TLR9 agonist adsorbed to alum adjuvant prevents asthma-like responses induced by Blomia tropicalis mite extract.

Blomia tropicalis mite is highly prevalent in tropical and subtropical regions and it is associated with allergic diseases such as rhinitis and asthma. By using an OVA-model of allergic lung disease, we have previously shown that sensitization in the presence of toll like receptors (TLRs) agonists attenuates subsequent OVA-induced allergic responses. Here, we evaluated the effect of CpG-ODN, a specific synthetic TLR-9 agonist, on the development of experimental asthma induced by Blomia tropicalis extract, a relevant source of aeroallergens. Among different protocols of Blomia tropicalis extract sensitization, the subcutaneous sensitization in the presence of alum adjuvant induced the highest Th2 responses, including high IgE levels. Adsorption of CpG to Blomia tropicalis extract/Alum attenuated the airway hyperreactivity, the infiltration of inflammatory cells including eosinophils, and the IL-5 content in BAL. In addition, lung peribronchial inflammatory infiltrate, mucus production and IL-5-producing CD3+ CD4+ T cells were significantly reduced in the Blomia tropicalis extract/Alum+CpG group. Importantly, CpG inhibited total IgE production as well as active systemic or cutaneous anaphylaxis reactions. Inhibition of pulmonary Th2 responses was associated with increased IL-10 production but not with IFN-γ production. Notably, in IL-10-deficient mice, sensitization with OVA/Alum+CpG resulted in intense lung neutrophilia and IFN-γ production, indicating that IL-10 is necessary to inhibit subsequent Th1 immunity. Our work highlights the mechanisms of allergy attenuation by CpG and it indicates the potential use of Alum-based formulation with CpG to treat allergic processes.

Evaluation of skin sensitivity in dogs bearing allergic dermatitis to standardized allergenic extract of house dust and storage mites

The objective of the study was to evaluate whether allergenic extracts of five house dust and storage mite species standardized for humans might be used for the diagnosis of canine atopic dermatitis (CAD). Extracts of Dermatophagoides pteronyssinus (Pyroglyphidae), D. farinae (Pyroglyphidae), Blomia tropicalis (Glycyphagidae), Lepidoglyphus destructor (Glycyphagidae) and Tyrophagus putrescentiae (Acaridae) were evaluated by intradermal testing in 20 healthy dogs (control) and 25 dogs with allergic dermatitis. A significant difference in the response was observed between the two groups (p<0.05). Only one dog (5 percent) in the control group reacted to the intradermal test, whereas 14 dogs (56 percent) in the allergic group were positive for at least one extract (odds ratio = 24.2). Most of the positive reactions observed in the allergic group occurred against the extracts of T. putrescentiae or L. destructor, each inducing reactions in 10 dogs (40 percent). D. farinae, D. pteronyssinus e B. tropicalis extracts induced reactions in 7 (28 percent), 3 (12 percent) and 3 (12 percent) dogs, respectively. The allergenic extracts standardized for humans evaluated in the present study may be used as a tool to complement the diagnosis of the disease, as well as to select potential allergen candidates for allergen-specific immunotherapy.(AU)

O presente trabalho teve como objetivo avaliar se extratos alergênicos de cinco espécies de ácaros da poeira domiciliar e produtos armazenados, padronizados para humanos, podem ser utilizados no diagnóstico da dermatite atópica canina. Extratos de Dermatophagoides pteronyssinus (Pyroglyphidae), D. farinae (Pyroglyphidae), Blomia tropicalis (Glycyphagidae), Lepidoglyphus destructor (Glycyphagidae) e Tyrophagus putrescentiae (Acaridae) foram avaliados através de testes intradérmicos em 45 cães, dos quais 20 normais e 25 com dermatite alérgica. Uma diferença significativa foi observada no padrão de respostas obtidas dos dois grupos (p<0.05). Apenas um animal (5 por cento) do grupo controle reagiu ao teste cutâneo, enquanto que no grupo dos alérgicos 14 cães (56 por cento) apresentaram pelo menos uma reação positiva (odds ratio = 24.2). As maiores freqüências de reações positivas observadas no grupo dos alérgicos foram aos extratos de T. putres-centiae ou L. destructor, cada um induzindo reações em 10(40 por cento) cães. Os extratos de D. farinae, D. pteronyssinus e B. tropicalis foram responsáveis por reações positivas em 7(28 por cento), 3(12 por cento) e 3(12 por cento) cães, respectivamente. Os extratos padronizados para humanos avaliados no presente estudo podem ser utilizados como complemento no diagnóstico da doença, assim como na seleção de alérgenos para a imunoterapia alérgeno-específica.(AU)

Evaluation of skin sensitivity in dogs bearing allergic dermatitis to standardized allergenic extract of house dust and storage mites

The objective of the study was to evaluate whether allergenic extracts of five house dust and storage mite species standardized for humans might be used for the diagnosis of canine atopic dermatitis (CAD). Extracts of Dermatophagoides pteronyssinus (Pyroglyphidae), D. farinae (Pyroglyphidae), Blomia tropicalis (Glycyphagidae), Lepidoglyphus destructor (Glycyphagidae) and Tyrophagus putrescentiae (Acaridae) were evaluated by intradermal testing in 20 healthy dogs (control) and 25 dogs with allergic dermatitis. A significant difference in the response was observed between the two groups (p<0.05). Only one dog (5 percent) in the control group reacted to the intradermal test, whereas 14 dogs (56 percent) in the allergic group were positive for at least one extract (odds ratio = 24.2). Most of the positive reactions observed in the allergic group occurred against the extracts of T. putrescentiae or L. destructor, each inducing reactions in 10 dogs (40 percent). D. farinae, D. pteronyssinus e B. tropicalis extracts induced reactions in 7 (28 percent), 3 (12 percent) and 3 (12 percent) dogs, respectively. The allergenic extracts standardized for humans evaluated in the present study may be used as a tool to complement the diagnosis of the disease, as well as to select potential allergen candidates for allergen-specific immunotherapy.

O presente trabalho teve como objetivo avaliar se extratos alergênicos de cinco espécies de ácaros da poeira domiciliar e produtos armazenados, padronizados para humanos, podem ser utilizados no diagnóstico da dermatite atópica canina. Extratos de Dermatophagoides pteronyssinus (Pyroglyphidae), D. farinae (Pyroglyphidae), Blomia tropicalis (Glycyphagidae), Lepidoglyphus destructor (Glycyphagidae) e Tyrophagus putrescentiae (Acaridae) foram avaliados através de testes intradérmicos em 45 cães, dos quais 20 normais e 25 com dermatite alérgica. Uma diferença significativa foi observada no padrão de respostas obtidas dos dois grupos (p<0.05). Apenas um animal (5 por cento) do grupo controle reagiu ao teste cutâneo, enquanto que no grupo dos alérgicos 14 cães (56 por cento) apresentaram pelo menos uma reação positiva (odds ratio = 24.2). As maiores freqüências de reações positivas observadas no grupo dos alérgicos foram aos extratos de T. putres-centiae ou L. destructor, cada um induzindo reações em 10(40 por cento) cães. Os extratos de D. farinae, D. pteronyssinus e B. tropicalis foram responsáveis por reações positivas em 7(28 por cento), 3(12 por cento) e 3(12 por cento) cães, respectivamente. Os extratos padronizados para humanos avaliados no presente estudo podem ser utilizados como complemento no diagnóstico da doença, assim como na seleção de alérgenos para a imunoterapia alérgeno-específica.