Allergen Inhalation Challenge Research Articles

Blood biomarkers of the late phase asthmatic response using RNA-Seq

Methods 35 individuals (17 ERs and 18 DRs) participated in the allergen inhalation challenge. Blood samples were obtained prior to and 2 hours post allergen inhalation challenge. HiSeq-Illumina paired-ends 100bp sequencing was performed. A UCSC transcriptome using both the UCSC gene and gene-isoform transcripts was created using the RSEM (RNA-Seq by Expectation Maximization) package. RSEM uses Bowtie to align read files to the reference transcripts and estimates the expected number of counts per transcript. The biomarker pipeline consisted of 20x5-fold deep cross-validation using limma voom (linear models for microarrays and RNA-Seq using variance modeling at the observational level) for differential expression and elastic net for classification. Gene set enrichment analysis was performed using GeneGo.

Transcriptional networks in whole blood of asthmatics

Background Allergen inhalation challenge causes significant changes in the blood transcriptomes of mild atopic asthmatic individuals [1]. Systems biology approaches have been used to identify transcriptional networks that reflect underlying disease processes. Such networks provide insights into the correlation patterns among genes and may identify specific molecular processes associated with asthmatic responses. Transcriptional networks can be identified using blood expression data and are associated with allergen-induced asthmatic responses.

The effect of the novel phosphodiesterase-4 inhibitor MEM 1414 on the allergen induced responses in mild asthma.

BackgroundInhaled allergen challenge is a standard method to study airway responses to inflammatory provocation and evaluate the therapeutic potential of novel anti-inflammatory compounds in asthma. MEM 1414 is a novel oral PDE4 inhibitor with high affinity and selectivity creating the potential for an improved side effect profile vs non-selective PDE inhibitors. We evaluated the tolerability and effect of MEM 1414 on airway responses in mild asthmatics.MethodsA randomised double blind placebo controlled cross over study in two centres, in which sixteen steroid naïve atopic asthmatics were challenged with inhaled allergen. Subjects were dosed with MEM 1414 (600 mg) or placebo, twice daily orally for 7 days. Allergen challenge was performed on day 6 (2 hours post-dose), and methacholine responsiveness was measured 24 hours post allergen (day 7). Biomarkers of drug effects using ex vivo LPS stimulation of whole blood production of interleukin (IL)-6 and leukotriene (LT)-B4 and fractional exhaled nitric oxide (FeNO) were measured on day 6 (0, 2 and 8 hours post-dose). Plasma pharmacokinetics were measured on days 1, 6 and 7. The primary endpoint was the effect on late asthmatic response to allergen.ResultsTreatment with MEM 1414 abrogated the late phase response with a mean difference in FEV1 (LAR 3–10 hours) of 104 ml (25%) vs placebo (p < 0.005), with no effect on the early response. Biomarker responses were also attenuated with MEM 1414 treatment with reductions in LPS-stimulated whole blood assays for TNFα at 8 hours (p < 0.03) and LTB4 at 24 hours (p = 0.0808) with no change in the IL-6 response. The MEM 1414 treatment phase was associated with higher incidence of nausea (6/16 MEM 1414 vs 2/16 placebo) and vomiting (3/16 vs 0/16 placebo).ConclusionsOral MEM 1414, a novel PDE4 inhibitor, significantly reduces the late response following inhaled allergen challenge. MEM 1414 also inhibited whole blood assays of cytokine production from inflammatory cells. MEM 1414 was associated with a typical adverse event profile of PDE4 inhibitors, namely nausea and vomiting although these were mild side effects.Trial registration numberCurrent controlled trials ISRCTN48047493.

T Helper 17 Cells and Related Cytokines after Allergen Inhalation Challenge in Allergic Asthmatics

Background: T helper (Th)17 cells may play a role in allergic asthma. This study assessed the effect of allergen inhalation challenge on circulating Th17 cells and related cytokines in allergic asthmatics. Methods: Peripheral blood mononuclear cells were collected from 16 atopic asthmatics before and 24 h after allergen challenge, as well as from 10 atopic nonasthmatics and 10 normal controls. Cells were stained for Th17 cytokines and their receptors (IL-17A, IL-17F, IL-21, IL-22, IL-17R, and IL-23R) using flow cytometry. Cytokine concentrations from cell culture supernatants were quantified using a multiplex assay for IL-17A, IL-17F, IL-21, IL-22, and IL-23. Results: At baseline, asthmatics had a higher percentage of circulating Th17 cells (1.2 ± 0.5%) compared to normal controls (0.9 ± 0.66%, p < 0.001) but not compared to atopic nonasthmatics (1.13 ± 0.5%). There was a significant increase in Th17 cells in asthmatics after allergen challenge to 1.55 ± 0.4% (p < 0.05) and a trend toward significance in IL-17R expression from 3.4 ± 4.3 to 6.86 ± 6.84% after allergen challenge (p = 0.06). There was also a significant reduction in IL-21-positive cells following allergen challenge from 3.46 ± 1.85 to 2.33 ± 1.37% (p < 0.001). There were no significant differences in IL-17F, IL-22 and IL-23R expression. The concentration of IL-17A in culture supernatant was significantly higher in asthmatics compared to normal controls and IL-17A significantly increased 24 h after allergen challenge. Conclusions: The increase of Th17 cells and IL-17A in atopic asthma after allergen inhalation challenge suggests a possible role for Th17 in allergen-induced airway responses.

Th17/Treg ratio derived using DNA methylation analysis is associated with the late phase asthmatic response.

BackgroundThe imbalance between Th17 and Treg cells has been studied in various diseases including allergic asthma but their roles have not been fully understood in the development of the late phase asthmatic response.ObjectivesTo determine changes in Th17 and Treg cell numbers between isolated early responders (ERs) and dual responders (DRs) undergoing allergen inhalation challenge. To identify gene expression profiles associated with Th17 and Treg cells.Methods14 participants (8 ERs and 6 DRs) with mild allergic asthma underwent allergen inhalation challenge. Peripheral blood was collected prior to and 2 hours post allergen challenge. DNA methylation analysis was used to quantifiy the relative frequencies of Th17, Tregs, total B cells, and total T cells. Gene expression from whole blood was measured using microarrays. Technical replication of selected genes was performed using nanoString nCounter Elements.ResultsThe Th17/Treg ratio significantly increased in DRs compared to ERs post allergen challenge compared to pre-challenge. Genes significantly correlated to Th17 and Treg cell counts were inversely correlated with each other. Genes significantly correlated with Th17/Treg ratio included the cluster of genes of the leukocyte receptor complex located on chromosome 19q 13.4.ConclusionsTh17/Treg imbalance post-challenge may contribute to the development of the late phase inflammatory phenotype.

Basophils are elevated in nasal polyps of patients with chronic rhinosinusitis without aspirin sensitivity

Basophils are elevated in nasal polyps of patients with chronic rhinosinusitis without aspirin sensitivity

Fatty acids, inflammation, and asthma

Fatty acids and consequently diet play an essential role in the formation of inflammatory mediators involved in the pathogenesis of asthma. Because intake variations of omega-6 (n-6) and omega-3 (n-3) fatty acids ultimately determine cell membrane incorporation, changes in diet have the potential to modify downstream production of inflammatory mediators derived from these compounds. It has long been hypothesized that decreasing the n-6/n-3 ratio could reduce the production of more proinflammatory mediators while increasing the formation of downstream metabolites that can serve to limit or resolve inflammation. In turn, these changes would result in improved asthma outcomes or would lower the risk for asthma incidence. This review will focus on the role of fatty acid inflammatory and resolving mediators and will summarize the clinical and epidemiologic data on how diet and obesity alter fatty acid profiles that can contribute to asthma.

Th17/Treg ratio derived using DNA methylation analysis discriminates allergen-induced early from dual asthmatic responses

Background Atopic allergic asthmatic individuals experience acute bronchoconstriction (early response) upon allergen exposure. Several hours after the initial exposure, some individuals exhibit a chronic late phase (dual responders, DRs) whereas others do not (early responders, ERs). The purpose of this study is to determine changes in Th17 and regulatory T (Treg) cell numbers and their associated gene expression profiles in whole blood between allergen-induced ERs and DRs. Methods 14 participants with mild, atopic asthma (8 ERs and 6 DRs) underwent a cat allergen inhalation challenge as part of the AllerGen Clinical Investigator Collaborative. Whole blood was collected immediately prior to challenge (pre) and 2 hours post-challenge. DNA methylation analysis was used to measure the frequency of Th17, Treg, B and T cells (Epiontis, Germany). Whole blood transcriptome profiling was performed using Affymetrix GeneChip ® Human Gene 1.0 ST Arrays. Statistical analysis was performed using R. Results Sum of the T cell and B cell frequencies obtained using the methylation assays strongly correlated (r = 0.95) with the lymphocyte frequency obtained using a hematolyzer. Allergen inhalation did not significantly (p>0.05) change Th17, Treg, B and T cell counts between ERs and DRs. However, the Th17/Treg ratio was significantly (p=0.03) different between ERs and DRs post challenge. 199 genes positively correlated with Th17 cells at an FDR of 5%. 463 genes positively correlated with Treg cells at an FDR of 5%. Th17 genes were inversely correlated with Treg genes. Conclusions Th17/Treg ratio derived using DNA methylation analysis discriminates allergen-induced early from dual asthmatic responses. The inverse correlation between Th17 genes and Treg genes may be indicative of the inflammatory or suppressive phenotypes of these cells.

Allergen-induced asthma.

It was only in the late 19th century that specific allergens, pollen, animal antigens and, later, house dust mite, were identified to cause upper and lower airway disease. Early allergen challenge studies, crudely monitored before measurement of forced expiratory volume in 1 s became widespread in the 1950s, focused on the immediate effects but noted in passing prolonged and/or recurrent asthma symptoms. The late asthmatic response, recurrent bronchoconstriction after spontaneous resolution of the early responses occurring 3 h to 8 h or more postchallenge, has been identified and well characterized over the past 50 years. The associated allergen-induced airway hyper-responsiveness (1977) and allergen-induced airway inflammation (1985) indicate that these late sequelae are important in the mechanism of allergen-induced asthma. Allergens are now recognized to be the most important cause of asthma. A standardized allergen inhalation challenge model has been developed and is proving to be a valuable research tool in the investigation of asthma pathophysiology and of potential new pharmacological agents for the treatment of asthma.

Poster 1007: Universal allergen particle generation for inhaled allergen challenges in the fraunhofer environmental challenge chamber (ECC)

Background Efficacy testing of immunotherapy in field studies is often hampered by variation of airborne allergens. Standardized allergen exposure in challenge chamber settings might overcome aforementioned limitations. However, airborne allergens such as house dust mite (HDM) or cat allergen are not available as standardized source material with distinct particle size. Therefore, we developed a method for universal allergen particle generation and conducted a pilot study to clinically validate this challenge paradigm for house dust mite.

OX40L blockade and allergen‐induced airway responses in subjects with mild asthma

BackgroundThe OX40/OX40L interaction contributes to an optimal T cell response following allergic stimuli and plays an important role in the maintenance and reactivation of memory T effector cells.ObjectiveWe tested whether treatment with an anti-OX40L monoclonal antibody (MAb) would inhibit allergen-induced responses in subjects with asthma.MethodsTwenty-eight mild, atopic asthmatic subjects were recruited for a double-blind, randomized, placebo-controlled, parallel-group trial (ClinicalTrials.gov identifier NCT00983658) to compare blockade of OX40L using a humanized anti-OX40L MAb to placebo-administered intravenously in 4 doses over 3 months. Allergen inhalation challenges were carried out 56 and 113 days after the first dose of study drug. The primary outcome variable was the late-phase asthmatic response. Other outcomes included the early-phase asthmatic response, airway hyperresponsiveness, serum IgE levels, blood and sputum eosinophils, safety and tolerability.ResultsTreatment with anti-OX40L MAb did not attenuate the early- or late-phase asthmatic responses at days 56 or 113 compared with placebo. In the anti-OX40L MAb treatment group, total IgE was reduced 17% from pre-dosing levels, and sputum eosinophils decreased 75% by day 113 (both P = 0.04). There was no effect of anti-OX40L MAb on airway hyperresponsiveness or blood eosinophils. The frequency of AEs was similar in both groups.Conclusion and Clinical RelevancePharmacological activity of anti-OX40L MAb was observed by decreases in serum total IgE and airway eosinophils at 16 weeks post-dosing, but there was no effect on allergen-induced airway responses. It is possible that the treatment duration or dose of antibody was insufficient to impact the airway responses.

Inhaled allergen challenge in assessment of biologics for asthma

Inhaled allergen challenge in assessment of biologics for asthma

The effects of lebrikizumab in patients with mild asthma following whole lung allergen challenge

BackgroundInterleukin 13 (IL13) is a T-helper type 2 (Th2) cytokine associated with inflammation and pathology in allergic diseases such as bronchial asthma. We have shown that treatment with lebrikizumab, an anti-IL13 monoclonal antibody, significantly improves prebronchodilator forced expiratory volume in 1 s (FEV1) in a subset of subjects with uncontrolled asthma.ObjectiveTo evaluate efficacy and safety of lebrikizumab in subjects with mild asthma who underwent bronchial allergen challenge.MethodsTwenty-nine subjects were randomized 1: 1–5 mg/kg lebrikizumab (n = 13) or placebo (n = 16) administered subcutaneously every 4 weeks over 12 weeks, a total of four doses. Primary efficacy outcome was late asthmatic response (LAR) at Week 13, defined as area under the curve of FEV1 measured 2–8 h following inhaled allergen challenge. Serum biomarkers were measured to verify IL13 pathway inhibition and identify patients with an increased response to lebrikizumab.ResultsAt Week 13, the LAR in lebrikizumab subjects was reduced by 48% compared with placebo subjects, although this was not statistically significant (95% confidence interval, −19%, 90%). Exploratory analysis indicated that lebrikizumab-treated subjects with elevated baseline levels of peripheral blood eosinophils, serum IgE, or periostin exhibited a greater reduction in LAR compared with subjects with lower baseline levels of these biomarkers. Lebrikizumab exerted systemic effects on markers of Th2 inflammation, reducing serum immunoglobulin E (IgE), chemokine ligands 13 and 17 by approximately 25% (P < 0.01). Lebrikizumab was well tolerated.Conclusion and Clinical RelevanceLebrikizumab reduced the LAR in subjects with mild asthma. Clinical trial number NCT00781443.

Inhibition of Spleen Tyrosine Kinase Attenuates Allergen-Mediated Airway Constriction

Spleen tyrosine kinase (SYK) is a key activator of signaling pathways downstream of multiple surface receptors implicated in asthma. SYK function has been extensively studied in mast cells downstream of the high-affinity IgE receptor, FcεR1. Preclinical studies have demonstrated a role for SYK in models of allergic inflammation, but a role in airway constriction has not been demonstrated. Here, we have used a potent and selective pharmacological inhibitor of SYK to determine the role of SYK in allergen-mediated inflammation and airway constriction in preclinical models. Attenuation of allergic airway responses was evaluated in a rat passive anaphylaxis model and rat and sheep inhaled allergen challenge models, as well as an ex vivo model of allergen-mediated airway constriction in rats and cynomolgus monkeys. Pharmacological inhibition of SYK dose-dependently blocked IgE-mediated tracheal plasma extravasation in rats. In a rat ovalbumin-sensitized airway challenge model, oral dosing with an SYK inhibitor led to a dose-dependent reduction in lung inflammatory cells. Ex vivo analysis of allergen-induced airway constriction in ovalbumin-sensitized brown Norway rats showed a complete attenuation with treatment of a SYK inhibitor, as well as a complete block of allergen-induced serotonin release. Similarly, allergen-mediated airway constriction was attenuated in ex vivo studies from nonhuman primate lungs. Intravenous administration of an SYK inhibitor attenuated both early- and late-phase allergen-induced increases in airway resistance in an Ascaris-sensitive sheep allergen challenge model. These data support a key role for SYK signaling in mediating allergic airway responses.

Gene-Metabolite Expression in Blood Can Discriminate Allergen-Induced Isolated Early from Dual Asthmatic Responses

Some asthmatic individuals undergoing allergen inhalation challenge develop an isolated early response whereas others develop a dual response (early plus late response). In the present study we have used transcriptomics (microarrays) and metabolomics (mass spectrometry) of peripheral blood to identify molecular patterns that can discriminate allergen-induced isolated early from dual asthmatic responses. Peripheral blood was obtained prior to (pre-) and 2 hours post allergen inhalation challenge from 33 study participants. In an initial cohort of 14 participants, complete blood counts indicated significant differences in neutrophil and lymphocyte counts at pre-challenge between early and dual responders. At post-challenge, significant genes (ALOX15, FADS2 and LPCAT2) and metabolites (lysolipids) were enriched in lipid metabolism pathways. Enzymes encoding for these genes are involved in membrane biogenesis and metabolism of fatty acids into pro-inflammatory and anti-inflammatory mediators. Correlation analysis indicated a strong negative correlation between ALOX15, FADS2, and IL5RA expression with 2-arachidonoylglycerophosphocholine levels in dual responders. However, measuring arachidonic acid and docosahexaenoic acid levels in a validation cohort of 19 participants indicated that the free form of DHA (nmoles/µg of protein) was significantly (p = 0.03) different between early and dual responders after allergen challenge. Collectively these results may suggest an imbalance in lipid metabolism which dictates pro- (anti-) inflammatory and pro-resolving mechanisms. Future studies with larger sample sizes may reveal novel mechanisms and therapeutic targets of the late phase asthmatic response.

Glutathione S‐transferase P1 Ile105Val polymorphism modulates allergen‐induced airway inflammation in human atopic asthmatics in vivo

Glutathione S-transferase P1 is a Phase II cytoprotective and detoxifying enzyme that is widely expressed in human airways. The glutathione S-transferase P1 Ile105Val polymorphism has been linked with atopic disorders and asthma. Yet, little remains known about the regulation of allergic inflammation by glutathione S-transferase P1 in human asthmatics. To establish the effect of the glutathione S-transferase P1 Ile105Val polymorphism on allergen-induced airway inflammation and oxidant stress, and non-specific bronchial hyperresponsiveness to methacholine and reactivity to specific allergen in mild human atopic asthmatics in vivo. Five Val(105)/Val(105) , twelve Val(105)/Ile(105) and twenty Ile(105)/Ile(105) mild atopic asthmatics underwent methacholine challenge, inhaled allergen challenge and endobronchial allergen provocation through a bronchoscope. A panel of inflammatory cytokines and chemokines, F2 -isoprostanes and isofuranes, markers of oxidative stress, thromboxane B2 and immunoglobulin E were measured in bronchoalveolar lavage fluid at baseline and 24 h after allergen instillation. Asthmatics with glutathione S-transferase P1 Val(105)/Val(105) compared with asthmatics with the glutathione S-transferase P1 Val(105)/Ile(105) and Ile(105)/Ile(105) had greater generation of acute phase cytokines (TNF-α, IL-6, CXCL8), IL-12, CCL11, thromboxane B2 and immunoglobulin E at 24 h after local allergen challenge. The GSTP1 genotype had no effect on airway hyperresponsiveness to methacholine and the reactivity to specific allergen. The glutathione S-transferase P1 Ile105Val polymorphism markedly modifies allergen-provoked airway inflammation in atopic asthmatics in vivo. Modulation of the biochemical milieu in response to allergen provides a mechanistic explanation for regulatory effects of glutathione S-transferase P1 polymorphism on airway pathophysiology, and may guide improvement of future therapeutic methods in human atopic asthmatics. These findings must me confirmed in a larger study population of asthmatics with various ethnicities.

Exhaled Breath Condensate Formate after Inhaled Allergen Provocation in Atopic Asthmatics In Vivo

Objective. The dual actions of S-nitrosoglutathione reductase comprise reduction of S-nitrosoglutathione, a potent endogenous airway smooth muscle relaxant that is depleted in asthmatics, and detoxification of formaldehyde to formate. Airway formate production is increased in children with asthma, suggesting increased activity of S-nitrosoglutathione reductase. We determined formate in exhaled breath condensate from adult atopic asthmatics with asthma exacerbation produced by inhaled allergen in vivo, Methods. Twenty-two adult atopic asthmatics underwent inhaled allergen challenge using specific allergen. Exhaled breath condensate was collected at baseline, 1 h after inhalation of the provocative dose of allergen, and then every 2 h for 8 h during the challenge. Formate was analyzed by ion chromatography, Results. Eleven asthmatics developed an isolated early airway response, and another 11 volunteers early response followed by late airway response (dual response). Formate concentrations doubled 1 h post-challenge in asthmatics with dual-airway response but essentially unchanged in patients with an isolated early reaction, Conclusions. Dual-airway response to allergen in atopic asthmatics could be associated with increased activity of S-nitrosoglutathione reductase as suggested by greater concentrations of formate in exhaled breath condensate. Measurement of formate in exhaled breath condensate could serve as a noninvasive biomarker of S-nitrosoglutathione reductase activity in vivo. Our results need to be confirmed in a larger group of asthmatics.

The 5‐lipoxygenase‐activating protein inhibitor, GSK2190915, attenuates the early and late responses to inhaled allergen in mild asthma

GSK2190915, a potent 5-lipoxygenase-activating protein inhibitor, prevents the synthesis of leukotrienes and 5-oxo-6,8,11,14-eicosatetraenoic acid (5-oxo-ETE). To assess the effect of GSK2190915 on the allergen-induced asthmatic responses. Nineteen eligible male subjects with mild asthma were enrolled in and completed this four-centre, double-blind, two-way crossover study (ClinicalTrials.gov NCT00748306). Subjects took GSK2190915 100mg and placebo orally once daily for 5days in randomized order. On Day 1 and 4 they had a methacholine challenge, on Day 3 they had an inhaled allergen challenge, and on Days 4 and 6 they had sputum induction. GSK2190915 attenuated the early (0-2h) and late (4-10h) asthmatic responses to inhaled allergen compared with placebo. There was a statistically significant attenuation of the early asthmatic response (EAR) by GSK2190915; treatment difference of GSK2190915 vs. placebo for the minimum FEV(1) EAR was 0.408L (0.205, 0.611). There was a statistically significant attenuation of the late asthmatic response (LAR) by GSK2190915; the treatment difference of GSK2190915 vs. placebo for the minimum FEV(1) LAR was 0.229L (0.041, 0.417). There was a statistically significant attenuation of allergen-induced sputum eosinophil count on Day 4 following GSK2190915: mean treatment difference (95% CI) between GSK2190915 and placebo was -9.95% (-18.15%, -1.77%). Compared with placebo, GSK2190915 100mg reduced median sputum LTB(4) by >90% on Days 4 and 6. There was no effect on methacholine PC(20) post allergen. GSK2190915 was generally well tolerated. GSK2190915 shows potential as a treatment for patients with asthma.

Effect of the circadian cycle in Late Asthmatic Response (LAR). Comparison between two allergic asthma models in rats and mice

The ovalbumin (OVA) model of allergic inflammation, both in rat and mouse is characterised by a late bronchoconstrictive response (LAR) after allergen challenge that can be measured using whole-body plethysmography (WBP) in conscious unrestrained animals. Circadian oscillations of lung mechanical properties have been reported in conscious undisturbed rodents. Potentially, these fluctuations could alter the pulmonary response induced by allergen provocation and the response of pharmacological treatments. This circadian influence has been showed in asthma patients [1], where an allergen inhalation challenge given in the evening produced a more frequent and severe LAR compared to that one given in the morning. The aim of this study was to assess whether LAR in OVA-sensitized rats and mice was affected differently when animals were exposed to allergen in different times of day. Firstly, to confirm the circadian oscillations, changes in several respiratory parameters were monitored during 24h in naive Brown Norway rats or C57/Black6 mice. Afterwards, OVA-sensitized animals were exposed to the allergen in different periods of the day and the pulmonary function parameters were monitored, including the LAR. In rats, LAR evoked in three different times of day (morning, afternoon or evening) showed no differences in severity, but was more frequent during the evening. In contrast, the LAR triggered in mice in the morning was more severe and more frequent than that evoked during the evening. These results suggest that species and day period of time to induce LAR in allergic animal models are critical and should be taken into account when evaluating the effects of new compounds on this read-out.

Immunotherapy – 2068. Immunomodulatory and safety profile of a novel anti-allergic vaccine based on allergens from dermatophagoides siboney and a combination adjuvant, in sensitized mice

This article was originally published online on 23 April 2013 Th1/Tr1 promoting adjuvants, in allergen-specific vaccines, could be a valuable alternative to the current allergen immunotherapy. It is now the pro-Th1 adjuvant effect of Neisseria meningitidis proteoliposome (PL). Previous studies in a prophylactic murine model of respiratory allergy the vaccine showed its immunogenicity and safety. To assess the immunogenicity and non-clinical safety profile of a novel anti-allergic vaccine candidate based on purified allergens from Dermatophagoides siboney and a combination adjuvant containing PL and Alum, in sensitized mice. In therapeutic experimental setting C57/Bl6 mice were first sensitized administering D. siboney allergen by IP route and exposing mice to allergen aerosols. Later, allergic mice were treated with 3 doses of the adjuvanted vaccine (2µg of Der s1) by subcutaneous route. Further, mice were subjected to inhalation allergen challenge. IgE, IgG1, and IgG2a allergen-specific antibody response was measured by ELISA. The specific cellular response (IL-13, IL-10 and INF-g), were evaluated in supernatants of Lymphocyte cultures stimulated with the allergen, by eBioscience kit for FACS. Systemic toxicity was assessed measuring body weight and macroscopic and histological examination of several organs and injection site. The experimental model reproduces the allergic condition with allergen-specific IgE production; increased blood eosinophils and Histology of lung tissues show all the characteristic of allergy inflammation. As in the previously tested preventive model, the vaccine induces a strong IgG and IgG1 antibody responses significantly higher than control groups, and moderate levels of IFN-g, although together with Tr1 (IL-10) and Th2 (Il-13) cytokines. After challenge, it was noted a significant increase (p<0.05) of the IgG/IgE ratio, with a decrease in bloods eosinophils and allergic inflammation in lung tissues as compared to placebo. No significant differences between body weights and differential leukocyte count in treated mice and placebo group was observed. Normal histology was observed. Local tolerance at the injection site suggests that granulomes in vaccinated subjects are caused by alum. The adjuvanted vaccine does not exacerbate the allergic response nor promote Th1 inflammation, supporting a satisfactory safety profile for further clinical trials in humans. This immunomodulatory effect suggests clinical benefits both in cellular and blocking antibody responses.