Project description:The aim of the study was to identify genes which are differentially expressed in the blood of dogs with canine atopic dermatitis (AD) in comparison to healthy control dogs. Diagnosis of AD was based on compatible history and clinical signs determined using Willemse and Prélaud diagnostic criteria, completed by Favrot criteria as follows: pruritus sine material, indoor lifestyle and the exclusion of other causes of pruritus ongoing for at least one year. Clinical diagnosis of atopic dermatitis was confirmed by serological allergy testing (IDEXX allergic panel test) and intradermal skin testing (Artuvetrin test set, Netherlands). In order to avoid the role of food antigens as a cause of the skin condition elimination diets was used for 6–8 weeks. No anti-inflammatory drugs were given for at least 3 weeks prior examination with serological test, intradermal test and blood collection. All dogs, which were classified to the investigated group had positive reactions in serological allergy testing and intradermal skin testing.
Project description:The aim of the study was to identify genes which are differentially expressed in the blood of dogs with canine atopic dermatitis (AD) before and after 6 months of allergen-specific immunotherapy (ASIT) in comparison to healthy control dogs. Diagnosis of AD was based on compatible history and clinical signs determined using Willemse and Prélaud diagnostic criteria, completed by Favrot criteria as follows: pruritus sine material, indoor lifestyle and the exclusion of other causes of pruritus ongoing for at least one year. Clinical diagnosis of atopic dermatitis was confirmed by serological allergy testing (IDEXX allergic panel test) and intradermal skin testing (Artuvetrin test set, Netherlands). In order to avoid the role of food antigens as a cause of the skin condition elimination diet was used for 6–8 weeks. No anti-inflammatory drugs were given for at least 3 weeks prior examination with serological test, intradermal test and blood collection. All dogs, which were classified to the investigated group had positive reactions in serological allergy testing and intradermal skin testing. Subsequently, subcutaneous allergen-specific immunotherapy was applied. Allergen extracts were prepared on the basis of the results of intradermal tests by the Artuvetrin company and were administered subcutaneously in increasing concentrations during 6 months according to the manufacturer's recommendations. Aside from gene regulation, this experiment also examined the participation of individual lymphocyte subpopulations (like: B, T, Th, Tc, Treg) and the level of interleukins in the blood of AD dogs before and after therapy.
Project description:The gut microbiota composition is unique to every individual but is shaped by common factors including diet, lifestyle, medication use, early-life determinants, living environment or genetics. Most of these factors may be influenced by ethnicity. This study explored variations in fecal microbiota composition in 6048 individuals with different ethnic backgrounds living in the same geographical area (Amsterdam, the Netherlands).
Project description:Cutaneous exposure to food antigen through impaired skin barrier has been shown to induce epicutaneous sensitization, and thereby cause IgE-mediated food allergy. We examined whether skin barrier impairment deteriorated food allergy symptoms in epicutaneously sensitized mice. To clarify the association between skin inflammation and food allergy symptoms, we analyzed gene expression at skin lesions using a GeneChip.
Project description:Atopic dermatitis is a multifactorial allergic skin disease in humans and dogs. Genetic predisposition, immunologic hyperreactivity, a defective skin barrier and environmental factors play a role in its pathogenesis. The aim of this study was to analyze gene expression in the skin of dogs sensitized to house dust mite antigens. Skin biopsies were collected from six sensitized and six non-sensitized Beagle dogs from normal, non-treated skin before and six and 24 hours after challenge using skin patches with allergen or saline as a negative control. Transcriptome analysis was performed by the use of DNA microarrays and expression of selected genes was validated by quantitative real-time RT-PCR. Expression data was compared between groups (unpaired design). After 24 hours 597 differentially expressed genes were detected, 361 with higher and 226 with lower mRNA concentration in allergen treated skin of sensitized dogs compared to their saline-treated skin and compared to the control specimens. Functional annotation clustering, pathway-and co-citation analysis showed, that the genes with increased expression were involved in inflammation, wound healing and immune response. In contrast, genes with decreased expression in sensitized dogs were associated with differentiation and barrier function of the skin. As the sensitized dogs did not show differences in the untreated skin compared to controls, inflammation after allergen patch test probably led to a decrease in the expression of genes important for barrier formation. Our results further confirm the similar pathophysiology of human and canine atopic dermatitis and revealed genes previously not known to be involved in canine atopic dermatitis. 60 canine (dog) skin tissue samples; six sensitized and six non-sensitized Beagle dogs; samples collected before (0h), 6h and 24h after challenge with allergen; samples collected from a skin area treated with saline and from an area treated with allergen
Project description:Under steady state conditions, the immune system is poised to sense and respond to the microbiota. As such, immunity to the microbiota, including T cell responses, is expected to precede any inflammatory trigger. How this pool of preformed microbiota-specific T cells contributes to tissue pathologies remains unclear. Here, using an experimental model of psoriasis, we show that recall responses to commensal skin fungi can significantly aggravate tissue inflammation. Enhanced pathology caused by fungi pre-exposure depends on Th17 responses and neutrophil extracellular traps and recapitulates features of the transcriptional landscape of human lesional psoriatic skin. Together, our results propose that recall responses directed to skin fungi can directly promote skin inflammation and that exploration of tissue inflammation should be assessed in the context of recall responses to the microbiota.
Project description:This study explores the impact of lifestyle and environment on gene expression through whole transcriptome profiling of peripheral blood samples in Fijian population (native Melanesians and Indians) living in the rural and urban areas.
Project description:Atopic dermatitis is a multifactorial allergic skin disease in humans and dogs. Genetic predisposition, immunologic hyperreactivity, a defective skin barrier and environmental factors play a role in its pathogenesis. The aim of this study was to analyze gene expression in the skin of dogs sensitized to house dust mite antigens. Skin biopsies were collected from six sensitized and six non-sensitized Beagle dogs from normal, non-treated skin before and six and 24 hours after challenge using skin patches with allergen or saline as a negative control. Transcriptome analysis was performed by the use of DNA microarrays and expression of selected genes was validated by quantitative real-time RT-PCR. Expression data was compared between groups (unpaired design). After 24 hours 597 differentially expressed genes were detected, 361 with higher and 226 with lower mRNA concentration in allergen treated skin of sensitized dogs compared to their saline-treated skin and compared to the control specimens. Functional annotation clustering, pathway-and co-citation analysis showed, that the genes with increased expression were involved in inflammation, wound healing and immune response. In contrast, genes with decreased expression in sensitized dogs were associated with differentiation and barrier function of the skin. As the sensitized dogs did not show differences in the untreated skin compared to controls, inflammation after allergen patch test probably led to a decrease in the expression of genes important for barrier formation. Our results further confirm the similar pathophysiology of human and canine atopic dermatitis and revealed genes previously not known to be involved in canine atopic dermatitis.