The success of TNF inhibitors for treatment of psoriasis and other inflammatory diseases was previously attributed to blockade of innate immunity. In a clinical trial using etanercept TNF blocking agent to treat psoriasis vulgaris, we used affymetrix gene arrays to analyze broad gene profiles in lesional skin at multiple timepoints during drug treatment (baseline, and weeks 1, 2, 4 and 12) compared to non-lesional skin. This analysis created a temporal model of TNF-dependent gene regulation that informs molecular mechanisms of TNF-mediated inflammation. We identified four gene clusters that were differentially down-modulated during etanercept treatment: the cluster down-regulated most rapidly contained mostly dendritic cell activation genes. Culturing human keratinocytes with TNF, IFNg and IL-17 generated a list of keratinocyte genes regulated by each cytokine. The IL-17 pathway genes were strongly down-modulated early, whereas IFNg pathway genes were not down-modulated until final disease resolution at week 12. Finally, we show that TNF blockade rapidly inhibits IL-12/IL-23 p40 subunit expression, and that p40 neutralization inhibits psoriatic dermal migr-mediated Th17 polarization. We hypothesize that etanercept inhibits myeloid dendritic cell production of IL-23, a Th17 survival cytokine, resulting in rapid downregulation of IL-17 pathway genes. This data links effects of TNF blockade on the innate immune system with the adaptive immune system.
Effective treatment of psoriasis with etanercept is linked to suppression of IL-17 signaling, not immediate response TNF genes.
Subject, Time
View SamplesThe effect of anti-IL-17 treatment on systemic inflammation is not fully understand. Using cDNA microarray, genomic analysis methods such as GSEA and ingenuity, we characterized the transcriptional changes in the blood of psoriasis patients afer systemic neutralization of IL-17 compared to baseline (before treatment). We also compared the whole blood-derived transcriptome between psoraisis patients at baseline and healthy volunteers to examine systemic inflammation in psoriasis patients.
IL-17 induces inflammation-associated gene products in blood monocytes, and treatment with ixekizumab reduces their expression in psoriasis patient blood.
Specimen part, Subject, Time
View SamplesAtopic dermatitis (AD) is a common inflammatory skin disease with a T(H)2 and T22 immune polarity. Despite recent data showing a genetic predisposition to epidermal barrier defects in some patients, a fundamental debate still exists regarding the role of barrier abnormalities versus immune responses in initiating the disease. An extensive study of nonlesional AD (ANL) skin is necessary to explore whether there is an intrinsic predisposition to barrier abnormalities, background immune activation, or both in patients with AD. We sought to characterize ANL skin by determining whether epidermal differentiation and immune abnormalities that characterize lesional AD (AL) skin are also reflected in ANL skin. We performed genomic and histologic profiling of both ANL and AL skin lesions (n = 12 each) compared with normal human skin (n = 10). We found that ANL skin is clearly distinct from normal skin with respect to terminal differentiation and some immune abnormalities and that it has a cutaneous expansion of T cells. We also showed that ANL skin has a variable immune phenotype, which is largely determined by disease extent and severity. Whereas broad terminal differentiation abnormalities were largely similar between involved and uninvolved AD skin, perhaps accounting for the background skin phenotype, increased expression of immune-related genes was among the most obvious differences between AL and ANL skin, potentially reflecting the clinical disease phenotype. Our study implies that systemic immune activation might play a role in alteration of the normal epidermal phenotype, as suggested by the high correlation in expression of immune genes in ANL skin with the disease severity index.
Nonlesional atopic dermatitis skin is characterized by broad terminal differentiation defects and variable immune abnormalities.
Specimen part, Subject
View SamplesIn this study we used genomic profiling to characterize differences in expression of genes related to epidermal growth/differentiation and inflammatory circuits in skin lesions of psoriasis and atopic dermatitis (AD), comparing expression values to normal skin. Skin biopsies were collected from 9 patients with chronic atopic dermatitis, 15 psoriasis patients, and 9 healthy volunteers.
Broad defects in epidermal cornification in atopic dermatitis identified through genomic analysis.
Specimen part, Subject
View SamplesBackground: IL-17 is the defining cytokine of the Th17, Tc17, and T cell populations that plays a critical role in mediating inflammation and autoimmunity. Psoriasis vulgaris is an inflammatory skin disease mediated by Th1 and Th17 cytokines with relevant contributions of IFN-, TNF-, and IL-17. Despite the pivotal role IL-17 plays in psoriasis, and in contrast to the other key mediators involved in the psoriasis cytokine cascade that are capable of inducing broad effects on keratinocytes, IL-17 was demonstrated to regulate the expression of a limited number of genes in monolayer keratinocytes cultured in vitro.
IL-17 induces an expanded range of downstream genes in reconstituted human epidermis model.
Specimen part, Treatment
View SamplesBackground: Previous work has identified CD11c+CD1c- dendritic cells (DCs) as the major inflammatory dermal DC population in psoriasis vulgaris and CD1c+ DCs as the resident cutaneous DC population. Objective: To further define molecular differences between these two myeloid dermal DC populations. Methods: Inflammatory and resident DCs were single-cell sorted from psoriasis lesional skin biopsies, and gene array expression profiling was performed. Results were confirmed with RT-PCR, flow cytometry, immunohistochemistry, and double label immunofluorescence. Pooled human keratinocytes were cultured for functional studies. Results: TNF-related apoptosis-inducing ligand (TRAIL), Toll-like receptors (TLRs) 1 and 2, S100A12/EN-RAGE, CD32, and many other inflammatory products were selectively expressed in inflammatory DCs than in resident DCs. Flow cytometry and immunofluorescence confirmed higher protein expression on CD1c- versus CD1c+ DCs. TRAIL receptor, death receptor 4 (DR4), was expressed on basal keratinocytes and blood vessels, and in vitro culture of keratinocytes with rh-TRAIL induced CCL20 leukocyte chemokine. Conclusion: CD11c+CD1c- inflammatory DCs in psoriatic lesional skin express a wide range of inflammatory molecules compared to skin resident CD1c+ DCs. Some molecules made by inflammatory DCs, including TRAIL, could have direct effects on keratinocytes or other skin cell types to promote disease pathogenesis.
Identification of TNF-related apoptosis-inducing ligand and other molecules that distinguish inflammatory from resident dendritic cells in patients with psoriasis.
Subject
View SamplesIn this study, we shought to identify the cytokines produced by skin-resident T cells in normal skin, localize the receptors for these cytokines, and examine how these cytokines alter gene expression profiles of the cells bearing cognate receptors.
Th17 cytokines interleukin (IL)-17 and IL-22 modulate distinct inflammatory and keratinocyte-response pathways.
No sample metadata fields
View SamplesHuman cytomegalovirus (HCMV) induces pro-inflammatory monocytes following infection and we have evidence that EGFR is a key mediator in this early activation. To begin to address how this signalling pathway is responsible for the rapid activation of infected monocytes, we examined the role this pathway played in the transcriptome of infected monocytes. Global transcriptional profiling using cDNA microarrays revealed a significant number of genes, including inflammatory genes, were regulated in a EGFR-dependent manner, identifying this pathway as a key cellular control point in the conversion of monocytes to an activated pro-inflammatory state following HCMV infection.
Activation of EGFR on monocytes is required for human cytomegalovirus entry and mediates cellular motility.
Specimen part
View SamplesAngiotensin II (Ang-II) regulates adrenal steroid production and gene transcription through several signaling pathways. Changes in gene transcription occur within minutes after Ang-II stimulation, causing an acute increase in aldosterone production and subsequent increase in the overall capacity to produce aldosterone. Our goal was to compare the Ang-II regulation of early gene expression and confirm the upregulation of selected genes using quantitative real-time RT-PCR (qPCR) across three species: human, bovine, and rat.
Angiotensin-II acute regulation of rapid response genes in human, bovine, and rat adrenocortical cells.
No sample metadata fields
View SamplesHuman cytomegalovirus (HCMV) induces pro-inflammatory monocytes following infection and we have evidence that phosphatidylinositol 3-kinase [PI(3)K] is a key mediator in this activation. To begin to address how this signalling pathway is responsible for the functional changes in infected monocytes, we examined the role this pathway played in the transcriptome of infected monocytes. Global transcriptional profiling using cDNA microarrays revealed a significant number of genes were regulated in a PI(3)K-dependent manner, identifying this pathway as a key cellular control point in the conversion of monocytes to an activated pro-inflammatory state following HCMV infection.
PI3K-dependent upregulation of Mcl-1 by human cytomegalovirus is mediated by epidermal growth factor receptor and inhibits apoptosis in short-lived monocytes.
Specimen part
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