Der P1 Research Articles

IL-33/ST2 axis promotes the inflammatory response of nasal mucosal epithelial cells through inducing the ERK1/2 pathway.

Allergic rhinitis (AR) is a nasal mucosal inflammatory disease mediated by environmental allergens. At present, the relationship between the IL-33/ST2 axis, ERK1/2 pathway and AR progression needs further exploration. In our study, an AR model was constructed in vitro by treating HNEpC cells with Der p1. qRT-PCR was applied to assess the mRNA levels of IL-33, ST2, TNF-α, IL-6, and IL-8. Western blotting was used to measure the protein levels of IL-33, ST2, and the downstream proteins p-ERK1/2, ERK1/2, p-RSK, and RSK. IL-6, IL-8, IL-33, and TNF-α protein levels in cell supernatants were evaluated by ELISA. Flow cytometry was performed to check cell apoptosis of HNEpC in the presence or absence of Der p1. Our results indicate that the relative levels of IL-33, ST2, TNF-α, IL-6, and IL-8 were increased significantly in the AR model group. The above effects were notably reversed after transfection with shIL-33 or shST2. IL-33 stimulation further resulted in the increase in both ST2 and inflammation-associated cytokines, and these effects were restored after shST2 treatment. Also, the levels of inflammatory factors induced by IL-33 stimulation or ST2 overexpression were reversed after applying an ERK1/2 pathway blocker. In conclusion, IL-33/ST2 mediated inflammation of nasal mucosal epithelial cells by inducing the ERK1/2 pathway.

An inflammatory stimulus sensitizes TRPA1 channel to increase cytokine release in human lung fibroblasts

External stimuli such as cigarette smoke and house dust mite are often involved in the development and exacerbation of asthma. These risk factors could activate or sensitize transient receptor potential channel ankyrin 1 (TRPA1), which are primarily expressed in neuronal structures but also in non-neuronal cells such as fibroblasts. However, the role of non-neuronal TRPA1 in the pathophysiology of airway diseases including asthma remains unclear. We investigated TRPA1 expression on human fibroblast cells and whether inflammatory mediators could modulate its function. This study utilized human lung fibroblast cell lines, Medical Research Council cell strain 5 (MRC-5) and HF19 cells frequently used on experimental studies regarding allergic and respiratory disorders. The human lung fibroblasts were stimulated with house dust mite (Der p1) or tumor necrosis factor alpha (TNF-α) for 24 h, and we quantified TRPA1 mRNA and protein by qRT-PCR and western blot analysis, respectively. TRPA1 mRNA expressions were upregulated after TNF-α treatment. Calcium imaging analysis revealed that TNF-α treatment apparently sensitized TRPA1-mediated calcium influx by TRPA1 agonist allyl isothiocyanate (AITC) and the selective TRPA1 channel blocker HC-030031 effectively reduced the calcium response. Lastly, TRPA1 activation was not only involved in increased IL-8 cytokine release, but also in upregulating gene expression of matrix metalloprotease 9 (MMP9) in the human lung fibroblasts treated with TNF-α Together, these results indicate that presence of inflammatory mediators such as TNF-α could upregulate the non-neuronal expression of TRPA1 on fibroblasts which may aggravate further the release of inflammatory cytokines observed in human airway diseases.

The protective effect of rural life on mite sensitization disappears among urban migrants in the South of Vietnam

BackgroundRapid urbanization combined with rural migration to urban areas in southern Vietnam could be risk factors for allergen sensitization, contributing to chronic respiratory diseases (CRD). We aimed to evaluate the prevalence of mite sensitization and its relation to house dust characteristics among rural and urban native and migrating populations with CRD. MethodsRural (n = 19) and urban (n = 46) dwellings were defined on the basis of a home typology. Controls were western Belgian houses (n = 14). Besides the house characteristics, both endotoxin and mite allergens were measured in the settled dusts. The sensitization to mite allergens was defined by positive skin prick test (SPT) and concentration of specific IgE (sIgE)≥ 0.7 U/mL. The prevalence of mite sensitization was evaluated among 610 patients with CRD and compared according to both their home types and places of birth and residences. ResultsThe concentration of endotoxin (but not mite allergen) was higher in rural compared to urban dusts (440 (95%CI: 314–566) versus 170 (95%CI: 115–226) EU/mg; p < 0.0001). The prevalence of positive sIgE to Der p1 and Der p2 was significantly lower in rural (9% and 5%) compared to urban (15% and 9%) population, consistent with the positive SPT to mite (14% and 21%, respectively). Among the urban migrants, the risk of mite sensitization (SPT) was higher compared to the rural natives (OR: 1.79 (1.02–3.15), p < 0.05) and not different to the urban ones (OR: 1.35 (0.82–2.23) p NS). ConclusionIn Vietnam, associated with higher endotoxin (but not allergen) dust concentrations, the risk of mite sensitization was lower in rural compared to the native urban population, but this protective effect could disappear among rural to urban migrants.

Der p2‑A20 DNA vaccine attenuates allergic inflammation in mice with allergic rhinitis

Allergic rhinitis (AR) is a common disease that requires more convenient, safe and effective antigen-specific immunotherapies. The present study aimed to investigate the therapeutic effect of intranasal administration of a eukaryotic expression vector co-expressing Der p2 and A20 protein (pVAX1-Der p2-A20) on mice with allergic rhinitis. The pVAX1-Der p2-A20 vaccine was prepared and encapsulated into poly(L-lactide-co-glycolide) (PLGA) nanoparticles. An allergic rhinitis Balb/c mouse model was established through intraperitoneal sensitization with recombinant Der p2 and cholera toxin followed by intranasal challenge with recombinant Der p2. The treatment effect of the DNA vaccine on nasal allergic inflammation was evaluated, and serum IgE, sIgE, IgG and cytokine levels were determined by ELISA. The percentage of CD4+CD25+Foxp3+Tregs in the spleen was detected by flow cytometry. The DNA vaccine co-expressing Der p2 and A20 was successfully constructed and encapsulated into PLGA nanoparticles. Der p2-A20 DNA vaccine intranasal administration markedly ameliorated Der p2-induced nasal allergic inflammation. The serum Der p2-specific IgE, IL-4 and IL-13 expression levels were inhibited, while the Der p2-specific IgG1, IgG2a and IFN-γ expression levels in the serum and splenic CD4+CD25+Foxp3+Treg population were significantly increased after Der p2-A20 DNA vaccine treatment. These results indicated that the Der p2-A20 DNA vaccine alleviates nasal allergic inflammation and promotes splenic Treg population in mice with allergic rhinitis.

Associations between evaporative cooling and dust-mite allergens, endotoxins, and β-(1→3)-d-glucans in house dust: A study of low-income homes.

Recent work suggests that evaporative coolers increase the level and diversity of bioaerosols, but this association remains understudied in low-income homes. We conducted a cross-sectional study of metropolitan, low-income homes in Utah with evaporative coolers (n=20) and central air conditioners (n=28). Dust samples (N=147) were collected from four locations in each home and analyzed for dust-mite allergens Der p1 and Der f1, endotoxins, and β-(1→3)-d-glucans. In all sample locations combined, Der p1 or Der f1 was significantly higher in evaporative cooler versus central air conditioning homes (OR=2.29, 95% CI=1.05-4.98). Endotoxin concentration was significantly higher in evaporative cooler versus central air conditioning homes in furniture (geometric mean (GM)=8.05 vs 2.85EU/mg, P<.01) and all samples combined (GM=3.60 vs 1.29EU/mg, P=.03). β-(1→3)-d-glucan concentration and surface loads were significantly higher in evaporative cooler versus central air conditioning homes in all four sample locations and all samples combined (P<.01). Our study suggests that low-income, evaporative cooled homes have higher levels of immunologically important bioaerosols than central air-conditioned homes in dry climates, warranting studies on health implications and other exposed populations.

The level of allergens in dust samples collected from selected schools in Shiraz, Iran and its asthma-risk implications

BackgroundBoth home and school are important places where children are exposed to various indoor allergens. This study aimed to identify the profile of indoor allergens in schools and its impact on asthma development. MethodsA total of 104 classrooms from 52 schools were selected for dust collection during the fall of 2017. The levels of indoor allergens including dust mite (Der f1, Der p1), cat (Fel d1), cockroach (Bla g1) and mouse (Mus m1) were measured by enzyme linked immunosorbent assay (ELISA). The diagnosis of asthma was made in all students of the selected classes by the allergist. The collected data were analyzed using SPSS version 21.0. ResultsOut of 2816 students in the selected classes, 180 students were involved with asthma. Students were mostly exposed to Bla g1 (83.1%), followed by Der f1 (51.5%), Mus m 1 (45.5%), Der p1 (8.9%) and Fel d1 (7.9%) in the dust collected from 101 classrooms. Although levels of all studied allergens in the settled dust of the classrooms were low, there was a relationship between Fel d1 in the classroom dust and development of asthma. ConclusionThis study showed considerable levels of cockroach allergens in schools. Exposure to cat allergen in our schools played an important role in asthma development; further school-based investigations require evaluating the role of classroom allergen on asthma development.

Endotoxin and Der p1 allergen levels in indoor air and settled dust in day-care centers in Tehran, Iran.

Allergens like endotoxin and mite allergen Der p 1 are associated with early wheezing and asthma morbidity. Day-care centers can be an important source of exposure to allergens. The aim of this study was to evaluate children's exposure to endotoxin and mite allergen (Der p 1) associated with total suspended particulate matter (TSP) and settled dust in day-care centers in two phases in years of 2015 and 2016 in Tehran city, Iran. Endotoxin and mite allergen Der p 1 in TSP and settled dust were measured in 23day-care centers in Tehran. After collecting dust samples and weighting them, and then their extraction, Endotoxin and Der p 1 allergen were determined using QCL-1000 Endpoint chromogenic LAL Assay and ELISA, respectively. The mean concentrations of endotoxin and mite allergen Der p 1 in settled dust were 0.3 EU/mg and 0.2ng/mg, respectively. The mean concentration of endotoxin and mite allergen Der p 1 in indoor air TSP were 0.8 EU/m3 and 0.4ng/m3, respectively. A significant negative correlation was found between endotoxin both in settled dust and in TSP with measured relative humidity in winter. Also, moderate correlation was observed between Der p 1 in settled dust and relative humidity in winter; however, the correlation between allergen in TSP and relative humidity was not significant. Day-care centers can be an important source of endotoxin and Der p 1 allergen, so, implementation of proper interventions in these places can reduce exposure to them.

Validation of Strasbourg environmental exposure chamber (EEC) ALYATEC® in mite allergic subjects with asthma

Objective: Environmental Exposure Chamber (EEC) should have standardized and controlled allergenic and non-allergenic exposures to perform reproducible clinical studies. The aim was to demonstrate that mite exposure in the Alyatec® EEC could induce early (EAR) and/or late asthmatic reactions (LAR) in at least 60% of subjects allergic to mite.Methods: The EEC has a volume of 147-m3 with 20 seats. The nebulized particle number, airborne Der p1, endotoxins, and volatile organic compound (VOC) concentrations were measured. Twenty-four asthmatics allergic to mite were randomly exposed to 15, 25, and 46 ng/m3 Der p1. Specificity was assessed in not mite-sensitized asthmatics.Results: No significant endotoxin or VOC contamination was measured. The mean inter-assay CVs were 12.5% for the airborne particle number and 28.7% for airborne Der p1 concentrations. For the three Der p1 concentrations, at least 88% of the subjects developed EAR and/or LAR, and at least 46% developed a dual response. No reaction occurred with placebo or in the control group. No severe bronchial reaction occurred.Conclusions: The Alyatec® EEC demonstrated a tight control of allergenic and non-allergenic exposures. The EEC was clinically validated, with airborne Der p1 levels close to levels found in natural settings.

Dendritic cells modified with Der p1 antigen as a therapeutic potential for allergic rhinitis in a murine model via regulatory effects on IL-4, IL-10 and IL-13

ObjectivesHouse dust mites, including Der p1, are common allergens. The current study was designed to explore the allergen-specific immune tolerance effects of Der p1-modified dendritic cells (DCs) through IL-4, IL-10 and IL-13 on an allergic rhinitis (AR) mouse model. MethodsA lentivirus was modified to express Derp1. Then, immature DCs from mice were infected with this modified lentivirus to generate a lenti-Derp1-GFP DCs. 24 mice were random divided into four groups (n = 6 each), AR mouse were sensitized by Derp1 allergens and treated with lenti-GFP DCs (GFP-DC/AR group), or lenti-Derp1-GFP DCs (Der p1-DC/AR group) and dexamethasone (Dex/AR group), mice in the control group were treated with PBS instead of Der p1 then also intraperitoneally injected with 5 × 106 lenti-GFP DCs/mouse. AR symptoms expressed by each mouse were recorded. The proportions of CD4+CD25+Foxp3+ regulatory T cells among CD4+ T cells in the peripheral blood, and mRNA and protein expression levels of IL-4, IL-10, and IL-13 were measured. ResultsDCs infected with lenti-Derp1-GFP stimulated the maturation of DCs. Compared with the GFP-DC/AR group, mice in the Der p1-DC/AR group showed an ameliorated allergic response, a significant decrease in the levels of serum IgE, IgG1, and histamine, and a decrease in the expression of IL-4 and IL-13 mRNA and protein in the nasal mucosa. The expression of IL-10 increased in the Der p1-DC/AR group to a level similar to that observed in the Dex/AR group. ConclusionsThese results indicate that Der p1-modified DCs have therapeutic potential for AR via downregulation of IL-4 and IL-13, and upregulation of IL-10.

IFN-γ stimulation of dental follicle mesenchymal stem cells modulates immune response of CD4+ T lymphocytes in Der p1+ asthmatic patients in vitro

BackgroundHouse dust mite (Dermataphagoides pteronyssinus) is a widespread risk factor in the development of asthma. CD4+ T lymphocytes have an important role in the pathogenesis of allergic asthma by polarizing to Th2 cells. ObjectiveWe aimed to evaluate the immunoregulatory effects of dental follicle mesenchymal stem cells with and without IFN-γ stimulation on peripheral blood mononuclear cells of house dust mite sensitive asthmatic patients, and compared those with Dexamethasone as a systemic steroid. Material and methodsPBMC of asthmatic patients and healthy individuals separately cultured with or without DF-MSCs in the presence and absence of IFN-γ or Der p1 or Dexamethasone for 72h. CD4+ T proliferation, cell viability, CD4+CD25+FoxP3+ Treg cell frequency and cytokine profiles of PBMC were evaluated via flow cytometry. ResultsDF-MSCs suppressed proliferation of CD4+ T lymphocytes (pCDmix<0.01, pDerp1<0.01, pIFN<0.005) by increasing the number of FoxP3 expressing CD4+CD25+ T regulatory cells (pCDmix<0.005, pDerp1<0.01, pIFN<0.001) and suppressed lymphocyte apoptosis (pCDmix<0.05, pDerp1<0.05, pIFN<0.05), while Dexamethasone increased the apoptosis and decreased Treg cell frequency in asthmatic patients. IFN-γ stimulation increased the suppressive effect of DF-MSCs and also enhanced the frequency of FoxP3 expressing CD4+CD25+ T regulatory cells. The cytokine levels were regulated by DF-MSCs by reducing IL-4 cytokine levels (pCDmix<0.01, pDerp1<0.05, pIFN<0.05) and upregulating IFN-γ levels (pCDmix<0.01, pDerp1<0.05, pIFN<0.005) in asthmatic patients. ConclusionIFN-γ stimulated DF-MSCs were found to have a high modulatory effect on CD4+ T cell responses, while Dexamethasone had an apoptotic effect on CD4+ T cells in asthmatic patients. DF-MSCs may be a new cell-based therapy option for allergic diseases including asthma.

IL-37 alleviates house dust mite-induced chronic allergic asthma by targeting TSLP through the NF-κB and ERK1/2 signaling pathways.

Interleukin (IL)-37 has been described as a negative regulator of immune responses and is critical for asthma pathogenesis, but the mechanisms behind the protective role of IL-37 against allergic asthma are less well understood. We show here that IL-37 administered intranasally inhibited house dust mite (HDM)-induced chronic airway eosinophilic inflammation, goblet cell hyperplasia, peribronchial collagen deposition and airway hyperresponsiveness (AHR) to methacholine. In contrast to a weakened Th2 response in the lung that was characterized by the downregulation of Th2-associated cytokines and chemokines in IL-37-treated mice, IL-37 has no effect on relevant markers of systemic Th2 immune including serum immunoglobulins expression and invitro production of Th2-associated cytokines by splenocytes on HDM recall. We demonstrated that the production of thymic stromal lymphopoietin (TSLP) in the lung tissue was associated with IL-37. Importantly, compared with IL-37 alone, TSLP coadministration with IL-37 restored HDM-induced airway inflammation and structural alterations, increased AHR to methacholine and promoted Th2-associated cytokine production. We further found that IL-37 inhibited the induction of TSLP expression by the main antigen of house dust mite, Der p1, by suppressing NF-κB and extracellular signal regulated kinase 1/2 (ERK1/2) activation in human bronchial epithelial (16-HBE) cells invitro. These data highlight the importance of TSLP in IL-37-mediated protective role in asthma. IL-37 might represent a useful innovative and alternative therapy to control TSLP production in the airway.

Bioaerosol of salt chambers in the \u2018Wieliczka\u2019 Salt Mine, Poland

The ‘Wieliczka’ Salt Mine with specific stable, microclimatic conditions is a unique place, where pulmonary and allergy-related diseases are treated. The aim of this study was to determine the occurrence of biological particles in the air of the ‘Wieliczka’ Salt Mine in relation to the location and time. Twenty measurements were taken quarterly in 2012–2016, in four salt chambers. The volumetric and impact methods were used to measure microbiological contamination, while the mite and cat allergens were measured using FEIA assay. The statistically significant differences among the study sites and time of measurements, treated as the following seasons, for spores and bacteria were found. Pollen grains were observed in the underground chambers rarely and in significantly lower quantities than outdoors. No statistically significant differences between the content of Der p1 and Fel d1 allergens among the study locations, seasons and patient presence/absence were found. The qualitative content of micro-organisms in the air of salt chambers seems to be related to the biological material carrying in by patients and staff.

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.

Effects of Vacuuming Mattresses on Allergic Rhinitis Symptoms in Children.

PurposeTo evaluate the effects of daily vacuuming of mattresses on the concentration of house dust mite (HDM) allergens and on allergic rhinitis (AR) symptoms in children sensitized to HDM.MethodsForty children between the ages of 6 and 12 years with mild persistent AR and sensitized only to HDM were enrolled and randomly allocated to 2 groups. Caregivers of children in the experimental group cleaned the children's rooms and vacuumed their mattresses daily for 2 weeks. Caregivers of children in the control group cleaned the children's rooms without vacuuming mattresses. Symptoms of AR were checked weekly and dust samples were collected from the mattresses before and after the study.ResultsDemographics at the beginning of the study were not significantly different between the 2 groups. In the experimental group, symptoms of AR and dust weight were significantly decreased after 2 weeks (total symptoms of AR, P <0.001; sneezing, P < 0.001; rhinorrhea, P <0.001; nasal obstruction, P < 0.001; itching, P <0.001; and dust weight, P = 0.006). The concentrations of HDM allergens were not changed significantly (Der p1, P = 0.333; Der f1, P = 0.841). In the control group, there were no significant changes in symptoms of AR, dust weight, or the concentration of HDM allergens.ConclusionsOur findings showed that daily vacuuming of mattresses reduced dust weight and symptoms of AR. However, the concentration of HDM allergens did not significantly decrease.

IL-33, IL-25 and TSLP contribute to development of fungal-associated protease-induced innate-type airway inflammation

Certain proteases derived from house dust mites and plants are considered to trigger initiation of allergic airway inflammation by disrupting tight junctions between epithelial cells. It is known that inhalation of proteases such as house dust mite-derived Der p1 and/or papaya-derived papain caused airway eosinophilia in naïve mice and even in Rag-deficient mice that lack acquired immune cells such as T, B and NKT cells. In contrast, little is known regarding the possible involvement of proteases derived from Aspergillus species (fungal-associated proteases; FAP), which are ubiquitous saprophytic fungi in the environment, in the development of allergic airway eosinophilia. Here, we found that inhalation of FAP by naïve mice led to airway eosinophilia that was dependent on protease-activated receptor-2 (PAR2), but not TLR2 and TLR4. Those findings suggest that the protease activity of FAP, but not endotoxins in FAP, are important in the setting. In addition, development of that eosinophilia was mediated by innate immune cells (ILCs) such as innate lymphoid cells, but not by acquired immune cells such as T, B and NKT cells. Whereas IL-33, IL-25 and thymic stromal lymphopoietin (TSLP) are involved in induction of FAP-induced ILC-mediated airway eosinophilia, IL-33—rather than IL-25 and/or TSLP—was critical for the eosinophilia in our model. Our findings improve our understanding of the molecular mechanisms involved in induction of airway inflammation by FAP.

Is there an association between indoor allergens and the severity of atopic dermatitis?

Atopic dermatitis (AD) is a multifactorial inflammatory skin disease with frequent hypersensitivity to allergens. However, the role of exposure to indoor allergens on AD severity is unclear. Children aged 0-17 years with active AD from central Chile were recruited; disease severity was evaluated with SCORAD and POEM scores. A home environment survey was applied to parents. Bedroom dust samples were collected for all subjects and analyzed by multiplex assay to quantify dust mite (Der p1, Der f1), dog (Can f1), cat (Fel d1), and alternaria alternata (Alt a1) allergens. Twenty-five children aged 3.9 ± 3.8 years were included. Fifty-two percent were female. Mean SCORAD was 29 ± 14 (range 11-61), and mean POEM was 10.7 ± 6.2. No direct association was found between tobacco exposure, pet ownership, aerosol use, visible dust, or home carpets/rugs with SCORAD (all P > 0.05). Dust samples from all homes had Can f1 and Fel d1 allergens, regardless of pet ownership. Homes that had indoor dogs or cats had significantly higher amounts of these allergens (P < 0.001). Forty percent of homes had dust mite allergens, and none had alternaria alternata. Children with AD living in homes with elevated dust mite and animal dander allergen concentrations had higher SCORAD than those from homes with low allergen concentrations (40 ± 13 vs. 26 ± 13, P = 0.025). High concentrations of indoor allergens may influence AD severity in children. Further studies assessing indoor allergens and allergen sensitization are warranted to fully evaluate the role of indoor allergens on AD.

Newly designed hemagglutinin-Der p 2 chimera is a potential candidate for allergen specific immunotherapy

AimTo investigate the immunomodulatory potential of a chimera composed of the receptor-binding domain of hemagglutinin 1 (H1s) from Influenza virus and Der p 2 (D2) allergen for allergen-specific immunotherapy of house-dust mite allergy (HDM). Main methodsH1sD2 chimera and D2 allergen were produced by genetic engineering in E. coli. Recombinant antigens were extracted from inclusion bodies by urea, then refolded and purified by immobilized- metal affinity chromatography (IMAC). Purity was verified by 2D-PAGE and secondary structures were assessed by CD spectroscopy. IgE reactivity of H1sD2 and D2 was tested in western blot with sera from 8 persons with clinical history of HDM allergy. Immunogenicity of H1sD2 and D2 were analyzed in Balb/c mice. Cytokine profile was analyzed by ELISA after stimulation of mouse spleen cells with H1sD2 and D2. Leukocyte population abundance of cells isolated from spleen and lymph node was assessed by flow cytometry. Key findingsPurified recombinant proteins H1sD2 (42 kDa) and D2 (15 kDa) revealed well defined secondary structures, and preserved IgE reactive epitopes. Analysis of supernatants of mouse spleen cells after stimulation with H1sD2 and D2, revealed a qualitatively different cytokine profile from H1sD2 immunized mouse cells (increase in IL10). CD8+ cells were decreased in the lymph node of D2 immunized mice, whereas H1sD2 immunization led to an increase of CD8+ cells in both the lymph node and the spleen. SignificanceH1sD2 chimera attenuates Der p 2-inherent Th2 response and directs the immune response toward Th1 and Treg phenotype.

Experimental study on dendritic cells modified by dust mite allergen gene in the treatment of allergic rhinitis in mouse

Objective: To explore the therapeutic effects of dendritic cells (DC) modified by the dust-mite-allergen(Der p1) gene on mouse model of allergic rhinitis (AR). Methods: DC modified by the Der p1 gene (Der p1-DC) were prepared.Using random number table, 24 Balb\c mice were divided into four groups: immature DC (imDC)/AR group, dexamethasone/AR group, Der p1-DC/AR group and control group, with 6 mice in each group.AR mouse model was built with Der p1 and the mouse model of AR was established.The AR mice were respectively given by abdominal injection of Der p1-DC, imDC and dexamethasone.Normal control mice were treated with physiologic saline.ELISA method was used for determining the content of IgE, IgG1and histamine in blood.The relative expression of mRNA of IL-4 and IL-13 on nasal mucosa with protein was analyzed by RT-PCR and Westen blot methods.All the data were statistically analyzed by SPSS 19.0 statistical software, and the variance analysis was used in multiple groups of average samples. Results: The contents of IgE, IgG1 and histamine in the mice of Der p1-DC/AR group were lower than those in imDC/AR group ((0.560±0.110) OD 450 nm vs (1.150±0.280) OD 450 nm, (0.690±0.054) OD 450 nm vs (0.920±0.125) OD 450 nm, (4 145±670) pg/ml vs (7 685±669) pg/ml, t value was 4.80, 4.14, 9.16, respectively, all P<0.05), and the expression of IL-4 and IL-13 on nasal mucosa in Der p1-DC/AR group was remarkedly lower than those in imDC/AR group (0.41±0.25 vs 1.59±1.02, 0.26±0.01 vs 1.10±0.09, t value was 2.75, 22.72, respectively, all P<0.05). There was no statistically significant difference between the mice treated with Der p1-DC and dexamethasone group. Conclusions: The results showed that Der p1-DC could reduce inflammation in AR mice and decrease the expression of IL-4 and IL-13. It suggested that Der p1-DC can be used in the immunotherapy of AR mouse.

Toll-Like Receptor Agonists Modulate Wound Regeneration in Airway Epithelial Cells.

Background: Impaired regeneration of airway epithelium may lead to persistence of inflammation and remodelling. Regeneration of injured epithelium is a complex phenomenon and the role of toll-like receptors (TLRs) in the stimulation of respiratory virus products in this process has not been established. Objective: This study was undertaken to test the hypothesis that the wound repair process in airway epithelium is modulated by microbial products via toll-like receptors. Methods: Injured and not-injured bronchial epithelial cells (ECs) (BEAS-2B line) were incubated with the TLR agonists poly(I:C), lipopolisacharide (LPS), allergen Der p1, and supernatants from virus-infected epithelial cells, either alone or in combination with TLR inhibitors. Regeneration and immune response in injured and not-injured cells were studied. Results: Addition of either poly(I:C) or LPS to ECs induced a marked inhibition of wound repair. Supernatants from RV1b-infected cells also decreased regeneration. Preincubation of injured and not-injured ECs with TLR inhibitors decreased LPS and poly(I:C)-induced repair inhibition. TGF-β and RANTES mRNA expression was higher in injured ECs and IFN-α, IFN-β, IL-8, and VEGF mRNA expression was lower in damaged epithelium as compared to not-injured. Stimulation with poly(I:C) increased IFN-α and IFN-β mRNA expression in injured cells, and LPS stimulation decreased interferons mRNA expression both in not-injured and injured ECs. Conclusion: Regeneration of the airway epithelium is modulated by microbial products via toll-like receptors.

Exposition domestique aux moisissures et aux allergènes d’acariens de patients parisiens

Moulds and mite allergens present in indoor environments are well known for their effects on respiratory health. From 2011 to 2015, the Paris Service for Environmental Health (SPSE) conducted investigations in 293 dwellings following medical referral. These audits included fungal analysis of air (in 12% of dwellings), in mattress surface and floor dust (24%), and mite allergen quantifications in mattresses and carpets (18%). Indoor air fungal concentrations are not significantly different from those in outdoor air. When there is no ventilation or when the system is malfunctioning, an increase in indoor/outdoor air ratios is observed, indicating mould enrichment in the dwelling's indoor air. With regard to house dust samples, fungal spore concentrations vary according to the media from which samples were collected. Mattress fungal contamination is higher in dwellings where observed surface moulds exceed 1 per square meter. In the same way Der p1 mite allergens levels are greater in mattress dust in dwellings where mould contamination is visible. This study describes the levels of contamination in the dwellings of Parisian patients.