Treatment with a Fel d 1 hypoallergen reduces allergic responses in a mouse model for cat allergy

Background: Allergen-specific immunotherapy (SIT) is currently the only curative treatment for allergy but the treatment needs to be improved. We hypothesize that covalent coupling of immunomodulating vitamin D3 to the major cat allergen Fel d 1 can enhance the beneficial effects of SIT to cat allergy. Methods: We treated mice sensitized to Fel d 1 with subcutaneous injections of two doses of recombinant Fel d 1 coupled to 1α,25-dihydroxyvitamin D3 (rFel d 1:VD3) and compared to treatment with the same doses of rFel d 1 in a mouse model for cat allergy. Airway hyperresponsiveness (AHR), cytokines and cells in bronchoalveolar lavage (BAL), in vitro activation of splenocytes to rFel d 1, and Fel d 1-specific immunoglobulins were evaluated. Results: Treatment with both doses of rFel d 1:VD3 decreased AHR, cellular influx and Th2 cytokines in BAL compared to untreated mice. High- and low-dose rFel d 1 treatment also decreased AHR and BAL Th2 cytokines, with less decrease for the low-dose treatment. Importantly, the total number of cells and eosinophils in BAL was markedly reduced at both high- and low-dose rFel d 1:VD3 compared to treatment with rFel d 1 alone. Finally, treatment with both rFel d 1 and rFel d 1:VD3 induced Fel d 1-specific serum IgG. Conclusion: Our results indicate a beneficial therapeutic effect of rFel d 1:VD3 on airway inflammation, AHR and rFel d 1-specific immune responses and thus suggest that this novel immunomodulatory candidate may improve both the efficacy and safety of SIT.

Section: Methodsmentioning

confidence: 99%

Covalent Coupling of Vitamin D3 to the Major Cat Allergen Fel d 1 Improves the Effects of Allergen-Specific Immunotherapy in a Mouse Model for Cat Allergy

Grundström

Neimert-Andersson

Kemi³

et al. 2011

“…This makes Fel d 1 an ideal target for investigating novel strategies for ASIT [23]. We have previously established a mouse model for cat allergy which we have applied to the evaluation of novel Fel d 1-based ASIT strategies [24,25,26,27]. The model reflects the acute phase of allergic disease and involves three biweekly subcutaneous (s.c.) sensitisations with recombinant (r) Fel d 1, followed by three intranasal (i.n.)…”

Section: Introductionmentioning

confidence: 99%

Development of a Mouse Model for Chronic Cat Allergen-Induced Asthma

Grundström

Saarne

Kemi³

et al. 2014

Background: Allergic asthma is a chronic inflammatory airway disease caused by exposure to airborne allergens. In order to develop novel therapies for allergic asthma, models that are relevant to human disease are needed. Methods: Female BALB/c mice were presensitised subcutaneously with alum-adsorbed recombinant cat allergen Fel d 1, followed by intranasal challenges with cat dander extract spiked with recombinant Fel d 1 for 7 weeks. For reference, mice were presensitised and challenged with ovalbumin following the same protocol. Airway hyperresponsiveness, serum antibodies, airway inflammation and cell infiltration, and cytokines in lung tissue and bronchoalveolar lavage were measured. Results: Mice presensitised with recombinant Fel d 1 and challenged with cat dander extract or presensitised and challenged with ovalbumin showed airway hyperresponsiveness in response to metacholine. Mice of the cat allergen model showed influx of neutrophils, eosinophils and lymphocytes in bronchoalveolar lavage, combined with increased levels of IL-17a and increased IL-4 mRNA expression in lung tissue. In contrast, mice sensitised and challenged with ovalbumin showed a predominant influx of eosinophils in bronchoalveolar lavage and had an increased expression of IL-5 in lung tissue. Both protocols induced features of lung tissue remodelling and allergen-specific antibody responses. Conclusions: The presented mouse model for cat allergen-induced asthma exhibits hallmarks of chronic allergic asthma, like airway hyperresponsiveness, a mixed neutrophilic/eosinophilic infiltration in bronchoalveolar lavage, expression of IL-17a and signs of remodelling in lung tissue. The model will provide a relevant platform for the development of novel treatment strategies.

“…SIT with various hypoallergens in a mouse model has also resulted in the induction of blocking IgG antibodies [24]. These blocking IgG antibodies are able to modulate allergic responses through several mechanisms [25,26,27,28]. …”

Section: Discussionmentioning

confidence: 99%

Immunotherapy with a Recombinant Hybrid Molecule Alleviates Allergic Responses More Efficiently than an Allergenic Cocktail or Pollen Extract in a Model of <b><i>Chenopodium album</i></b> Allergy

Nouri

Sankian²,

Afsharzadeh³

et al. 2013

Background: The aim of this study is to assess the therapeutic potential of a recombinant hybrid molecule (rHM) alongside an allergenic cocktail from recombinant wild-type allergens as well as pollen extract on Chenopodium album allergy, using a BALB/c mouse model. Methods: The BALB/c mice had already been sensitized to C. album via intraperitoneal injections of alum-adsorbed allergenic cocktail and immunotherapy procedure was followed by subcutaneous injections of the rHM, allergenic cocktail and pollen extract at weekly intervals. Humoral immune responses were determined via measurement of specific antibodies in serum. Splenocytes of immunized mice were stimulated in vitro and then proliferation responses, cytokine secretion and mRNA expression of genes involved in immunotherapy were examined by ELISA and real-time PCR. Results: Sensitized mice were identified with high specific IgE against allergenic cocktail when compared with healthy mice. Immunotherapy with the rHM induced the highest ratio of the IgG2a/IgG1 levels compared to allergenic cocktail or C. album pollen extract. The rHM was able to induce proliferative responses as well as the allergenic cocktail in cultured splenocytes. Immunotherapy with the rHM significantly improved secretion of IFN-γ and IL-10, while secretion of IL-13 rapidly diminished. Interestingly, mRNA expression of GATA3 was strongly decreased in rHM-treated mice whereas mRNA expression of T-bet and Foxp3 was significantly increased. Conclusion: Our results prove that immunotherapy with the rHM effectively controlled allergic responses by shifting from a Th2-like immune response to a Th1-dominated immune response.