ScLL also inhibited IkappaBalpha degradation, a negative regulator of proinflammatory NF-kappaB. Taken together, these results provide the first description of a single factor isolated from S. carinatum latex extract with immunoregulatory functions and suggest that ScLL may be useful in the treatment of allergic inflammatory disorders.

Inhibition of PI3K and calcineurin suppresses chemoattractant receptor-homologous molecule expressed on Th2 cells (CRTH2)-dependent responses of Th2 lymphocytes to prostaglandin D2

Interaction of prostaglandin D2 (PGD2) with chemoattractant receptor-homologous molecule expressed on Th2 cells (CRTH2) triggers chemotaxis and pro-inflammatory cytokine production by Th2 lymphocytes. We have investigated the role of inhibitors of various cell-signalling pathways on the responses of human CRTH2+ CD4+ Th2 cells to PGD2. Phosphatidylinositol 3-kinase (PI3K) and Ca2+/calcineurin/nuclear factor of activated T cells (NFAT) pathways were activated by PGD2 in Th2 cells in a CRTH2-dependent manner. Inhibition of the PI3K pathway with LY294002 significantly reduced both PGD2-induced cell migration and cytokine (interleukin-4, interleukin-5 and interleukin-13) production. The inhibitory effect of LY294002 on cell migration is likely to be related to cytoskeleton reorganization as it showed a similar potency on PGD2-induced actin polymerization. The calcineurin inhibitors, tacrolimus (FK506) and cyclosporin A, had no effect on cell migration but completely blocked both cytokine production and the nuclear translocation of NFATc1 suggesting that Ca2+/calcineurin/NFAT is involved in CRTH2-dependent cytokine production but not chemotaxis. The promotion of NFAT nuclear location by PI3K activation may be mediated by negative regulation of glycogen synthase kinase-3beta (GSK3beta), since the PGD2-stimulated increase in phospho-GSK3beta was down-regulated by LY294002, and inhibition of GSK3beta by SB216763 enhanced PGD2-induced Th2 cytokine production and reversed the inhibitory effect of LY294002. These data suggest that PI3K and Ca2+/calcineurin/NFAT signalling pathways are critically involved in pro-inflammatory responses of Th2 cells to PGD2.

Does acupuncture or Chinese herbal medicine have a role in the treatment of allergic rhinitis?

PURPOSE OF REVIEW

Complementary medicines, including acupuncture and Chinese herbal medicine, are being used increasingly for the management of allergies such as allergic rhinitis. Until relatively recently, however, evidence for the efficacy and safety of these therapies in allergic conditions has been lacking.

RECENT FINDINGS

A limited number of well conducted studies, all with small sample sizes, have demonstrated the promising therapeutic potential of acupuncture and Chinese herbal medicine for allergic rhinitis. The possible additional benefit of combining the two therapies, however, is yet to be confirmed. There are concerns about the appropriateness of the sham/placebo controls that have been used in acupuncture studies and also about the safety evaluation of individual herbs and herbal formulations. In addition to well established symptom scores and specific quality of life questionnaires, the concurrent use of conventional anti-allergy medications has been utilized as an outcome measure in a number of trials that have evaluated the effectiveness of acupuncture and Chinese herbal medicine for allergic rhinitis.

SUMMARY

Tentatively, it appears that acupuncture and Chinese herbal medicine can be effective treatments for allergic rhinitis. Confirmatory evidence, however, is needed from large and, ideally, multi-centre trials.

Highly conserved gene expression profiles in humans with allergic rhinitis altered by immunotherapy

BACKGROUND

Atopic diseases, resulting from hypersensitivity to a wide variety of allergens, affect 10-20% of the population. Immunotherapy is an effective treatment for atopic diseases, but its mechanisms are not fully understood.

OBJECTIVE

We studied gene expression profiles in the peripheral blood mononuclear cells (PBMC) and examined whether the individuals with allergic rhinitis (AR) have a unique gene expression profile and how the immunotherapy affect the gene expression profiles.

METHODS

We used cDNA microarray and 'expression analysis systemic explorer' to examine the gene expression profiles in the PBMC of atopic subjects and other groups.

RESULTS

We identified a highly conserved gene expression profile in atopic subjects that permitted their accurate segregation from control or autoimmune subjects. A major feature of this profile was the under-expression of a variety of genes that encode proteins required for apoptosis and over-expression of genes that encode proteins critical for stress responses and signal transduction. We also identified 563 genes that can segregate individuals with AR based upon receipt of immunotherapy.

CONCLUSION

There is a highly conserved gene expression profile in the PBMC of individuals with AR. This profile can be used to identify individuals with AR and to evaluate responses to immunotherapy. Quantitative endpoints, such as gene expression, may assist clinicians faced with clinical decisions in the diagnosis of patients and the evaluation of response to therapy. The knowledge of the possible genetic basis for immunotherapy efficacy may also lead to novel therapeutic approaches for atopic diseases.

Potential role of interleukin-10-secreting regulatory T cells in allergy and asthma

Allergic diseases are caused by aberrant T-helper-2 immune responses in susceptible individuals. Both naturally occurring CD4(+)CD25(+) regulatory T cells and inducible populations of antigen-specific interleukin-10-secreting regulatory T cells inhibit these inappropriate immune responses in experimental models. This article discusses the evidence that regulatory T-cell function might be impaired in allergic and asthmatic disease and that certain therapeutic regimens might function, at least in part, to promote regulatory T-cell generation. Current research strategies seek to exploit these observations to improve the generation of allergen-specific regulatory T-cell populations with the potential to provide the safe and long-term alleviation of disease symptoms.

PDE4 inhibitors as new anti-inflammatory drugs: effects on cell trafficking and cell adhesion molecules expression

Phosphodiesterase 4 (PDE4) is a major cyclic AMP-hydrolyzing enzyme in inflammatory and immunomodulatory cells. The wide range of inflammatory mechanisms under control by PDE4 points to this isoenzyme as an attractive target for new anti-inflammatory drugs. Selective inhibitors of PDE4 have demonstrated a broad spectrum of anti-inflammatory activities including the inhibition of cellular trafficking and microvascular leakage, cytokine and chemokine release from inflammatory cells, reactive oxygen species production, and cell adhesion molecule expression in a variety of in vitro and in vivo experimental models. The initially detected side effects, mainly nausea and emesis, appear at least partially overcome by the 'second generation' PDE4 inhibitors, some of which like roflumilast and cilomilast are in the later stages of clinical development for treatment of chronic obstructive pulmonary disease. These new drugs may also offer opportunities for treatment of other inflammatory diseases.

Label-free, real-time monitoring of IgE-mediated mast cell activation on microelectronic cell sensor arrays

Immunoglobulin E (IgE)-mediated mast cell activation is involved in the immediate phase of allergic reactions and plays a central role in the onslaught and persistence of allergic diseases. IgE-mediated mast cell activation includes two important events: cell sensitization resulting from IgE binding to Fc (FcepsilonRI) receptor and cell activation triggered by allergen-mediated oligomerization of membrane-bound IgE. Real-time monitoring of these events is needed to dissect the molecular mechanisms underlying IgE-mediated mast cell activation. Existing technologies are limited to label-based end-point assay formats, which detect either early signaling or final phase of mast cell activation. We describe a microelectronic cell sensor-based technology allowing dynamic monitoring of IgE-mediated mast cell sensitization and activation in real-time without any labeling steps. RBL-2H3 mast cells were cultured onto the surface of microelectronic cell sensor arrays integrated into the bottom of microtiter plates, which record electric properties, such as impedance between cell membrane and sensor surface. In the presence of the allergen, dinitrophenyl (DNP)-bovine serum albumin (BSA), anti-DNP IgE-sensitized cells were activated within 5 min and the entire activation process was quantitatively and continuously recorded. Impedance measurements correlate with morphological dynamics and mediator release as measured by beta-hexosaminidase activity, and can be blocked by pharmacological agents, inhibiting IgE-mediated signaling. The assay on microelectronic cell sensor arrays can be scaled up for high-throughput screening of pharmacological inhibitors of IgE-mediated mast cell activation and other cell-based receptor-ligand assays.