Acaricidal activities of some essential oils and their monoterpenoidal constituents against house dust mite,Dermatophagoides pteronyssinus (Acari:Pyroglyphidae)

The acaricidal activities of fourteen essential oils and fourteen of their major monoterpenoids were tested against house dust mites Dermatophagoides pteronyssinus. Five concentrations were used over two different time intervals 24 and 48 h under laboratory conditions. In general, it was noticed that the acaricidal effect based on LC50 of either essential oils or monoterpenoids against the mite was time dependant. The LCso values were decreased by increasing of exposure time. Clove, matrecary, chenopodium, rosemary, eucalyptus and caraway oils were shown to have high activity. As for the monoterpenoids, cinnamaldehyde and chlorothymol were found to be the most effective followed by citronellol. This study suggests the use of the essential oils and their major constituents as ecofriendly biodegradable agents for the control of house dust mite, D. pteronyssinus.

Comparison of Three Methods of Protein Extraction from Dermatophagoides Pteronyssinus for Two-dimensional Electrophoresis

Obiective To explore an effective method of Dermatophagoides pteronyssinus protein extraction suitable for two-dimensional electrophoresis （2-DE） analysis. Methods The extracts of Dermatophagoides pteronyssinus were prepared with Coca＇s solution, lysis buffer of 2-DE, and Trizol reagent, respectively. Bicinchoninic acid （BCA） assay was used to determine the total protein concentration of the samples. The efficiency of different protein extraction methods were evaluated with 2-DE analysis. Results The concentrations of extracted protein by methods of Coca＇s solution, lysis buffer, and Trizol reagent were 0.63 g/L, 0.90 g/L, and 0.80 g/L, respectively. The 2-DE analysis results showed that some protein spots in low molecular weight （LMW） range could be detected with the Coca＇s solution method. With the lysis buffer of 2-DE method, more protein spots in LMW range could be detected, while the medium molecular weight （MMW） protein spots were absent. Several MMW protein spots （174-178 kD and 133 kD） and more LMW protein spots were detected withTrizol reagent method. Conclusions Among Coca＇s solution, lysis buffer of 2-DE, and Trizol reagent, the concentration of extracted protein of Dermatophagoides pteronyssinus by lysis buffer of 2-DE is the highest. However, most protein components of Dermatophagoides pteronyssinus purified mite bodies can be extracted by Trizol reagent, which may generally reflect the whole profile of Dermatophagoides pteronyssinus allergens.

Comparison and Evaluation of Several Dermatophagoides Pteronyssinus Allergen Extracts for Skin Prick Test

Objective To evaluate the significance of several Dermatophagoides pteronyssinus allergen extracts for skin prick test(SPT) in patients allergic to Dermatophagoides pteronyssinus.Methods Two hundred and nineteen patients enrolled in Peking Union Medical College Hospital underwent SPT and serum specific IgE assay to detect the Dermatophagoides pteronyssinus allergen.Three kinds of house dust mite allergen extracts were used for SPT,including the Dermatophagoides pteronyssinus extract prepared by our laboratory(group A),standardized Dermatophagoides pteronyssinus extract(group B),and mixed extracts of Dermatophagoides pteronyssinus and Dermatophagoides farinae(group C).Human serum specific IgE result was regarded as the reference standard for diagnosis of Dermatophagoides pteronyssinus allergy.The receiver operating characteristic(ROC) curve was used to evaluate the diagnostic performance of SPT with the extracts of three groups.Results SPT results showed that the median wheal diameter of group A,group B,and group C was 0.43,0.35,and 0.28 cm,respectively,with significant difference among three groups(P<0.05).The difference was significant between group A and B(P<0.01) as well as group A and C(P<0.01),but not between group B and C(P>0.05).There was no local urticaria or systemic allergic reactions following the procedure of SPT.Local reaction was observed in 5 patients and delayed reaction was in 2 patients of group A.As for group B and C,local reaction occurred in 3 cases and delayed reaction in 2 cases in each group.The area under ROC curve of SPT with extract in group A,group B,and group C was 0.765,0.801,and 0.782,respectively.Based on the detection results of serum specific IgE,the sensitivity of SPT in diagnosis of Dermato-phagoides pteronyssinus allergy with extract of group A,group B,and group C was 92.4%,87.0%,and 81.5%,and the specificity was 60.6%,73.2%,and 74.8%,respectively.Conclusion The Dermatophagoides pteronyssinus extract for SPT prepared by our laboratory offers good sensitivity and specificity comparable to commercially available allergen extracts,and it may be an appropriate candidate for clinical screening and diagnosis of Dermatophagoides pteronyssinus allergy.

Effect of a commercial air ionizer on dust mites Dermatophagoides pteronyssinus and Dermatophagoides farinae(Acari:Pyroglyphidae) in the laboratory

Objective:To investigate the short and long tenn efficacy of a commercial air ionizer in killing Dermatophagoides pteronyssinus(D.pteronyssinus)and Dermalophagoides farinae(D.farinae)mites.Methods:The effect of a commercial ionizer on D.pteronyssinus and D.farinae was evaluated in the laboratory,using a specially designed test.Mortality was assessed after 6,16and 24 hours for direct exposure and after 24,36,48,60 and 72 hours for exposure in simulated mattress.New batches of mites were used for each exposure time.Results:LT_(50)for direct exposure of ionizer was 10 hours for D.pteronyssinus and 18 hours for D.farinae.The LT_(50)for exposure in simulated mattress was 132 hours or 5.5 days for D.pteronyssinus and 72 hours or 3days for D.farinae.LT_(95)for direct exposure of ionizer was 36 hours for D.pteronyssinus and D.farinae.Meanwhile,the LT_(95)for exposure in simulated mattress was 956 hours or 39.8 days for D.pteronyssinus and 403 hours or 16.8 days for D.farinae.Conclusions:This study demonstrates the increasing mite mortalities with increasing exposure time of a commercial ionizer and suggests that negative ions produced by an ionizer kill dust mites and can be used to reduce natural mile populations on exposed surfaces such as floors,clothes,curtains,etc.However,there is reduced efficacy on mites inside stuffed materials as in mattresses and furniture.

Effect of germicidal UV-C light(254 nm)on eggs and adult of house dustmites,Dermatophagoides pteronyssinus and Dermatophagoides farinae(Astigmata:Pyroglyhidae)

Objective:To examined the immediate and 24 hours post-irradiation germicidal effects of UV-C lamp on.eggs and adults of house dust mites Dermatophagoides pteronyssinus(D.pteronyssinus)and Dermatophagoides farinae(D.farinae).Methods:This study investigated the immediate and24 hours post irradiation mortalities of adult mites exposed to UV-C at different exposure times(5mins,10 mins,15 mins,20 mins,30 mins and 60 mins)and distances(10 cm,25 cm,33 cm,45 cm and 55 cm).Fresh eggs of the 2 dust mites were also irradiated at 10,35 and 55 cm for 0.5,1,2,3,and 5 minutes,and observed daily post-irradiation for up to 7 days.Results:Highest immediate mortality of 100%occurred with direct irradiation al 10 cm distance from UV-C lamp and for 60mins,for both species of mites.The post 24 hours mean mortality rates were(58.4±17.4)%for D.pteronyssinus and(27.7±9.7)%for D.fitrinae when irradiated for 1 hour at 55 cm distance under UV-C lamp.When mites were irradiated in the presence of culture media,the highest mortality rates were lower compared to the direct irradiation;at 10 cm distance and 60 mins exposure,the mean mortality was(74.0±6.8)%for D.pteronyssinus and(70.3±6.7)%for D.farinae.Egg hatchability for both species of mites was also notably reduced by greater than 50%following irradiation.Conclusions:Ultraviolet C irradiation is lethal to an array of organisms by damaging their nucleic acids(DNA and RNA).This study demonstrates the increasing mite mortalities with increasing exposure times and decreasing distances.

EFFECTS OF SDS,PBS SOLUTIONS UPON FLUORESCENCE VALUES OF DERMATOPHAGOIDES PTERRONYSSINUS RADIOALLERGOSORBENT TEST INHIBITION

Objective To explore the effects of SDS, PBS re-dissolvent solutions on fluorescence values of radioallergosorbent test (RAST) inhibition. Methods Dermatophagoides pterronyssinus allergen immunoCAP and UniCAP 100 System were used. The Sera Pool consisted of 20 Dermatophagoides pterronyssinus allergic patients sera, their specific IgE fluorescence values were between 12 505 and 24 776. Results Fluorescence value percentages decreased: 62.9%, 54.1%, 43.5%, 6.7%, 3.7%, 2.6%, 2.2%, and 1.4% respectively, when SDS concentrations were at 2%, 1%, 0.5%, 0.25%, 0.1%, 0.05%, 0.025%, and 0.01%. Fluorescence values decreased more than 5% with SDS concentrations equal to 0.25% or higher. PBS in 0.1 and 0.01 mol/L concentrations decreased fluorescence values 2.9% and 0.9% respectively. Conclusions SDS is a commonly used surfactants in allergen extract and re-dissolvent prepared allergen precipitation for RAST inhibition. Thus effects of surfactants (e.g. SDS) upon the RAST inhibition tests must be considered when they were used as re-dissolvent agents to improve protein resolution in RAST inhibition.

Effects of dermatophagoides farinae drops combined with pidotimod on inflammatory response and immune response in children with allergic rhinitis combined with asthma

Objective: To investigate the effects of dermatophagoides farinae drops combined with pidotimod on inflammatory response and immune response in children with allergic rhinitis combined with asthma. Methods: A total of 118 children with allergic rhinitis combined with asthma who were treated in our hospital between December 2014 and May 2017 were selected as the research subjects and divided into the control group (n=59) and the dermatophagoides farinae drops group (n=59) by random number table method. Control group received both conventional therapy and pidotimod therapy, and dermatophagoides farinae drops group received both conventional therapy and dermatophagoides farinae drops combined with pidotimod therapy. The differences in inflammatory factor, cellular immunity index and humoral immunity index levels were compared between the two groups before treatment (T0), after 3 months of treatment (T1), after 6 months of treatment (T2) and after 12 months of treatment (T3). Results: At T0, inflammatory factor, cellular immunity index and humoral immunity index levels were not significantly different between the two groups. At T1, T2 and T3, serum inflammatory factor IL-2 contents of dermatophagoides farinae drops group were higher than those of control group at the corresponding time points whereas IL-4, IL-5, IL-9 and IL-18 contents were lower than those of control group at the corresponding time points;peripheral blood cellular immunity indexes CD3+, CD4+, CD8+ and CD4+/CD8+levels were higher than those of control group at the corresponding time points;serum humoral immunity indexes IgA, IgM and IgG contents were higher than those of control group at the corresponding time points whereas IgE contents were lower than those of control group at the corresponding time points. Conclusion: Dermatophagoides farinae drops combined with pidotimod therapy can effectively reduce the inflammatory response degree and optimize the cellular and humoral immune function of the children with allergic rhinitis combined with asthma.

Assessment of the ventilation function and serum biochemical indexes after sublingual dermatophagoides farinae drops combined with loratadine treatment of children with asthma and allergic rhinitis

Objective:To study the ventilation function after sublingual dermatophagoides farinae drops combined with loratadine treatment of children with asthma and allergic rhinitis and the influence on serum biochemical indexes.Methods: A total of 40 children with asthma and allergic rhinitis treated in our hospital between September 2013 and March 2015 were collected and divided into the control group (n=22) who accepted loratadine therapy alone and the observation group (n=18) who accepted sublingual dermatophagoides farinae drops combined with loratadine therapy after the treatment was reviewed. Before treatment and after 6 months and 1 year of treatment, spirometer was used to test ventilation function indexes;ELISA method was used to determine the contents of inflammatory mediators;RIA method was used to determine the contents of airway remodeling indicators.Results:Before treatment, differences in ventilation function index levels as well as inflammatory mediator and airway remodeling index contents were not statistically significant between two groups of children. After 6 months and 1 year of treatment, FEV1, FVC and PEF levels of observation group were higher than those of control group;serum IL-2 content was higher than that of control group while IL-5, IL-17 and IL-33 contents were lower than those of control group;serum PDGF-BB, TGF-β1 and NF-κB contents were lower than those of control group.Conclusion:Sublingual dermatophagoides farinae drops combined with loratadine therapy can optimize the ventilation function, reduce the systemic inflammatory response and inhibit airway remodeling in children with asthma and allergic rhinitis.

Cloning, sequence analysis and expression in E. coli of the group 3 allergen of Dermatophagoides farinae

Background The dust mites, which are mostly represented by Dermatophagoides spp. （Acari： Pyroglyphidae）, are the major sources of indoor allergens. Identification and characterization of these mite allergen molecules are an important step in the development of new effective diagnostic procedures and possible therapeutic strategies for allergic disorders associated with dust mites. Methods Total RNA was extracted from Dermatophagoides farinae. The gene coding for Der f 3 was amplified by RT-PCR with the primers designed based on previous sequence published in GenBank. The target gene was cloned intermediately into pMD19-T plasmid and finally into plasmid pET28a （＋）, expressed in E. coil BL21 at the aid of the inducer isopropyI-D-thiogalactopyranoside （IPTG）. The physicochemical properties, spatial structure of the allergen were analyzed with bioinformatics software. Results The cDNA coding for group 3 allergen of Dermatophagoides farinae from China was cloned and expressed successfully. Sequencing analysis showed that there were nineteen mismatched nucleotides in five Der f3 cDNA clones in comparison with the reference （GenBank Accession No. AY283291）, which resulted in deduced amino acid sequence incompatibility in eleven residues. Bioinformatics analysis revealed that the Der f 3 pro-protein was an extracellular hydrophobic protein, consisting of 259 amino acids with a 16 amino acid signal peptide. The protein was deduced to have three chymotrypsin active sites （53-68 AA, 108-122 AA and 205-217 AA）, one N-glycosylation site, one cAMP- and cGMP-dependent protein kinase phosphorylation site, four protein kinase C phosphorylation sites, two casein kinase II phosphorylation sites, and five N-myristoylation sites. Conclusions Der f3 is an extracellular hydrophobic protein which possesses multiple activation and phosphorylation sites. Polymorphism may exist in the Der f3 gene but this needs to be further confirmed in the future.

Diagnostic accuracy and safety of Dermatophagoides pteronyssinus extracts used for skin prick test

Background:Dermatophagoides pteronyssinus is a common allergen causing allergic diseases in China.The aim of this study was to evaluate the efficacy and safety of D.pteronyssinus extracts produced by Peking Union Medical College Hospital(PUMCH)for the skin prick test(SPT)in the diagnosis of D.pteronyssinus allergy.Methods:A total of 910 subjects with allergic diseases were prescribed D.pteronyssinus SPT and specific sIgE(sIgE)test among the Outpatients of Department of Allergy,PUMCH from August 10,2015 to August 30,2017.Receiver operating characteristic curve(ROC)analysis was performed according to the results of D.pteronyssinus-sIgE detection.The accuracy of D.pteronyssinus extracts used for SPT in the diagnosis of D.pteronyssinus allergy was evaluated under different cutoff values.Adverse events after SPT were recorded to evaluate safety.Results:There were 796 and 618 subjects in the full analysis set(FAS)and the per protocol set(PPS),respectively.The areas under the curve of FAS and PPS were 0.871 and 0.873,respectively.According to the ROC of PPS,the optimal and 95%specificity diagnostic cutoff values of D.pteronyssinus SPT mean wheal diameter were 3.25 and 3.75 mm,respectively.No adverse events occurred.Conclusion:The extracts of D.pteronyssinus for SPT were simple,highly accurate,and safe and should be considered for recommendation in the clinical diagnosis of D.pteronyssinus allergy.

Indoor Allergen Levels and Household Distributions in Nine Cities Across China

Objective Chinese allergic subjects have high levels of sensitization to house dust mite （HDM） and other indoor allergens. This study quantifies common indoor allergen levels in Chinese households. Methods Dust samples were collected from nine cities. Major allergens Der p 1 and Der f I from Dermatophagoides pteronyssinus and D. farinae, and specific antigens of Blomia tropicalis, Tyrophagus putrescentiae, Acarus siro, and cockroach species Blattella germanica and Periplaneta americana were measured by ELISA.Results HDM allergens were found in dust samples from bedding in 95% of the Chinese households. The median levels varied from 〈0.006 to 9.2 μg/g of dust, depending on the city. The percentages of households having HDM allergen levels associated with the risk of developing allergy sensitization and asthma were 65% and 25%, respectively. Specific antigens of the storage mite and cockroach were only found in samples from the southern and tropical regions of China. Levels of mite allergens were generally higher in samples from bedding compared to samples from the living room, even for storage mites, whereas levels of cockroach antigens were higher in the living room samples.Conclusion HDM allergens are present in bedding dust samples from most Chinese households. Cities in southern and central China have relatively high levels of HDM major allergens compared to cities in northern and western China. Antigens of storage mites and cockroaches are not as common as HDM allergens.

Acaricidal activity of Cymbopogon citratus and Azadirachta indica against house dust mites

Objective:To examine the acaricidal effects of the essential oil of Cymbopogon citratits leaf extract(lemongrass)and ethanolic Azadirachta indica leaf extract(neem)against house dust mites Dermatophagoides farinae(D.farinae)and Dermalophagoides pteronyssinus(D.pteronyssinus).Methods:Twenty-five adults mites were placed onto treated filter paper that is soaked with plant extract and been tested at different concentrations(50.00%,25.00%,12.50%,6.25%and 3.13%)and exposure times(24hrs,48hrs,72hrs and 96 hrs).All treatments were replicated 7 times,and the experiment repeated once.The topical and contact activities of the two herbs were investigated.Results:Mortalities from lemongrass extract were higher than neem for both topical and contact activities.At 50%concentration,both 24 hrs topical and contact exposures to lemongrass resulted in more than 91%mortalities for both species of inites.At the same concentration and exposure time,neem resulted in topical mortalities of 40.3%and 15.7%against D.pteronyssinus and D.farinae respectively;contact mortalities were 8.0%and 8.9%against the 2 mites,respectively.There was no difference in topical mortalities of D.pteronyssinus from exposure to concentrations oflemongrass and neem up to 12.50%;lemongrass was more effective than neem at the higher concentrations.Conclusions:Generally,topical mortalities of D.farinae due to lemongrass are higher than that due to neem.Contact mortalities of lemongrass are always higher that neem against both species of mites.

House dust mite allergen Der f enhanced bronchial epithelial cell cytokine expression

The house dust mites (Dermatophagoides farinae, Derf) are the major source of aeroaller gens implicated in the expression of atopic disorders, including asthma, allergic rhinitis and atopic dermatitis. In particular, strong circumstantial evidence suggests that house dust mite antigens are important precipitating factors of asthma. Many house dust mite allergens are proteases that can elicit airway inflammation by stimulating the release of cytokines from bronchial epithelial cells. To investigate whether Der f allergen proteases induced cytokine production from the epithelial cell line BEAS-2B, BEAS-2B cells were cultured with 4 different concentrations of Derf (0.02, 0.2, 2, 20μg/ml) for 24-96 h, after which supernatants were assayed for interleukin (IL)-6 and IL-8 with ELISA. Reverse transcription-PCR was also performed. The cell sheets were intact throughout the observation in control group without any exposure to Der f antigen. In the experimental groups cells treated with Der f allergen showed changes in the anchorage status of the monolayer. There was a significant increase in the level of cytokine production compared with the untreated sample. The release of IL-6 and IL-8 increased in a concentration-dependent manner (P <0.05, respectively) with the addition of increasing dosage of Der f to the cell sheets. Levels of IL-6 and IL-8 began to rise at 24 h and 48 h after allergen exposure, and they increased significantly in the supematants at 72 h and 96 h. At the same time the concentration dependence of induction of IL-6 and IL-8 expression as well as an increase in the expression of IL-6 and IL-8 mRNA manifested evidently. HDM-induced airway inflammation may include Der f-mediated release of inflammatory mediators, and the proteolytic activity of an allergen may stimulate the release of proinflammatory cytokines from human bronchial epithelium. It is suggested that IL-6 and IL-8 production by bronchial epithelial cells may play a role in the pathogenesis of allergic asthma.

T cell responses to der f2 mite allergens in Thai allergic patients

Dermatophagoides farinae group 2 (Der f2) is a highly polymorphic allergen that shows a distinct pattern of sequence divergence. The effect of the variants on antibody and T cell responses has not been compared. The aim of the present study was to evaluate IgE binding, transcription and translations for IL-5, IFN-γ and TGF-β induced by mite allergens. Sera from 24 HDM-allergic patients and 20 non-allergic subjects were measured for IgE reactivity by ELISA. PBMC was cultured with mite allergens (Df, rDerf2) and mitogen (PHA). The supernatants and cell pellet obtained were evaluated for cytokine production by ELISA and cytokine gene expression by RT-PCR, respectively. Four patients showed IgE reactivity to both allergens. Five patients showed IgE reactivity to Df. Other allergic patients and all non-allergic subjects did not show IgE reactivity to mite allergens. Both allergens showed similar levels of IL-5 and IFN-γ transcriptions in allergic patients and non-allergic subjects. The rDer f2 induced IL-5 protein from allergic patients higher than non-allergic subjects, while Df showed IL-5 protein from allergic patients similar to non-allergic subjects. Df induced IFN-protein from allergic patients higher than non-allergic subjects whereas rDer f2 induced IFN-protein from allergic patients similar to non-allergic subjects. The ratio of IFN-γ to IL-5 production after stimulation with rDer f2 was higher in non-allergic subjects than in allergic patients. Our data demonstrated that the changes in the sequence of rDer f2 compared with native Df had effect on cytokine production in both allergic patients and non-allergic subjects.

Topical Application of Cudrania tricuspidata Stem Extract Inhibits Atopic Dermatitis-Like Skin Lesions in an NC/Nga Mouse Model: An Experimental Animal Study

Atopic dermatitis (AD) is a chronic inflammatory skin disease characterized by elevated immunoglobulin E (IgE), mast cell infiltration and skin lesions including pruritus, erythema and eczema. Cudrania tricuspidata extracts have been clinically administered for a long time in the East Asia including Korean and China as a home-remedy to diminish the inflammation of gastritis and hepatitis. To examine whether it works on AD or not, an AD-like animal model was experimented in this study. AD was induced by applying Dermatophagoides farinae (D. farinae) extract to the backs of 9-week old NC/Nga mice for 21 days. Following this, an ethanol extract of C. tricuspidata stems (EECT) was applied topically for 14 days to the sensitized skin, while distilled water was used as a control (EECT0 mice). Anti-AD effects of EECT were evaluated using scores for AD-like skin lesions, serum IgE levels and mast cell counts in the skin dermal layers to assess inflammation. Topically applied ethanol extract of Cudrania tricuspidata stems (EECT 7.5, 25 and 75 mg/mL) markedly reduced AD-like skin lesions after 4 days (by 30.1%, 31.4% and 38.5%, respectively) and also after 14 days (by 63.6%, 66.1% and 49.6%, respectively), while distilled water improved AD by 17.8% and 38.7%, respectively (p D. farinae extract (p = 0.003) and EECT attenuated the mast cell overproduction, and reduced mast cell degranulation markedly. Attenuation was most obvious in the early stage of EECT treatment when the AD was most acute.

Resistance of Commercial Bed Covers against Faecal Pellets of House Dust Mites:Behaviour of Seams and Zippers

This study evaluated the allergen impermeability against airborne allergens of dust mite droppings through all parts of commercial bed covers, including surface seams and zippers. Specimens were taken from places with and without seams and zipper. A novel penetration cell was developed to expose the specimens to an inoculum of purified mite droppings that was assessed for its allergen content Der p1 prior to the penetration tests. Using covers of different construction and material, the penetration level increased significantly in the presence of seams and zippers and could reach up to 6% depending on the seam’s/zipper’s characteristics and quality. Therefore, zippers and seams have to be considered as access points for the penetration of mite droppings. As for the penetration of airborne mite particles through the zipper, the penetration level was greatly attenuated by the presence of a cover strip. Depending on the respective quality and the construction type, the mite allergen Der p1 penetrated most likely through the zipper and seams of the specimens, already after a single laundry cycle. Hence, laundry may compromise the barrier performance and proves to be an important quality feature. In all samples, the textile surface showed sufficient allergen impermeability. Our conclusions provide recommendations to both manufacturers and users.

Allergen micro-array detection of specific IgE-reactivity in Chinese allergy patients

Background Allergen micro-arrays are powerful tools for screening of serum IgE-reactivity. In this study allergen micro-arrays were used to identify dominating IgE-binding allergens and cross-reactivity patterns among selected Chinese allergy patients. Methods The study was conducted using patient sera from the cities of Guangzhou, Nanjing, Chengdu and Shenyang. In total 100 sera with Dermatophagoides pteronyssinus （Der p） specific IgE-levels higher than 50 kU/L were selected for testing against 103 individual allergens. Results Among 100 selected patients, 95% showed IgE-reactivity towards house-dust mite allergens Dermatophagoides farinae （Der f） 1, Der f 2 and Der p 2 and 94% were IgE positive against Der p 1, and 60% of sera contained IgE reacting against allergen Euroglyphus maynei （Eur m） 2. IgE against cat allergen, Felisdomesticus （Fel d） 1, was seen in 20%. Only 2% showed specific IgE-reactivity to Der p 10, a panallergen belonging to the tropomyosin family. Serum IgE-reactivity towards other allergens was in general low. IgE-reactivity against pollen allergens showed geographic differences. Conclusions This study clearly confirms that group 1 and group 2 are major allergens of house dust mites. These selected house-dust mite allergy patients are close to being mono-sensitized. Der p 10 is not an important allergen for cross-reactivity. Specific IgE-sensitization towards pollen allergens is low in southern China compared to other regions. The prevalence of food and stinging insect allergens known to give rise to IgE-mediated cross-reactivity is 2% or less.

DNA vaccine encoding Der p 2 allergen generates immunologic protection in recombinant Der p 2 allergen-induced allergic airway inflammation mice model

Background DNA immunization is a promising novel type of immunotherapy against allergy. An estimated 79.2% patients with asthma, wheezing and/or rhinitis suffer from Dermatophagoides pteronyssinus group 2 (Der p 2) allegen. The aim of the present study was to determine whether DNA vaccine encoding Der p 2 could generate immunologic protection in recombinant Der p 2 (rDer p 2) allergen-induced allergic airway inflammation mice model and to understand the role of DNA vaccination in specific-allergen immunotherapy for asthma. Methods After DNA vaccination, BALB/c mice were sensitized by intraperitoneal injection (i.p) and challenged by intranasal instillation of rDer p 2. The lung tissues were assessed using hematoxylin and eosin. Mucus-producing goblet cells were identifed using periodic acid-Schiff(PAS)/alcian blue. The total cell number and composition of bronchoalveolar lavage samples were determined. The levels of the cytokines IL-4 and IFN-γ, as well as IgE and IgG_(2a)in the serum were determined by enzyme-linked immunosorbent assay. Allergen-specific IL-4 and IFN-γ production by spleen cells were also measured by enzyme-linked immunosorbent assay. Expression of signal transducer and activator of transcription 6 (STAT6) in splenocytes were determined by Western blot. Results DNA vaccine encoding Der p 2 allergen inhibited extensive infiltration of inflammatory cells and production of mucin induced by allergen. The influx of eosinophils into the lung interstitium was significantly reduced after administration of DNA vaccine. Significant reductions of IL-4 and increase in levels of IFN-γ in bronchoalveolar lavage fluid were observed. The allergen-specific IgE was markedly decreased in mice receiving DNA vaccination. Allergen could induce higher IFN-γ, weaker IL-4 in cultured spleen cells from mice receiving DNA vaccine. DNA vaccination inhibited STAT6 expression of spleen cells induced by allergen. Conclusion These results indicated that DNA vaccine encoding Der p 2 allergen generates immunologic protection in recombinant Der p 2 allergen-induced allergic airway inflammation mice model with regulating the immune response towards a Th1-type reaction.

Induction of Th1-Type Immune Response by Chitosan Nanoparticles Containing Plasmid DNA Encoding House Dust Mite Allergen Der p2 for Oral Vaccination in Mice

This study was to prepare the chitosan-pDer p 2 nanoparticles and to investigate the effect of chitosan-DNA nanoparticles on immune response in mice by oral delivery of chitosan-DNA nanoparticles. The nanoparticles were synthesized by complexing chitosan with plasmid DNA. The DNA was fully complexed into chitosan-DNA nanoparticles, suggesting a 100% encapsulation efficiency. Chitosan-DNA complex renders a significant protection of the plasmid. No effect on cell viability was observed in both cell types and average cell viability over 100% was obtained. Oral gene delivery with chitosan-DNA nanoparticles can generate a higher level expression of gene in vivo. Oral chitosan-pDer p 2 nanoparticles in BALB/c mice can induce IFN-γ in serum and prevent subsequent sensitization of Th2 cell-regulated specific IgE responses. The data indicate that the oral administration of chitosan-pDer p 2 nanoparticles results in the expression of Der p 2 in the epithelial cells of both stomach and small intestine and the induction of Th1-type immune response. Cellular ＆ Molecular Immunology.

Therapeutic Effects of DNA Vaccine on Allergen-Induced Allergic Airway Inflammation in Mouse Model

Vaccination with DNA encoding Dermatophagoides pteronyssinus group 2 （Der p 2） allergen previously showed its effects of immunologic protection on Der p 2 allergen-induced allergic airway inflammation in mice. In present study, we investigated whether DNA vaccine encoding Der p 2 could exert therapeutic role on allergen-induced allergic airway inflammation in mouse model and explored the mechanism of DNA vaccination in asthma specific-allergen immunotherapy. After sensitized and challenged by Der p 2, the BALB/c mice were immunized with DNA vaccine. The degrees of cellular infiltration were scored. IgE levels in serum and IL-4/IL-13 levels in BALF were determined by ELISA. The lung tissues were assessed by histological examinations. Expressions of STAT6 and NF-kB in lung were determined by immunohistochemistry staining. Vaccination of mice with DNA vaccine inhibited the development of airway inflammation and the production of mucin induced by allergen, and reduced the level of Der p 2-specific IgE level. Significant reductions of eosinophil infiltration and levels of IL-4 and IL-13 in BALF were observed after vaccination. Further more, DNA vaccination inhibited STAT6 and NF-kB expression in lung tissue in Der p 2-immunized mice. These results indicated that DNA vaccine encoding Der p 2 allergen could be used for therapy of allergen-induced allergic airway inflammation in our mouse model. Cellular ＆ Molecular Immunology.