House Dust Mite Dermatophagoides Research Articles

Minimum Allergen Screening Panel for Allergic Rhinitis in Bangalore: A Cross Sectional Study.

Allergic rhinitis (AR) is a very common condition presenting to an Otorhinolaryngologist. Prevalence of AR is on the increase and it has significant impact on quality of life of the patient. Skin prick test (SPT) is a simple test to determine allergen sensitization status in patients with AR. There is wide variation in allergen panel used in SPT among various allergy clinics and many centres use a large panel of allergens which requires multiple skin pricks for the patient undergoing the test. Our aim was to identify a minimum panel of allergens among patients with symptoms of AR undergoing SPT which could be used as a screening panel for AR. The present study is a cross sectional study in patients with symptoms of AR undergoing SPT at Allergy clinic of Bangalore Baptist hospital over a period of 18months from January 2018. 149 patients were included in the study and 26 patients who had negative SPT for all allergens tested were excluded. Prevalence of sensitization for individual allergens was calculated. House dust mite (Dermatophagoides pteronyssinus and Dermatophagoides farinae) was the most prevalent allergen to which 73.9% and 65.8% of our study population was sensitized respectively. We identified a minimum allergen panel of 3 allergens (Dermatophagoides pteronyssinus, Lambs quarter and Dermatophagoides farinae) which could identify > 90% of patients sensitized in the study group.

Dominant Aero-Allergens Involved in Causing Allergic Rhinitis with Special Reference to Dust Mite Allergy and Skin Prick Test in Tripura: A Prospective Study.

Allergic rhinitis (AR) is one of the commonest forms of allergy in the world which causes significant morbidity. The prevalence has all the more increased because of increasing air pollution. Though skin prick testing (SPT) and sublingual immunotherapy (SLIT) have now been widely accepted world wide as important tool, offering prospective long term remission or cure for allergic rhinitis yet some still debate the accuracy and efficacy of both. This prospective study was conducted from February 2018 to May 2020, from amongst the patients of allergic rhinitis, presenting to the author in his private clinic. There were total 37 patients who presented with symptoms suggestive of allergic rhinitis and who underwent SPT for various common aeroallergens, as suggested by their history. The age range of the patients was from 6 to 60years, with a mean age of 27.62years. There were 23 male and 14 female patients with a male to female ratio of 1.76:1. The commonest age group affected is 21-30year group. Out of the total 37 patients of allergic rhinitis, who underwent SPT, 32 (86.5%) had a positive response and 05 (13.5%) patients had a negative response. Out of the 32 patients with positive response, 30 (93.8%) had positive reactions to multiple allergens and just 2 (6.2%) had positive reaction to single allergen. The commonest aeroallergen detected by SPT was house dust mite (bed mite) Dermatophagoides ( D )-pteronyssinus, and another house dust mite (floor mite), D -farinae, followed by Blomia, another floor mite. Out of the 32 SPT positive cases 10 (31.3%) patients opted for SLIT, after knowing the pros and cons. It can be concluded from this preliminary study that there is no doubt that SPT is a very informative confirmatory test for diagnosing allergens causing allergic rhinitis. The commonest allergen involved in causing allergic rhinitis in and around Tripura are the dust mites, commonest being D -pteronyssinus and D -farinae. SLIT has a good acceptance in the allergic rhinitis patients and out of ten all of the patients reported significant symptomatic improvement. This allergen mapping in this area is probably the first of its kind, which will help in deciding future strategies in management of AR, by immunotherapy or avoidance measures. In future many more patients may get benefit of long term cure from it.

96 Sublingual allergen-specific immunotherapy in pediatric patients: biomarkers and molecular allergy diagnostics as predictors of therapeutic success

Abstract Background Efficacy of allergen-specific immunotherapy (ASIT) in patients with asthma could be significantly enhanced when physicians have an opportunity to identify those who are most likely to respond, determine when to stop treatment, and predict relapse. Thus, molecular allergy diagnostic is an effective tool that could help to individualize the diagnosis and treatment of asthma by accurate detection of the causative and cross-reactive allergens in pediatric patients. Cytokines are known as reliable diagnostic and prognostic biomarkers for asthma and can be used to evaluate the therapeutic effect. Objectives To evaluate the roles of molecular allergy diagnostic and biomarkers (L-10, IFNγ и TGFβ) as predictors of ASIT efficacy in pediatric patients with asthma. Design/Methods Eighty children aged 5 to 18 years with mild and moderate atopic bronchial asthma were included in the study. Sixty-eight out of 80 (85%) were found to have sensitization to house dust mites Dermatophagoides Pteronyssinus and/or Dermatophagoides Farinae. All these patients underwent molecular diagnostics using ImmunoCAP (Phadia 100) to determine the major (r Der p1, r Der p 2) and minor allergens (r Der p10) of the house dust mites. Twenty-eight patients with mild and moderate asthma were found to have a high sensitivity to these allergens and received SLIT with a mixture of house dust mites (Dermatophagoides Pteronyssinus and/or Dermatophagoides Farinae). To compare the efficacy of SLIT, we evaluated the severity of asthma clinical symptoms on a point scale from 0 to 3, and biomarker levels (IL-10, IFNγ и TGFβ) before and 6 months after SLIT. Twelve healthy children were included in the study as a reference group. Results At the beginning of the study, the average daily score in the SLIT group of 2.5 ± 0.7, and after 6 months of treatment, it decreased to 0.5 ± 0.2. The levels of biomarkers were markedly decreased prior to the treatment, especially TGFβ levels, and normalized at the end of treatment (Tab.1). Conclusion These findings support the efficacy of molecular diagnosis to determine the efficacy of allergen-specific immunotherapy in patients with asthma.

Glycoprotein profile from House Dust Mite Dermatophagoides pteronyssinus reveals distinct antigenic and allergenic profile among allergic patients and healthy subjects

Glycoprotein profile from House Dust Mite Dermatophagoides pteronyssinus reveals distinct antigenic and allergenic profile among allergic patients and healthy subjects

Molecular Dynamics Simulations of Mite Aquaporin DerfAQP1 from the Dust Mite Dermatophagoides farinae (Acariformes: Pyroglyphidae).

Aquaporins are a large family of transmembrane channel proteins that facilitate the passive but highly selective transport of water and other small solutes across biological membranes. House dust mite (Dermatophagoides farinae) is the major source of household immunogens, and we have recently reported six cDNA sequence encoding aquaporins from this mite species. To better understand the structure and role of mite aquaporin, we constructed a tertiary structure for DerfAQP1 by homology modeling from the X-ray structure of malaria aquaporin PfAQP (Protein Data Bank code No. 3C02) and conducted molecular dynamics simulation. The simulation arranged seven water molecules in a single file through the pores of the DerfAQP1. Further, two conserved Asn-Pro-Ala motifs were located on Asn203 and Asn77; residues Arg206, Trp57, Met190, Gly200, and Asp207 constituted an extracellular vestibule of the pore; and residues His75, Val80, Ile65, and Ile182 constituted the cytoplasmic portions. The overall free energy profile for water transport through DerfAQP1 revealed an energy barrier of ~2.5 kcal/mol. These results contribute to the understanding of mite physiology and pathology.

Allergic sensitisation in South Africa: Exploring regional variation in sensitisation.

Allergy is a common health problem in South Africa (SA), and a rational approach to allergy testing is essential to ensure cost-effective as well as optimal patient diagnosis and management. To review allergy testing data with respect to current national testing recommendations, and to explore the regional variations in sensitisation. Retrospective data review on allergy testing from a private pathology provider in SA over a 2-year period. Data on skin-prick testing (SPT) and allergen-specific IgE testing originating from all the provinces of SA were collected and analysed with regards to allergen positivity rate and regional sensitisation patterns. Among the patients (N=450320) tested for a suspected inhalant allergy, 46% tested positive. Only 45% of these received additional testing for the nine recommended inhalant allergens included in the current national testing protocol. Among the patients (N=6775) who received SPT for a suspected inhalant allergy, 59% yielded one or more positive results. The most frequent sensitising allergens were house dust mite (Dermatophagoides pteronyssinus) and grass pollen. The house dust mite, Blomia tropicalis, was a significant sensitiser in coastal regions. SPT identified two other important regional allergens which are not included in the current recommendations for inhalant allergen-specific IgE testing. The current diagnostic recommendations include allergens that demonstrate significant sensitisation in all regions of SA. Two additional allergens that show significant regional sensitisation in the South African population were identified. These findings may aid the recommendations for the most appropriate and cost-effective approach to allergy testing of symptomatic patients in SA.

Studies of royal jelly and associated cross-reactive allergens in atopic dermatitis patients.

Royal jelly (RJ), a creamy substance secreted by honeybees, is the exclusive diet for queen bee differentiation and life maintenance. RJ has been used in cosmetics, beverages, medicines, and supplements worldwide. However, allergy is a concerning issue for RJ, especially in atopic dermatitis (AD) and asthma patients. In some cases, allergic reactions are seen after the first intake of RJ, suggesting the existence of allergens cross-reactive with RJ. Information about the cross-reactive allergens is very important for the safe application of RJ; however, study of this cross-reactivity is quite limited. In this study, we attempted to identify allergens cross-reactive with RJ by using serum samples from 30 AD patients who had never been exposed to RJ. In an enzyme-linked immunosorbent assay (ELISA) experiment, RJ-binding IgE antibodies were detected in the serum of 10 out of 30 patients, and their antibody titers ranged from 4- to 2,048-fold dilution ratios. Additionally, 3 AD patients were determined to be positive in a skin-prick test (SPT) with an RJ solution. Significant correlations were observed between the anti-RJ antibody titer and nonspecific IgE and between the anti-RJ antibody titer and the Eczema Area and Severity Index score. We further examined the cross-reactivity between RJ and 14 typical allergens by using an ELISA-inhibition assay and demonstrated that the following 6 allergens showed cross-reactivity with RJ: the European house dust mite (HDM) (Dermatophagoides pteronyssinus), American HDM (Dermatophagoides farinae), snow crab (Chionocetes spp.), edible crab (Cancer pagurus), German cockroach (Blatella germanica), and honeybee venom (Apis mellifera). In conclusion, people with a history of allergic diseases, including AD, asthma, and allergic rhinitis, should be cautioned against consuming RJ products because of the potential for cross-reactive responses to ensure the safe and successful use of RJ supplements.

Strain-Specific Differences in House Dust Mite (Dermatophagoides farinae)-Induced Mouse Models of Allergic Rhinitis.

Objectives.Limited information is available regarding strain-related differences in mouse models of allergic rhinitis induced by Dermatophagoides farinae (Der f1). In this study, we compared differences between two mouse strains and determined the optimal dose of Der f1 for allergic rhinitis mouse models.Methods.Forty-eight mice were assigned to the following six groups (n=8 per group): group A (control, BALB/c), group B (Der f1-sensitized BALB/c, 25 µg), group C (Der f1-sensitized BALB/c, 100 µg), group D (control, C57BL/6), group E (Der f1-sensitized C57BL/6, 25 µg), and group F (Der f1-sensitized C57BL/6, 100 µg). Allergic inflammation was induced with Der f1 and alum sensitization, followed by an intranasal challenge with Der f1. Rubbing and sneezing scores, eosinophil and neutrophil infiltration, and immunoglobulin, cytokine, and chemokine levels in the nasal mucosa and from splenocyte cultures were assessed.Results.Rubbing and sneezing scores were higher in groups B, C, E, and F than in groups A and D, with a similar pattern in both strains (i.e., group B vs. E and group C vs. F). Serum immunoglobulin levels were significantly elevated compared to the control in groups B and C, but not in groups E and F. Eosinophil and neutrophil infiltration increased (all P<0.05) after the Der f1 challenge (groups B, C, E, and F) compared to the control (groups A and D) in both the BALB/c and C57BL/6 strains, without any significant difference between the two strains (group A vs. D, group B vs. E, and group C vs. F) (P>0.05). BALB/c mice (group B) showed a greater elevation of splenic interleukin (IL)-4 (P<0.01), IL-5 (P<0.01), and IL-6 levels (P<0.05) and nasal IL-4 mRNA levels (P<0.001) than the C57BL/6 mice (group E). Interestingly, mice treated with 100 µg Der f1 showed a weaker allergic response than those treated with 25 µg.Conclusion.We found 25 µg to be a more appropriate dose for Der f1 sensitization. BALB/c mice are more biased toward a Th2 response and are a more suitable model for allergic rhinitis than C57BL/6 mice. This study provides information on the appropriate choice of a mouse model for allergic rhinitis.

Antigenic cross-reactivity between Schistosoma mansoni and allergenic invertebrates putatively due to shared glycanic epitopes

Previous studies have shown that rabbit IgG antibodies against Schistosoma mansoni egg antigens (SmSEA) cross-react with allergens in natural rubber latex, peanuts and grass and tree pollens. Here we describe antigenic molecules that cross-react with rabbit anti-S. mansoni IgG antibodies in extracts of the house dust mite (HDM) Dermatophagoides farinae, the Australian cockroach (ACR) Periplaneta australasiae and in the venom of the honey bee Apis mellifera (HBV). Tandem mass spectrometry identified the cross-reactive allergens as Der f 15 in HDM, two homologues of the Periplaneta americana cockroach allergen Cr-PI/Per a 3 in ACR and two isoforms of the allergen Api m 1 (phospholipase A2: PLA2) in HBV. Cross-reactive rabbit anti-SmSEA IgG antibodies eluted from the three invertebrate allergens reacted with S. mansoni egg antigens and variably with schistosome cercarial and worm antigens. Treatment of the electroblotted allergens with sodium metaperiodate abrogated most of the cross-reactivity of the rabbit anti-SmSEA antibodies, suggesting it was due to cross-reactive carbohydrate determinants (CCDs). Furthermore, analyses of the allergens’ amino acid sequences indicated that they had potential for both N- and O-linked glycosylation. A potential role for the CCDs shared by the schistosome and invertebrates in inducing an allergy-protective effect, as proposed by the hygiene hypothesis, is discussed.

Topical Vitamin D May Modulate Human Sinonasal Mucosal Responses to House Dust Mite Antigen.

Respiratory epithelium is a key defense against inhaled pathogens. Vitamin D3 (VD) has been suggested to modulate airway inflammation; however, its effect on innate airway defenses, the physical barrier, mucociliary apparatus, and cytokine release remains unclear. To investigate the outcomes of VD application prior to challenge in an in vitro model of human sinonasal epithelium, through assessment of epithelial transepithelial resistance (TER), cilia beat frequency (CBF), and interleukin (IL)-6 release, and secondarily to determine whether topical VD is beneficial to patients with inflammatory sinonasal pathology. Primary human sinonasal epithelial cells from patients with eosinophilic chronic rhinosinusitis (eCRS) and healthy controls were cultured in air-liquid interface (ALI). Well-differentiated cultures from each patient were pretreated for 24 hours with 4 different VD doses. Toxicity was quantified at 24 hours in unchallenged ALI by lactate dehydrogenase (LDH) assay. Innate responses were assessed by measuring TER and CBF before and up to 24 hours after house dust mite Dermatophagoides pteronyssinus challenge. IL-6 release was evaluated 24-hour postchallenge. Fifteen patients (53 ± 13.5 years, 60% females, 53% eCRS) representing 120 ALI wells were assessed. VD (0, 25, 50, 150 IU/mL) released less LDH than vehicle, indicating noncytotoxicity (0.15 ± 0.02; 0.15 ± 0.00; 0.14 ± 0.02; 0.11 ± 0.01 vs 0.17 ± 0.03, P = .004). VD increased TER for eCRS wells at 5 minutes (50 IU/mL: Δ6.76 ± 3.93 vs Δ3.87 ± 2.46, P = .04) and 24 hours (50 IU/mL: Δ0.88 ± 0.49 vs Δ0.40 ± 0.42, P = .02; 150 IU/mL: Δ1.06 ± 0.58 vs Δ0.47 ± 0.46, P = .01). CBF increased at 1 hour for eCRS wells (50 IU/mL: Δ0.62 ± 0.14 vs Δ0.41 ± 0.13, P = .001; 150 IU/ml: Δ0.60 ± 0.13 vs Δ0.38 ± 0.11, P < .001). IL-6 release was similar between normal and eCRS wells. Topical VD supplementation in eCRS patients may be beneficial for innate epithelial defenses. VD is noncytotoxic and does not adversely affect the physical barrier, mucociliary apparatus, or IL-6 release. Further studies should clarify its potential as a therapeutic agent.

Determination of sensitization to dust mite allergens D. pteronyssinus and D. farinae in patients with respiratory allergic diseases using immunoblot and multiplex component testing

Objective — to evaluate the diagnostic parameters of the immunoblot and ImmunoCAP ISAC methods for determining sensitization to allergens of the house dust mite Dermatophagoides pteronyssinus and Dermatophagoides farinae in patients with respiratory allergic diseases — allergic rhinitis and bronchial asthma.Materials and methods. In the process of this study, 40 patients with bronchial asthma and/or allergic rhinitis were examined using two different methods of specific allergological diagnosis (in vitro). The study was open, randomized, comparative. The quantitative determination of specific IgE in blood serum was carried out using the RIDA® AllergyScreen immunoblot method (R-Biopharm AG, Germany) at the private laboratory of the Allergo-Immunological Center CPR LLC. Examination by the method of ImmunoCAP ISAC was performed in the Clinic of Allergology and Immunology «Forpost».Results and discussion. Sensitization to D. farinae allergen was 35.0 % (14 people) with specific IgE by the Rida AllergyScreen method, 42.5 % (17 people) with specific IgE by the ImmunoCAP ISAC method; sensitization to D. рteronyssinus allergen was 35.0 % (14 people) with specific IgE by the Rida AllergyScreen method, 40.0 % (16 people) with specific IgE by the ImmunoCAP ISAC method.Conclusions. As a method for the quantitative determination of specific IgE to the D. farinae allergen, the immunoblot compared with ImmunoCAP ISAC has high specificity and predictability of a positive result (100 %), but the sensitivity and predictability of a negative result are 82.35 % (95 % CI: 56.57—96.20) and 88.46 % (95 % CI: 73.30—95.54), respectively, and the accuracy of the method is 92.5 % (95 % CI: 79.61—98.43).As a method for the quantitative determination of specific IgE to the D. pteronyssinus allergen, the immunoblot compared with ImmunoCAP ISAC, similar to the results of preliminary testing, has high specificity and predictability of a positive result (100 %), however, the sensitivity and predictability of a negative result have a value of 75.00 % (95 % CI: 47.62—92.73) and 85.71 % (95 % CI: 71.97—93.34), respectively, and the accuracy of the method is 90.00 % (95 % CI: 76.34; 97.21).

Dermatophagoides pteronyssinus-induced pro-inflammatory responses mediated via STAT3 and NF-kappaB signaling pathways in human bronchial epithelial cells – Inhibitory effects of Lafoensia pacari and ellagic acid

The house dust mite allergen Dermatophagoides pteronyssinus (Der p) is a major driver of allergic asthma. Studies from our group demonstrated anti-eosinophilic effects of ethanolic extract of Lafoensia pacari stem bark (and ellagic acid, isolated from L. pacari extract), used as traditional medicine in Brazil to naturally treat inflammatory conditions. Here, we extended these results through performing phytochemical analysis of the constituents of L. pacari using liquid chromatography-mass spectrometry and evaluating the anti-inflammatory effects of both L. pacari and ellagic acid in the human BEAS-2B bronchial epithelial cell line stimulated with Der p. Ellagic acid (major constituent), gallic acid, ferulic acid, chlorogenic acid and rosmarinic acid, but not flavonoids (rutin, kaempferol, luteolin and quercetin), were found in the L. pacari. Pro-inflammatory mediators, IL-6, IL-8 and CCL-2 production were increased in BEAS-2B stimulated with Der p (10 μg/mL, 24 h) compared to control. L. pacari (250 μg/mL) and ellagic acid (100 μM) significantly reduced the concentration of these mediators. L. pacari increased the production of the anti-inflammatory cytokine, IL-10. These results were associated with the downregulation of NF-κB and STAT3 pathways. These findings indicate a novel anti-inflammatory action for L. pacari and ellagic acid in the airways allergic inflammatory response.

Core/Sheath-Structured Composite Nanofibers Containing Cinnamon Oil: Their Antibacterial and Antifungal Properties and Acaricidal Effect against House Dust Mites.

This study aimed to fabricate core/sheath-structured composite nanofibers containing cinnamon oil by emulsion electrospinning and to investigate their acaricidal effect on house dust mites as well as their antibacterial and antifungal properties in relation to cinnamon oil concentration in the nanofibers. An oil-in-water emulsion, which comprised cinnamon oil and poly(vinyl alcohol) solution as oil and water phases, respectively, was used to prepare core/sheath-structured nanofibers. The morphology and the inner structure of the electrospun nanofibers were observed by scanning electron microscopy and confocal laser scanning microscopy. Core/sheath-structured nanofibers containing cinnamon oil were successfully prepared by emulsion electrospinning. The composite nanofibers prepared from an emulsion containing 20 wt% of cinnamon oil exhibited a strong acaricidal effect against house dust mites (Dermatophagoides farinae). The composite nanofibers fabricated from an emulsion containing 4.29 wt% of cinnamon oil showed excellent antimicrobial effects against Staphylococcus aureus and a series of fungi that can trigger respiratory- and skin-related diseases. The release profile of cinnamon oil from the core/sheath-structured nanofibers showed a continuous release of functional ingredients over 28 days. Our findings demonstrate that the use of such fibrous structures could be a promising approach for delivering naturally derived bioactive agents in a controlled way.

Similarities and differences in the effects of sensitisation and challenge with Dermatophagoides farinae and Dermatophagoides pteronyssinus extracts in a murine asthma surrogate

Patients with atopic asthma may become sensitised to the grain storage mite Dermatophagoides farinae (Der f), the house dust mite Dermatophagoides pteronyssinus (Der p) or both, but thus far little attention has been paid to date to possible variation in their pathophysiological effects. Here we present a side by side comparison of the effects of extracts of these two dust mites in a murine surrogate of atopic asthma. Compared with the Der p-challenged mice, however, the mice-challenged with Der f had favour changes in lung tissue elasticity and expression in matrix metalloproteinases in lung tissue, while the mice challenged with Der p showed more neutrophils infiltrating around the airway and stronger expression of steroid-resistant related cytokines in the lung tissue. Our data suggest that different dust mite crude extracts might lead different pathological characteristics, at least in murine models of asthma.

Antibody blockade of Dectin-2 suppresses house dust mite-induced Th2 cytokine production in dendritic cell- and monocyte-depleted peripheral blood mononuclear cell co-cultures from asthma patients

BackgroundDectin-2, which is a C-type lectin, interacts with the house dust mite (HDM) Dermatophagoides pteronyssinus allergen. This study aimed to investigate whether Dectin-2 blockade by antagonistic monoclonal antibodies (MoAbs) attenuates HDM-induced allergic responses.MethodsTwo anti-Dectin-2 MoAbs were generated and validated for specific binding to Dectin-2 Fc fusion protein (Dectin-2.Fc) and inhibition of Dectin-2.Fc/HDM interaction. Patients with asthma exhibiting high titers of anti-D. pteronyssinus IgE were enrolled. Peripheral blood mononuclear cells with depleted CD14+ monocytes were obtained from these patients and co-cultured with autologous monocyte-derived conventional dendritic cells in the presence of D. pteronyssinus or its group 2 allergens (Der p 2). Interleukin (IL)-5 and IL-13 levels in the culture supernatants were determined using ELISA in the presence or absence of anti-Dectin-2 MoAbs.ResultsTwo MoAbs, 6A4G7 and 17A1D10, showed specific binding to recombinant Dectin-2.Fc and inhibited HDM binding to Dectin-2.Fc. Both anti-Dectin-2 MoAbs inhibited IL-5 and IL-13 production in co-cultures with Der p 2 stimulation in a dose-dependent manner. 6A4G7 and 17A1D10 (3 μg/mL) significantly inhibited Der p 2-induced (3 μg/mL) IL-5 production by 69.7 and 86.4% and IL-13 production by 84.0 and 81.4%, respectively. Moreover, this inhibitory effect of the two MoAbs remained significant in the presence of D. pteronyssinus.ConclusionsAnti-Dectin-2 MoAbs significantly inhibited HDM-induced allergic responses in vitro and therefore have the potential to become therapeutic agents in mite-induced allergic diseases.

Lung–Restricted Inhibition of Janus Kinase 1 Is Effective in Rodent Models of Asthma

Multiple type 2 cytokines, including interleukin-4, interleukin-5, interleukin-9, interleukin-13, and thymic stromal lymphopoietin, drive the pathophysiology of an important subset of asthma. These and other cytokines, such as interleukin-6 and type I and type II interferons, depend on Janus kinase 1 (JAK1) for signal transduction. iJak-381 is a synthesized, small, and inhalable molecule that was specifically designed for lung-restricted JAK1 inhibition. The purpose of this study was to conduct preclinical studies to test whether local inhibition of JAK1 can inhibit allergic inflammation in the lungs.The study tested iJak-381 in mice and guinea pigs. Guinea pigs are an ideal species to study lung inflammation because their lung anatomy is similar to humans, and they mount a robust response to inhaled challenges.The authors developed a dry powder inhalation system for iJak-381 and tested its ability to suppress inhaled ovalbumin-induced pulmonary inflammation and airway hyperresponsiveness in murine and guinea pig models.iJak-381 suppressed signal transducer and activator of transcription 6 activation by interleukin-13. iJak381 also suppressed ovalbumin-induced lung inflammation in both murine and guinea pig asthma models. Using human allergens (Aspergillus, Alternaria, and house dust mite Dermatophagoides farinae), iJak-381 had a strong suppressive effect on neutrophilic inflammation compared with systemic corticosteroids. Lastly, iJak-381 reduced lung pathology without inhibiting systemic JAK1 activity.The authors concluded that lung-restricted inhibition of JAK1 suppressed asthma-related lung inflammation in 2 rodent models without systemic JAK inhibition. Because iJak-381 also suppressed neutrophilic inflammation in the lungs, the authors suggest that a combination of inhaled JAK1 inhibition with corticosteroid administration may be an efficacious approach to asthma treatment.This study highlights the importance of JAK1 signaling in asthma pathogenesis and suggests a therapeutic benefit to lung-restricted JAK1 inhibition. JAK1 inhibition may improve lung function by inhibiting both type 2 cytokine signaling and antigen-driven eosinophilic and neutrophilic inflammation in the lungs. More importantly, the inhaled route may provide clinical relief without systemic side effects. These promising preclinical findings suggest that clinical studies should be pursued to test iJak-381 efficacy and safety in asthma.

A Human IgE Antibody Binding Site on Der p 2 for the Design of a Recombinant Allergen for Immunotherapy.

Der p 2 is one of the most important allergens from the house dust mite Dermatophagoides pteronyssinus Identification of human IgE Ab binding epitopes can be used for rational design of allergens with reduced IgE reactivity for therapy. Antigenic analysis of Der p 2 was performed by site-directed mutagenesis based on the x-ray crystal structure of the allergen in complex with a Fab from the murine IgG mAb 7A1 that binds an epitope overlapping with human IgE binding sites. Conformational changes upon Ab binding were confirmed by nuclear magnetic resonance using a 7A1-single-chain variable fragment. In addition, a human IgE Ab construct that interferes with mAb 7A1 binding was isolated from a combinatorial phage-display library constructed from a mite-allergic patient and expressed as two recombinant forms (single-chain Fab in Pichia pastoris and Fab in Escherichia coli). These two IgE Ab constructs and the mAb 7A1 failed to recognize two Der p 2 epitope double mutants designed to abolish the allergen-Ab interaction while preserving the fold necessary to bind Abs at other sites of the allergen surface. A 10-100-fold reduction in binding of IgE from allergic subjects to the mutants additionally showed that the residues mutated were involved in IgE Ab binding. In summary, mutagenesis of a Der p 2 epitope defined by x-ray crystallography revealed an IgE Ab binding site that will be considered for the design of hypoallergens for immunotherapy.

Gene synthesizing, expression and immunogenicity characterization of recombinant translation elongation factor 2 from Dermatophagoidesfarinae.

House dust mite (HDM) hypersensitivity increasingly affects millions of individuals worldwide. Although numerous major allergens produced by HDM species have been characterized, some of the less potent allergens remain to be studied. The present study aimed to obtain the recombinant allergen of Translation Elongation Factor 2 (TEF 2) from the HDM Dermatophagoides farinae by synthesizing, and then expressing the recombinant TEF 2 to identify its immunogenicity. In the present study, the D. farinae TEF 2 (Der f TEF 2) was synthesized, expressed and purified. The molecular characteristics of Der f TEF 2 were analyzed using bioinformatics approaches. The recombinant protein was purified via affinity chromatography, and the allergenicity was assessed using immunoblotting, ELISAs and skin prick tests. The gene for TEF 2 consists of 2,535 bp and encodes an 844-amino acid protein. A positive response to recombinant Der f TEF 2 was detected in 16.2% of 37 patients with HDM allergies using skin prick tests. In addition, the immunoblotting indicated that the protein showed a high ability to bind serum IgE from patients allergic to HDMs, and that the recombinant TEF 2 was highly immunogenic. Bioinformatics analysis predicted 17 peptides as B cell epitopes (amino acids 29–35, 55–64, 92–99, 173–200, 259–272, 311–318, 360–365, 388–395, 422–428, 496–502, 512–518, 567–572, 580–586, 602–617, 785–790, 811–817 and 827–836) and 14 peptides as T cell epitopes (amino acids 1–15, 65–79, 120–134, 144–159, 236–250, 275–289, 404–418, 426–440, 463–477, 510–524, 644–658, 684–698, 716–730 and 816–830). The software DNAStar predicted the secondary structure of TEF 2, and showed that 27 α-helices and five β-sheets were found in the protein. In conclusion, the present study cloned and expressed the Der f TEF 2 gene, and the recombinant protein exhibited immunogenicity, providing a theoretical bases, and references, for the diagnosis and treatment of allergic disease.

P2Y6 signaling in alveolar macrophages prevents leukotriene-dependent type 2 allergic lung inflammation.

Antagonists of the type 1 cysteinyl leukotriene receptor (CysLT1R) are widely used to treat asthma and allergic rhinitis, with variable response rates. Alveolar macrophages express UDP-specific P2Y6 receptors that can be blocked by off-target effects of CysLT1R antagonists. Sensitizing intranasal doses of an extract from the house dust mite Dermatophagoides farinae (Df) sharply increased the levels of UDP detected in bronchoalveolar lavage fluid of mice. Conditional deletion of P2Y6 receptors before sensitization exacerbated eosinophilic lung inflammation and type 2 cytokine production in response to subsequent Df challenge. P2Y6 receptor signaling was necessary for dectin-2-dependent production of protective IL-12p40 and Th1 chemokines by alveolar macrophages, leading to activation of NK cells to generate IFN-γ. Administration of CysLT1R antagonists during sensitization blocked UDP-elicited potentiation of IL-12p40 production by macrophages in vitro, suppressed the Df-induced production of IL-12p40 and IFN-γ in vivo, and suppressed type 2 inflammation only in P2Y6-deficient mice. Thus, P2Y6 receptor signaling drives an innate macrophage/IL-12/NK cell/IFN-γ axis that prevents inappropriate allergic type 2 immune responses on respiratory allergen exposure and counteracts the Th2 priming effect of CysLT1R signaling at sensitization. Targeting P2Y6 signaling might prove to be a potential additional treatment strategy for allergy.

Dynamics of the microbial community during growth of the house dust mite Dermatophagoides farinae in culture.

The variation in house dust mite microbial communities is important because various microorganisms modulate the production of allergens by their mite hosts and/or contaminate immunotherapeutic extracts. Temporal changes in mite microbiomes and the mite culture environment occurring at different stages of mite culture development are particularly understudied in this system. Here, we analyzed the dynamics of microbial communities during the culture growth of Dermatophagoides farinae. Changes in microbiomes were related to three key variables: the mite population density, microbial microcosm respiration and concentration of guanine (the mite nitrogenous waste metabolite). Mite populations exhibited the following phases: exponential growth, plateau and exponential decline. The intracellular bacterium Cardinium and the yeast Saccharomyces cerevisiae prevailed in the internal mite microbiomes, and the bacterium Lactobacillus fermentum was prevalent in the mite diet. The reduction in the mite population size during the late phases of culture development was related to the changes in their microbial profiles: the intracellular bacterium Cardinium was replaced by Staphylococcus, Oceanobacillus and Virgibacillus, and S. cerevisiae was replaced by the antagonistic fungi Aspergillus penicillioides and Candida. Increases in the guanine content were positively correlated with increases in the Staphylococcus and A. penicillioides profiles in the culture environment. Our results show that the mite microbiome exhibits strong, dynamic alterations in its profiles across different mite culture growth stages.