RESUMEN
Age-related microangiopathy, also known as small vessel disease (SVD), causes damage to the brain, retina, liver, and kidney. Based on the DNA damage theory of aging, we reasoned that genomic instability may underlie an SVD caused by dominant C-terminal variants in TREX1, the most abundant 3'-5' DNA exonuclease in mammals. C-terminal TREX1 variants cause an adult-onset SVD known as retinal vasculopathy with cerebral leukoencephalopathy (RVCL or RVCL-S). In RVCL, an aberrant, C-terminally truncated TREX1 mislocalizes to the nucleus due to deletion of its ER-anchoring domain. Since RVCL pathology mimics that of radiation injury, we reasoned that nuclear TREX1 would cause DNA damage. Here, we show that RVCL-associated TREX1 variants trigger DNA damage in humans, mice, and Drosophila, and that cells expressing RVCL mutant TREX1 are more vulnerable to DNA damage induced by chemotherapy and cytokines that up-regulate TREX1, leading to depletion of TREX1-high cells in RVCL mice. RVCL-associated TREX1 mutants inhibit homology-directed repair (HDR), causing DNA deletions and vulnerablility to PARP inhibitors. In women with RVCL, we observe early-onset breast cancer, similar to patients with BRCA1/2 variants. Our results provide a mechanistic basis linking aberrant TREX1 activity to the DNA damage theory of aging, premature senescence, and microvascular disease.
Asunto(s)
Daño del ADN , Exodesoxirribonucleasas , Fosfoproteínas , Animales , Exodesoxirribonucleasas/genética , Exodesoxirribonucleasas/metabolismo , Humanos , Fosfoproteínas/genética , Fosfoproteínas/metabolismo , Ratones , Reparación del ADN por Recombinación , Fenotipo , Mutación , Drosophila/genética , Envejecimiento/genética , Envejecimiento/metabolismo , Femenino , Drosophila melanogaster/genética , Masculino , Enfermedades de la Retina , Enfermedades Vasculares , Enfermedades Desmielinizantes del Sistema Nervioso Central HereditariasRESUMEN
Stimulator of interferon genes (STING) is a sensor of cyclic dinucleotides including cyclic GMP-AMP, which is produced by cyclic GMP-AMP synthase (cGAS) in response to cytosolic DNA. The cGAS-STING signaling pathway regulates both innate and adaptive immune responses, as well as fundamental cellular functions such as autophagy, senescence, and apoptosis. Mutations leading to constitutive activation of STING cause devastating human diseases. Thus, the cGAS-STING pathway is of great interest because of its role in diverse cellular processes and because of the potential therapeutic implications of targeting cGAS and STING. Here, we review molecular and cellular mechanisms of STING signaling, and we propose a framework for understanding the immunological and other cellular functions of STING in the context of disease.
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Nucleotidiltransferasas , Transducción de Señal , Humanos , Transducción de Señal/fisiología , Nucleotidiltransferasas/genética , Nucleotidiltransferasas/metabolismo , Inflamación/metabolismo , ADN/metabolismo , Citosol/metabolismo , Inmunidad InnataRESUMEN
Retinal vasculopathy with cerebral leukoencephalopathy and systemic manifestations (RVCL-S) is a rare autosomal dominant disease resulting from a frame-shift mutation in TREX1, an intracellular 3'-5' exonuclease 1. Hepatic findings include an elevated alkaline phosphatase (ALP) and nodular regenerative hyperplasia (NRH). Affected individuals typically succumb to brain lesions before clinically apparent hepatic manifestations; thus, little else is known about the hepatic pathology. Autopsy reports and a liver section from each (n = 11) of three unrelated kindreds with the most common mutation in TREX1 (V235Gfs∗6) were studied with standard and immunohistochemical stains. Cases were compared with "normal liver" controls from similar autopsy years. Cases consisted of six men and five women who died at a median age of 50 yr (range, 41-60 yr.). Seven had elevated ALP. Two had liver atrophy. Foci of NRH were variably detected in all. Inhomogeneous distribution of other findings included patternless parenchymal fibrous bands, approximation of vascular structures, and commonly, architectural changes of vascular structures. Only bile duct epithelia were unaffected. In addition, small trichrome-positive nodules were found along vein walls or isolated in the parenchyma. Rare foci of non-NRH hepatocytic nodules were noted in 3. Increased CD34 and altered α-SMA IHC expression were variably noted. Periportal ductules and perivenular K7 IHC expression were increased to unpredictable degrees. The extensive but inhomogeneous histopathologic findings in livers of autopsied patients with RVCL-S appear to involve hepatic vascular structures. These findings validate inclusion of vascular liver involvement beyond NRH in this complex hereditary disorder.
Asunto(s)
Leucoencefalopatías , Hepatopatías , Enfermedades Vasculares , Masculino , Humanos , Femenino , Hiperplasia/patología , Hígado/patología , Leucoencefalopatías/genética , Leucoencefalopatías/patología , Enfermedades Vasculares/genética , Enfermedades Vasculares/patología , Hepatopatías/genética , Hepatopatías/patologíaRESUMEN
The human genome project led to the advancement of genetic technologies and genomic medicine for a variety of human diseases, including monogenic autoimmune and autoinflammatory diseases. As a result, the genome of an individual can now be rapidly sequenced at a low cost, and this technology is beginning to change the practice of rheumatology. In this Perspective, we describe how new sequencing technologies combined with careful clinical phenotyping have led to the discovery of rare rheumatic diseases and their corresponding disease-causing mutations. Additionally, we explore ways in which single-gene mutations, including somatic mutations, are creating opportunities to develop personalized medicines. To illustrate this idea, we focus on diseases affecting the TREX1-cGAS-STING pathway, which is associated with monogenic autoinflammatory diseases and vasculopathies. For many of the affected patients and families, there is an urgent, unmet need for the development of personalized therapies. New innovations related to small molecular inhibitors and gene therapies have the potential to benefit these families, and might help drive further innovations that could prove useful for patients with more common forms of autoimmunity and autoinflammation.
Asunto(s)
Enfermedades Autoinmunes , Enfermedades Autoinflamatorias Hereditarias , Humanos , Inflamación , Medicina de Precisión , AutoinmunidadRESUMEN
STING gain-of-function mutations cause STING-associated vasculopathy with onset in infancy (SAVI) in humans, a disease characterized by spontaneous lung inflammation and fibrosis. Mice with STING gain-of-function mutations (SAVI mice) develop αß T cell-dependent lung disease and also lack lymph nodes. Although SAVI has been regarded as a type I interferonopathy, the relative contributions of the three interferon receptors are incompletely understood. Here, we show that STING gain of function led to upregulation of IFN-γ-induced chemokines in the lungs of SAVI mice and that deletion of the type II IFN receptor (IFNGR1), but not the type I IFN receptor (IFNAR1) or type III IFN receptor (IFNλR1), ameliorated lung disease and restored lymph node development in SAVI mice. Furthermore, deletion of IFNGR1, but not IFNAR1 or IFNλR1, corrected the ratio of effector to Tregs in SAVI mice and in mixed bone marrow chimeric mice. Finally, cultured SAVI mouse macrophages were hyperresponsive to IFN-γ, but not IFN-ß, in terms of Cxcl9 upregulation and cell activation. These results demonstrate that IFNGR1 plays a major role in autoinflammation and immune dysregulation mediated by STING gain of function.
Asunto(s)
Enfermedades Pulmonares , Enfermedades Vasculares , Animales , Mutación con Ganancia de Función , Humanos , Pulmón , Proteínas de la Membrana/genética , Ratones , Linfocitos T , Enfermedades Vasculares/genéticaRESUMEN
STING modulates immunity by responding to bacterial and endogenous cyclic dinucleotides (CDNs). Humans and mice with STING gain-of-function mutations develop a syndrome known as STING-associated vasculopathy with onset in infancy (SAVI), which is characterized by inflammatory or fibrosing lung disease. We hypothesized that hyperresponsiveness of gain-of-function STING to bacterial CDNs might explain autoinflammatory lung disease in SAVI mice. We report that depletion of gut microbes with oral antibiotics (vancomycin, neomycin, and ampicillin [VNA]) nearly eliminates lung disease in SAVI mice, implying that gut microbes might promote STING-associated autoinflammation. However, we show that germ-free SAVI mice still develop severe autoinflammatory disease and that transferring gut microbiota from antibiotics-treated mice to germ-free animals eliminates lung inflammation. Depletion of anaerobes with metronidazole abolishes the protective effect of the VNA antibiotics cocktail, and recolonization with the metronidazole-sensitive anaerobe Bacteroides thetaiotaomicron prevents disease, confirming a protective role of a metronidazole-sensitive microbe in a model of SAVI.
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Microbioma Gastrointestinal/fisiología , Enfermedades Pulmonares/fisiopatología , Animales , Humanos , Ratones , Mutación , Transducción de SeñalRESUMEN
Interferons (IFNs) are key controllers of viral replication, with intact IFN responses suppressing virus growth and spread. Using the murine norovirus (MNoV) system, we show that IFNs exert selective pressure to limit the pathogenic evolutionary potential of this enteric virus. In animals lacking type I IFN signaling, the nonlethal MNoV strain CR6 rapidly acquired enhanced virulence via conversion of a single nucleotide. This nucleotide change resulted in amino acid substitution F514I in the viral capsid, which led to >10,000-fold higher replication in systemic organs including the brain. Pathogenicity was mediated by enhanced recruitment and infection of intestinal myeloid cells and increased extraintestinal dissemination of virus. Interestingly, the trade-off for this mutation was reduced fitness in an IFN-competent host, in which CR6 bearing F514I exhibited decreased intestinal replication and shedding. In an immunodeficient context, a spontaneous amino acid change can thus convert a relatively avirulent viral strain into a lethal pathogen.
Asunto(s)
Infecciones por Caliciviridae/virología , Proteínas de la Cápside/genética , Norovirus/genética , Norovirus/patogenicidad , Virulencia/genética , Animales , Infecciones por Caliciviridae/genética , Infecciones por Caliciviridae/inmunología , Aptitud Genética/genética , Inmunidad Innata/inmunología , Ratones , Norovirus/inmunología , Polimorfismo de Nucleótido Simple , Virulencia/inmunología , Replicación ViralRESUMEN
OBJECTIVE: Little is known about temporal changes in nasal bacteria in granulomatosis with polyangiitis (GPA). This study was undertaken to examine longitudinal changes in the nasal microbiome in association with relapse in GPA patients. METHODS: Bacterial 16S ribosomal RNA gene sequencing was performed on nasal swabs from 19 patients with GPA who were followed up longitudinally for a total of 78 visits, including 9 patients who experienced a relapse and 10 patients who remained in remission. Relative abundance of bacteria and ratios between bacteria were examined. Generalized estimating equation models were used to evaluate the association between bacterial composition and 1) disease activity and 2) levels of antineutrophil cytoplasmic antibody (ANCA) with specificity for proteinase 3 (PR3), adjusted for medication. RESULTS: Corynebacterium and Staphylococcus were the most abundant bacterial genera across all nasal samples. Patients with quiescent disease maintained a stable ratio of Corynebacterium to Staphylococcus across visits. In contrast, in patients who experienced a relapse, a significantly lower ratio was observed at the visit prior to relapse, followed by a higher ratio at the time of relapse (adjusted P < 0.01). Species-level analysis identified an association between a higher abundance of nasal Corynebacterium tuberculostearicum and 1) relapse (adjusted P = 0.04) and 2) higher PR3-ANCA levels (adjusted P = 0.02). CONCLUSION: In GPA, significant changes occur in the nasal microbiome over time and are associated with disease activity. The occurrence of these changes months prior to the onset of relapse supports a pathogenic role of nasal bacteria in GPA. Our results uphold existing hypotheses implicating Staphylococcus as an instigator of disease and have generated a novel finding involving Corynebacterium as a potential mediator of disease in GPA.
Asunto(s)
Granulomatosis con Poliangitis/microbiología , Microbiota , Cavidad Nasal/microbiología , Adulto , Corynebacterium/aislamiento & purificación , Femenino , Humanos , Masculino , Persona de Mediana Edad , Staphylococcus/aislamiento & purificaciónRESUMEN
Here, we report our studies of immune-mediated regulation of Zika virus (ZIKV), herpes simplex virus 1 (HSV-1), and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in the human cornea. We find that ZIKV can be transmitted via corneal transplantation in mice. However, in human corneal explants, we report that ZIKV does not replicate efficiently and that SARS-CoV-2 does not replicate at all. Additionally, we demonstrate that type III interferon (IFN-λ) and its receptor (IFNλR1) are expressed in the corneal epithelium. Treatment of human corneal explants with IFN-λ, and treatment of mice with IFN-λ eye drops, upregulates antiviral interferon-stimulated genes. In human corneal explants, blockade of IFNλR1 enhances replication of ZIKV and HSV-1 but not SARS-CoV-2. In addition to an antiviral role for IFNλR1 in the cornea, our results suggest that the human cornea does not support SARS-CoV-2 infection despite expression of ACE2, a SARS-CoV-2 receptor, in the human corneal epithelium.
Asunto(s)
Betacoronavirus/fisiología , Córnea/virología , Infecciones por Coronavirus/transmisión , Herpesvirus Humano 1/fisiología , Interferones/inmunología , Neumonía Viral/transmisión , Virus Zika/fisiología , Animales , Betacoronavirus/inmunología , COVID-19 , Córnea/inmunología , Infecciones por Coronavirus/inmunología , Infecciones por Coronavirus/virología , Herpes Simple/inmunología , Herpes Simple/transmisión , Herpes Simple/virología , Humanos , Ratones , Pandemias , Neumonía Viral/inmunología , Neumonía Viral/virología , SARS-CoV-2 , Replicación Viral/fisiología , Infección por el Virus Zika/inmunología , Infección por el Virus Zika/transmisión , Infección por el Virus Zika/virología , Interferón lambdaRESUMEN
OBJECTIVE: To characterize lesion evolution and neurodegeneration in retinal vasculopathy with cerebral leukoencephalopathy and systemic manifestations (RVCL-S) using multimodal MRI. METHODS: We prospectively performed MRI and cognitive testing in RVCL-S and healthy control cohorts. Gray and white matter volume and disruption of white matter microstructure were quantified. Asymmetric spin echo acquisition permitted voxel-wise oxygen extraction fraction (OEF) calculation as an in vivo marker of microvascular ischemia. The RVCL-S cohort was included in a longitudinal analysis of lesion subtypes in which hyperintense lesions on fluid-attenuated inversion recovery (FLAIR), T1-postgadolinium, and diffusion-weighted imaging were delineated and quantified volumetrically. RESULTS: Twenty individuals with RVCL-S and 26 controls were enrolled. White matter volume and microstructure declined faster in those with RVCL-S compared to controls. White matter atrophy in RVCL-S was highly linear (ρ = -0.908, p < 0.0001). Normalized OEF was elevated in RVCL-S and increased with disease duration. Multiple cognitive domains, specifically those measuring working memory and processing speed, were impaired in RVCL-S. Lesion volumes, regardless of subtype, progressed/regressed with high variability as a function of age, while FLAIR lesion burden increased near time to death (p < 0.001). CONCLUSION: RVCL-S is a monogenic microvasculopathy affecting predominantly the white matter with regard to atrophy and cognitive impairment. White matter volumes in RVCL-S declined linearly, providing a potential metric against which to test the efficacy of future therapies. Progressive elevation of white matter OEF suggests that microvascular ischemia may underlie neurodegeneration in RVCL-S.
Asunto(s)
Disfunción Cognitiva/patología , Enfermedades Desmielinizantes del Sistema Nervioso Central Hereditarias/patología , Degeneración Nerviosa/patología , Enfermedades de la Retina/patología , Enfermedades Vasculares/patología , Sustancia Blanca/patología , Adulto , Disfunción Cognitiva/diagnóstico por imagen , Femenino , Enfermedades Desmielinizantes del Sistema Nervioso Central Hereditarias/diagnóstico por imagen , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Degeneración Nerviosa/diagnóstico por imagen , Neuroimagen/métodos , Enfermedades de la Retina/diagnóstico por imagen , Enfermedades Vasculares/diagnóstico por imagen , Sustancia Blanca/diagnóstico por imagenRESUMEN
Zika virus (ZIKV) is a mosquito-borne virus of the flavivirus genus in the Flaviviridae family. Flaviviruses are single-stranded, positive-sense RNA viruses that have been responsible for numerous human epidemics. Notable flaviviruses include mosquito-borne viruses such as yellow fever virus (YFV), Dengue virus (DENV), West Nile virus (WNV), Japanese encephalitis virus (JEV), as well as tick-borne viruses including Powassan virus (POWV) and tick-borne encephalitis virus (TBEV). Despite having been relatively obscure until the past decade, ZIKV has become a major global health concern, and is a topic of active research following multiple outbreaks across the globe. Here, we discuss ZIKV pathogenesis and the associated immunopathology, as well as advances in research, therapies, and vaccines developed using models of ZIKV pathogenesis.
Asunto(s)
Virus del Nilo Occidental , Infección por el Virus Zika , Virus Zika , Animales , Humanos , Virus del Nilo Occidental/genética , Virus Zika/genética , Virus Zika/inmunología , Infección por el Virus Zika/inmunología , Infección por el Virus Zika/patologíaRESUMEN
STING gain-of-function causes autoimmunity and immunodeficiency in mice and STING-associated vasculopathy with onset in infancy (SAVI) in humans. Here, we report that STING gain-of-function in mice prevents development of lymph nodes and Peyer's patches. We show that the absence of secondary lymphoid organs is associated with diminished numbers of innate lymphoid cells (ILCs), including lymphoid tissue inducer (LTi) cells. Although wild-type (WT) α4ß7+ progenitors differentiate efficiently into LTi cells, STING gain-of-function progenitors do not. Furthermore, STING gain-of-function impairs development of all types of ILCs. Patients with STING gain-of-function mutations have fewer ILCs, although they still have lymph nodes. In mice, expression of the STING mutant in RORγT-positive lineages prevents development of lymph nodes and reduces numbers of LTi cells. RORγT lineage-specific expression of STING gain-of-function also causes lung disease. Since RORγT is expressed exclusively in LTi cells during fetal development, our findings suggest that STING gain-of-function prevents lymph node organogenesis by reducing LTi cell numbers in mice.
Asunto(s)
Diferenciación Celular/inmunología , Inmunidad Innata/inmunología , Ganglios Linfáticos/inmunología , Linfocitos/citología , Linfocitos T Colaboradores-Inductores/inmunología , Animales , Mutación con Ganancia de Función/inmunología , Tejido Linfoide/inmunología , Ratones , Organogénesis/inmunologíaRESUMEN
Stimulator of Interferon Genes (STING) is a critical component of host innate immune defense but can contribute to chronic autoimmune or autoinflammatory disease. Once activated, the cyclic guanosine monophosphate (GMP)-adenosine monophosphate (AMP) (cGAMP) synthase (cGAS)-STING pathway induces both type I interferon (IFN) expression and nuclear factor-κB (NF-κB)-mediated cytokine production. Currently, these two signaling arms are thought to be mediated by a single upstream kinase, TANK-binding kinase 1 (TBK1). Here, using genetic and pharmacological approaches, we show that TBK1 alone is dispensable for STING-induced NF-κB responses in human and mouse immune cells, as well as in vivo. We further demonstrate that TBK1 acts redundantly with IκB kinase ε (IKKε) to drive NF-κB upon STING activation. Interestingly, we show that activation of IFN regulatory factor 3 (IRF3) is highly dependent on TBK1 kinase activity, whereas NF-κB is significantly less sensitive to TBK1/IKKε kinase inhibition. Our work redefines signaling events downstream of cGAS-STING. Our findings further suggest that cGAS-STING will need to be targeted directly to effectively ameliorate the inflammation underpinning disorders associated with STING hyperactivity.
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Quinasa I-kappa B/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Animales , Femenino , Células HEK293 , Humanos , Quinasa I-kappa B/fisiología , Inmunidad Innata , Factor 3 Regulador del Interferón/metabolismo , Interferón beta/metabolismo , Masculino , Proteínas de la Membrana/metabolismo , Proteínas de la Membrana/fisiología , Ratones , Ratones Endogámicos C57BL , Células Mieloides/metabolismo , FN-kappa B/metabolismo , Nucleótidos Cíclicos/metabolismo , Fosforilación , Proteínas Serina-Treonina Quinasas/fisiología , Transducción de Señal/inmunologíaRESUMEN
Although the pathogen recognition receptor pathways that activate cell-intrinsic antiviral responses are well delineated, less is known about how the host regulates this response to prevent sustained signaling and possible immune-mediated damage. Using a genome-wide CRISPR-Cas9 screening approach to identify host factors that modulate interferon-stimulated gene (ISG) expression, we identified the DNA binding protein Barrier-to-autointegration factor 1 (Banf1), a previously described inhibitor of retrovirus integration, as a modulator of basal cell-intrinsic immunity. Ablation of Banf1 by gene editing resulted in chromatin activation near host defense genes with associated increased expression of ISGs, including Oas2, Rsad2 (viperin), Ifit1, and ISG15 The phenotype in Banf1-deficient cells occurred through a cGAS-, STING-, and IRF3-dependent signaling axis, was associated with reduced infection of RNA and DNA viruses, and was reversed in Banf1 complemented cells. Confocal microscopy and biochemical studies revealed that a loss of Banf1 expression resulted in higher level of cytosolic double-stranded DNA at baseline. Our study identifies an undescribed role for Banf1 in regulating the levels of cytoplasmic DNA and cGAS-dependent ISG homeostasis and suggests possible therapeutic directions for promoting or inhibiting cell-intrinsic innate immune responses.IMPORTANCE Although the interferon (IFN) signaling pathway is a key host mechanism to restrict infection of a diverse range of viral pathogens, its unrestrained activity either at baseline or in the context of an immune response can result in host cell damage and injury. Here, we used a genome-wide CRISPR-Cas9 screen and identified the DNA binding protein Barrier-to-autointegration factor 1 (Banf1) as a modulator of basal cell-intrinsic immunity. A loss of Banf1 expression resulted in higher level of cytosolic double-stranded DNA at baseline, which triggered IFN-stimulated gene expression via a cGAS-STING-IRF3 axis that did not require type I IFN or STAT1 signaling. Our experiments define a regulatory network in which Banf1 limits basal inflammation by preventing self DNA accumulation in the cytosol.
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Proteínas de Unión al ADN/inmunología , Interacciones Huésped-Patógeno , Proteínas de la Membrana/inmunología , Proteínas Nucleares/inmunología , Nucleotidiltransferasas/inmunología , Animales , Sistemas CRISPR-Cas , Línea Celular , Proteínas de Unión al ADN/genética , Edición Génica , Regulación de la Expresión Génica , Homeostasis/inmunología , Humanos , Inmunidad Innata , Interferones/inmunología , Ratones , Microglía/inmunología , Proteínas Nucleares/genética , Transducción de SeñalRESUMEN
Immune regulation at the maternal-fetal interface is complex due to conflicting immunological objectives: protection of the fetus from maternal pathogens and prevention of immune-mediated rejection of the semiallogeneic fetus and placenta. Interferon (IFN) signaling plays an important role in restricting congenital infections as well as in the physiology of healthy pregnancies. In this review, we discuss the antiviral and pathogenic effects of type I IFN (IFN-α, IFN-ß), type II IFN (IFN-γ), and type III IFN (IFN-λ) during pregnancy, with an emphasis on mouse and non-human primate models of congenital Zika virus infection. In the context of these animal model systems, we examine the role of IFN signaling during healthy pregnancy. Finally, we review mechanisms by which dysregulated type I IFN responses contribute to poor pregnancy outcomes in humans with autoimmune disease, including interferonopathies and systemic lupus erythematosus.
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Inmunidad Innata , Interferones/inmunología , Resultado del Embarazo , Transducción de Señal/inmunología , Animales , Antivirales/inmunología , Enfermedades Autoinmunes/complicaciones , Modelos Animales de Enfermedad , Femenino , Humanos , Interferones/clasificación , Ratones , Placenta/inmunología , Placenta/virología , Embarazo , Complicaciones Infecciosas del Embarazo/virología , Primates , Infección por el Virus Zika/inmunologíaRESUMEN
Autosomal dominant STAT1 mutations in humans have been associated with chronic mucocutaneous candidiasis (CMC), as well as with increased susceptibility to herpesvirus infections. Prior studies have focused on mucosal and Th17-mediated immunity against Candida, but mechanisms of impaired antiviral immunity have not previously been examined. To begin to explore the mechanisms of STAT1-associated immunodeficiency against herpesviruses, we generated heterozygous STAT1 R274W knock-in mice that have a frequently reported STAT1 mutation associated in humans with susceptibility to herpesvirus infections. In primary macrophages and fibroblasts, we found that STAT1 R274W had no appreciable effect on cell-intrinsic immunity against herpes simplex virus 1 (HSV-1) or gammaherpesvirus 68 (γHV68) infection. However, intraperitoneal inoculation of mice with γHV68 was associated with impaired control of infection at day 14 in STAT1 R274W mice compared with that in wild-type (WT) littermate control animals. Infection of STAT1 R274W mice was associated with paradoxically decreased expression of IFN-stimulated genes (ISGs) and gamma interferon (IFN-γ), likely secondary to defective CD4+ and CD8+ T cell responses, including diminished numbers of antigen-specific CD8+ T cells. Viral pathogenesis studies in WT and STAT1 R274W mixed bone marrow chimeric mice revealed that the presence of WT leukocytes was sufficient to limit infection and that antigen-specific STAT1 R274W CD8+ T cell responses were impaired even in the presence of WT leukocytes. Thus, in addition to regulating Th17 responses against Candida, a STAT1 gain-of-function mutant impedes antigen-specific T cell responses against a common gammaherpesvirus in mice.IMPORTANCE Mechanisms of immunodeficiency related to STAT1 gain of function have not been previously studied in an animal model of viral pathogenesis. Using virological and immunological techniques, we examined the immune response to γHV68 in heterozygous mice that have an autosomal dominant mutation in the STAT1 coiled-coil domain (STAT1 R274W). We observed impaired control of infection, which was associated with diminished production of gamma interferon (IFN-γ), fewer effector CD4+ and CD8+ T cells, and a reduction in the number of antigen-specific CD8+ T cells. These findings indicate that a STAT1 gain-of-function mutation limits production of antiviral T cells, likely contributing to immunodeficiency against herpesviruses.
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Linfocitos T CD8-positivos/inmunología , Mutación con Ganancia de Función , Infecciones por Herpesviridae/inmunología , Mutación Missense , Rhadinovirus/inmunología , Factor de Transcripción STAT1/metabolismo , Animales , Linfocitos T CD4-Positivos/inmunología , Células Cultivadas , Modelos Animales de Enfermedad , Fibroblastos/inmunología , Fibroblastos/virología , Técnicas de Sustitución del Gen , Interferón gamma/metabolismo , Macrófagos/inmunología , Macrófagos/virología , Ratones , Factor de Transcripción STAT1/genéticaRESUMEN
Commensal microbes profoundly impact host immunity to enteric viral infections1. We have shown that the bacterial microbiota and host antiviral cytokine interferon-λ (IFN-λ) determine the persistence of murine norovirus in the gut2,3. However, the effects of the virome in modulating enteric infections remain unexplored. Here, we report that murine astrovirus can complement primary immunodeficiency to protect against murine norovirus and rotavirus infections. Protection against infection was horizontally transferable between immunocompromised mouse strains by co-housing and fecal transplantation. Furthermore, protection against enteric pathogens corresponded with the presence of a specific strain of murine astrovirus in the gut, and this complementation of immunodeficiency required IFN-λ signalling in gut epithelial cells. Our study demonstrates that elements of the virome can protect against enteric pathogens in an immunodeficient host.
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Infecciones por Caliciviridae/prevención & control , Gastroenteritis/prevención & control , Tracto Gastrointestinal/virología , Huésped Inmunocomprometido , Interferones/metabolismo , Norovirus/inmunología , Animales , Astroviridae/clasificación , Astroviridae/genética , Astroviridae/aislamiento & purificación , Astroviridae/fisiología , Infecciones por Caliciviridae/inmunología , Infecciones por Caliciviridae/virología , Trasplante de Microbiota Fecal , Heces/virología , Femenino , Gastroenteritis/inmunología , Gastroenteritis/virología , Tracto Gastrointestinal/metabolismo , Mucosa Intestinal/metabolismo , Masculino , Ratones , Transducción de Señal , Esparcimiento de VirusRESUMEN
STING gain-of-function mutations cause lung disease and T cell cytopenia through unknown mechanisms. Here, we found that these mutants induce chronic activation of ER stress and unfolded protein response (UPR), leading to T cell death by apoptosis in the StingN153S/+ mouse and in human T cells. Mechanistically, STING-N154S disrupts calcium homeostasis in T cells, thus intrinsically primes T cells to become hyperresponsive to T cell receptor signaling-induced ER stress and the UPR, leading to cell death. This intrinsic priming effect is mediated through a novel region of STING that we name "the UPR motif," which is distinct from known domains required for type I IFN signaling. Pharmacological inhibition of ER stress prevented StingN153S/+ T cell death in vivo. By crossing StingN153S/+ to the OT-1 mouse, we fully restored CD8+ T cells and drastically ameliorated STING-associated lung disease. Together, our data uncover a critical IFN-independent function of STING that regulates calcium homeostasis, ER stress, and T cell survival.
Asunto(s)
Apoptosis/genética , Linfocitos T CD8-positivos/metabolismo , Calcio/metabolismo , Estrés del Retículo Endoplásmico/genética , Homeostasis/genética , Proteínas de la Membrana/metabolismo , Animales , Modelos Animales de Enfermedad , Estrés del Retículo Endoplásmico/efectos de los fármacos , Mutación con Ganancia de Función , Células HEK293 , Humanos , Enfermedades Pulmonares/metabolismo , Activación de Linfocitos/genética , Proteínas de la Membrana/genética , Ratones , Ratones Transgénicos , Transfección , Respuesta de Proteína Desplegada/genéticaRESUMEN
BACKGROUND: Monogenic interferonopathies are thought to be mediated by type I interferon. For example, a gain-of-function mutation in stimulator of interferon genes (STING; N153S) upregulates type I interferon-stimulated genes and causes perivascular inflammatory lung disease in mice. The equivalent mutation in human subjects also causes lung disease, which is thought to require signaling through the cyclic GMP-AMP synthase (cGAS)-STING pathway and subsequent activation of interferon regulatory factors (IRFs) 3 and 7, type I interferon, and interferon-stimulated genes. OBJECTIVE: We set out to define the roles of cGAS, IRF3, IRF7, the type I interferon receptor (IFN-α and IFN-ß receptor subunit 1 [IFNAR1]), T cells, and B cells in spontaneous lung disease in STING N153S mice. METHODS: STING N153S mice were crossed to animals lacking cGAS, IRF3/IRF7, IFNAR1, adaptive immunity, αß T cells, and mature B cells. Mice were evaluated for spontaneous lung disease. Additionally, bone marrow chimeric mice were assessed for lung disease severity and survival. RESULTS: Lung disease in STING N153S mice developed independently of cGAS, IRF3/IRF7, and IFNAR1. Bone marrow transplantation revealed that certain features of STING N153S-associated disease are intrinsic to the hematopoietic compartment. Recombination-activating gene 1 (Rag1)-/- STING N153S mice that lack adaptive immunity had no lung disease, and T-cell receptor ß chain (Tcrb)-/- STING N153S animals only had mild disease. STING N153S led to a reduction in percentages and numbers of naive and regulatory T cells, as well as an increased frequency of cytokine-producing effector T cells. CONCLUSION: Spontaneous lung disease in STING N153S mice develops independently of type I interferon signaling and cGAS. STING N153S relies primarily on T cells to promote lung disease in mice.
Asunto(s)
Enfermedades Pulmonares/inmunología , Proteínas de la Membrana/inmunología , Linfocitos T/inmunología , Animales , Linfocitos B/inmunología , Trasplante de Médula Ósea , Femenino , Mutación con Ganancia de Función , Interferón Tipo I/inmunología , Pulmón/inmunología , Masculino , Proteínas de la Membrana/genética , Ratones Transgénicos , Nucleotidiltransferasas/inmunología , Bazo/inmunologíaRESUMEN
PURPOSE: To report the successful use of tofacitinib in the treatment of refractory uveitis and scleritis. OBSERVATIONS: Two patients, one with scleritis and another with anterior and intermediate uveitis, presented with refractory disease after failure of multiple steroid-sparing therapies. Treatment with tofacitinib led to durable resolution of uveitis and scleritis. CONCLUSIONS AND IMPORTANCE: Tofacitinib is a potential novel treatment option for refractory, noninfectious inflammatory eye disease.