Systematic Characterization of the Group 2 House Dust Mite Allergen in Dermatophagoides microceras

BackgroundAllergic asthma, a chronic airway inflammatory disease, is a critical public health problem. Indoor house dust mites (HDMs) could cause allergic asthma. The prevalence of sensitization to Dermatophagoides microceras (Der m) was approximately 80% and is related to the immunoglobulin E crossing-reactivity of mites belonging to the same genus, Dermatophagoides pteronyssinus (Der p) and Dermatophagoides farina (Der f). However, studies on Der m are scant.MethodsWe used integrated OMICs approaches to identify and characterize the group 2 mite allergen-like protein in Der m (Der m 2). We established a Der m 2-induced allergic asthma mouse model and treated the mice with a fungal immunomodulatory protein (FIP-fve) isolated from Flammulina veluptipes to evaluate the allergenicity of Der m 2 and the immunomodulatory effects of FIP-fve.ResultsBy performing de novo draft genome assembly and comparative genome analysis, we identified the putative 144-amino acid Der m 2 in silico and further confirmed its existence through liquid chromatography–tandem mass spectrometry. Der m 2 is a lipopolysaccharides (LPS)-binding protein. Thus, we examined the LPS-binding activity of recombinant Der m 2 by performing molecular docking analysis, co-immunoprecipitation (Co-IP), and a pull-down assay. Der m 2 elicited the production of pro-inflammatory cytokines, interleukin (IL)-6, and IL-8 in BEAS-2B cells, a human bronchial epithelial cell line, and induced airway hyperresponsiveness in mice. Furthermore, in mice sensitized with Der m 2, the administration of FIP-fve in either the earlier stage or the late stage, FIP-fve alleviated allergic asthma by moderating airway inflammation and remodeling.ConclusionsDer m 2 induced inflammatory responses in cell and mouse models. FIP-fve alleviated inflammation in Der m 2-induced asthma in mice by exerting an immunomodulatory effect.

Comparative Genomics Reveals Insights into the Divergent Evolution of Astigmatic Mites and Household Pest Adaptations

Highly diversified astigmatic mites comprise many medically important human household pests such as house dust mites causing roughly 1–2% of the allergic diseases globally; however, their evolutionary origin, diverse lifestyles including reversible parasitism and quick adaptation to rather new human household environments have not been illustrated at genomic level, which hamper the allergy prevention and our exploration of these household pests. Using six high-quality assembled and annotated genomes, this comparative genomics study not only refuted the monophyly of mites and ticks, but also thoroughly explored the divergence of Acariformes and the divergent evolution of astigmatic mites. In the monophyletic Acariformes, Prostigmata known as notorious plant pests first evolved, then rapidly evolving Astigmata diverged from soil oribatid mites. Within astigmatic mites, a wide range of gene families rapidly expanded via tandem gene duplications, including ionotropic glutamate receptors, triacylglycerol lipases, serine proteases and UDP glucuronosyltransferases (UGTs), which enriched their capacities of adapting to rapidly changing household environments. The gene diversification after tandem duplications provided plenty of genetic resources for their adaptations of sensing environmental signals, digestion, and detoxification. Whilst many gene decay events only occurred in the skin-burrowing parasitic mite Sarcoptes scabiei. Throughout the evolution of Acariformes, massive horizontal gene transfer events occurred in gene families such as UGTs and several important fungal cell wall lytic enzymes, which enable the detoxification and associated digestive functions and provide perfect drug targets for pest control. Our comparative study sheds light on the rapid divergent evolution of astigmatic mites from the divergence of Acariformes to their diversification and provides novel insights into the genetic adaptations and even control of human household pests.

Elovanoids Counteract Inflammatory Signaling, Autophagy, Endoplasmic Reticulum Stress, and Senescence Gene Programming in Human Nasal Epithelial Cells Exposed to Allergens

To contribute to further understanding the cellular and molecular complexities of inflammatory-immune responses in allergic disorders, we have tested the pro-homeostatic elovanoids (ELV) in human nasal epithelial cells (HNEpC) in culture challenged by several allergens. ELV are novel bioactive lipid mediators synthesized from the omega-3 very-long-chain polyunsaturated fatty acids (VLC-PUFA,n-3). We ask if: (a) several critical signaling events that sustain the integrity of the human nasal epithelium and other organ barriers are perturbed by house dust mites (HDM) and other allergens, and (b) if ELV would participate in beneficially modulating these events. HDM is a prevalent indoor allergen that frequently causes allergic respiratory diseases, including allergic rhinitis and allergic asthma, in HDM-sensitized individuals. Our study used HNEpC as an in vitro model to study the effects of ELV in counteracting HDM sensitization resulting in inflammation, endoplasmic reticulum (ER) stress, autophagy, and senescence. HNEpC were challenged with the following allergy inducers: LPS, poly(I:C), or Dermatophagoides farinae plus Dermatophagoides pteronyssinus extract (HDM) (30 µg/mL), with either phosphate-buffered saline (PBS) (vehicle) or ELVN-34 (500 nM). Results show that ELVN-34 promotes cell viability and reduces cytotoxicity upon HDM sensitization of HNEpC. This lipid mediator remarkably reduces the abundance of pro-inflammatory cytokines and chemokines IL-1β, IL-8, VEGF, IL-6, CXCL1, CCL2, and cell adhesion molecule ICAM1 and restores the levels of the pleiotropic anti-inflammatory IL-10. ELVN-34 also lessens the expression of senescence gene programming as well as of gene transcription engaged in pro-inflammatory responses. Our data also uncovered that HDM triggered the expression of key genes that drive autophagy, unfolded protein response (UPR), and matrix metalloproteinases (MMP). ELVN-34 has been shown to counteract these effects effectively. Together, our data reveal a novel, pro-homeostatic, cell-protective lipid-signaling mechanism in HNEpC as potential therapeutic targets for allergies.

Abnormal sperm morphology is associated with sensitization to inhaled allergens

Background: Allergy is associated with the loss of tolerance of environmental antigens, combined with a pathological immune response. There were no studies up to date that would show whether the quality of semen decreases in people with allergic diseases. Material and methods: The research included men who reported to the Gynecological Outpatient Clinic due to reproductive difficulties, defined as the lack of pregnancy after one year of regular intercourse. Semen quality was assessed according to the World Health Organization (WHO) standard. All patients underwent skin prick tests with the most important inhalation allergens (such as hazel, silver birch, mugwort, rye, dog, cat, Dermatophagoides farinae, Dermatophagoides pteronyssinus, alder, Alternaria alternata, Cladosporium herbarum, and grass mix). The data was statistically analyzed. Results: Results of 52 patients aged 25–52 years (34.62 ± 4.96) were analyzed. The mean BMI (Body mass index) was 28.25 (+ −3.77). It was found that 38 men (73%) had increased body weight, and 14 men (26.9%) were obese (BMI > = 30). 13 patients were smokers (25%), and 24 patients (46%) had skin tests positive for at least one inhaled allergen. Sperm tail defects were statistically more significant in patients allergic to birch, rye, cat, alder, and grass. In patients allergic to Alternaria alternata, head defects were statistically more significant ( p < .05). No association was found between allergy to house dust mites, mugwort, hazel, and dogs and the deterioration of semen. Conclusion: Allergy due to inhalation allergens had an influence on the quality of male semen. Further research is necessary to establish the immunological bases of this phenomenon.

Food and Aeroallergen Sensitization in IgE -Mediated Asthma in Egypt

Purpose: Identifying the distribution of allergens is valuable to the effective diagnosis and treatment of allergic disease. So, our aim is to explore the sensitization of food and aeroallergens in Egyptian patients with atopic asthma. Methods: Cross-sectional study recruited 268 Egyptian patients with atopic asthma. Asthmatic patients were assessed by the enzyme allegro sorbent test (EAST) method for specific IgE to a panel of 19 common regional inhaled allergens and 15 food allergens. Results and Discussion: One hundred percent of the patients were sensitive to at least one allergen. Allergy to food allergens only was 2.9%; inhaled allergens only were 26.2% and both were70.9%. Fungi (62%) were the most frequent sensitizing aeroallergen amongst our asthmatic patients, followed by the pollen allergens (42.5%) and house dust mites (HDMs) (26%). Cows’ milk (30.5%) was the most frequent sensitizing food amongst our asthmatic patients, followed by eggs (22.4%) and fish (21.6%). Mono-sensitized patients accounted for 6.7% of all cases, while polysensitized was 93.3%. Moderate and severe asthma showed a significantly higher frequency of polysensitization compared to mild asthma. Conclusion: Fungi and cow's milk are the chief sensitizing allergens in Egyptian patients with atopic asthma. This study represents the first report of sensitization in atopic adult asthma using a large extract panel in Upper Egypt.

Parental Perspectives on the Implementation of House Dust Mite Avoidance Measures for Children with House Dust Mite Sensitization

ABSTRACTObjective: The avoidance of house dust mite (HDM) is crucial in the management of HDM allergies. We aimed to demonstrate the implementation and perspective of the parents whose children had HDM allergy/sensitization to HDM avoidance measures. Materials and Methods: Parents of the patients with HDM sensitization were interviewed via telephone questionnaires.Results: One hundred and three patients with asthma (73.8%), allergic rhinitis (AR) (77.7%) and/or atopic dermatitis (AD) (29.1%) aged four to 18 years were included in the study. Seventy-one patients had multiple allergic diseases (68.9%). Of the parents, 39.8% fully adhered to HDM avoidance measures, and their education status was as follows: 41.5% illiterate/elementary/middle school, 31.7% high school, and 26.8% associate’s degree/university. In addition, 32.2% of the mothers who were partially adherent (n=62) were illiterate or had graduated from elementary/middle school, 33.9% had graduated from high school, and 33.9% had an associate’s degree or had graduated from university. Forty-one (39.8%) mothers were working, and most of them (61%) had graduated from university or had an associate’s degree. Nearly half of the mothers who were partially adherent to HDM measures were working (n=32). In the multivariate analysis, the risk factors for partial adherence to measures was to be a working mother [OR:4.072, 95%CI: 1.350-12.882, p=0.013] and to have the belief that the measures were useless [OR:4.886, 95%CI: 1.499-15.923, p=0.008]. However, no relationship was shown between adherence to the measures and the severity of AR or AD, asthma control status and having multiple allergic diseases.Conclusion: Full adherence to HDM avoidance measures was considerably dependent on the mothers’ working status and belief in the ineffectiveness of the measures whereas there was no relationship to the severity of allergic diseases. This study also revealed how the education status of the mothers affected the adherence to allergen avoidance measures in real life.Keywords: Children, Dermatophagoides pteronyssinus,Dermatophagoides farinae, house dust mites, avoidance measures, parents, pediatrics, questionnaire

Impact of house dust mite-driven asthma on children’s school performance and activity

Evidence regarding asthma’s impact on children’s daily lives is limited. This prospective and cross-sectional, observational, multicenter study assessed school/work and activity impairment in children and adolescents with allergic asthma and their caregivers and allergen immunotherapy (AIT) effects. Included patients were schooled children and adolescents (5 to 17 years) with allergic asthma due to house dust mites (HDM). Impairment of school/work (i.e., absenteeism and presenteeism) and activity was measured in patients and their caregivers using the Work Productivity Impairment Questionnaire plus Classroom Impairment Questions: Allergy Specific (WPAI + CIQ:AS). HDM allergic patients with school impairment received subcutaneous AIT with a MicroCrystalline Tyrosine-associated allergoid. WPAI + CIQ:AS and effectiveness variables were compared between baseline and 1-year post-AIT. Of the 113 patients included, 59 (52.2%) and 51 (45.1%) showed school and activity impairment, respectively, missing a mean (SD) of 37.6 (24.4) % and 42.6 (25.6) % of school and activity time, respectively. Twenty-six (23%) caregivers reported activity impairment and, of the 79 (69.9%) employed, 30 (38%) reported work impairment. Of the 65 patients with school/activities impairment, 41 (63.1%) received AIT, of which 21 (51.2%) completed 1 year of treatment. Effectiveness variables and WPAI + CIQ:AS significantly improved: Mean (SD) school impairment decreased from 39.7 (26.7) to 2.1 (7.1) % (p < 0.001) and activity impairment from 46.2 (34.6) to 1.4 (3.6) % (p < 0.001).Conclusion: Allergic asthma due to HDMs results in school/work and activity impairment in children and adolescents and their caregivers. One year of AIT provided clinical benefits and reduced school and activity impairment. What is Known:• Allergic asthma impairs children’s school performance and daily activities.• Allergen immunotherapy modifies allergic disease course and ameliorates its symptoms. What is New:• Asthma symptoms due to allergy to house dust mites impair children’s school attendance and productivity and daily activity and their caregivers’ work performance and daily lives.• Allergen immunotherapy with a house dust mite MicroCrystalline Tyrosine (MCT)-associated allergoid seems to provide clinical benefits, associated with decreased school and activity impairment, supporting it as an effective treatment option.

Analysis of the dynamics of clinical indicators in patients with allergic rhinitis with sensitization to pollen and household allergens using combined allergen-specific immunotherapy

The aim of this study was to evaluate the clinical efficacy of combined allergen-specific immunotherapy (ASIT) in patients with allergic rhinitis (AR) with combined sensitization to pollen and household allergens. To achieve this goal, 49 patients with AR of working age were examined – 35.5±1.5 years with clinical manifestations of seasonal rhinoconjunctival syndrome with a long period of 9.2±1.1 years, among which there were 25 (51.0%) males and 24 (49%) females. All patients were divided into 2 homogeneous groups by age, sex, duration of the disease, the average number of etiologically significant allergens: the main one – 31 patients who received combined ASIT with solutions of pollen and household allergens and a comparison group – 18 patients for whom only pollen allergens were used. Allergological examination included anamnesis, skin tests with pollen allergens (wormwood, ragweed, quinoa, corn, etc.) and household (house dust, mites, epidermal agents) and / or molecular research methods using the ALEX technology. The quantitative integral assessment of the intensity of AR clinical symptoms was calculated as a total score for the main symptoms. The maximum score for the severity of nasal symptoms – 12, eye - 6, total – 18. The results obtained and their analysis indicate that under the influence of ASIT pollen and household allergens in patients there is a significant and reliable decrease in the intensity of clinical manifestations of seasonal rhinoconjunctive syndrome: nasal manifestations – by 52,2%, conjunctival – by 60%, integral – by 54.3% and an increase of 2.2 times in the percentage of patients in the main group with the disappearance or minimization of clinical symptoms of the disease after treatment compared with patients from the comparison group, which convincingly proves and confirms high efficiency of the selected type of therapy in patients with AR in combination with sensitization to pollen and household allergens.

Nasal Nitric Oxide and Nasal Cytology as Predictive Markers of Short-Term Sublingual Allergen-Specific Immunotherapy Efficacy in Children with Allergic Rhinitis

Background Few studies have been conducted on the short-term response to sublingual immunotherapy (SLIT). Objective The purpose of our experimental trial was to evaluate if two markers such as nasal nitric oxide (nNO) and nasal cytology could be useful to identify a precocious clinical efficacy of SLIT treatment. Methods We enrolled 34 children aged 6 to 14 years old with diagnosis of allergic rhinitis (AR) and documented sensitization towards house dust mites. We started allergoid-monomeric tablets immunotherapy along with any conventional therapy for AR and we evaluated at baseline (T0), after one (T1), two (T2), three (T3), and six months (T6) the effects of the treatment through the study of: i) a visual analogue scale (VAS 1-10); ii) measurement of nNO; iii) measurement of FeNO; iv) nasal cytology; v) spirometry; and vi) evaluation of any conventional therapy. Results We observed an improvement in symptoms evaluated by global VAS (T0 vs. T6: 47.13 vs. 17.57; p < .05) and a statistically significant reduction of nNO (1035.2 ± 956.08 vs. 139.2 ± 59.01; p < .05). In this case, significance was reached when the patients completed the 6 months of treatment. Cytological evaluation revealed significant reduction in nasal eosinophils (T0 vs. T6: 87% vs. 16%; p < .01). Moreover, at T0, 56% of patients had also neutrophils that were reduced up to the 8% at T6 (p < .05). Conclusions Our data confirm the effectiveness of SLIT treatment from a clinical perspective and identifies two biomarkers, such as nNO and nasal cytology, as predictive of treatment efficacy in the short term.

Systemic and local cytokine profile and risk factors for persistent allergic airway inflammation in patients sensitised to house dust mite allergens

Objective To evaluate cytokine profile, vitamin D status, symptom score and quality of life in patients with persistent allergic airway diseases sensitised to house dust mites (HDM) in comparison with healthy individuals. Material and methods Patients sensitized to HDM with persistent AR and having symptoms for at least 2 years with or without AA were involved into the study. Measurements of vitamin D level in serum and IL-10, IL-13, IL-17, IL-22, IL-33 and IFN-gamma in serum and nasal lavage were performed by ELISA. Results Eighty-one subjects were involved into the study. Serum IL-10 concentration was higher in patients with AR than in patients with AR and AA (6.71 ± 1.73 vs. 1.98 ± 0.24, p < 0.05). IFN-gamma level in nasal lavage was higher in patients with AR and AA than in patients with AR (p < 0.01) and healthy individuals (p < 0.05) (7.50 ± 0.37 vs. 6.80 ± 0.99 vs. 6.50 ± 0.22). Serum IL-22 negatively correlated with IL-22 in nasal lavage, whereas serum IFN-gamma positively correlated with IFN-gamma in nasal lavage. Positive correlation between serum IL-17 and total IgE and negative correlation between IL-17 in nasal lavage and eosinophils in nasal smear were found in patients with AR and AA. Serum IFN-gamma decreased the risk of AR for healthy individuals. Serum IL-10 and vitamin D decreased risk for development of AA for patients with AR. IL-22 in serum and IL-10 and IL-33 in nasal lavage increased this risk. Conclusion Novel cytokines such as IL-22, IL-17 and IL-33 and vitamin D may be involved in pathogenesis of persistent airway inflammation in patients sensitized to HDM.