Project description:The goal of this study was to characterize altered inducible immune networks in Systemic onset juvenile idiopathic arthritis (sJIA), an IL-1-driven autoinflammatory disease of unknown etiology. To this end, we developed a high-throughput assay that quantifies the transcriptional and protein-level responses of blood leukocytes to innate stimuli. Herein, we report transcriptional data from healthy adult blood stimulated with 16 different conditions, including TLR ligands, cytosolic receptor ligands and inflammatory cytokines. We further report blood transcriptional profiles from sJIA patients with various disease activity and treatment statuses, both ex vivo (baseline) and after in vitro stimulation with a subset of innate stimuli including heat-killed bacterial pathogens.
Project description:Despite great scientific and technological advances, immune alterations predisposing to sporadic human inflammatory diseases remain mostly unknown. To fill this gap, we developed a strategy to evaluate blood leukocyte responses to innate stimuli, simultaneously at the transcriptional, cellular and secreted protein levels. The data were integrated using weighted gene co-expression network analysis. When applied to systemic juvenile idiopathic arthritis (sJIA), an autoinflammatory disease of unknown etiology, this approach identified gene sets associated with specific cytokine environments and activated leukocyte subsets. During the remission phase of disease and off treatment, sJIA patients displayed dysregulated responses to TLR4, TLR8 and TLR7 stimulation in blood. Isolated sJIA monocytes accumulated higher levels of intracellular IL-1β after stimulation, and underexpressed the IL-1 inhibitor AHR at baseline. In line with the recent demonstration that AHR downregulation in monocytes is linked to macrophage differentiation, we show that the differentiation of sJIA monocytes in vitro was skewed towards macrophages, away from dendritic cell phenotype. This might contribute to the increased incidence of macrophage activation syndrome in these patients. The integrated analysis of these high-dimensional data can thus help unravel underlying immune alterations predisposing to complex inflammatory diseases.
Project description:The objective of this study is to: 1) Characterize the innate immune responsiveness of patients with inborn errors in Toll-IL1 receptor signaling pathway (IRAK4, MyD88 deficiencies) compared to healthy subjects, through the analysis of blood leukocytes' transcriptional profiles after stimulation with ligands for the whole set of Toll-like receptors and IL-1Rs plus whole bacteria. 2) Understand the redundancies in TLR pathway in humans. 3) Explore the use of blood profiling approaches to assess the immune status of an individual by using Primary Immune Deficiencies as a proof of principle.
Project description:Systemic juvenile idiopathic arthritis (SJIA) is a chronic childhood arthropathy with features of autoinflammation. Early inflammatory SJIA is associated with expansion and activation of neutrophils with a sepsis-like phenotype, but neutrophil phenotypes present in longstanding and clinically inactive disease (CID) are unknown. The objective of this study was to examine activated neutrophil subsets, S100 alarmin release, and gene expression signatures in children with a spectrum of SJIA disease activity. Methods: Highly-purified neutrophils were isolated using a two-step procedure of density-gradient centrifugation followed by magnetic-bead based negative selection prior to flow cytometry or cell culture to quantify S100 protein release. Whole transcriptome gene expression profiles were compared in neutrophils from children with both active SJIA and CID. Results: Patients with SJIA and active systemic features demonstrated a higher number of CD16+CD62Llo neutrophil population compared to controls. This neutrophil subset was not seen in patients with CID or patients with active arthritis not exhibiting systemic features. Using imaging flow cytometry, CD16+CD62Llo neutrophils from patients with active SJIA and features of macrophage activation syndrome (MAS) had increased nuclear hypersegmentation compared to CD16+CD62L+ neutrophils. Serum levels of S100A8/A9 and S100A12 were strongly correlated with peripheral blood neutrophil counts. Neutrophils from active SJIA patients did not show enhanced resting S100 protein release; however, regardless of disease activity, neutrophils from SJIA patients did show enhanced S100A8/A9 release upon PMA stimulation compared to control neutrophils. Furthermore, whole transcriptome analysis of highly purified neutrophils from children with active SJIA identified 214 differentially expressed genes compared to neutrophils from healthy controls. The most significantly upregulated gene pathway was Immune System Process, including AIM2, IL18RAP, and NLRC4. Interestingly, this gene set showed intermediate levels of expression in neutrophils from patients with long-standing CID yet persistent serum IL-18 elevation. Indeed, all patient samples regardless of disease activity demonstrated elevated inflammatory gene expression, including inflammasome components and S100A8. Conclusion: We identify features of neutrophil activation in SJIA patients with active disease and CID, including a proinflammatory gene expression signature, reflecting persistent innate immune activation. Taken together, these studies expand understanding of neutrophil function in chronic autoinflammatory disorders such as SJIA.
Project description:TruCulture human whole blood ex vivo stimulation was performed on 17 healthy individuals and 17 post-onset type 1 diabetics, then gene expression was analyzed using Nanostring to characterize stimulated innate immune responses. Ex vivo whole blood stimulation revealed higher induced IFN-1 responses in type 1 diabetes as compared to healthy controls.
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:Kynureninase is a member of a large family of catalytically diverse but structurally homologous pyridoxal 5'-phosphate (PLP) dependent enzymes known as the aspartate aminotransferase superfamily or alpha-family. The Homo sapiens and other eukaryotic constitutive kynureninases preferentially catalyze the hydrolytic cleavage of 3-hydroxy-l-kynurenine to produce 3-hydroxyanthranilate and l-alanine, while l-kynurenine is the substrate of many prokaryotic inducible kynureninases. The human enzyme was cloned with an N-terminal hexahistidine tag, expressed, and purified from a bacterial expression system using Ni metal ion affinity chromatography. Kinetic characterization of the recombinant enzyme reveals classic Michaelis-Menten behavior, with a Km of 28.3 +/- 1.9 microM and a specific activity of 1.75 micromol min-1 mg-1 for 3-hydroxy-dl-kynurenine. Crystals of recombinant kynureninase that diffracted to 2.0 A were obtained, and the atomic structure of the PLP-bound holoenzyme was determined by molecular replacement using the Pseudomonas fluorescens kynureninase structure (PDB entry 1qz9) as the phasing model. A structural superposition with the P. fluorescens kynureninase revealed that these two structures resemble the "open" and "closed" conformations of aspartate aminotransferase. The comparison illustrates the dynamic nature of these proteins' small domains and reveals a role for Arg-434 similar to its role in other AAT alpha-family members. Docking of 3-hydroxy-l-kynurenine into the human kynureninase active site suggests that Asn-333 and His-102 are involved in substrate binding and molecular discrimination between inducible and constitutive kynureninase substrates.
Project description:Objective. Previous observations suggest that active systemic juvenile idiopathic arthritis (sJIA) is associated with a prominent erythropoiesis gene expression signature. The aim of this study was to determine the association of this signature with peripheral blood mononuclear cell (PBMC) subpopulations and its specificity for sJIA as compared to related conditions. 125 patients with JIA (18 sJIA and 107 non-sJIA) and 29 controls were studied. PBMC were isolated and analyzed for multiple surface antigens by flow cytometry and for gene expression profiles. The proportions of different PBMC subpopulations were compared among sJIA, non-sJIA patients and controls and subsequently correlated with the strength of the erythropoiesis signature. Additional gene expression data from patients with familial hemophagocytic lymphohistiocytosis (FHLH) and from a published sJIA cohort were analyzed to determine if the erythropoiesis signature was present. Keywords: Patient Vs Control, reassassment of phenotype Peripheral blood samples were obtained from 29 healthy children and 125 children with JIA . RNA was purified from Ficoll-isolated mononuclear cells, fluorescently labeled and then hybridized to Affymetrix U133 Plus 2.0 GeneChips. Data were analyzed using ANOVA at a 5% false discovery rate threshold after Robust Multi-Array Average pre-processing and Distance Weighted Discrimination normalization.