Dust Mite Allergy Research Articles

Differential Protein Expression by Dendritic Cells from Atopic and Non-Atopic Individuals after Stimulation by the Major House Dust Mite Allergen Der p 1

Background: Dendritic cells (DCs) are sentinels of the immune system and are known to play a key role in allergic responses. However, it is not clear how DCs that have been exposed to an allergen support Th2 type immune responses. It is possible that DCs from atopic individuals are inherently programmed to support allergic disease, or it is the exposure of dendritic cells to allergens that is key to the development of allergic sensitisation. Methods: We used 2D gel electrophoresis and MALDI mass spectrometry to compare the proteome of DCs from atopic and non-atopic individuals in both the resting state and after stimulation with the major house dust mite allergen Der p 1. Results: Our data show that unstimulated DCs from atopic and non-atopic individuals are very similar at the whole cell proteome level, showing few differentially expressed proteins. However, upon stimulation with Der p 1, a number of additional proteins are differentially expressed, and of these several were of potential relevance to Th2 cell differentiation and the allergic response, including GTP-binding regulatory protein Gi alpha-2, frabin and cathepsin D. Conclusion: Whilst there are inherent differences between DCs from atopic and non-atopic individuals, it seems that exposure to allergen plays a key role in differential expression of proteins by these key immune cells. Further studies should now focus on establishing the biological relevance of these proteins as biomarkers in house dust mite allergy and their role in allergen induced Th2 cell differentiation.

CD4+ T cells from allergic individuals recognize epitopes from the common household allergens Der p 1 and Alt a 1 and secrete Th2 cytokines (36.8)

Abstract Allergy is initiated by adaptive Th2-mediated responses; however, little is known about CD4+ T cell epitopes within many common allergens. The objectives of this study were to utilize MHC class II tetramers to identify CD4+ T cell epitopes within household allergens and to isolate allergen reactive T cells for further phenotypic analysis. PBMCs were isolated from the blood of subjects with dust mite and mold (Alternaria) allergies and from non-allergic control subjects, and CD4+ T cells were assayed for responses to sets of allergen-derived peptides. Dust mite allergen epitopes within the Der p 1 protein were mapped for DRB1*0301, *0401, *0701, and *1501 individuals; Alternaria allergen epitopes within the Alt a 1 protein were mapped for DRB1*0301, *0401, *0701, and *1101 individuals. Tetramer-positive responses to allergen epitopes were frequently seen in CD4+ T cells from allergic subjects. A high proportion of tetramer-positive cells from allergic individuals secreted IL-5 while TNF-α, IL-10 and IFN-γ secretion occurred less frequently, indicating that the cytokine response to these allergens is predominantly Th2 polarized. Identification of CD4+ T cell epitopes and characterization of T cell responses to allergens will further our understanding of allergic disease and may prove helpful to improve specific immunotherapy.

Innovation in immunotherapy

Innovation in immunotherapy

Immunomodulatory properties of Lactobacillus plantarum and its use as a recombinant vaccine against mite allergy

Selected lactic acid bacteria were reported to prevent atopic dermatitis and experimental asthma but the mechanisms of their immunomodulatory effects are not fully elucidated. In this study, the signaling pathways triggered by Lactobacillus plantarum NCIMB8826 were investigated and the potential use of this strain producing a variant of the mite allergen Der p 1 as live vaccine vehicle was evaluated. Mouse bone marrow-derived dendritic cells were stimulated with wild-type or a L. plantarum teichoic acid mutant to evaluate the secretion of cytokines. A recombinant L. plantarum expressing Der p 1 was engineered, its in vitro immunomodulatory properties were characterized and its prophylactic potential was evaluated in a Der p 1-sensitization murine model. Mouse dendritic cells stimulated by L. plantarum triggered the release of interleukin-10 (IL-10), IL-12 p40, IL-12 p70 and tumor necrosis factor-alpha (TNF-alpha). IL-12 p40 secretion was dependent on nuclear factor-kappaB (NF-kappaB), mitogen-activated protein (MAP) kinases, Toll-like receptor 2 (TLR2), TLR9 and on the bacterial teichoic acid composition. Recombinant L. plantarum producing Der p 1 exhibited similar immunostimulatory properties as wild-type. Prophylactic intranasal pretreatment of mice with this recombinant strain prevented the development of the typical Th2-biased allergic response by a drastic reduction of specific IgE and the induction of protective allergen-specific IgG2a antibodies. Moreover, both wild-type or recombinant L. plantarum reduced airway eosinophilia following aerosolized allergen exposure and IL-5 secretion upon allergen restimulation. By combining both Th1-type immunostimulatory properties and an efficient allergen delivery capacity, recombinant L. plantarum producing Der p 1 represents a promising vaccine against house dust mite allergy.

Effects of Sequential Dermatophagoides Pteronyssinus Antigen Stimulation on Anatomy and Physiology of the Larynx

The goal of this investigation was to study the effects of sequential dust mite antigen stimulation on the appearance and function of the larynx. To that end, we designed a randomized, placebo-controlled, double-blind, prospective analysis of adults who had tested positive for perennial dust mite allergy. The larynx of patients who received the active antigen was challenged directly with a low (1:100) and a high (1:40) concentration of the dust mite allergen via an oral nebulizer. Voice laboratory assessment tools included voice and allergy questionnaires, videostroboscopic examination of the larynx, acoustic and speech aerodynamic analyses, and digital audio voice recordings. The study was prematurely terminated after 2 patients had been treated with the highest concentration of the antigenic suspension because of adverse effects, including chest tightness, coughing, and voice difficulties. Both of these patients had demonstrated viscous endolaryngeal secretions and vocal fold edema on videostroboscopy. No reactions were noted at the lower concentration of antigen exposure or in 1 control patient who completed the study. We believe that our findings, as preliminary as they are, may serve as an initial template for the differential diagnosis and treatment of other patients with inhalant allergies who present with chief complaints suggestive of allergic laryngitis.

Skin tests, T cell responses and self‐reported symptoms in children with allergic rhinitis and asthma due to house dust mite allergy

In allergic responses, a distinction is made between an early-phase response, several minutes after allergen exposure, and a late-phase response after several hours. During the late phase, eosinophils and T cells infiltrate the mucosa and play an important role in inflammation. The aim of this study was to examine the relationship between allergen-induced late-phase skin responses and in vitro T cell reactivity. In addition, the relationship between allergen-induced skin or T cell responses and the severity of self-reported symptoms was studied in children with house dust mite allergy. A total of 59 house dust mite-allergic children (6-18 years) were recruited in general practice. These children or their parents rated their nasal and asthma symptoms on diary cards during 1 month. Allergen skin tests were performed and read after 15 min (early phase) and 6 h (late phase). Allergen-specific T cell proliferation was determined, and Th2 cytokine (IL-5 and IL-13) secretion was analysed. The size of the late-phase skin response correlated with in vitro T cell proliferation (r(s)=0.38, P=0.003) but not with Th2 cytokine secretion (r(s)=0.16, P=0.2 for both IL-5 and IL-13). Moreover, the late-phase skin response and T cell proliferation correlated with asthma symptoms (r(s)=0.30, P=0.02 for skin response and r(s)=0.28, P=0.03 for T cell proliferation) but not with nasal symptoms (r(s)=0.19, P=0.15 for skin response and r(s)=0.09, P=0.52 for T cell proliferation). The early-phase skin response correlated with the nasal symptom score (r(s)=0.34, P=0.01) but not with asthma symptom scores (r(s)<0.005, P=0.97). In this study, the late-phase skin test response correlated with in vitro T cell proliferation but not with Th2 cytokine secretion. We found weak or no correlations between late-phase skin responses and symptoms of asthma or rhinitis in children with house dust mite allergy. This suggests that late-phase skin responses reflect certain T cell properties but are of limited value for the evaluation of airway symptoms in atopic children.

Isolation and characterization of the 68 kD allergen from house dust mite Dermatophagoides pteronyssinus

House dust mites (HDM) represent a major source of allergens, contributing to the increasing incidence of type I hypersensitivity disease worldwide. Over 30 different IgE-binding proteins from the HDM extract were detected. Although group 1 and 2 have been identified as major allergens, due to the safety and efficacy of allergy diagnosis and immunotherapy, there is a need to carefully evaluate the clinical relevance of other allergens present in the HDM extract. In regard to this, a high molecular mass allergen of about 68 kD was purified from the HDM extract using a combination of gel permeation chromatography and reversed-phase chromatography. The IgG and IgE reactivity of the purified protein were preserved during the purification process, as confirmed by Western blot analysis with polyclonal rabbit antibodies and dot blot analysis with a pool of sera from subjects with house dust mite allergy, respectively. In addition, the IgE reactivity was confirmed using ELISA testing with nine patient sera. The biological potency of the 68 kD allergen was confirmed by skin prick testing in five allergic subjects, suggesting that the high molecular mass allergen is a good candidate for component-resolved diagnosis of house dust mite allergy and eventual therapeutic treatment.

House dust mite allergy: complete removal of the provoking allergen is a primary therapeutic approach*

*Comment on Gotzsche PC, Johansen HK: House dust mite control measures for asthma: systematic review, Allergy 2008

Randomized double-blind placebo-controlled trial of sublingual immunotherapy in children with house dust mite allergy in primary care: study design and recruitment

BackgroundFor respiratory allergic disorders in children, sublingual immunotherapy has been developed as an alternative to subcutaneous immunotherapy. Sublingual immunotherapy is more convenient, has a good safety profile and might be an attractive option for use in primary care. A randomized double-blind placebo-controlled study was designed to establish the efficacy of sublingual immunotherapy with house dust mite allergen compared to placebo treatment in 6 to18-year-old children with allergic rhinitis and a proven house dust mite allergy in primary care. Described here are the methodology, recruitment phases, and main characteristics of the recruited children.MethodsRecruitment took place in September to December of 2005 and 2006. General practitioners (in south-west Netherlands) selected children who had ever been diagnosed with allergic rhinitis. Children and parents could respond to a postal invitation. Children who responded positively were screened by telephone using a nasal symptom score. After this screening, an inclusion visit took place during which a blood sample was taken for the RAST test.ResultsA total of 226 general practitioners invited almost 6000 children: of these, 51% was male and 40% <12 years of age. The target sample size was 256 children; 251 patients were finally included. The most frequent reasons given for not participating were: absence or mildness of symptoms, absence of house dust mite allergy, and being allergic to grass pollen or tree pollen only. Asthma symptoms were reported by 37% of the children. Of the enrolled children, 71% was sensitized to both house dust mite and grass pollen. Roughly similar proportions of children were diagnosed as being sensitized to one, two, three or four common inhalant allergens.ConclusionOur study was designed in accordance with recent recommendations for research on establishing the efficacy of sublingual immunotherapy; 98% of the target sample size was achieved. This study is expected to provide useful information on sublingual immunotherapy with house dust mite allergen in primary care. The results on efficacy and safety are expected to be available by 2010.Trial registrationthe trial is registered as ISRCTN91141483 (Dutch Trial Register)

Safety and Immunogenicity of a Cluster Specific Immunotherapy in Children with Bronchial Asthma and Mite Allergy

Background: Cluster specific immunotherapy (SIT) is a modern form of allergen immunotherapy allowing safe administration of high allergen doses in a short time interval compared to classic SIT. In the current study, we investigated the safety profile and immunological effect of cluster SIT in children with allergic asthma due to house dust mite allergy. Methods: A total of 34 children (6–18 years) with allergic asthma were assigned to cluster (n = 22) or classic SIT (n = 12). To achieve a maintenance dose of allergen extract, cluster patients received 14 injections of house dust mite allergen within 6 weeks, whereas the classic SIT group received 14 injections within 14 weeks. Safety was monitored by recording adverse events. Immunogenicity was measured by specific IgG_Mite and IgG4_Mite, by antibody-blocking properties on basophil activation, and by the T cell subset transcription factors Foxp3, T-bet, and GATA-3. Results: There were no significant differences in local and systemic side effects between the two groups. In the cluster group, serum levels of specific IgG_Mite (p < 0.001) and specific IgG4_Mite (p < 0.001) significantly increased after 8 weeks, while it took 12 weeks in the classic SIT group. These data were confirmed by blocking CD63 expression as well as release of cysteinyl leukotrienes after in vitro basophil stimulation. No differences in transcription factor expression were found in the two groups. Conclusion: Cluster SIT is safe in children. Additionally, our data demonstrated an even more rapid induction of specific immune tolerance. Cluster SIT is an attractive alternative to conventional up-dosing schedules with fewer consultations for the patients.

The urokinase system in patients with intermittent and persistent allergic rhinitis

Local and systemic changes in hemostasis are associated with allergic diseases. Apart from their well documented role in regulation of plasminogen activation, components of the urokinase system may be involved in modulation of cellular activities during immune inflammatory responses. So far, little has been known about the function of the system in allergic inflammation. In the present study, we assessed circulating levels of the urokinase system components such as urokinase-type plasminogen activator (uPA), soluble form of uPA receptor (CD87), and the inhibitor--plasminogen activator inhibitor type 1. The study comprised of patients suffering from allergic rhinitis, however, without any asthmatic symptoms. Plasma levels of uPA and soluble form of uPA receptor antigens, and plasminogen activator inhibitor type 1 activity were measured in 17 patients with grass pollens-induced intermittent allergic rhinitis and 15 patients with persistent allergic rhinitis due to house dust mite allergy, as well as in 20 sex-matched and age-matched healthy nonatopic participants. We did not observe any statistically significant differences in the levels of the urokinase system components between patients with intermittent allergic rhinitis and persistent allergic rhinitis, and the controls. The circulating levels of uPA, its soluble receptor, and its inhibitor did not differ between allergic rhinitis patients and healthy participants, therefore it seems that the systemic release and activity of the urokinase system molecules may be not significantly changed in the course of nasal allergic inflammation induced by periodic or continuous exposure to a natural allergen.

Baseline laryngeal effects among individuals with dust mite allergy

To examine baseline effects of perennial allergy on laryngeal appearance, laryngeal function, and perceived vocal handicap among individuals without current allergy or voice symptoms. This pilot study included 47 adults: 21 with positive and 26 with negative skin test responses for the dust mite, Dermatophagoides pteronyssinus. Subjects were tested for sensitivity to dust mite antigen by prick testing. Laryngeal appearance and function were studied with laryngovideostroboscopy, acoustic and speech aerodynamic analysis, and voice sampling. These parameters were blindly analyzed by three trained examiners. Subjects also completed the Voice Handicap Index (VHI) as a measure of vocal handicap. Subjects allergic to dust mites perceived significantly greater vocal handicap on the VHI than did nonallergic subjects. No significant differences were noted between groups in laryngeal appearance or function. These pilot data suggest that, at baseline, allergic individuals perceive greater vocal handicap than their nonallergic counterparts (P = 0.04), even in the absence of current allergy symptoms or observable physical or functional abnormalities. These preliminary observations can serve as an impetus for further research into this important area, including the potential interrelationship between acid reflux disease and allergic laryngeal inflammation.

Comparison of the Long-Term Efficacy of Subcutaneous and Sublingual Immunotherapies in Perennial Rhinitis

Background: Both sublingual and subcutaneous immunotherapies have a documented clinical efficacy, but only a few comparative studies have been performed. Objectives: To evaluate and compare the long-term efficacies of subcutaneous and sublingual immunotherapy. Methods: One hundred and ninety-three patients with house dust mite allergies, out of an original total of 230, were treated with subcutaneous and sublingual house dust mite-specific immunotherapies for 3 years and also observed for 3 years after discontinuation of the treatment. The patients were randomized into 2 groups: the sublingual group (97 patients) and the subcutaneous group (96 patients). The therapy’s success was evaluated using the symptom score, skin prick test results, and the nasal allergen challenge score. The patients were evaluated at the beginning of the study, at the end of years 1, 2, and 3, and also at the end of the 1st and 3rd years after discontinuation of the specific immunotherapy treatment. Results: Immunotherapy induced a significant improvement during the treatment and the follow-up period. We found a greater improvement in the subcutaneous group compared to the sublingual group when we looked at the comparative results of the total 6 years. Conclusion: We suggest subcutaneous immunotherapy for patients with perennial allergic rhinitis due to the better results that were obtained during our study period. Nevertheless, sublingual immunotherapy is now accepted by WHO as a valid alternative to the subcutaneous route and should be used in all patients who require immunotherapy and do not accept the subcutaneous route of allergen administration.

Is allergenic similarity predictable in respiratory allergies?

First degree relatives of patients with allergic diseases are at increased risk of having the disorder. However, it is not clear whether two such related patients with allergic diseases are sensitive to the same antigens or not. The aim of this study to determine whether or not first degree relatives with respiratory allergies are more likely to be skin test positive to the same allergen extracts as unrelated patients. Skin test results for 35 common aeroallergens were compared in 264 pairs of genetically related subjects and 264 pairs of age and sex matched, but unrelated, subjects. We calculate the percentages of the concordant and discordant results in each group. Results are compared by using chi2 test. For all related and unrelated groups combined, there were significant differences with mites (der. pteronyssinus, der. farinae) and some moulds (aspergillus mix and rhizopus nigricans) (p<0.05); When the groups were subdivided into parent-child pairs and same or different sibling pairs, and the same comparisons were made, a significant difference was only found in both sibling pairs (p<0.05), not in parent-child pairs (p>0.05). Since there was no both positivity with aspergillus mix and rhizopus nigricans in the two groups, these two allergens were excluded from the study. It is concluded that we could not say that if one or both of parents are atopic to any allergens, their child will be atopic to the same allergens. Besides, when a respiratory allergy occurs in siblings, only the one who has house dust mite allergy sensitivity can possess the similar antigen sensitivity.

Analysis of basophil activation by flow cytometry in pediatric house dust mite allergy

Detection of allergen-induced basophil activation by flow cytometry has been shown to be a useful tool for allergy diagnosis. The aim of this study was to assess the potential of this technique for the diagnosis of pediatric house dust mite allergy. Quantification of total and specific IgE and basophil activation test were performed to evaluate mite allergic (n = 24), atopic (n = 23), and non-allergic children (n = 9). Allergen-induced basophil activation was detected as a CD63-upregulation. Receiver operating characteristics (ROC) curve analysis was performed to calculate the optimal cut-off value of activated basophils discriminating mite allergic and non-allergic children. ROC curve analysis yielded a threshold value of 18% activated basophils when mite-sensitized and atopic children were studied [area under the curve (AUC) = 0.99, 95% confidence interval (CI) = 0.97-1.01, p < 0.001] with a sensitivity and specificity of 96% for 16 microg/ml mite extract. Analysis of the data obtained with 1.6 microg/ml mite extract defined a cut-off value of 8% activated basophils (AUC = 0.96, 95% CI = 0.91-1.01; p < 0.001) with a sensitivity of 82% and specificity of 100%. Comparison between mite allergic and non-allergic children produced a cut-off of 8% activated basophils (AUC = 1.0) with 16 microg/ml allergen extract and a sensitivity and specificity of 100%. The same threshold and specificity values were obtained with 1.6 microg/ml extract (AUC = 97%, 95% CI = 0.92-1.02; p < 0.001) but sensitivity decreased to 83%. Two atopic children showed negative skin prick and basophil activation tests and high specific IgE (>43 kU/l) values for Dermatophagoides pteronyssinus allergen. They also showed positive prick (wheal diameter >1.0 cm) and basophil activation (>87%) tests and high specific IgE (>100 kU/l) with shrimp allergen. Shrimp sensitization was demonstrated by high levels of Pen a 1-specific IgE (>100 kU/l). Cross-reactivity between mite and shrimp was confirmed by fluorescence enzyme immunoassay (FEIA-CAP) inhibition study in these two cases. This study demonstrated that the analysis of allergen-induced CD63 upregulation by flow cytometry is a reliable tool for diagnosis of mite allergy in pediatric patients, with sensitivity similar to routine diagnostic tests and a higher specificity. Furthermore, this method can provide additional information in case of disagreement between in vivo and in vitro test results.

Wirkung und Verträglichkeit des Homöopathikums aus Adhatoda vasica bei Patienten mit Hausstaubmilbenallergie

OBJECTIVE: In a drug monitoring study, the efficacy and safety of Adhatoda vasica was studied on patients ages 12 to 80 with dust mite allergies. METHODS: The drug monitoring study (DMS) was performed with 103 patients suffering from symptoms of dust mite allergy (at least 4 of the following symptoms: runny nose, congested nose, sneezing, red eyes, itching eyes, watery eyes, coughing or difficulty breathing). The patient population was composed of 35 children over the age of 12 and 68 adults. The patients took, every hour or half hour up to 12 times daily, 10 drops (maximum 120 drops per day) of the investigational product, over a period of 7-9 days. To evaluate the efficacy, the decrease in allergy symptoms was assessed by means of a scaled evaluation by the physicians, as well as by a global evaluation of the efficacy by the physicians and the patients. Safety was estimated by the occurrence of adverse events, as well as by a global evaluation by the physicians and patients. RESULTS: Upon completion of the DMS, 83,5 % of the total group, 74,3 % of the children’s group, and 88,2 % of the adult group showed an improvement in dust mite allergy symptoms. Global evaluation of the efficacy by the physicians and the patients was 72 and 77 % respectively an assessment of very good” to satisfactory”. The global evaluation of the safety was rated 99 % by the physicians and 96 % by the patients very good” or good”. During the treatment period, 6 adverse events (AE) occurred. None of these AEs was classified as an adverse drug reaction.

Dust-mite avoidance measures in patients on immunotherapy

The compliance of dust-mite (DM) allergic patients receiving immunotherapy (IT) with environmental avoidance measures has not been reported. To investigate patient practices, a questionnaire was distributed to patients receiving IT for indoor allergens. Ninety-three of 200 patients (46%) with indoor allergies completed the questionnaire. Of the 93 patients, 69% were allergic to DMs, 45% were allergic to pets, 17% were allergic to mold, and 3% were allergic to cockroaches. Of 64 patients allergic to DMs, 53% reported use of mattress covers, 61% reported use of pillow covers, 81% reduced moisture in their homes, 83% washed their bed linens in water that was >130 degrees F, 77% vacuumed or dusted weekly, and 21% replaced carpets with polished flooring. Fifty-two percent of patients who did not use covers and 49% who did not replace their carpets cited cost as the most common reason. Education about the use of DM covers was reported by 97% of patients allergic to DMs, predominantly by physicians. In conclusion, many patients on IT for DM allergy do not use avoidance measures for decreasing allergen exposure. Cost appears to influence compliance with several measures including protective mattress and pillow covers. It may be unreasonable to require most patients to use such avoidance measures before being candidates for IT.

Constitutive nitric oxide synthase gene polymorphisms and house dust mite respiratory allergy in an Algerian patient group

Genetic polymorphisms in neuronal nitric oxide synthase (NOS1) and calmodulin-dependent endothelial NOS (NOS3) genes are known to influence the course of allergic respiratory disorders. We investigated the role of NOS1 -84 G-->A and NOS3 -786 T-->C, 894 G-->T and 27 base pair (bp) repeat polymorphisms in 125 patients suffering from asthma and/or rhinitis and monosensitized against Dermatophagoides pteronyssinus (Dpter) and 111 controls from Algeria. We found a higher frequency of the -786 C NOS3 allele in patients than in controls [corrected P value (Pc) = 0.04], especially in female cases (Pc = 0.02) and that the 'ab' genotype of the 27-bp polymorphism was significantly associated with specific immunoglobulin E production against Dpter (P = 0.006). This study brings further support for the participation of NOS3 gene polymorphism in the pathogenesis of respiratory allergic disorders.

Major House Dust Mite Allergens Dermatophagoides pteronyssinus 1 and Dermatophagoides farinae 1 Degrade and Inactivate Lung Surfactant Proteins A and D

Lung surfactant proteins (SP) A and D are calcium-dependent carbohydrate-binding proteins. In addition to playing multiple roles in innate immune defense such as bacterial aggregation and modulation of leukocyte function, SP-A and SP-D have also been implicated in the allergic response. They interact with a wide range of inhaled allergens, competing with their binding to cell-sequestered IgE resulting in inhibition of mast cell degranulation, and exogenous administration of SP-A and SP-D diminishes allergic hypersensitivity in vivo. House dust mite allergens are a major cause of allergic asthma in the western world, and here we confirm the interaction of SP-A and SP-D with two major mite allergens, Dermatophagoides pteronyssinus 1 and Dermatophagoides farinae 1, and show that the cysteine protease activity of these allergens results in the degradation of SP-A and SP-D under physiological conditions, with multiple sites of cleavage. A recombinant fragment of SP-D that is effective in diminishing allergic hypersensitivity in mouse models of dust mite allergy was more susceptible to degradation than the native full-length protein. Degradation was enhanced in the absence of calcium, with different sites of cleavage, indicating that the calcium associated with SP-A and SP-D influences accessibility to the allergens. Degradation of SP-A and SP-D was associated with diminished binding to carbohydrates and to D. pteronyssinus 1 itself and diminished capacity to agglutinate bacteria. Thus, the degradation and consequent inactivation of SP-A and SP-D may be a novel mechanism to account for the potent allergenicity of these common dust mite allergens.

Generation of a transgenic rice seed-based edible vaccine against house dust mite allergy

As an alternative approach to conventional allergen-specific immunotherapy, transgenic rice seed expressing a major house dust mite (HDM) allergen, Der p 1, was developed as an edible vaccine. The C-terminal KDEL-tagged Der p 1 allergen specifically accumulated in seed endosperm tissue under the control of the endosperm-specific GluB1 promoter. Der p 1 reached a maximum concentration of 58 μg/grain and was deposited in the endoplasmic reticulum (ER)-derived protein body I (PB-I). Plant-derived Der p 1 was posttranslationally modified with high-mannose-type glycan structures. Glycosylated Der p 1 displayed reduced IgE binding capacity in comparison with its unglycosylated counterpart in vitro. Our results indicate that transgenic Der p 1 rice seeds are a safe, potential oral delivery vaccine for the treatment of HDM allergy.