Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.22.65 (Der p 1)
 346 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Experiments were done to clarify the mechanisms associated with releasability of histamine. First, washed leukocytes from 23 asthmatic patients sensitive to mite allergen were challenged with Der p 1, a major allergen isolated from Dermatophagoides pteronyssinus, or anti-IgE. A significant correlation was observed between the ratio of Der p 1-specific IgE titer to total IgE level (S/T) in the patient's plasma and either the reactivity (maximal percentage of histamine release; rs = 0.514, P = 0.016, n = 23) or the sensitivity (the minimum allergen concentration required to achieve 25% histamine release; rs = -0.790, P = 0.0002) to Der p 1. Additionally, the reactivity to Der p 1 was significantly correlated with that to anti-IgE (rs = 0.690, P = 0.0012), indicating that an intrinsic cellular property may be one of the contributing factors in immunologic histamine release. In a second series of experiments, sinus mast cells were passively sensitized with immunoglobulins prepared from the patient's plasma. A statistically significant correlation was found between either the reactivity or the sensitivity to Der p 1 and S/T, thus indicating that S/T is an indicator of the releasability of histamine. When basophils or mast cells were passively sensitized with mouse IgE and subsequently stimulated with antimouse IgE, the reactivity to antihuman IgE was significantly correlated with that to antimouse IgE (rs = 0.966, P = 0.0023, n = 11). These observations suggest that an intrinsic cellular property regulates reactivity in immunologic histamine release. Taken together, our results suggest that an intrinsic cellular property, as well as specific IgE antibody levels on the cell surface, is an important factor in determining histamine release in response to IgE-dependent activation.
 ...
PMID:IgE-mediated basophil releasability is influenced by intrinsic factors and by IgE on the cell surface. 883 23

We investigated the levels of mite allergens (Der p 1, Der f 1, Der 2, and Lep d 1) in dust samples from the homes of 59 patients with asthma, 36 sensitized to house-dust mites (HDM) and 23 to grass pollen (controls), living in Porto, northern Portugal. The relationship between exposure and sensitization to HDM and the influence of housing conditions on mite-allergen levels were also evaluated. Der p 1 (median 9.2 micrograms/g) and Der 2 (4.6 micrograms/g) were the main allergens, while Der f 1 and Lep d 1 levels were always < 1 microgram/g dust and undetectable in 11% and 47% of samples, respectively. All HDM-sensitized asthmatics were exposed to Der p 1 levels > 2 micrograms/g and their homes contained significantly higher levels of Der p 1 (median 12.5 vs 6.4 micrograms/g; P = 0.008) and Der 2 (6.2 vs 3.0 micrograms/g; P = 0.004) when compared to the control group. A significant correlation was observed between the exposure to Der p 1 and the wheal area at skin testing with the Dermatophagoides pteronyssinus (Dp) extract (P = 0.01) as well as with serum specific IgE levels to Dp (P = 0.03). Patients with higher levels of serum specific IgE (> or = 17.5 HRU/ml) were also more frequently exposed to Der p 1 levels > or = 10 micrograms/g (P = 0.002). Old homes, presence of carpets, and signs of dampness were conditions associated with significantly higher levels of mite allergens. In conclusion, we found high levels of Der p 1 and Der 2 particularly in the homes of HDM-sensitized patients and we confirm the relationship between exposure and sensitization to HDM, assessed by both in vivo and in vitro methods. In additional to a favorable outdoor climate, we found in our region housing conditions propitious to mite growth, suggesting that specific geographic characteristics must also be taken into account for the correct planning of mite-avoidance measures.
 ...
PMID:Indoor mite allergens in patients with respiratory allergy living in Porto, Portugal. 889 15

Two assays have been developed to measure arthropod levels in house dust. The first assay measures silverfish antigens. The second assay measures invertebrate tropomyosin and gives a global assessment of the level of arthropod-derived material. These assays and a Der p 1 and Der p 2 assay were used to analyse 53 dust samples. In most dust samples the ratio of tropomyosin/Der p 2 was higher than in mite body extract, indicating that the assay measures other arthropods besides mites. Silverfish antigen was detectable in most of the dust samples. In many homes in which the inhabitants were unaware of the presence of silverfish, silverfish antigen was detectable. Therefore for information on exposure an immunochemical analysis is superior to a questionnaire.
 ...
PMID:Silverfish protein in house dust in relation to mite and total arthropod level. 891 3

DNA immunization has been an attractive approach in altering the host immune response to antigen. To examine the utility of DNA immunization in allergic response, we examined the in vivo efficacy of an 'allergen-gene immunization' approach in the modulation of allergen-specific IgE responses in mice. Our results showed first that I.m. injection of a gene construct (pCMVD) containing an important house dust mite allergen gene (Dermatophagoides pteronyssinus group 5 allergen; Der p 5) results in the induction of Der p 5-specific IgG antibodies, but not IgE antibody. We next examined the effect of transduced allergen gene on the expression of specific IgE response in mice after i.p. challenge with recombinant Der p 5 (rDer p 5). Both vector (mock) control- and pCMVD-treated mice were i.p. sensitized with rDer p 5 at 3 weeks after injection of gene construct. Results showed that there is a 90% reduction in the level of specific IgE in pCMVD-treated mice when compared with mock-treated mice. Furthermore, the suppression of specific IgE response can be adoptively transferred with CD8+ T cells from pCMVD-treated mice and such inhibition is in an antigen-specific manner, since the level of specific IgE to an irrelevant allergen, Der p 1, remained unchanged in comparison to that of the mock-treated group. In addition, Der p 5-specific CD8+ T cells could produce high levels of IFN-gamma which probably inhibit allergen-specific IgE responses. Taken together, our results suggest that allergen-gene transfer is effective in the modulation of allergen-specific IgE responses and may provide a novel therapeutic approach.
 ...
PMID:Inhibition of specific IgE response in vivo by allergen-gene transfer. 892 18

The study aimed to investigate the possible diagnostic significance of T-cell proliferative responses to purified Der p 1 antigen in allergic children with and without allergic sensitization to house-dust-mite (HDM) allergens. T-cell reactivity to purified Der p 1 antigen was analyzed in 24 children with allergic sensitization to HDM demonstrated by RAST and/or positive skin prick tests. Twelve healthy young adults and 11 children with allergic sensitizations other than HDM served as controls. Of 25 HDM-allergic patients, 16 displayed strong T-cell reactivity to Der p 1 (stimulation indices > 3): nine patients showed no T-cell proliferation despite the presence of specific IgE, and five showed no responses despite positive skin prick test. In two patients, a weak T-cell response to Der p 1 could be demonstrated in the absence of specific IgE and negative skin test result. The two affected subjects did not show evidence of mite allergy. No T-cell responses were observed in adult controls (stimulation indices < 3). We conclude that the assessment of T-cell reactivity to Der p 1 is of little value for the diagnosis of HDM allergy. The importance of T-cell proliferative responses for the study of the pathogenesis of HDM allergy remains unchallenged.
 ...
PMID:Diagnostic significance of in vitro T-cell proliferative responses to house-dust mite Der p 1 in children with dust-mite allergy. 894 44

Little information is available on mite allergen levels and rates of sensitization to domestic mites in South America. The purpose of this study was to establish the rate of sensitization to domestic mites in asthmatics and measure mite allergen levels in pillows and mattresses of mite allergic individuals in Santa Fe, Argentina. Dust samples were collected from the pillows and mattresses of 56 asthmatics (24 females and 32 males, mean age 17.6 +/- 11.5 years), who had been previously skin tested with standardized extracts of Dermatophagoides pteronyssinus, Dermatophagoides farinae and (1:50 w/v) extracts of Aleuroglyphus ovatus, Blomia tropicalis, Chortoglyphus arcuatus. A wheal > or = 3 mm was considered positive. Sensitization to Lepidoglyphus destructor and Euroglyphus maynei was determined by RAST and considered positive when a serum bound > or = 1% of the total counts added. Forty six individuals had a positive skin test to D. pteronyssinus, 43 to D. farinae, 27 to A. ovatus, 38 to B. tropicalis, 27 to C. arcuatus; 38 of 54 individuals had a positive RAST to E. maynei and 22 of 54 to L. destructor. The mean Group 1 (Der p 1 + Derf 1) level in pillows (n = 48) was 6.7 micrograms/g (1-55.4) and in mattresses (n = 52) 4.3 micrograms/g (1-38.8). There is a high degree of sensitization to domestic mites among asthmatics in Santa Fe. High mite allergen levels (> 2 micrograms/g) can be detected very often in pillows and mattresses.
 ...
PMID:Mite sensitivity and exposure in the city of Santa Fe, Argentina. 895 37

In 12 house-dust-mite-infested double beds, one of the mattresses was replaced by a new one, the other being regarded as a mite source. All new mattresses were treated in a double-blind fashion, with either benzyl benzoate or placebo before being placed on the bed as well as 1 year later. They were examined for mites and allergen concentrations over a period of 18 months. This period of time covered two mite seasons. Dust samples were taken bimonthly and analyzed by guanine test strip, microscopic mite counting, and determination of the mite allergens Der p 1 (Dermatophagoides pteronyssinus) and Der f 1 (D. farinae) by ELISA. Although, at the end of the observation period, the new mattresses still had significantly lower mite and allergen levels than the old mattresses, there were no significant differences between the placebo and the benzyl benzoate groups. In our setting, benzyl benzoate plus frequent cleansing was not significantly more effective in controlling mites than frequent cleansing alone.
 ...
PMID:Does benzyl benzoate prevent colonization of new mattresses by mites? A prospective study. 902 Apr 14

The group I (Der p 1) allergen of Dermatophagoides pteronyssinus (house dust mite, HDM) contains several T helper (Th) epitopes recognized by C57BL/6 mice, with the peptide (111-139) containing a dominant MHC class II-restricted epitope (113-127). Since CD8+ T cells are thought to play a role in the regulation of allergic disease, we examined the Der p 1 sequence for potential MHC class I-binding motifs and observed that residues 111-119 (FGISNYCQI) contain motifs for H-2Db and Kb. Furthermore, immunization of C57BL/6 mice with unadjuvanted Ty virus-like particles (VLP) carrying Der p 1 (111-139), a method known to induce murine cytotoxic T lymphocyte (CTL) responses, primed Der p 1 (111-119)-specific Db-restricted CTL which produce high levels of IFN-gamma and low levels of IL-5 and IL-6 in vitro (T1-type CTL). VLP carrying the minimal epitope (FGISNYCQI) also induced a CTL response following immunization without adjuvant by various routes. Der p 1 (111-139)-VLP adjuvanted with alum did not prime CTL in C57BL/6 mice but were found to prime Th1-type CD4+ T cells that recognize the overlapping peptide (113-127) and native protein. The ability to successfully predict allergen-specific CD8+ T cell epitopes and prime CD8+ and/or CD4+ T cell responses provides an opportunity to dissect the relative roles of these T cells in the regulation of allergic responses and may offer therapeutic potential for reprogramming Th2-type allergic responses.
 ...
PMID:Prediction of murine MHC class I epitopes in a major house dust mite allergen and induction of T1-type CD8+ T cell responses. 904 9

Allergen avoidance is regarded as an important approach to management of atopic asthma. The effect of Intervent bed covering systems on house dust mite (HDM) allergen exposure, asthma symptoms and markers of inflammation was investigated in 31 HDM sensitive asthmatic children. Dust concentrations of Dermatophagoides pteronyssinus allergen 1 (Der p 1) were monitored before and after covering the mattress, duvet and pillow with active and placebo covers for 3 months, in a single-blind, cross-over trial. Twice daily peak expiratory flow rate (PEFR), daily symptom scores and treatment schedule were recorded. Bronchial hyperresponsiveness was monitored by histamine challenge (provocative concentration of histamine causing a 20% fall in forced expiratory volume in one second (PC20)), and inflammation by measuring eosinophil cationic protein (ECP), eosinophil protein X (EPX), eosinophil peroxidase (EPO), and soluble interleukin-2 receptor (sIL-2R) in serum. There was a significant reduction in Der p 1 when the mattress, duvet and pillow were covered with the active bedding. There was no significant improvement in symptoms of asthma, PEFR, bronchodilator usage of PC20. Also, ECP, EPX, sIL-2R concentrations did not change for either treatment. EPO concentrations were significantly lower in the active compared to the placebo period. The active bed covers reduced retrievable Dermatophagoides pteronyssinus allergen 1 (Der p 1) from the bedding, with short term clinical benefit.
 ...
PMID:Effect of a bed covering system in children with asthma and house dust mite hypersensitivity. 904 33

Asthma and allergy are extremely frequent diseases, affecting 5-10% and 30% of the population, respectively. The prevalence of asthma has increased in many developed countries, which may be due to several factors, including increased exposure to house dust mite (HDM) allergens. HDM to which humans are most frequently sensitized are Dermatophagoides pteronyssinus, Dermatophagoides farinae, and Euroglyphus maynei. These mites multiply in carpets, bedding and upholstered furniture in a hot and humid atmosphere. The allergens are digestive enzymes of the mites. Several epidemiological studies have shown that an increase in exposure to HDMs is associated with an increase in the prevalence of sensitization and asthma, whereas mite avoidance leads to a decrease in respiratory symptoms of sensitized asthmatic subjects. Sensitized subjects have specific immunoglobulin G and E (IgG and IgE) humoral responses, as well as proliferative T-cell responses to HDM allergens. Experimental exposure to HDM allergens induces bronchoalveolar inflammatory responses, that are characterized by the recruitment and activation of eosinophils, mastocytes, neutrophils, monocytes and lymphocytes. The cysteine protease activity of Der p 1 (a major allergen of D. pteronyssinus) has been shown to increase airway mucosal permeability, and may thereby contribute to the pathogenesis of airway inflammation and hyperresponsiveness by nonimmunological mechanisms. These epidemiological and experimental data support the recommendations for mite avoidance, especially in persons at high risk of developing asthma.
 ...
PMID:Allergic and nonallergic interactions between house dust mite allergens and airway mucosa. 907 12


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>