SciCombinator

Discover the most talked about and latest scientific content & concepts.

Concept: House dust mite

171

Overexpression of the transforming growth factor β family signalling molecule smad2 in the airway epithelium provokes enhanced allergen-induced airway remodelling in mice, concomitant with elevated levels of interleukin (IL)-25.

Concepts: Immune system, Asthma, Acari, Arachnid, Mite, House dust mite

139

Few studies addressed trans-regional differences in allergen sensitization between areas within a similar latitudinal range but with distinct geomorphological features. We investigated specific IgE (sIgE) positivity to common allergens in populations from two southern China provinces. Using a uniformed protocol, serum samples were collected from 2778 subjects with suspected atopy in coastal Guangdong and inland Yunnan. The overall prevalence of sIgE positivity were 57.8% (95% CI: 56.0%, 59.6%) from Guangdong vs 60.9% (95% CI: 59.1%, 62.7%) from Yunnan. House dust mite (d1) was the most common allergen in both regions. Among d1-sensitized subjects, only 35.7% (208/583) in Guangdong and 22.9% (147/642) in Yunnan tested positive for d1 alone. Among those poly-sensitized d1-positive subjects, cockroach was the most common co-sensitizing aeroallergen. 41.9% of the d1-sensitized Guangdong subjects showed high-class sIgE reactivity (≥class 4), in contrast to a very low percentage of such reactivity in Yunnan. However, 36.3% of d1-sensitized subjects in Yunnan were concomitantly positive for tree pollen mix. Surprisingly, Yunnan subjects showed high prevalence of sIgE positivity for crabs and shrimps, either by overall or by age-group analysis, compared with their Guangdong counterparts (both P < 0.05). These findings may add to data about local allergies in China and worldwide.

Concepts: Asthma, Allergy, Atopy, Allergen, People's Republic of China, Arachnid, Mite, House dust mite

107

Shrimp and house dust mite (HDM) allergies are common in Canadians. Often, both of these allergies occur in the same patient. This may be due to homology of tropomyosin or other potentially shared proteins. The aim of our study was to assess the frequency of house dust mite sensitization in a shrimp allergic Canadian population.

Concepts: Asthma, Canada, Acari, Arachnid, Mite, House dust mite, Ontario, Southern Ontario

32

Papain is commonly used in food, pharmaceutical, textile and cosmetic industries and is known to induce occupational allergic asthma. We have previously shown that the papain-like cysteine protease Der p 1 from house dust mite per se exhibits percutaneous sensitization potential. We aimed here to investigate the potential of papain itself in epicutaneous sensitization. The effects of papain on tight junction proteins were tested in-vitro in human primary keratinocytes. Using C57BL/6 WT and TLR4-deficient mice, we analyzed the sensitization potential of papain, its effects on the skin barrier and immune cell recruitment. Our results show, that papain affects the skin barrier by increasing transepidermal water loss, degrading tight junction proteins and inducing vasodilation. When topically applied, papain exhibited a high epicutaneous inflammatory potential by recruiting neutrophils, mast cells and CD3-positive cells and by induction of a TH2-biased antibody response. However, its high potency for specific sensitization via the skin was independent of its enzymatic function. The mechanism for specific sensitization was TLR4-independent and, in spite of its capacity to degrade epidermal tight junction proteins, does not rely on its enzymatic function. From our data we conclude that papain has all features to act as a strong allergen via the skin.Journal of Investigative Dermatology accepted article preview online, 23 February 2015. doi:10.1038/jid.2015.58.

Concepts: Immune system, Antibody, Enzyme, Asthma, Immunology, Allergy, Mast cell, House dust mite

28

There is an unmet need for effective new and innovative treatments for asthma. It is becoming increasingly evident that bacterial stimulation can have beneficial effects at attenuating allergic airway disease through immune modulation. Our aim was to test the ability of a novel inactivated microbe-derived therapeutic based on Klebsiella (KB) in a model of allergic airway disease in mice. BALB/c mice were exposed intranasally to house dust mite (HDM) for two weeks. Mice were treated prophylactically via subcutaneous route with either KB or placebo for one week prior to HDM exposure and throughout the two week exposure period. 24 hours after the last exposure, lungs were analysed for inflammatory cell infiltrate, gene expression, cytokine levels, goblet cell metaplasia, and serum was analysed for allergen-specific serum IgE levels. HDM exposed mice developed goblet cell hyperplasia, elevated allergen-specific serum IgE, airway eosinophilia, and a concomitant increase in TH2 cytokines including IL-4, IL-13 and IL-5. Treatment with KB attenuated HDM-mediated airway eosinophilia, total bronchoalveolar lavage (BAL) cell numbers, BAL TH2 cytokine production, and goblet cell metaplasia. Our prophylactic intervention study illustrates the potential of subcutaneous treatment with bacterial derived biologics as a promising approach for allergic airway disease treatment.

Concepts: Immune system, Antibody, Gene, Cytokine, Asthma, Immunoglobulin E, Allergy, House dust mite

28

The toxicity of red pine needle hydrodistillate (RPN-HD), 19 RPN-HD constituents and another 12 structurally related compounds and the control efficacy of four experimental spray formulations containing RPN-HD (0.5. 1, 2 and 3% sprays) to adult Dermatophagoides farinae were evaluated.

Concepts: House dust mite, Pine, Pinus classification, Pinus

28

The acaricidal activities of an active constituent derived from Ostericum koreanum roots and its derivatives were determined using fumigant and direct-contact toxicity bioassays against Dermatophagoides farinae and D. pteronyssinus. This was compared with that of commercial acaricide (benzyl benzoate). In the fumigant toxicity bioassay, 4-chloro-6-isopropyl-3-methylphenol (0.29 μg/cm2) was 37.17 times more effective than benzyl benzoate (10.78 μg/cm2) against D. farinae, followed by 6-fluoro-3-methylphenol (0.57 μg/cm2), 3-methylphenol (0.63 μg/cm2), 4-chloro-3-methylphenol (0.75 μg/cm2), and 4-isopropyl-3-methylphenol (0.78 μg/cm2). In the direct-contact toxicity bioassay, 4-chloro-6-isopropyl-3-methylphenol (0.21 μg/cm2) was 36.81 times more toxic than benzyl benzoate (7.73 μg/cm2) against D. farinae, followed by 6-fluoro-3-methylphenol (0.40 μg/cm2), 3-methylphenol (0.41 μg/cm2), 4-isopropyl-3-methylphenol (0.56 μg/cm2), and 4-chloro-3-methylphenol (0.60 μg/cm2). The acaricidal effects of 3-methyphenol derivatives against D. pteronyssinus were similar to those against D. farinae. In structure-activity relationships, acaricidal activities could be related to the introduction of chloro, fluoro, and isopropyl functional groups onto the 3-methylphenol skeleton. These results indicate that naturally occurring 3-methylphenol and its derivatives have potential house dust mite control agents.

Concepts: Asthma, Acari, Arachnid, Mite, House dust mite

27

BACKGROUND: Epithelial permeability is highly dependent upon the integrity of tight junctions, which are cell-cell adhesion complexes located at the apical aspect of the lateral membrane of polarized epithelial cells. We hypothesize that sinonasal epithelial exposure to Der p 1 house dust mite antigen decreases expression of tight junction proteins (TJPs), representing a potential mechanism for increased permeability and presentation of antigens across the sinonasal epithelial layer. METHODS: Confluent cultured primary human sinonasal epithelial cells were exposed to recombinant Der p 1 antigen vs control, and transepithelial resistance measurements were performed over 24 hours. Antibody staining for a panel of TJPs was examined with immunofluorescence/confocal microscopy and Western blotting. Tissue for these experiments was obtained from 4 patients total. RESULTS: Der p 1 exposed sinonasal cells showed a marked decrease in transepithelial resistance when compared to control cells. In addition, results of Western immunoblot and immunofluorescent labeling demonstrated decreased expression of TJPs claudin-1 and junction adhesion molecule-A (JAM-A) in Der p 1-exposed cultured sinonasal cells vs controls. CONCLUSION: Der p 1 antigen exposure decreases sinonasal epithelium TJP expression, most notably seen in JAM-A and claudin-1 in these preliminary experiments. This decreased TJP expression likely contributes to increased epithelial permeability and represents a potential mechanism for transepithelial antigen exposure in allergic rhinitis.

Concepts: Antibody, Protein, Asthma, Epithelium, Endothelium, Skin, House dust mite, Tight junction

26

Allergic diseases such as asthma and rhinitis are common in many countries. Globally the most common allergen associated with symptoms is produced by house dust mites. Although the bed has often been cited as the main site of exposure to mite allergens, surprisingly this has not yet been directly established by measurement due to a lack of suitable methods. Here we report on the development of novel methods to determine the pattern of personal exposure to mite allergen bioaerosols over 24-hour periods and applied this in a small field study using 10 normal adults. Air was sampled using a miniature time-based air-sampler of in-house design located close to the breathing zone of the participants, co-located with a miniature time-lapse camera. Airborne particles, drawn into the sampler at 2L/min via a narrow slot, were impacted onto the peripheral surface of a disk mounted on the hour-hand of either a 12 or 24 hour clock motor. The impaction surface was either an electret cloth, or an adhesive film; both novel for these purposes. Following a review of the time-lapse images, disks were post-hoc cut into subsamples corresponding to eight predetermined categories of indoor or outdoor location, extracted and analysed for mite allergen Der p 1 by an amplified ELISA. Allergen was detected in 57.2% of the total of 353 subsamples collected during 20 days of sampling. Exposure patterns varied over time. Higher concentrations of airborne mite allergen were typically measured in samples collected from domestic locations in the day and evening. Indoor domestic Der p 1 exposures accounted for 59.5% of total exposure, whereas total in-bed-asleep exposure, which varied 80 fold between individuals, accounted overall for 9.85% of total exposure, suggesting beds are not often the main site of exposure. This study establishes the feasibility of novel methods for determining the time-geography of personal exposure to many bioaerosols and identifies new areas for future technical development and clinical applications.

Concepts: Asthma, Allergy, Arachnid, Mite, House dust mite, 12-hour clock, Date and time notation by country, 24-hour clock

25

Allergen immunotherapy is a treatment modality which can be applied using different vaccines. The aim of this study was to quantify and compare the allergen content of different house dust mites' sublingual treatments and to review the evidence on their efficacy.

Concepts: Immune system, Asthma, Immunology, Allergen immunotherapy, Mite, House dust mite, House, Dust