Transcription termination factor Rho is essential in enterobacteria. We inhibited Rho activity with bicyclomycin and used microarray experiments to assess Rho function on a genome-wide scale. Rho is a global regulator of gene expression that matches E. coli transcription to translational needs. Remarkably, genes that are most repressed by Rho are prophages and other horizontally-acquired portions of the genome. Elimination of these foreign DNA elements increases resistance to bicyclomycin. Although rho remains essential, such reduced-genome bacteria no longer require Rho cofactors NusA and NusG. Thus, Rho termination, supported by NusA and NusG, is required to suppress the toxic activity of foreign DNA.
Termination factor Rho and its cofactors NusA and NusG silence foreign DNA in E. coli.
Compound
View SamplesThe 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 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 SamplesThe process for making monocyte derived DCs (moDCs) has been previously described (46). All analysis was performed on day 5 immature DCs. Etanercept 10mg/mL was added to experimental wells on days 0, 2, and 4. We chose this concentration of etanercept as it approximates the plasma concentration of drug when given 50mg BIW.
Amelioration of epidermal hyperplasia by TNF inhibition is associated with reduced Th17 responses.
No sample metadata fields
View SamplesMycosis Fungoides (MF) is typically characterized by a mature CD4+ memory T-cell phenotype, and regarded as a helper T-cell (Th)2-skewed disease. Here, using skin samples from MF (n=21), healthy volunteers (n=17), atopic dermatitis (n=17), and psoriasis (n=9), we performed RT-PCR to show highest interleukin (IL)-32 mRNA expression in MF compared to benign inflammatory diseases, and its increasing expression with disease progression. By immunohistochemistry and immunofluorescence, we confirmed IL-32 protein expression by numerous CD3+CD4+ T-cells and some epidermotropic T-cells in MF lesions. IL-32 is expressed by MyLa cells (MF cell line) and promoted their proliferation and viability in a dose-dependent fashion. IL-32-treated MyLa and HH cells (CTCL cell line) showed upregulation of cell proliferation and survival genes. Of major 'polar' T-cell cytokines, only IFN- mRNA increases with MF progression and positively correlates with IL-32 mRNA expression levels. Th2 cytokines do not show consistent increases with MF progression nor positive correlation with IL-32 mRNA expression levels. Furthermore, by flow cytometry, IL-32 production by circulating activated T-cells in healthy individulas was found in IFN-+ and IFN-- cells but not in IL-4+ or IL-13+ cells. In conclusion, we identified IL-32+ cells as likely tumor cells in MF, and clearly showed that IL-32 mRNA expression levels increase with MF progression. We found that IL-32 mRNA expression levels in MF are significantly higher than those in other skin diseases, and that some IL-32+ T-cells are independent from defined Th subsets. Thus IL-32 may play a unique role in MF progression as an autocrine cytokine.
IL32 is progressively expressed in mycosis fungoides independent of helper T-cell 2 and helper T-cell 9 polarization.
Specimen part, Cell line
View SamplesAtopic dermatitis (AD) is the most common inflammatory skin disease, with high unmet need for new therapies that are safe for chronic use. Emerging data suggest that TH2-cytokines play important roles in a variety of allergic and atopic conditions, including asthma and AD. In early phase clinical trials, dupilumab (a fully human monoclonal antibody against IL-4R that potently blocks IL-4 and IL-13 signaling) rapidly and markedly improved clinical measures in adults with either asthma (with elevated eosinophil counts) or moderate-to-severe AD. The pathomechanisms that may be impacted by IL-4/13 blockade in these disease settings have not yet been characterized in detail.
Dupilumab improves the molecular signature in skin of patients with moderate-to-severe atopic dermatitis.
Specimen part, Treatment, Subject, Time
View SamplesAtopic dermatitis (AD) is a common disease, with an increasing prevalence. The primary pathogenesis of the disease is still elusive, resulting in lack of specific treatments. The prevailing view is that AD is a biphasic, T-cell polarized disease, with Th2 predominating acute AD, and a switch to Th1 characterizing chronic disease. Identification of factors that participate in onset of lesions and maintenance of chronic lesions is critical for development of targeted therapeutics. We performed global genomic, molecular and cellular profiling of paired non-lesional, acute, and chronic skin biopsies from ten AD patients. Onset of acute lesions is associated with a striking increase in a subset of terminal differentiation proteins, specifically the IL-22-modulated S100A7-9. Correspondingly, acute disease is associated with significant increases in gene expression levels of the major Th22- (IL-22) and Th2- (IL-4, IL-31) cytokines and Th17-regulated genes (CCL20, PI3/Elafin), without significant changes in IL-17. A lesser induction of Th1- (IFN, MX-1, CXCL9-11) associated genes was detected in acute disease. Chronic skin lesions are characterized by significantly intensified activation of Th22, Th2 and Th1. Our data establish increased expression of S100A7-9 and other epidermal genes at onset of acute AD, with parallel activation of Th2 and Th22 cytokines. Our findings suggest an absence of switch mechanism in chronic disease and instead indicate that progression to chronic lesions is associated with intensified activation of immune axes that initiate onset of acute lesions, particularly Th22 and Th2. This alters the prevailing view of pathogenesis, with important therapeutic implications.
Progressive activation of T(H)2/T(H)22 cytokines and selective epidermal proteins characterizes acute and chronic atopic dermatitis.
Age, Subject
View SamplesBackground: Atopic dermatitis (AD) is a common inflammatory skin disease exhibiting a predominantly Th2/T22 immune activation and a defective epidermal barrier. Narrow-band UVB (NB-UVB) is considered an efficient treatment for moderate to severe AD. In psoriasis, NB-UVB has been found to suppress the Th1/Th17 immune polarization with subsequent reversal of epidermal hyperplasia. The immunomodulatory effects of this treatment are largely unknown in AD. Our study evaluates the effects of NB-UVB on immune and barrier abnormalities in AD, aiming to establish reversibility of disease and biomarkers of therapeutic response. Methods: 12 moderate-to-severe chronic AD patients received NB-UVB phototherapy 3 times weekly for up to 12 weeks. Lesional and non-lesional skin biopsies were obtained before and after treatment and evaluated by gene-expression and immunohistochemistry studies. Results: All patients had at least a 50% reduction in SCORing of AD (SCORAD) index with NB-UVB phototherapy. The Th2, T22, and Th1 immune pathways were suppressed and measures of epidermal hyperplasia and differentiation also normalized after phototherapy. The reversal of disease activity was associated with elimination of inflammatory leukocytes, Th2/T22-associated cytokines and chemokines, and normalized expression of barrier proteins. Conclusions: Our study shows reversal of both the epidermal defects and underlying immune activation in AD. By determining the correlation of variables with therapeutic response, we have defined a set of biomarkers of disease response that associate resolved Th2 and T22 inflammation with reversal of barrier pathology. This data supports the inside-out hypothesis of AD, suggesting that it is a disease primarily driven by an immune stimulus.
Reversal of atopic dermatitis with narrow-band UVB phototherapy and biomarkers for therapeutic response.
Specimen part, Treatment, Subject, Time
View Samples