Flavivirus antagonism of type I interferon signaling reveals prolidase as a regulator of IFNAR1 trafficking and expression
Ontology highlight
ABSTRACT: Type I interferon (IFN-I) signals through two receptor subunits, IFNAR1 and IFNAR2, to regulate sterile and infectious immunity. IFNAR1 expression is tightly regulated to prevent autoimmunity although the mechanisms governing this are incompletely understood. We investigated the strategies used by two flaviviruses, tick-borne encephalitis virus and West Nile virus, to antagonize IFN-I signaling. Infection with these viruses resulted in depletion of IFNAR1 associated with the function of the viral IFN-I antagonist, NS5. NS5 function was dependent on its ability to associate with prolidase (PEPD), a cellular dipeptidase. PEPD was required for IFNAR1 maturation and accumulation, as well as gene induction following IFNAR1 stimulation. The relevance of PEPD to human biology was confirmed in fibroblasts derived from patients with genetic prolidase deficiency that expressed low IFNAR1 and exhibited reduced responses to IFNAR1. Thus, by understanding flavivirus IFN-I antagonism, PEPD is revealed as a central regulator of IFN-I responses in humans. RNA was isolated from replicates of 4 cultured dermal fibroblast lines derived from patients with genetic prolidase deficiency (PEPD), as well as from 4 cultured dermal fibroblast lines derived from normal healthy donors. These were run on Agilent microarrays to compare differences in gene expression observed in PEPD fibroblasts compared with normal fibroblasts.
Project description:Type I interferon (IFN-I) signals through two receptor subunits, IFNAR1 and IFNAR2, to regulate sterile and infectious immunity. IFNAR1 expression is tightly regulated to prevent autoimmunity although the mechanisms governing this are incompletely understood. We investigated the strategies used by two flaviviruses, tick-borne encephalitis virus and West Nile virus, to antagonize IFN-I signaling. Infection with these viruses resulted in depletion of IFNAR1 associated with the function of the viral IFN-I antagonist, NS5. NS5 function was dependent on its ability to associate with prolidase (PEPD), a cellular dipeptidase. PEPD was required for IFNAR1 maturation and accumulation, as well as gene induction following IFNAR1 stimulation. The relevance of PEPD to human biology was confirmed in fibroblasts derived from patients with genetic prolidase deficiency that expressed low IFNAR1 and exhibited reduced responses to IFNAR1. Thus, by understanding flavivirus IFN-I antagonism, PEPD is revealed as a central regulator of IFN-I responses in humans.
Project description:We provide an original multi-stage approach identifying a gene signature to assess the fibroblast polarization. Prototypic polarizations (inflammatory/fibrotic) were induced by seeded mouse embryonic fibroblasts (MEFs) with TNFα or TGFß1, respectively. The transcriptomic and proteomic profiles were obtained by RNA microarray and LC/MS-MS. Gene Ontology and pathways analysis were performed among the differentially expressed genes (DEGs) and proteins (DEPs). Balb/c mice underwent daily intradermal injections of HOCl (or PBS) as an experimental murine model of inflammation-mediated fibrosis in a time-dependent manner. As results, 1,456 and 2,215 DEGs, and 289 and 233 DEPs were respectively found in MEFs in response to TNFα or TGFß1, respectively. Among the most significant pathways, we combined 26 representative genes to encompass the proinflammatory and profibrotic polarizations of fibroblasts. Based on principal component analysis, this signature deciphered baseline state, proinflammatory polarization, and profibrotic polarization as accurately as did RNA microarray and LC/MS-MS. Then, we assessed the gene signature on dermal fibroblasts isolated from the experimental murine model. We observed a proinflammatory polarization at day 7, and a mixture of a proinflammatory and profibrotic polarizations at day 42 in line with histological findings. Our approach provides a small-size and convenient gene signature to assess murine fibroblast polarization.
Project description:To investigate the contribution of fibroblast-derived extracellular matrices (ECMs) to the resistance to targeted therapies in BRAF-mutated melanoma cells, we generated native-like 3D ECMs from human primary fibroblasts obtained from healthy individuals or melanoma patients. Cell-derived matrices from human dermal fibroblasts (HDF), skin melanoma associated fibroblasts (MAF) and two different lymph node fibroblast reticular cells (FRC) were denuded of cells and their composition was analyzed by mass spectrometry.
Project description:In this study, we compared gene expression and genome methylation of diverse fibroblast populations from a patient suffering from acrolentiginous melanoma (Breslow 4.0 mm, Clark IV, B-Raf V600E mutated). Stromal cells from the metastasis, i.e., melanoma associated fibroblasts (MAF), were positive for smooth muscle actin (SMA). Autologous control fibroblasts (ACF) isolated from distant uninvolved skin of the same patient during B-Raf inhibitor therapy and before clinical progression of the disease exhibited also strong SMA expression. Similar phenotype was observed in control dermal fibroblasts (CDF) from different donors yet exclusively after stimulation by TGF-β1. The identified differences in gene transcription as well as in DNA methylation indicate systemic activation of dermal fibroblasts in a patient with malignant melanoma. This dataset contains transcription profiling data, complementary methylation profiling data are available under accession E-MTAB-4965.
Project description:Integrins play a vital role in coordinating between the extracellular matrix (ECM) and the intracellular environment, thus enabling transduction of biomechanical signals to maintain tissue homeostasis. Here we investigate the significance of collagen-binding integrins in regulating fibroblast functions with relevance to fibrosis. Our data suggest that secretome from primary dermal fibroblasts isolated from mice lacking three collagen-binding integrins α1, α2 and α11 shows downregulation of several proteins essential for structure and regulation of crucial pro-fibrotic ECM components. In summary, abrogation of integrin-mediated cell-collagen association attenuates fibrosis.
Project description:In this study, we compared gene expression and genome methylation of diverse fibroblast populations from a patient suffering from acrolentiginous melanoma (Breslow 4.0 mm, Clark IV, B-Raf V600E mutated). Stromal cells from the metastasis, i.e., melanoma associated fibroblasts (MAF), were positive for smooth muscle actin (SMA). Autologous control fibroblasts (ACF) isolated from distant uninvolved skin of the same patient during B-Raf inhibitor therapy and before clinical progression of the disease exhibited also strong SMA expression. Similar phenotype was observed in control dermal fibroblasts (CDF) from different donors yet exclusively after stimulation by TGF-β1. The identified differences in gene transcription as well as in DNA methylation indicate systemic activation of dermal fibroblasts in a patient with malignant melanoma. This dataset contains genome methylation profiling data, complementary transcriptome profiling data are available under accession E-MTAB-4964.
Project description:Autoantibodies (Aab) are frequent in systemic sclerosis (SSc). While recognized as potent biomarkers, their pathogenic role is much debated. This study explored the effect of purified IgG from SSc patients on the phenotype and function of healthy dermal fibroblast (FB) using an innovative multi-omics approach.
Project description:We hypothesize that human RIPK3 deficiency does not result in impairment of type I IFN mediated antiviral immunity, contrasting with the situation in deficiencies of the TLR3-IFNAR1 circuit. To test the cellular responses to HSV1 at the wide transcriptome level, bulk RNA sequencing was performed with human primary fibroblasts without or with HSV-1 infection for 24 hours, in cells from healthy controls, RIPK3 HSE patient and other patients with recessive TLR3, IFNAR1 or NEMO deficiency.
Project description:Inborn errors of TLR3-dependent IFN-α/β- and -λ-mediated immunity in the central nervous system (CNS) can underlie herpes simplex virus 1 (HSV-1) encephalitis (HSE). The respective contributions of IFN-α/β- and -λ are unknown. We report a child homozygous for a genomic deletion of the entire coding sequence and part of the 3’UTR of the last exon of IFNAR1, who died from HSE at the age of two years. An older cousin died following vaccination against measles, mumps and rubella at 12 months of age, and another 17-year-old cousin homozygous for the same variant has had other viral illnesses. The encoded IFNAR1 protein is expressed on the cell surface but is truncated and cannot interact with the tyrosine kinase TYK2. The patient’s fibroblasts and EBV-B cells did not respond to IFN-α2b or IFN-β, in terms of STAT1, STAT2 and STAT3 phosphorylation, or the induction of IFN-stimulated genes (ISGs). Transcriptome analysis revealed a complete abolition of genome-wide ISG induction in response to IFN-α2b in IFNAR1-deficient fibroblasts from the patient. These fibroblasts were susceptible to viruses, including HSV-1, even in the presence of exogenous IFN-α2b or IFN-β. HSE is therefore a consequence of inherited complete IFNAR1 deficiency. This experiment of Nature indicates that IFN-α/β are essential for anti-HSV-1 immunity in the CNS.
Project description:The goal of this study was to determine the similarity between human dermal microvascular endothelial cells, induced endothelial cells from fibroblasts, and fibroblasts through RNA-seq expression analysis. RNA samples from independently induced cultures, plus fibroblast and human dermal microvascular endothelial cultures were converted into individual cDNA libraries using Illumina TruSeq methods and subjected to single-end 50 base-sequence analysis at 20-30 million read depths. Examination of one fibroblast culture, one human dermal mibrovascular endothelial cell culture, and two induced endothelial cell cultures.