Project description:Genome-wide association studies (GWAS) have boosted our knowledge of genetic risk variants in autoimmune diseases (AIDs). Most of the risk variants are located within or near genes with immunological functions, and the majority is found to be non-coding, pointing towards a regulatory role. We have performed a cis expression quantitative trait locus (eQTL) screen to investigate whether single nucleotide polymorphisms (SNPs) associated with AIDs influence gene expression in thymus. Genotyping was performed using the Immunochip and 353 AID associated SNPs were tested against expression of surrounding genes (+/- 1 Mb) from human thymic tissue (N=42). We identified eight genes where the expression was associated with AID risk SNPs at a study-wide level of significance (P < 2.57x10-5). Five genes (FCRL3, RNASET2, C2orf74, SIRPG and SYS1) displayed cis eQTL signals also in other tissues, while for two loci (NPIPB8 and LOC388814), the eQTL signal appear to be thymus-specific. Since many AID risk variants from GWAS have been subsequently fine-mapped in recent Immunochip projects, we explored the overlap between these novel AID risk variants and the thymic eQTL regions. Moreover, we examined the functional annotation of the seven expression altering SNPs (eSNPs). Our study reveals autoimmune risk variants that act as eQTLs in thymus. We have highlighted functional variants within these genetic regions that potentially can represent causal autoimmune risk variants. Total RNA from 42 human thymic samples were obtained from children undergoing cardiac surgery.
Project description:The interplay between environmental and genetic factors plays a key role in the development of many autoimmune diseases. In particular, the Epstein-Barr virus (EBV) is an established contributor to multiple sclerosis, lupus, and other disorders. Previously, we demonstrated that the EBV nuclear antigen 2 (EBNA2) transactivating protein occupies up to half of the risk loci for a set of seven autoimmune disorders. To further examine the mechanistic roles played by EBNA2 at these loci on a genome-wide scale, we globally examined gene expression, chromatin accessibility, chromatin looping, and EBNA2 binding, in a B cell line that was 1) uninfected, 2) infected with a strain of EBV lacking EBNA2, or 3) infected with a strain that expresses EBNA2. We identified >400 EBNA2-dependent differentially expressed human genes and >5,000 EBNA2 binding events in the human genome. ATAC-seq analysis revealed >2,000 regions in the human genome with EBNA2-dependent chromatin accessibility, and HiChIP-seq data revealed >1,700 regions where EBNA2 altered chromatin looping interactions. Importantly, autoimmune genetic risk loci were highly enriched at the sites of these EBNA2-dependent chromatin-altering events. We present examples of autoimmune risk genotype-dependent EBNA2 events, nominating genetic risk mechanisms for autoimmune risk loci such as ZMIZ1. Taken together, our results reveal important interactions between host genetic variation and EBNA2-driven disease mechanisms. Further, our study highlights a critical role for EBNA2 in rewiring human gene regulatory programs through rearrangement of the chromatin landscape and nominates these interactions as components of genetic mechanisms that influence the risk of multiple autoimmune diseases.
Project description:The interplay between environmental and genetic factors plays a key role in the development of many autoimmune diseases. In particular, the Epstein-Barr virus (EBV) is an established contributor to multiple sclerosis, lupus, and other disorders. Previously, we demonstrated that the EBV nuclear antigen 2 (EBNA2) transactivating protein occupies up to half of the risk loci for a set of seven autoimmune disorders. To further examine the mechanistic roles played by EBNA2 at these loci on a genome-wide scale, we globally examined gene expression, chromatin accessibility, chromatin looping, and EBNA2 binding, in a B cell line that was 1) uninfected, 2) infected with a strain of EBV lacking EBNA2, or 3) infected with a strain that expresses EBNA2. We identified >400 EBNA2-dependent differentially expressed human genes and >5,000 EBNA2 binding events in the human genome. ATAC-seq analysis revealed >2,000 regions in the human genome with EBNA2-dependent chromatin accessibility, and HiChIP-seq data revealed >1,700 regions where EBNA2 altered chromatin looping interactions. Importantly, autoimmune genetic risk loci were highly enriched at the sites of these EBNA2-dependent chromatin-altering events. We present examples of autoimmune risk genotype-dependent EBNA2 events, nominating genetic risk mechanisms for autoimmune risk loci such as ZMIZ1. Taken together, our results reveal important interactions between host genetic variation and EBNA2-driven disease mechanisms. Further, our study highlights a critical role for EBNA2 in rewiring human gene regulatory programs through rearrangement of the chromatin landscape and nominates these interactions as components of genetic mechanisms that influence the risk of multiple autoimmune diseases.
Project description:The interplay between environmental and genetic factors plays a key role in the development of many autoimmune diseases. In particular, the Epstein-Barr virus (EBV) is an established contributor to multiple sclerosis, lupus, and other disorders. Previously, we demonstrated that the EBV nuclear antigen 2 (EBNA2) transactivating protein occupies up to half of the risk loci for a set of seven autoimmune disorders. To further examine the mechanistic roles played by EBNA2 at these loci on a genome-wide scale, we globally examined gene expression, chromatin accessibility, chromatin looping, and EBNA2 binding, in a B cell line that was 1) uninfected, 2) infected with a strain of EBV lacking EBNA2, or 3) infected with a strain that expresses EBNA2. We identified >400 EBNA2-dependent differentially expressed human genes and >5,000 EBNA2 binding events in the human genome. ATAC-seq analysis revealed >2,000 regions in the human genome with EBNA2-dependent chromatin accessibility, and HiChIP-seq data revealed >1,700 regions where EBNA2 altered chromatin looping interactions. Importantly, autoimmune genetic risk loci were highly enriched at the sites of these EBNA2-dependent chromatin-altering events. We present examples of autoimmune risk genotype-dependent EBNA2 events, nominating genetic risk mechanisms for autoimmune risk loci such as ZMIZ1. Taken together, our results reveal important interactions between host genetic variation and EBNA2-driven disease mechanisms. Further, our study highlights a critical role for EBNA2 in rewiring human gene regulatory programs through rearrangement of the chromatin landscape and nominates these interactions as components of genetic mechanisms that influence the risk of multiple autoimmune diseases.
Project description:The interplay between environmental and genetic factors plays a key role in the development of many autoimmune diseases. In particular, the Epstein-Barr virus (EBV) is an established contributor to multiple sclerosis, lupus, and other disorders. Previously, we demonstrated that the EBV nuclear antigen 2 (EBNA2) transactivating protein occupies up to half of the risk loci for a set of seven autoimmune disorders. To further examine the mechanistic roles played by EBNA2 at these loci on a genome-wide scale, we globally examined gene expression, chromatin accessibility, chromatin looping, and EBNA2 binding, in a B cell line that was 1) uninfected, 2) infected with a strain of EBV lacking EBNA2, or 3) infected with a strain that expresses EBNA2. We identified >400 EBNA2-dependent differentially expressed human genes and >5,000 EBNA2 binding events in the human genome. ATAC-seq analysis revealed >2,000 regions in the human genome with EBNA2-dependent chromatin accessibility, and HiChIP-seq data revealed >1,700 regions where EBNA2 altered chromatin looping interactions. Importantly, autoimmune genetic risk loci were highly enriched at the sites of these EBNA2-dependent chromatin-altering events. We present examples of autoimmune risk genotype-dependent EBNA2 events, nominating genetic risk mechanisms for autoimmune risk loci such as ZMIZ1. Taken together, our results reveal important interactions between host genetic variation and EBNA2-driven disease mechanisms. Further, our study highlights a critical role for EBNA2 in rewiring human gene regulatory programs through rearrangement of the chromatin landscape and nominates these interactions as components of genetic mechanisms that influence the risk of multiple autoimmune diseases.
Project description:The interplay between environmental and genetic factors plays a key role in the development of many autoimmune diseases. In particular, the Epstein-Barr virus (EBV) is an established contributor to multiple sclerosis, lupus, and other disorders. Previously, we demonstrated that the EBV nuclear antigen 2 (EBNA2) transactivating protein occupies up to half of the risk loci for a set of seven autoimmune disorders. To further examine the mechanistic roles played by EBNA2 at these loci on a genome-wide scale, we globally examined gene expression, chromatin accessibility, chromatin looping, and EBNA2 binding, in a B cell line that was 1) uninfected, 2) infected with a strain of EBV lacking EBNA2, or 3) infected with a strain that expresses EBNA2. We identified >400 EBNA2-dependent differentially expressed human genes and >5,000 EBNA2 binding events in the human genome. ATAC-seq analysis revealed >2,000 regions in the human genome with EBNA2-dependent chromatin accessibility, and HiChIP-seq data revealed >1,700 regions where EBNA2 altered chromatin looping interactions. Importantly, autoimmune genetic risk loci were highly enriched at the sites of these EBNA2-dependent chromatin-altering events. We present examples of autoimmune risk genotype-dependent EBNA2 events, nominating genetic risk mechanisms for autoimmune risk loci such as ZMIZ1. Taken together, our results reveal important interactions between host genetic variation and EBNA2-driven disease mechanisms. Further, our study highlights a critical role for EBNA2 in rewiring human gene regulatory programs through rearrangement of the chromatin landscape and nominates these interactions as components of genetic mechanisms that influence the risk of multiple autoimmune diseases.
Project description:Systemic lupus erythematosus (SLE) is the prototypic systemic autoimmune disease. It is thought that many common variant gene loci of weak effect act additively to predispose to common autoimmune diseases, while the contribution of rare variants remains unclear. Here we describe that rare coding variants in lupus-risk genes are present in most SLE patients and healthy controls. We demonstrate the functional consequences of rare and low frequency missense variants in the interacting proteins BLK and BANK, which are present alone, or in combination, in a substantial proportion of lupus patients. The rare variant found in patients, but not those found exclusively in controls, impair suppression of IRF and type-I IFN in human B cell lines and increase pathogenic lymphocytes in lupus-prone mice. Thus, rare gene variants are common in SLE and likely contribute to genetic risk.
Project description:To fully comprehend how genetic variants influence phenotypes, we must understand the functions of the epigenome. To assess the degree to which genetic variants influence epigenome activity, we integrate epigenetic and genotypic data from lupus patient lymphoblastoid cell lines to identify variants that induce allelic imbalance in the magnitude of histone post-translational modifications, referred to herein as histone quantitative trait loci (hQTLs). We demonstrate that enhancer hQTLs are enriched on autoimmune disease risk haplotypes and disproportionately influence gene expression variability compared with non-hQTL variants in strong linkage disequilibrium. We show that the epigenome regulates HLA class II genes differently in individuals who carry HLA-DR3 or HLA-DR15 haplotypes, resulting in differential 3D chromatin conformation and gene expression. Finally, we identify significant expression QTL (eQTL) x hQTL interactions that reveal substructure within eQTL gene expression, suggesting potential implications for functional genomic studies that leverage eQTL data for subject selection and stratification.
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.