Project description:Atherosclerosis is a chronic inflammatory disease. Lesion progression is primarily mediated by cells of the monocyte/macrophage lineage. Interleukin-17A is a pro-inflammatory cytokine, which modulates immune cell trafficking and is involved inflammation in (auto)immune and infectious diseases. But the role of IL-17A still remains controversial. In the current study we investigated effects of IL-17A on advanced murine and human atherosclerosis, the common disease phenotype in clinical care. 26-weeks old apolipoprotein E-deficient (Apoe-/-) mice were fed a standard chow diet and treated either with IL-17A mAb (n=15) or irrelevant immunoglobulin (n=10) for 16 weeks. Furthermore, essential mechanisms of IL-17A in atherogenesis were studied in vitro. Inhibition of IL-17A markedly prevented atherosclerotic lesion progression (P=0.001) by reducing inflammatory burden and cellular infiltration (P=0.01) and improved lesion stability (P=0.01). In vitro experiments showed that IL-17A plays a role in chemoattractance, monocyte adhesion, sensitization of antigen-presenting cells toward pathogen-derived TLR4 ligands. Also, IL-17A induced a unique transcriptome pattern in monocyte-derived macrophages distinct from known macrophage types. Stimulation of human carotid plaque tissue ex vivo with IL-17A induced a pro-inflammatory milieu and up-regulation of molecules expressed by the IL-17A-induced macrophage subtype. We here show for the first time that functional blockade of IL-17A prevents atherosclerotic lesion progression and induces plaque stabilization in advanced lesions in Apoe-/- mice. The underlying mechanisms involve reduced inflammation and distinct effects of IL-17A on monocyte / macrophage lineage. In addition, translational experiments underline the relevance for the human system. Effects of IL-17A on human monocyte-derived macrophages were assessed (n=2 per group).
Project description:The levels of IL-17 are elevated in the serum of psoriasis patients. However, the effects of IL-17 on circulating leukocytes bearing the IL-17 receptors are not fully understood. Of particular interest are monocytes, as the activation and recruitment of effector monocytes underlies the pathobiology of a number systemic inflammatory diseases, including psoriasis co-morbidities, such as atherosclerosis, metabolic regulation in adipose tissue and psoriatic arthritis. Human monocytes highly express both IL-17RA and IL-17RC and chemotraffick in response to IL-17. We explored the impact of IL-17 on blood monocytes. Using cDNA microarray, , we molecularly characterized how human blood monocytes respond to IL-17A in vitro. total RNA was extratced from CD14+ monocytes (isolated from human blood) after 24hr culture with or without IL-17A (200ng/mL)
Project description:IL-17A is a pro-inflammatory cytokine that promotes host defense against infections and contributes to the pathogenesis of chronic inflammatory diseases. Dendritic cells (DC) are antigen-presenting cells responsible for adaptive immune responses. Here, we report that IL-17A induces intense remodeling of lipid metabolism in human monocyte-derived DC, as revealed by microarrays analysis. In particular NR1H3/LXR-a and its target genes were significantly upregulated in response to IL-17A. IL-17A induced accumulation of Oil Red O-positive lipid droplets in DC leading to the generation of lipid-laden DC. A lipidomic study established that all the analyzed lipid species, i.e phospholipids, cholesterol, triglycerides, cholesteryl esters were elevated in IL-17A-treated DC. The increased expression of membrane lipid transporters in IL-17A-treated DC as well as their enhanced ability to uptake the fatty acid Bodipy-FL-C16 suggested that lipid uptake was the main mechanism responsible for lipid accumulation in response to IL-17A. IL-17A-induced lipid laden DC were able to stimulate allogeneic T cell proliferation in vitro as efficiently as untreated DC, indicating that IL-17A-treated DC are potently immunogenic. This study, encompassed in the field of immunometabolism, points out for the first time IL-17A as a modulator of lipid metabolism in DC and provides a rationale to delineate the importance of lipid-laden DC in IL-17A-related inflammatory diseases. We used microarrays analysis to understand the impact of IL-17A on human monocyte-derived human dendritic cells. We found overexpression of many genes involved in lipid metabolism in IL-17A-treated dendritic cells compared to untreated dendritic cells. In particular NR1H3/LXR-a and its target genes were significantly upregulated in response to IL-17A. IL-17A induced accumulation of Oil Red O-positive lipid droplets in DC leading to the generation of lipid-laden DC. A lipidomic study established that all the analyzed lipid species, i.e phospholipids, cholesterol, triglycerides, cholesteryl esters were elevated in IL-17A-treated DC. The increased expression of membrane lipid transporters in IL-17A-treated DC as well as their enhanced ability to uptake the fatty acid Bodipy-FL-C16 suggested that lipid uptake was the main mechanism responsible for lipid accumulation in response to IL-17A. IL-17A-induced lipid laden DC were able to stimulate allogeneic T cell proliferation in vitro as efficiently as untreated DC, indicating that IL-17A-treated DC are potently immunogenic. This study, encompassed in the field of immunometabolism, points out for the first time IL-17A as a modulator of lipid metabolism in DC and provides a rationale to delineate the importance of lipid-laden DC in IL-17A-related inflammatory diseases. RNA was extracted from untreated in vitro-generated DC at day 0 (DC, 4 biological replicates ) or DC cultured for 12 days with IL-17A, in the absence or presence of IFN-g (DC-17 and DC-G17, 5 biological replicates)
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.
Project description:Atherosclerosis is a chronic inflammatory disease. Lesion progression is primarily mediated by cells of the monocyte/macrophage lineage. Interleukin-17A is a pro-inflammatory cytokine, which modulates immune cell trafficking and is involved inflammation in (auto)immune and infectious diseases. But the role of IL-17A still remains controversial. In the current study we investigated effects of IL-17A on advanced murine and human atherosclerosis, the common disease phenotype in clinical care. 26-weeks old apolipoprotein E-deficient (Apoe-/-) mice were fed a standard chow diet and treated either with IL-17A mAb (n=15) or irrelevant immunoglobulin (n=10) for 16 weeks. Furthermore, essential mechanisms of IL-17A in atherogenesis were studied in vitro. Inhibition of IL-17A markedly prevented atherosclerotic lesion progression (P=0.001) by reducing inflammatory burden and cellular infiltration (P=0.01) and improved lesion stability (P=0.01). In vitro experiments showed that IL-17A plays a role in chemoattractance, monocyte adhesion, sensitization of antigen-presenting cells toward pathogen-derived TLR4 ligands. Also, IL-17A induced a unique transcriptome pattern in monocyte-derived macrophages distinct from known macrophage types. Stimulation of human carotid plaque tissue ex vivo with IL-17A induced a pro-inflammatory milieu and up-regulation of molecules expressed by the IL-17A-induced macrophage subtype. We here show for the first time that functional blockade of IL-17A prevents atherosclerotic lesion progression and induces plaque stabilization in advanced lesions in Apoe-/- mice. The underlying mechanisms involve reduced inflammation and distinct effects of IL-17A on monocyte / macrophage lineage. In addition, translational experiments underline the relevance for the human system.
Project description:IL-17A is a pro-inflammatory cytokine that promotes host defense against infections and contributes to the pathogenesis of chronic inflammatory diseases. Dendritic cells (DC) are antigen-presenting cells responsible for adaptive immune responses. Here, we report that IL-17A induces intense remodeling of lipid metabolism in human monocyte-derived DC, as revealed by microarrays analysis. In particular NR1H3/LXR-a and its target genes were significantly upregulated in response to IL-17A. IL-17A induced accumulation of Oil Red O-positive lipid droplets in DC leading to the generation of lipid-laden DC. A lipidomic study established that all the analyzed lipid species, i.e phospholipids, cholesterol, triglycerides, cholesteryl esters were elevated in IL-17A-treated DC. The increased expression of membrane lipid transporters in IL-17A-treated DC as well as their enhanced ability to uptake the fatty acid Bodipy-FL-C16 suggested that lipid uptake was the main mechanism responsible for lipid accumulation in response to IL-17A. IL-17A-induced lipid laden DC were able to stimulate allogeneic T cell proliferation in vitro as efficiently as untreated DC, indicating that IL-17A-treated DC are potently immunogenic. This study, encompassed in the field of immunometabolism, points out for the first time IL-17A as a modulator of lipid metabolism in DC and provides a rationale to delineate the importance of lipid-laden DC in IL-17A-related inflammatory diseases. We used microarrays analysis to understand the impact of IL-17A on human monocyte-derived human dendritic cells. We found overexpression of many genes involved in lipid metabolism in IL-17A-treated dendritic cells compared to untreated dendritic cells. In particular NR1H3/LXR-a and its target genes were significantly upregulated in response to IL-17A. IL-17A induced accumulation of Oil Red O-positive lipid droplets in DC leading to the generation of lipid-laden DC. A lipidomic study established that all the analyzed lipid species, i.e phospholipids, cholesterol, triglycerides, cholesteryl esters were elevated in IL-17A-treated DC. The increased expression of membrane lipid transporters in IL-17A-treated DC as well as their enhanced ability to uptake the fatty acid Bodipy-FL-C16 suggested that lipid uptake was the main mechanism responsible for lipid accumulation in response to IL-17A. IL-17A-induced lipid laden DC were able to stimulate allogeneic T cell proliferation in vitro as efficiently as untreated DC, indicating that IL-17A-treated DC are potently immunogenic. This study, encompassed in the field of immunometabolism, points out for the first time IL-17A as a modulator of lipid metabolism in DC and provides a rationale to delineate the importance of lipid-laden DC in IL-17A-related inflammatory diseases.
Project description:IL-17A influences essential functions of the monocyte / macrophage lineage and is involved in advanced murine and human atherosclerosis