Ustekinumab provides clinical benefit to psoriasis patients, but precise cellular and molecular changes underlying its therapeutic utility are not yet fully understood. To assess differences between ustekinumab responders vs. non responders in modulating specific inflammatory pathways and provide reference data for exploring molecular effects of next-generation interleukin(IL)-17 and IL-23-antagonists in psoriasis.
Modulation of inflammatory gene transcripts in psoriasis vulgaris: Differences between ustekinumab and etanercept.
Specimen part, Treatment, Subject, Time
View SamplesA gene expression profiling sub-study was conducted in which skin biopsy samples (n=192) were collected for RNA extraction and hybridization to microarrays from patients with moderate-to-severe psoriasis who participated in ACCEPT, an IRB-approved Phase 3, multicenter, randomized trial.
Modulation of inflammatory gene transcripts in psoriasis vulgaris: Differences between ustekinumab and etanercept.
Specimen part, Treatment, 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: 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 SamplesThis SuperSeries is composed of the SubSeries listed below.
CD14 regulates the dendritic cell life cycle after LPS exposure through NFAT activation.
Specimen part
View SamplesInterleukin-2 (IL-2) is one of the molecules produced by mouse dendritic cells (DCs) after stimulation by Toll like receptor (TLR) agonists. By analogy with the events following T-cell receptor (TCR) engagement leading to IL-2 production we have observed that DC stimulation with lipopolysaccharide (LPS) induces Src-family kinase and phospholipase C (PLC)2 activation, influx of extracellular Ca2+ and calcineurin-dependent nuclear NFAT translocation. We have also observed that the initiation of this pathway is independent of TLR4 engagement, and dependent exclusively on CD14. To determine the role of NFAT in LPS activated dendritic cells we have performed microarray analysis in conditions allowing or inhibiting NFAT activation. We show here that LPS-induced NFAT activation via CD14 is necessary to cause death of terminally differentiated DCs, an event that is essential for maintaining self-tolerance and preventing autoimmunity. Consequently, blocking this pathway in vivo causes prolonged DC survival and an increase in T cell priming capability.
CD14 regulates the dendritic cell life cycle after LPS exposure through NFAT activation.
Specimen part
View SamplesDendritic cells (DCs) are a special class of leukocytes able to activate both innate and adaptive immune responses. They interact with microbes through germline-encoded pattern-recognition receptors (PRRs), which recognize molecular patterns expressed by various microorganisms. Upon antigen binding, PRRs instruct DCs for the appropriate priming of natural killer cells, followed by specific T-cell responses. Once completed the effector phase, DCs reach the terminal differentiation stage and eventually die by apoptosis. We have observed that following lipopolysaccharide (LPS)-stimulation the initiation of the apoptotic pathway in DCs is due the activation of NFAT proteins. Indeed, LPS induces Src-family kinase and phospholipase C (PLC)2 activation, influx of extracellular Ca2+ and calcineurin-dependent nuclear NFAT translocation. The initiation of this pathway is independent of TLR4 engagement, and dependent exclusively on CD14. According with this observation CD14-deficient DCs do not die following LPS stimulation. Nevertheless, CD14-deficient DC death following LPS activation can be restored by co-stimulating DCs with LPS and thapsigargin. Thapsigargin empties the intracellular calcium stores by blocking calcium pumping into the sarcoplasmic and endoplasmic reticulum and thereby activates plasma membrane calcium channels. This, in turn, allows an influx of calcium into the cytosol and NFAT activation. To identify the NFAT controlled apoptosis genes in LPS activated DCs we have performed a kinetic microarray analysis (0, 48 and 60 h) in conditions allowing or inhibiting NFAT activation. Four genes have been selected: Nur77, Gadd45g, Ddit3/Gadd153/Chop-10 and Tia1.
CD14 regulates the dendritic cell life cycle after LPS exposure through NFAT activation.
Specimen part
View SamplesMacrophages and dendritic cells (DCs) differently contribute to the generation of coordinated immune system responses against infectious agents. They interact with microbes through germline-encoded pattern-recognition receptors (PRRs), which recognize molecular patterns expressed by various microorganisms. Upon antigen binding, PRRs instruct DCs for the appropriate priming of natural killer cells, followed by specific T-cell responses. Once completed the effector phase, DCs reach the terminal differentiation stage and eventually die by apoptosis. By contrast, following antigen recognition, macrophages initiate first the inflammatory process and then switch to an anti-inflammatory phenotype for the restoration of tissue homeostasis. Following lipopolysaccharide (LPS)-stimulation the initiation of the apoptotic pathway in DCs is due the activation of NFAT proteins. DC stimulation with lipopolysaccharide (LPS) induces Src-family kinase and phospholipase C (PLC)2 activation, influx of extracellular Ca2+ and calcineurin-dependent nuclear NFAT translocation. The initiation of this pathway is independent of TLR4 engagement, and dependent exclusively on CD14. We asked whether macrophage survival after LPS encounter was due to their inability to activate the Ca2+ pathway.
CD14 regulates the dendritic cell life cycle after LPS exposure through NFAT activation.
Specimen part
View Samples