Project description:In psoriasis, inflammation and epidermal hyperplasia are thought to be controlled by T cell-derived cytokines. Evidence now suggests that Th17 and Th22 cells infiltrate psoriasis lesions and by secreting IL-17 and IL-22, respectively, may drive disease-specific gene or cell responses. While studies in model systems indicate that IL-22 has a dominant pathogenic role, there is evolving evidence that IL-17 contributes to features of psoriasis. To more fully understand the role of IL-17 in human disease pathogenesis, we examined psoriatic skin lesions obtained from patients treated with an anti-IL-17 (IL-17 A) monoclonal antibody, LY2439821. In a phase 1, randomized, double-blind, placebo-controlled dose escalation trial, patients with chronic psoriasis were randomized to receive 3 doses of subcutaneous LY2439821 at 5 mg (n=8), 15 mg (n=8), 50 mg (n=8), 150 mg (n=8) or placebo (n=8) at weeks 0, 2 and 4. Repeat biopsies were taken from the same lesional area at baseline, week 2 and 6. At week 6, a PASI75 was observed in 0/8, 2/8, 5/7 and 8/8 patients receiving 5 mg, 15 mg, 50 mg or 150 mg LY2439821 respectively and 0/8 patients receiving placebo. The antibody was well-tolerated. In patients receiving the two highest doses, histological and immunohistochemical analyses of biopsies revealed significant reductions from baseline in keratinocyte proliferation, hyperplasia and epidermal thickness after 2 weeks, as well as reduced infiltration into the dermis and epidermis by T-cells (CD3+) and dendritic cells (CD11c and DC-LAMP). Keratinocyte expression of innate defense proteins, S100A7, S100A8, beta-defensin2 and LL37/cathelicidin was also reduced. By week 6, the skin appeared normal with a reversal of disease defining pathological features. Quantitative RT-PCR revealed decreased expression of interferon gamma (IFN-gamma), IL-22 and IL-17, key cytokines from T cell subsets Th1, Th22 and Th17, respectively. In order to explore the extent to which IL-17 blockade influences an even broader set of inflammatory or psoriatic disease related genes, mRNA levels from skin biopsy samples were evaluated using whole genome microarrays. At week 2, the highest dose of LY2439821 modulated over 1500 genes significantly (>1.5 fold change [FC], p<0.05). Of these, 51 genes were strongly suppressed (>7-fold) including IL-19, lipocalin, amphiregulin, granzyme B, and several chemokines. In a separate analysis, those genes known to be synergistically regulated by both IL-17 and TNF-alpha showed the greatest normalization in expression compared to genes known to be regulated by TNF-alpha alone, IFN-gamma or Interferon alpha. Our data suggest that Th17 cells, through the expression of IL-17, mediate psoriasis pathogenesis, and that neutralization of IL-17 with LY2439821 suppresses signaling through multiple inflammatory circuits by inhibiting expression of cytokines from multiple T cell subsets, as well as chemokines, and antimicrobial proteins from keratinocytes. In a phase 1, randomized, double-blind, placebo-controlled dose escalation trial, patients with chronic psoriasis were randomized to receive 3 doses of subcutaneous LY2439821 at 5 mg (n=8), 15 mg (n=8), 50 mg (n=8), 150 mg (n=8) or placebo (n=8) at weeks 0, 2 and 4. Repeat biopsies were taken from the same lesional area at baseline, week 2 and 6. At week 6, a PASI75 was observed in 0/8, 2/8, 5/7 and 8/8 patients receiving 5 mg, 15 mg, 50 mg or 150 mg LY2439821 respectively and 0/8 patients receiving placebo.

Project description: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 emigre-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. Experiment Overall Design: In this study 15 patients with moderate-to-severe psoriasis were given 50mg of etanercept (Amgen) biweekly for 12 weeks. And analyzed using gene array on mRNA extracted from tissue collected at each biopsy time point (non-lesional Time: 0; lesional Time: 0, weeks 1, 2, 4, and 12). Patients were stratified as 'responders' or 'non-responders' based on whether or not they achieved histologic disease resolution by week 12 of etanercept treatment (decreased epidermal thickening, normalization of proliferation marker Ki67, and loss of differentiation marker K16).

Project description:In psoriasis, inflammation and epidermal hyperplasia are thought to be controlled by T cell-derived cytokines. Evidence now suggests that Th17 and Th22 cells infiltrate psoriasis lesions and by secreting IL-17 and IL-22, respectively, may drive disease-specific gene or cell responses. While studies in model systems indicate that IL-22 has a dominant pathogenic role, there is evolving evidence that IL-17 contributes to features of psoriasis. To more fully understand the role of IL-17 in human disease pathogenesis, we examined psoriatic skin lesions obtained from patients treated with an anti-IL-17 (IL-17 A) monoclonal antibody, LY2439821. In a phase 1, randomized, double-blind, placebo-controlled dose escalation trial, patients with chronic psoriasis were randomized to receive 3 doses of subcutaneous LY2439821 at 5 mg (n=8), 15 mg (n=8), 50 mg (n=8), 150 mg (n=8) or placebo (n=8) at weeks 0, 2 and 4. Repeat biopsies were taken from the same lesional area at baseline, week 2 and 6. At week 6, a PASI75 was observed in 0/8, 2/8, 5/7 and 8/8 patients receiving 5 mg, 15 mg, 50 mg or 150 mg LY2439821 respectively and 0/8 patients receiving placebo. The antibody was well-tolerated. In patients receiving the two highest doses, histological and immunohistochemical analyses of biopsies revealed significant reductions from baseline in keratinocyte proliferation, hyperplasia and epidermal thickness after 2 weeks, as well as reduced infiltration into the dermis and epidermis by T-cells (CD3+) and dendritic cells (CD11c and DC-LAMP). Keratinocyte expression of innate defense proteins, S100A7, S100A8, beta-defensin2 and LL37/cathelicidin was also reduced. By week 6, the skin appeared normal with a reversal of disease defining pathological features. Quantitative RT-PCR revealed decreased expression of interferon gamma (IFN-gamma), IL-22 and IL-17, key cytokines from T cell subsets Th1, Th22 and Th17, respectively. In order to explore the extent to which IL-17 blockade influences an even broader set of inflammatory or psoriatic disease related genes, mRNA levels from skin biopsy samples were evaluated using whole genome microarrays. At week 2, the highest dose of LY2439821 modulated over 1500 genes significantly (>1.5 fold change [FC], p<0.05). Of these, 51 genes were strongly suppressed (>7-fold) including IL-19, lipocalin, amphiregulin, granzyme B, and several chemokines. In a separate analysis, those genes known to be synergistically regulated by both IL-17 and TNF-alpha showed the greatest normalization in expression compared to genes known to be regulated by TNF-alpha alone, IFN-gamma or Interferon alpha. Our data suggest that Th17 cells, through the expression of IL-17, mediate psoriasis pathogenesis, and that neutralization of IL-17 with LY2439821 suppresses signaling through multiple inflammatory circuits by inhibiting expression of cytokines from multiple T cell subsets, as well as chemokines, and antimicrobial proteins from keratinocytes.

Project description:Transcriptional profiling of Homo sapiens inflammatory skin diseases (whole skin biospies): Psoriasis (Pso), vs Atopic Dermatitis (AD) vs Lichen planus (Li), vs Contact Eczema (KE), vs Healthy control (KO) In recent years, different genes and proteins have been highlighted as potential biomarkers for psoriasis, one of the most common inflammatory skin diseases worldwide. However, most of these markers are not psoriasis-specific but also found in other inflammatory disorders. We performed an unsupervised cluster analysis of gene expression profiles in 150 psoriasis patients and other inflammatory skin diseases (atopic dermatitis, lichen planus, contact eczema, and healthy controls). We identified a cluster of IL-17/TNFα-associated genes specifically expressed in psoriasis, among which IL-36γ was the most outstanding marker. In subsequent immunohistological analyses IL-36γ was confirmed to be expressed in psoriasis lesions only. IL-36γ peripheral blood serum levels were found to be closely associated with disease activity, and they decreased after anti-TNFα-treatment. Furthermore, IL-36γ immunohistochemistry was found to be a helpful marker in the histological differential diagnosis between psoriasis and eczema in diagnostically challenging cases. These features highlight IL-36γ as a valuable biomarker in psoriasis patients, both for diagnostic purposes and measurement of disease activity during the clinical course. Furthermore, IL-36γ might also provide a future drug target, due to its potential amplifier role in TNFα- and IL-17 pathways in psoriatic skin inflammation. In recent years, different genes and proteins have been highlighted as potential biomarkers for psoriasis, one of the most common inflammatory skin diseases worldwide. However, most of these markers are not psoriasis-specific but also found in other inflammatory disorders. We performed an unsupervised cluster analysis of gene expression profiles in 150 psoriasis patients and other inflammatory skin diseases (atopic dermatitis, lichen planus, contact eczema, and healthy controls). We identified a cluster of IL-17/TNFα-associated genes specifically expressed in psoriasis, among which IL-36γ was the most outstanding marker. In subsequent immunohistological analyses IL-36γ was confirmed to be expressed in psoriasis lesions only. IL-36γ peripheral blood serum levels were found to be closely associated with disease activity, and they decreased after anti-TNFα-treatment. Furthermore, IL-36γ immunohistochemistry was found to be a helpful marker in the histological differential diagnosis between psoriasis and eczema in diagnostically challenging cases. These features highlight IL-36γ as a valuable biomarker in psoriasis patients, both for diagnostic purposes and measurement of disease activity during the clinical course. Furthermore, IL-36γ might also provide a future drug target, due to its potential amplifier role in TNFα- and IL-17 pathways in psoriatic skin inflammation.

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Suppression of inflammation in psoriasis blood after IL-17 treatment with ixekizumab

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