RESUMO
The role of the autoimmune regulator (Aire) in central immune tolerance and thymic self-representation was first described more than 20 years ago, but fascinating new insights into its biology continue to emerge, particularly in the era of advanced single-cell genomics. We briefly describe the role of human genetics in the discovery of Aire, as well as insights into its function gained from genotype-phenotype correlations and the spectrum of Aire-associated autoimmunity-including insights from patients with Aire mutations with broad and diverse implications for human health. We then highlight emerging trends in Aire biology, focusing on three topic areas. First, we discuss medullary thymic epithelial diversity and the role of Aire in thymic epithelial development. Second, we highlight recent developments regarding the molecular mechanisms of Aire and its binding partners. Finally, we describe the rapidly evolving biology of the identity and function of extrathymic Aire-expressing cells (eTACs), and a novel eTAC subset called Janus cells, as well as their potential roles in immune homeostasis.
Assuntos
Proteína AIRE , Autoimunidade , Fatores de Transcrição , Humanos , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética , Animais , Timo/imunologia , Timo/metabolismo , Mutação , Tolerância Imunológica , Células Epiteliais/metabolismo , Células Epiteliais/imunologia , Doenças Autoimunes/imunologia , Doenças Autoimunes/genética , Doenças Autoimunes/metabolismoRESUMO
CRISPR technology has opened a new era of genome interrogation and genome engineering. Discovered in bacteria, where it protects against bacteriophage by cleaving foreign nucleic acid sequences, the CRISPR system has been repurposed as an adaptable tool for genome editing and multiple other applications. CRISPR's ease of use, precision, and versatility have led to its widespread adoption, accelerating biomedical research and discovery in human cells and model organisms. Here we review CRISPR-based tools and discuss how they are being applied to decode the genetic circuits that control immune function in health and disease. Genetic variation in immune cells can affect autoimmune disease risk, infectious disease pathogenesis, and cancer immunotherapies. CRISPR provides unprecedented opportunities for functional mechanistic studies of coding and noncoding genome sequence function in immunity. Finally, we discuss the potential of CRISPR technology to engineer synthetic cellular immunotherapies for a wide range of human diseases.
Assuntos
Doenças Autoimunes/imunologia , Terapia Baseada em Transplante de Células e Tecidos/métodos , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas/genética , Infecções/imunologia , Neoplasias/imunologia , Animais , Doenças Autoimunes/genética , Sistemas CRISPR-Cas , Edição de Genes , Predisposição Genética para Doença , Variação Genética , Humanos , Imunidade , Infecções/genética , Neoplasias/genéticaRESUMO
Genome technologies have defined a complex genetic architecture in major infectious, inflammatory, and autoimmune disorders. High density marker arrays and Immunochips have powered genome-wide association studies (GWAS) that have mapped nearly 450 genetic risk loci in 22 major inflammatory diseases, including a core of common genes that play a central role in pathological inflammation. Whole-exome and whole-genome sequencing have identified more than 265 genes in which mutations cause primary immunodeficiencies and rare forms of severe inflammatory bowel disease. Combined analysis of inflammatory disease GWAS and primary immunodeficiencies point to shared proteins and pathways that are required for immune cell development and protection against infections and are also associated with pathological inflammation. Finally, sequencing of chromatin immunoprecipitates containing specific transcription factors, with parallel RNA sequencing, has charted epigenetic regulation of gene expression by proinflammatory transcription factors in immune cells, providing complementary information to characterize morbid genes at infectious and inflammatory disease loci.
Assuntos
Doenças Autoimunes/genética , Síndromes de Imunodeficiência/genética , Infecções/genética , Inflamação/genética , Vacinas/imunologia , Animais , Epigênese Genética , Exoma/genética , Estudos de Associação Genética , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Imunidade/genética , Infecções/imunologia , RiscoRESUMO
Autoimmune diseases disproportionately affect females more than males. The XX sex chromosome complement is strongly associated with susceptibility to autoimmunity. Xist long non-coding RNA (lncRNA) is expressed only in females to randomly inactivate one of the two X chromosomes to achieve gene dosage compensation. Here, we show that the Xist ribonucleoprotein (RNP) complex comprising numerous autoantigenic components is an important driver of sex-biased autoimmunity. Inducible transgenic expression of a non-silencing form of Xist in male mice introduced Xist RNP complexes and sufficed to produce autoantibodies. Male SJL/J mice expressing transgenic Xist developed more severe multi-organ pathology in a pristane-induced lupus model than wild-type males. Xist expression in males reprogrammed T and B cell populations and chromatin states to more resemble wild-type females. Human patients with autoimmune diseases displayed significant autoantibodies to multiple components of XIST RNP. Thus, a sex-specific lncRNA scaffolds ubiquitous RNP components to drive sex-biased immunity.
Assuntos
Autoanticorpos , Doenças Autoimunes , RNA Longo não Codificante , Animais , Feminino , Humanos , Masculino , Camundongos , Autoanticorpos/genética , Doenças Autoimunes/genética , Autoimunidade/genética , Ribonucleoproteínas/genética , Ribonucleoproteínas/metabolismo , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Cromossomo X/genética , Cromossomo X/metabolismo , Inativação do Cromossomo X , Caracteres SexuaisRESUMO
Patients with autoinflammatory diseases present with noninfectious fever flares and systemic and/or disease-specific organ inflammation. Their excessive proinflammatory cytokine and chemokine responses can be life threatening and lead to organ damage over time. Studying such patients has revealed genetic defects that have helped unravel key innate immune pathways, including excessive IL-1 signaling, constitutive NF-κB activation, and, more recently, chronic type I IFN signaling. Discoveries of monogenic defects that lead to activation of proinflammatory cytokines have inspired the use of anticytokine-directed treatment approaches that have been life changing for many patients and have led to the approval of IL-1-blocking agents for a number of autoinflammatory conditions. In this review, we describe the genetically characterized autoinflammatory diseases, we summarize our understanding of the molecular pathways that drive clinical phenotypes and that continue to inspire the search for novel treatment targets, and we provide a conceptual framework for classification.
Assuntos
Doenças Autoimunes/genética , Doenças Autoimunes/imunologia , Predisposição Genética para Doença , Inflamação/genética , Inflamação/imunologia , Animais , Doenças Autoimunes/metabolismo , Autoimunidade , Modelos Animais de Doenças , Humanos , Imunidade Inata , Síndromes de Imunodeficiência/genética , Síndromes de Imunodeficiência/imunologia , Síndromes de Imunodeficiência/metabolismo , Inflamação/metabolismo , Mediadores da Inflamação/metabolismo , Interferons/metabolismo , Interleucina-1/metabolismo , Transtornos Linfoproliferativos/genética , Transtornos Linfoproliferativos/imunologia , Transtornos Linfoproliferativos/metabolismo , Ativação de Macrófagos/imunologia , Macrófagos/imunologia , Macrófagos/metabolismo , NF-kappa B/metabolismo , Transdução de SinaisRESUMO
Pathogenic autoantibodies arise in many autoimmune diseases, but it is not understood how the cells making them evade immune checkpoints. Here, single-cell multi-omics analysis demonstrates a shared mechanism with lymphoid malignancy in the formation of public rheumatoid factor autoantibodies responsible for mixed cryoglobulinemic vasculitis. By combining single-cell DNA and RNA sequencing with serum antibody peptide sequencing and antibody synthesis, rare circulating B lymphocytes making pathogenic autoantibodies were found to comprise clonal trees accumulating mutations. Lymphoma driver mutations in genes regulating B cell proliferation and V(D)J mutation (CARD11, TNFAIP3, CCND3, ID3, BTG2, and KLHL6) were present in rogue B cells producing the pathogenic autoantibody. Antibody V(D)J mutations conferred pathogenicity by causing the antigen-bound autoantibodies to undergo phase transition to insoluble aggregates at lower temperatures. These results reveal a pre-neoplastic stage in human lymphomagenesis and a cascade of somatic mutations leading to an iconic pathogenic autoantibody.
Assuntos
Autoanticorpos/genética , Doenças Autoimunes/genética , Linfócitos B/imunologia , Linfoma/genética , Animais , Autoanticorpos/imunologia , Doenças Autoimunes/imunologia , Doenças Autoimunes/patologia , Linfócitos B/patologia , Proteínas Adaptadoras de Sinalização CARD/genética , Proteínas de Transporte/genética , Evolução Clonal/genética , Evolução Clonal/imunologia , Ciclina D3/genética , Guanilato Ciclase/genética , Humanos , Proteínas Imediatamente Precoces/genética , Região Variável de Imunoglobulina/genética , Região Variável de Imunoglobulina/imunologia , Proteínas Inibidoras de Diferenciação/genética , Linfoma/imunologia , Linfoma/patologia , Camundongos , Mutação/genética , Mutação/imunologia , Proteínas de Neoplasias/genética , Análise de Sequência de DNA/métodos , Análise de Sequência de RNA/métodos , Análise de Célula Única/métodos , Proteína 3 Induzida por Fator de Necrose Tumoral alfa/genética , Proteínas Supressoras de Tumor/genética , Recombinação V(D)J/genéticaRESUMO
Monogenic autoimmune syndromes provide a rare yet powerful glimpse into the fundamental mechanisms of immunologic tolerance. Such syndromes reveal not only the contribution of an individual breakpoint in tolerance but also patterns in the pathogenesis of autoimmunity. Disturbances in innate immunity, a system built for ubiquitous sensing of danger signals, tend to generate systemic autoimmunity. For example, defects in the clearance of self-antigens and chronic stimulation of type 1 interferons lead to the systemic autoimmunity seen in C1q deficiency, SPENCDI, and AGS. In contrast, disturbances of adaptive immunity, which is built for antigen specificity, tend to produce organ-specific autoimmunity. Thus, the loss of lymphocyte homeostasis, whether through defects in apoptosis, suppression, or negative selection, leads to organ-specific autoimmunity in ALPS, IPEX, and APS1. We discuss the unique mechanisms of disease in these prominent syndromes as well as how they contribute to the spectrum of organ-specific or systemic autoimmunity. The continued study of rare variants in autoimmune disease will inform future investigations and treatments directed at rare and common autoimmune diseases alike.
Assuntos
Doenças Autoimunes/genética , Doenças Autoimunes/imunologia , Autoimunidade/genética , Animais , Humanos , Síndromes de Imunodeficiência/genética , Síndromes de Imunodeficiência/imunologia , Especificidade de Órgãos/genética , Especificidade de Órgãos/imunologiaRESUMO
T helper cell differentiation occurs in the context of the extracellular cytokine milieu evoked by diverse microbes and other pathogenic stimuli along with T cell receptor stimulation. The culmination of these signals results in specification of T helper lineages, which occurs through the combinatorial action of multiple transcription factors that establish distinctive transcriptomes. In this manner, inducible, but constitutively active, master regulators work in conjunction with factors such as the signal transducer and activator of transcriptions (STATs) that sense the extracellular environment. The acquisition of a distinctive transcriptome also depends on chromatin modifications that impact key cis elements as well as the changes in global genomic organization. Thus, signal transduction and epigenetics are linked in these processes of differentiation. In this review, recent advances in understanding T helper lineage specification and deciphering the action of transcription factors are summarized with emphasis on comprehensive views of the dynamic T cell epigenome.
Assuntos
Epigênese Genética , Regulação da Expressão Gênica , Linfócitos T Auxiliares-Indutores/imunologia , Linfócitos T Auxiliares-Indutores/metabolismo , Transcrição Gênica , Animais , Doenças Autoimunes/genética , Diferenciação Celular/genética , Diferenciação Celular/imunologia , Linhagem da Célula/genética , Epigenômica , Humanos , RNA não Traduzido/genética , RNA não Traduzido/metabolismo , Elementos Reguladores de Transcrição , Linfócitos T Auxiliares-Indutores/citologia , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismoRESUMO
The presence of DNA in the cytoplasm is normally a sign of microbial infections and is quickly detected by cyclic GMP-AMP synthase (cGAS) to elicit anti-infection immune responses. However, chronic activation of cGAS by self-DNA leads to severe autoimmune diseases for which no effective treatment is available yet. Here we report that acetylation inhibits cGAS activation and that the enforced acetylation of cGAS by aspirin robustly suppresses self-DNA-induced autoimmunity. We find that cGAS acetylation on either Lys384, Lys394, or Lys414 contributes to keeping cGAS inactive. cGAS is deacetylated in response to DNA challenges. Importantly, we show that aspirin can directly acetylate cGAS and efficiently inhibit cGAS-mediated immune responses. Finally, we demonstrate that aspirin can effectively suppress self-DNA-induced autoimmunity in Aicardi-Goutières syndrome (AGS) patient cells and in an AGS mouse model. Thus, our study reveals that acetylation contributes to cGAS activity regulation and provides a potential therapy for treating DNA-mediated autoimmune diseases.
Assuntos
DNA/imunologia , Nucleotidiltransferases/metabolismo , Tolerância a Antígenos Próprios/imunologia , Acetilação , Sequência de Aminoácidos , Animais , Aspirina/farmacologia , Doenças Autoimunes/genética , Doenças Autoimunes/imunologia , Doenças Autoimunes/metabolismo , Doenças Autoimunes do Sistema Nervoso/genética , Doenças Autoimunes do Sistema Nervoso/imunologia , Doenças Autoimunes do Sistema Nervoso/metabolismo , Autoimunidade , Linhagem Celular , DNA/genética , DNA/metabolismo , Modelos Animais de Doenças , Exodesoxirribonucleases/metabolismo , Células HEK293 , Células HeLa , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Modelos Moleculares , Mutação , Malformações do Sistema Nervoso/genética , Malformações do Sistema Nervoso/imunologia , Malformações do Sistema Nervoso/metabolismo , Nucleotidiltransferases/antagonistas & inibidores , Nucleotidiltransferases/química , Nucleotidiltransferases/genética , Células THP-1RESUMO
Circular RNAs (circRNAs) produced from back-splicing of exons of pre-mRNAs are widely expressed, but current understanding of their functions is limited. These RNAs are stable in general and are thought to have unique structural conformations distinct from their linear RNA cognates. Here, we show that endogenous circRNAs tend to form 16-26 bp imperfect RNA duplexes and act as inhibitors of double-stranded RNA (dsRNA)-activated protein kinase (PKR) related to innate immunity. Upon poly(I:C) stimulation or viral infection, circRNAs are globally degraded by RNase L, a process required for PKR activation in early cellular innate immune responses. Augmented PKR phosphorylation and circRNA reduction are found in peripheral blood mononuclear cells (PBMCs) derived from patients with autoimmune disease systemic lupus erythematosus (SLE). Importantly, overexpression of the dsRNA-containing circRNA in PBMCs or T cells derived from SLE can alleviate the aberrant PKR activation cascade, thus providing a connection between circRNAs and SLE.
Assuntos
RNA Circular/metabolismo , RNA Circular/fisiologia , eIF-2 Quinase/metabolismo , Adolescente , Adulto , Doenças Autoimunes/genética , Linhagem Celular , Endorribonucleases/metabolismo , Feminino , Humanos , Imunidade Inata/genética , Leucócitos Mononucleares/imunologia , Leucócitos Mononucleares/metabolismo , Lúpus Eritematoso Sistêmico/genética , Pessoa de Meia-Idade , Fosforilação , RNA/metabolismo , Splicing de RNA/genética , Estabilidade de RNA/fisiologia , RNA Circular/genética , RNA de Cadeia Dupla/metabolismo , Viroses/metabolismo , eIF-2 Quinase/imunologiaRESUMO
Mitochondrial abnormalities have been noted in lupus, but the causes and consequences remain obscure. Autophagy-related genes ATG5, ATG7 and IRGM have been previously implicated in autoimmune disease. We reasoned that failure to clear defective mitochondria via mitophagy might be a foundational driver in autoimmunity by licensing mitochondrial DNA-dependent induction of type I interferon. Here, we show that mice lacking the GTPase IRGM1 (IRGM homolog) exhibited a type I interferonopathy with autoimmune features. Irgm1 deletion impaired the execution of mitophagy with cell-specific consequences. In fibroblasts, mitochondrial DNA soiling of the cytosol induced cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING)-dependent type I interferon, whereas in macrophages, lysosomal Toll-like receptor 7 was activated. In vivo, Irgm1-/- tissues exhibited mosaic dependency upon nucleic acid receptors. Whereas salivary and lacrimal gland autoimmune pathology was abolished and lung pathology was attenuated by cGAS and STING deletion, pancreatic pathology remained unchanged. These findings reveal fundamental connections between mitochondrial quality control and tissue-selective autoimmune disease.
Assuntos
Doenças Autoimunes/metabolismo , Autoimunidade , Fibroblastos/metabolismo , Proteínas de Ligação ao GTP/metabolismo , Mitocôndrias/metabolismo , Mitofagia , Animais , Doenças Autoimunes/genética , Doenças Autoimunes/imunologia , Doenças Autoimunes/patologia , Células Cultivadas , Fibroblastos/imunologia , Fibroblastos/patologia , Proteínas de Ligação ao GTP/deficiência , Proteínas de Ligação ao GTP/genética , Regulação da Expressão Gênica , Macrófagos/imunologia , Macrófagos/metabolismo , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/metabolismo , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos Endogâmicos C57BL , Mitocôndrias/genética , Mitocôndrias/imunologia , Mitocôndrias/patologia , Nucleotidiltransferases/genética , Nucleotidiltransferases/metabolismo , Transdução de Sinais , Receptor 7 Toll-Like/genética , Receptor 7 Toll-Like/metabolismoRESUMO
CD8+ T cells are critical mediators of cytotoxic effector function in infection, cancer and autoimmunity. In cancer and chronic viral infection, CD8+ T cells undergo a progressive loss of cytokine production and cytotoxicity, a state termed T cell exhaustion. In autoimmunity, autoreactive CD8+ T cells retain the capacity to effectively mediate the destruction of host tissues. Although the clinical outcome differs in each context, CD8+ T cells are chronically exposed to antigen in all three. These chronically stimulated CD8+ T cells share some common phenotypic features, as well as transcriptional and epigenetic programming, across disease contexts. A better understanding of these CD8+ T cell states may reveal novel strategies to augment clearance of chronic viral infection and cancer and to mitigate self-reactivity leading to tissue damage in autoimmunity.
Assuntos
Doenças Autoimunes/imunologia , Autoimunidade , Linfócitos T CD8-Positivos/imunologia , Doenças Transmissíveis/imunologia , Linfócitos do Interstício Tumoral/imunologia , Neoplasias/imunologia , Animais , Doenças Autoimunes/genética , Doenças Autoimunes/metabolismo , Antígeno B7-H1/imunologia , Antígeno B7-H1/metabolismo , Linfócitos T CD8-Positivos/efeitos dos fármacos , Linfócitos T CD8-Positivos/metabolismo , Doença Crônica , Doenças Transmissíveis/genética , Doenças Transmissíveis/metabolismo , Citocinas/imunologia , Citocinas/metabolismo , Epigênese Genética , Humanos , Inibidores de Checkpoint Imunológico/uso terapêutico , Linfócitos do Interstício Tumoral/efeitos dos fármacos , Linfócitos do Interstício Tumoral/metabolismo , Neoplasias/tratamento farmacológico , Neoplasias/genética , Neoplasias/metabolismo , Fenótipo , Receptor de Morte Celular Programada 1/imunologia , Receptor de Morte Celular Programada 1/metabolismo , Receptores de Antígenos de Linfócitos T/imunologia , Receptores de Antígenos de Linfócitos T/metabolismo , Transdução de SinaisRESUMO
The past decade has seen an explosion in the use of DNA-based microarrays. These techniques permit assessment of RNA abundance on a genome-wide scale. Medical applications emerged in the field of cancer, with studies of both solid tumors and hematological malignancies leading to the development of tests that are now used to personalize therapeutic options. Microarrays have also been used to analyze the blood transcriptome in a wide range of diseases. In human autoimmune diseases, these studies are showing potential for identifying therapeutic targets as well as biomarkers for diagnosis, assessment of disease activity, and response to treatment. More quantitative and sensitive high-throughput RNA profiling methods are starting to be available and will be necessary for transcriptome analyses to become routine tests in the clinical setting. We expect this to crystallize within the coming decade, as these methods become part of the personalized medicine armamentarium.
Assuntos
Doenças Autoimunes/genética , Doenças Autoimunes/imunologia , Animais , Doenças Autoimunes/sangue , Doenças Autoimunes/tratamento farmacológico , Biomarcadores/sangue , Genômica , Ensaios de Triagem em Larga Escala , Humanos , Análise de Sequência com Séries de OligonucleotídeosRESUMO
The association between cancer and autoimmune disease is unexplained, exemplified by T cell large granular lymphocytic leukemia (T-LGL) where gain-of-function (GOF) somatic STAT3 mutations correlate with co-existing autoimmunity. To investigate whether these mutations are the cause or consequence of CD8+ T cell clonal expansions and autoimmunity, we analyzed patients and mice with germline STAT3 GOF mutations. STAT3 GOF mutations drove the accumulation of effector CD8+ T cell clones highly expressing NKG2D, the receptor for stress-induced MHC-class-I-related molecules. This subset also expressed genes for granzymes, perforin, interferon-γ, and Ccl5/Rantes and required NKG2D and the IL-15/IL-2 receptor IL2RB for maximal accumulation. Leukocyte-restricted STAT3 GOF was sufficient and CD8+ T cells were essential for lethal pathology in mice. These results demonstrate that STAT3 GOF mutations cause effector CD8+ T cell oligoclonal accumulation and that these rogue cells contribute to autoimmune pathology, supporting the hypothesis that somatic mutations in leukemia/lymphoma driver genes contribute to autoimmune disease.
Assuntos
Doenças Autoimunes , Leucemia Linfocítica Granular Grande , Animais , Camundongos , Doenças Autoimunes/genética , Doenças Autoimunes/patologia , Linfócitos T CD8-Positivos , Mutação com Ganho de Função , Leucemia Linfocítica Granular Grande/genética , Leucemia Linfocítica Granular Grande/patologia , Mutação , Subfamília K de Receptores Semelhantes a Lectina de Células NK/genética , Fator de Transcrição STAT3/genética , Fator de Transcrição STAT3/metabolismoRESUMO
Methionine-1 (M1)-linked ubiquitin chains regulate the activity of NF-κB, immune homeostasis, and responses to infection. The importance of negative regulators of M1-linked chains in vivo remains poorly understood. Here, we show that the M1-specific deubiquitinase OTULIN is essential for preventing TNF-associated systemic inflammation in humans and mice. A homozygous hypomorphic mutation in human OTULIN causes a potentially fatal autoinflammatory condition termed OTULIN-related autoinflammatory syndrome (ORAS). Four independent OTULIN mouse models reveal that OTULIN deficiency in immune cells results in cell-type-specific effects, ranging from over-production of inflammatory cytokines and autoimmunity due to accumulation of M1-linked polyubiquitin and spontaneous NF-κB activation in myeloid cells to downregulation of M1-polyubiquitin signaling by degradation of LUBAC in B and T cells. Remarkably, treatment with anti-TNF neutralizing antibodies ameliorates inflammation in ORAS patients and rescues mouse phenotypes. Hence, OTULIN is critical for restraining life-threatening spontaneous inflammation and maintaining immune homeostasis.
Assuntos
Doenças Autoimunes/genética , Autoimunidade/genética , Enzimas Desubiquitinantes/metabolismo , Endopeptidases/metabolismo , Inflamação/genética , Animais , Anticorpos Neutralizantes/uso terapêutico , Doenças Autoimunes/imunologia , Doenças Autoimunes/terapia , Linfócitos B/imunologia , Citocinas/metabolismo , Enzimas Desubiquitinantes/genética , Modelos Animais de Doenças , Endopeptidases/genética , Mutação em Linhagem Germinativa , Humanos , Inflamação/imunologia , Inflamação/terapia , Infliximab/uso terapêutico , Metionina/metabolismo , Camundongos , Camundongos Mutantes , Células Mieloides/imunologia , Poliubiquitina/metabolismo , Deleção de Sequência , Síndrome , Linfócitos T/imunologia , Fator de Necrose Tumoral alfa/antagonistas & inibidoresRESUMO
Genome-wide association studies are transformative in revealing the polygenetic basis of common diseases, with autoimmune diseases leading the charge. Although the field is just over 10 years old, advances in understanding the underlying mechanistic pathways of these conditions, which result from a dense multifactorial blend of genetic, developmental and environmental factors, have already been informative, including insights into therapeutic possibilities. Nevertheless, the challenge of identifying the actual causal genes and pathways and their biological effects on altering disease risk remains for many identified susceptibility regions. It is this fundamental knowledge that will underpin the revolution in patient stratification, the discovery of therapeutic targets and clinical trial design in the next 20 years. Here we outline recent advances in analytical and phenotyping approaches and the emergence of large cohorts with standardized gene-expression data and other phenotypic data that are fueling a bounty of discovery and improved understanding of human physiology.
Assuntos
Doenças Autoimunes/genética , Doenças Autoimunes/microbiologia , Mapeamento Cromossômico , Variação Genética , Estudo de Associação Genômica Ampla , Humanos , Infecções/complicações , Microbiota , Distribuição Aleatória , Tamanho da AmostraRESUMO
The immune response to pathogens varies substantially among people. Whereas both genetic and nongenetic factors contribute to interperson variation, their relative contributions and potential predictive power have remained largely unknown. By systematically correlating host factors in 534 healthy volunteers, including baseline immunological parameters and molecular profiles (genome, metabolome and gut microbiome), with cytokine production after stimulation with 20 pathogens, we identified distinct patterns of co-regulation. Among the 91 different cytokine-stimulus pairs, 11 categories of host factors together explained up to 67% of interindividual variation in cytokine production induced by stimulation. A computational model based on genetic data predicted the genetic component of stimulus-induced cytokine production (correlation 0.28-0.89), and nongenetic factors influenced cytokine production as well.
Assuntos
Citocinas/biossíntese , Adolescente , Adulto , Idoso , Doenças Autoimunes/genética , Doenças Autoimunes/imunologia , Citocinas/genética , Feminino , Perfilação da Expressão Gênica , Genômica , Humanos , Masculino , Metabolômica , Metagenômica , Pessoa de Meia-Idade , Fenótipo , Biologia de Sistemas , Adulto JovemRESUMO
Despite recent discoveries of genetic variants associated with autoimmunity and infection, genetic control of the human immune system during homeostasis is poorly understood. We undertook a comprehensive immunophenotyping approach, analyzing 78,000 immune traits in 669 female twins. From the top 151 heritable traits (up to 96% heritable), we used replicated GWAS to obtain 297 SNP associations at 11 genetic loci, explaining up to 36% of the variation of 19 traits. We found multiple associations with canonical traits of all major immune cell subsets and uncovered insights into genetic control for regulatory T cells. This data set also revealed traits associated with loci known to confer autoimmune susceptibility, providing mechanistic hypotheses linking immune traits with the etiology of disease. Our data establish a bioresource that links genetic control elements associated with normal immune traits to common autoimmune and infectious diseases, providing a shortcut to identifying potential mechanisms of immune-related diseases.
Assuntos
Doenças Autoimunes/genética , Doenças do Sistema Imunitário/genética , Imunofenotipagem , Adulto , Idoso , Feminino , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Humanos , Leucócitos/citologia , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Receptores de IgG/genética , Linfócitos T Reguladores/citologiaRESUMO
Mosaic loss of the X chromosome (mLOX) is the most common clonal somatic alteration in leukocytes of female individuals1,2, but little is known about its genetic determinants or phenotypic consequences. Here, to address this, we used data from 883,574 female participants across 8 biobanks; 12% of participants exhibited detectable mLOX in approximately 2% of leukocytes. Female participants with mLOX had an increased risk of myeloid and lymphoid leukaemias. Genetic analyses identified 56 common variants associated with mLOX, implicating genes with roles in chromosomal missegregation, cancer predisposition and autoimmune diseases. Exome-sequence analyses identified rare missense variants in FBXO10 that confer a twofold increased risk of mLOX. Only a small fraction of associations was shared with mosaic Y chromosome loss, suggesting that distinct biological processes drive formation and clonal expansion of sex chromosome missegregation. Allelic shift analyses identified X chromosome alleles that are preferentially retained in mLOX, demonstrating variation at many loci under cellular selection. A polygenic score including 44 allelic shift loci correctly inferred the retained X chromosomes in 80.7% of mLOX cases in the top decile. Our results support a model in which germline variants predispose female individuals to acquiring mLOX, with the allelic content of the X chromosome possibly shaping the magnitude of clonal expansion.
Assuntos
Aneuploidia , Cromossomos Humanos X , Células Clonais , Leucócitos , Mosaicismo , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Alelos , Doenças Autoimunes/genética , Bancos de Espécimes Biológicos , Segregação de Cromossomos/genética , Cromossomos Humanos X/genética , Cromossomos Humanos Y/genética , Células Clonais/metabolismo , Células Clonais/patologia , Exoma/genética , Proteínas F-Box/genética , Predisposição Genética para Doença/genética , Mutação em Linhagem Germinativa , Leucemia/genética , Leucócitos/metabolismo , Modelos Genéticos , Herança Multifatorial/genética , Mutação de Sentido Incorreto/genéticaRESUMO
The single-nucleotide polymorphism rs1990760 in the gene encoding the cytosolic viral sensor IFIH1 results in an amino-acid change (A946T; IFIH1T946) that is associated with multiple autoimmune diseases. The effect of this polymorphism on both viral sensing and autoimmune pathogenesis remains poorly understood. Here we found that human peripheral blood mononuclear cells (PBMCs) and cell lines expressing the risk variant IFIH1T946 exhibited heightened basal and ligand-triggered production of type I interferons. Consistent with those findings, mice with a knock-in mutation encoding IFIH1T946 displayed enhanced basal expression of type I interferons, survived a lethal viral challenge and exhibited increased penetrance in autoimmune models, including a combinatorial effect with other risk variants. Furthermore, IFIH1T946 mice manifested an embryonic survival defect consistent with enhanced responsiveness to RNA self ligands. Together our data support a model wherein the production of type I interferons driven by an autoimmune risk variant and triggered by ligand functions to protect against viral challenge, which probably accounts for its selection within human populations but provides this advantage at the cost of modestly promoting the risk of autoimmunity.