RESUMEN
Gain-of-function mutations in stimulator of interferon gene 1 (STING1) result in STING-associated vasculopathy with onset in infancy (SAVI), a severe autoinflammatory disease. Although elevated type I interferon (IFN) production is thought to be the leading cause of the symptoms observed in patients, STING can induce a set of pathways, which have roles in the onset and severity of SAVI and remain to be elucidated. To this end, we performed a multi-omics comparative analysis of peripheral blood mononuclear cells (PBMCs) and plasma from SAVI patients and healthy controls, combined with a dataset of healthy PBMCs treated with IFN-ß. Our data reveal a subset of disease-associated monocyte, expressing elevated CCL3, CCL4, and IL-6, as well as a strong integrated stress response, which we suggest is the result of direct PERK activation by STING. Cell-to-cell communication inference indicates that these monocytes lead to T cell early activation, resulting in their senescence and apoptosis. Last, we propose a transcriptomic signature of STING activation, independent of type I IFN response.
Asunto(s)
Interferón Tipo I , Enfermedades Vasculares , Humanos , Monocitos/metabolismo , Leucocitos Mononucleares/metabolismo , Enfermedades Vasculares/genética , Enfermedades Vasculares/metabolismo , Interferón Tipo I/metabolismo , ARNRESUMEN
Loss of NBEAL2 function leads to grey platelet syndrome (GPS), a bleeding disorder characterized by macro-thrombocytopenia and α-granule-deficient platelets. A proportion of patients with GPS develop autoimmunity through an unknown mechanism, which might be related to the proteins NBEAL2 interacts with, specifically in immune cells. Here we show a comprehensive interactome of NBEAL2 in primary T cells, based on mass spectrometry identification of altogether 74 protein association partners. These include LRBA, a member of the same BEACH domain family as NBEAL2, recessive mutations of which cause autoimmunity and lymphocytic infiltration through defective CTLA-4 trafficking. Investigating the potential association between NBEAL2 and CTLA-4 signalling suggested by the mass spectrometry results, we confirm by co-immunoprecipitation that CTLA-4 and NBEAL2 interact with each other. Interestingly, NBEAL2 deficiency leads to low CTLA-4 expression in patient-derived effector T cells, while their regulatory T cells appear unaffected. Knocking-down NBEAL2 in healthy primary T cells recapitulates the low CTLA-4 expression observed in the T cells of GPS patients. Our results thus show that NBEAL2 is involved in the regulation of CTLA-4 expression in conventional T cells and provide a rationale for considering CTLA-4-immunoglobulin therapy in patients with GPS and autoimmune disease.
Asunto(s)
Síndrome de Plaquetas Grises , Humanos , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Plaquetas/metabolismo , Proteínas Sanguíneas/genética , Antígeno CTLA-4/genética , Antígeno CTLA-4/metabolismo , Síndrome de Plaquetas Grises/genética , Síndrome de Plaquetas Grises/metabolismoRESUMEN
BACKGROUND: Allogenic hematopoietic stem cell transplantation (HSCT) and gene therapy (GT) are potentially curative treatments for severe combined immunodeficiency (SCID). Late-onset posttreatment manifestations (such as persistent hepatitis) are not uncommon. OBJECTIVE: We sought to characterize the prevalence and pathophysiology of persistent hepatitis in transplanted SCID patients (SCIDH+) and to evaluate risk factors and treatments. METHODS: We used various techniques (including pathology assessments, metagenomics, single-cell transcriptomics, and cytometry by time of flight) to perform an in-depth study of different tissues from patients in the SCIDH+ group and corresponding asymptomatic similarly transplanted SCID patients without hepatitis (SCIDH-). RESULTS: Eleven patients developed persistent hepatitis (median of 6 years after HSCT or GT). This condition was associated with the chronic detection of enteric viruses (human Aichi virus, norovirus, and sapovirus) in liver and/or stools, which were not found in stools from the SCIDH- group (n = 12). Multiomics analysis identified an expansion of effector memory CD8+ T cells with high type I and II interferon signatures. Hepatitis was associated with absence of myeloablation during conditioning, split chimerism, and defective B-cell function, representing 25% of the 44 patients with SCID having these characteristics. Partially myeloablative retransplantation or GT of patients with this condition (which we have named as "enteric virus infection associated with hepatitis") led to the reconstitution of T- and B-cell immunity and remission of hepatitis in 5 patients, concomitantly with viral clearance. CONCLUSIONS: Enteric virus infection associated with hepatitis is related to chronic enteric viral infection and immune dysregulation and is an important risk for transplanted SCID patients with defective B-cell function.
Asunto(s)
Infecciones por Enterovirus , Trasplante de Células Madre Hematopoyéticas , Hepatitis , Inmunodeficiencia Combinada Grave , Virosis , Humanos , Inmunodeficiencia Combinada Grave/terapia , Inmunodeficiencia Combinada Grave/etiología , Linfocitos T CD8-positivos , Trasplante de Células Madre Hematopoyéticas/efectos adversos , Trasplante de Células Madre Hematopoyéticas/métodos , Virosis/etiología , Hepatitis/etiologíaRESUMEN
BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in children is generally milder than in adults, but a proportion of cases result in hyperinflammatory conditions often including myocarditis. METHODS: To better understand these cases, we applied a multiparametric approach to the study of blood cells of 56 children hospitalized with suspicion of SARS-CoV-2 infection. Plasma cytokine and chemokine levels and blood cellular composition were measured, alongside gene expression at the bulk and single-cell levels. FINDINGS: The most severe forms of multisystem inflammatory syndrome in children (MIS-C) related to SARS-CoV-2 that resulted in myocarditis were characterized by elevated levels of pro-angiogenesis cytokines and several chemokines. Single-cell transcriptomics analyses identified a unique monocyte/dendritic cell gene signature that correlated with the occurrence of severe myocarditis characterized by sustained nuclear factor κB (NF-κB) activity and tumor necrosis factor alpha (TNF-α) signaling and associated with decreased gene expression of NF-κB inhibitors. We also found a weak response to type I and type II interferons, hyperinflammation, and response to oxidative stress related to increased HIF-1α and Vascular endothelial growth factor (VEGF) signaling. CONCLUSIONS: These results provide potential for a better understanding of disease pathophysiology. FUNDING: Agence National de la Recherche (Institut Hospitalo-Universitaire Imagine, grant ANR-10-IAHU-01; Recherche Hospitalo-Universitaire, grant ANR-18-RHUS-0010; Laboratoire d'Excellence ''Milieu Intérieur," grant ANR-10-LABX-69-01; ANR-flash Covid19 "AIROCovid" and "CoVarImm"), Institut National de la Santé et de la Recherche Médicale (INSERM), and the "URGENCE COVID-19" fundraising campaign of Institut Pasteur.
Asunto(s)
COVID-19 , Miocarditis , Adulto , COVID-19/complicaciones , Quimiocinas , Niño , Citocinas , Células Dendríticas , Humanos , Monocitos , FN-kappa B , SARS-CoV-2/genética , Síndrome de Respuesta Inflamatoria Sistémica , Factor A de Crecimiento Endotelial VascularRESUMEN
OBJECTIVE: This study aims to assess the effect of a preoperative parasternal plane block (PSB) on opioid consumption required to maintain hemodynamic stability during sternotomy for coronary artery bypass graft surgery. METHODS: This double-blind, randomized, placebo-controlled trial prospectively enrolled 35 patients scheduled for coronary artery bypass graft surgery under general anesthesia with propofol and remifentanil. Patients were randomized to receive preoperative PSB using either ropivacaine (PSB group) or saline solution (placebo group) (1:1 ratio). The primary endpoint was the maximal effect-site concentration of remifentanil required to maintain heart rate and blood pressure within the recommended ranges during sternotomy. RESULTS: Median maximum concentration of remifentanil necessary to maintain adequate hemodynamic status during sternotomy was significantly reduced in PSB group (4.2 (2.5-6.0) ng/mL) compared with placebo group (7.0 (5.2-8.0) ng/mL) (p=0.02). Mean maximum concentration of propofol used to control depth of anesthesia was also reduced (3.9±1.1 µg/mL vs 5.0±1.5 µg/mL, PSB vs placebo, respectively; p=0.02). This reduction in propofol consumption during sternotomy enabled a more adequate level of sedation to be maintained in patients (minimum patient state index was 11.7±8.7 in placebo group and 18.3±6.8 in PSB group; p=0.02). PSB reduced postoperative inflammatory response by limiting concentrations of proinflammatory cytokines IL-8, IL-18, IL-23, IL-33 and MCP-1 measured in the first 7-day after surgery (p<0.05). CONCLUSIONS: Preoperative PSB reduced the maximum concentrations of remifentanil and propofol required to maintain hemodynamic stability and depth of anesthesia during sternotomy. TRIAL REGISTRATION NUMBER: NCT03734159.Sébastien Bloc, M.D.1,2; Brieuc P. Pérot, Ph.D.3; Hadrien Gibert, M.D.1; Jean-Dominique Law Koune, M.D.1; Yannick Burg, M.D.1; Didier Leclerc, M.D.1; Anne-Sophie Vuitton, M.D.1; Christophe De La Jonquière, M.D.1; Marine Luka, L.S.3; Thierry Waldmann, M.D.4; Nicolas Vistarini, M.D.4; Stéphane Aubert, M.D.4; Mickaël M. Ménager, Ph.D.3; Messaouda Merzoug, Ph.D.2; Cécile Naudin, Ph.D.2; Pierre Squara, M.D.2,5.
Asunto(s)
Analgésicos Opioides , Propofol , Analgésicos Opioides/efectos adversos , Anestésicos Intravenosos , Puente de Arteria Coronaria/efectos adversos , Método Doble Ciego , Humanos , Esternotomía/efectos adversosRESUMEN
Tetraspanin (TSPAN) protein family forms a family of transmembrane proteins that act as organizers/scaffold for other proteins. TSPANs are primarily present on plasma membranes although they are also found in other biological membranes. They are organized in tetraspanin-enriched microdomains (TEMs), which allow spatiotemporal tuning of protein functions through the control of their membrane localization. TSPAN6 and TSPAN7 are close paralogs expressed in different tissues, TSPAN7 being highly expressed in the brain. Their functions only started to be unveiled in the late 2000's and are still poorly understood. Here, we introduce how TSPAN7 was first highlighted has a protein mutated in some forms of X-linked mental retardation, which was later proposed to be caused by defects in neuronal morphogenesis and synaptic transmission. We then discuss the impacts TSPAN7 has on cell morphology of dendritic cells and osteoclasts, through rearrangement of actin cytoskeleton and how TSPAN7 was shown to be a target of autoantibody in patients suffering from type 1 diabetes. Finally, we are addressing the double edge sword that is TSPAN7 in cancer. In the second part of this review, we address the known roles of TSPAN6 and how this protein was shown to participate in synaptic transmission and in amyloid precursor protein secretion, which may contribute to Alzheimer's disease pathology. We conclude this review by discussing the anti-inflammatory effect of TSPAN6.
Asunto(s)
Encéfalo/fisiopatología , Diabetes Mellitus Tipo 1/fisiopatología , Neoplasias/fisiopatología , Proteínas del Tejido Nervioso/fisiología , Tetraspaninas/fisiología , Virosis/inmunología , Enfermedad de Alzheimer/fisiopatología , Humanos , Inmunidad Innata , Inflamación/fisiopatología , Proteínas de la Membrana/fisiología , Transmisión SinápticaRESUMEN
Dendritic cells (DCs) serve a key function in host defense, linking innate detection of microbes to activation of pathogen-specific adaptive immune responses. DCs express cell surface receptors for HIV-1 entry, but are relatively resistant to productive viral replication. They do, however, facilitate infection of co-cultured T-helper cells through a process referred to as trans-infection. We previously showed that tetraspanin 7 (TSPAN7), a transmembrane protein, is involved, through positive regulation of actin nucleation, in the transfer of HIV-1 from the dendrites of immature monocyte-derived DCs (iMDDCs) to activated CD4+ T lymphocytes. Various molecular mechanisms have been described regarding HIV-1 trans-infection and seem to depend on DC maturation status. We sought to investigate the crosstalk between DC maturation status, TSPAN7 expression and trans-infection. We followed trans-infection through co-culture of iMDDCs with CD4+ T lymphocytes, in the presence of CXCR4-tropic replicative-competent HIV-1 expressing GFP. T cell infection, DC maturation status and dendrite morphogenesis were assessed through time both by flow cytometry and confocal microscopy. Our previously described TSPAN7/actin nucleation-dependent mechanism of HIV-1 transfer appeared to be mostly observed during the first 20 h of co-culture experiments and to be independent of HIV replication. In the course of co-culture experiments, we observed a progressive maturation of MDDCs, correlated with a decrease in TSPAN7 expression, a drastic loss of dendrites and a change in the shape of DCs. A TSPAN7 and actin nucleation-independent mechanism of trans-infection, relying on HIV-1 replication, was then at play. We discovered that TSPAN7 expression is downregulated in response to different innate immune stimuli driving DC maturation, explaining the requirement for a TSPAN7/actin nucleation-independent mechanism of HIV transfer from mature MDDCs (mMDDCs) to T lymphocytes. As previously described, this mechanism relies on the capture of HIV-1 by the I-type lectin CD169/Siglec-1 on mMDDCs and the formation of a "big invaginated pocket" at the surface of DCs, both events being tightly regulated by DC maturation. Interestingly, in iMDDCs, although CD169/Siglec-1 can capture HIV-1, this capture does not lead to HIV-1 transfer to T lymphocytes.
Asunto(s)
Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD4-Positivos/virología , Células Dendríticas/fisiología , Infecciones por VIH/inmunología , Proteínas del Tejido Nervioso/inmunología , Tetraspaninas/inmunología , Diferenciación Celular/inmunología , Células Cultivadas , Dendritas/fisiología , Células HEK293 , VIH-1 , Humanos , Monocitos/inmunología , Monocitos/virología , Proteínas del Tejido Nervioso/genética , Lectina 1 Similar a Ig de Unión al Ácido Siálico/inmunología , Tetraspaninas/genética , Factores de Tiempo , Transducción GenéticaRESUMEN
Transcriptional programming of the innate immune response is pivotal for host protection. However, the transcriptional mechanisms that link pathogen sensing with innate activation remain poorly understood. During HIV-1 infection, human dendritic cells (DCs) can detect the virus through an innate sensing pathway, leading to antiviral interferon and DC maturation. Here, we develop an iterative experimental and computational approach to map the HIV-1 innate response circuitry in monocyte-derived DCs (MDDCs). By integrating genome-wide chromatin accessibility with expression kinetics, we infer a gene regulatory network that links 542 transcription factors with 21,862 target genes. We observe that an interferon response is required, yet insufficient, to drive MDDC maturation and identify PRDM1 and RARA as essential regulators of the interferon response and MDDC maturation, respectively. Our work provides a resource for interrogation of regulators of HIV replication and innate immunity, highlighting complexity and cooperativity in the regulatory circuit controlling the response to infection.
Asunto(s)
Células Dendríticas/metabolismo , Redes Reguladoras de Genes , VIH-1/inmunología , Inmunidad Innata/genética , Monocitos/metabolismo , Diferenciación Celular , Cromatina/metabolismo , Células Dendríticas/virología , Femenino , Regulación de la Expresión Génica , Células HEK293 , Infecciones por VIH/inmunología , Infecciones por VIH/virología , Humanos , Interferón Tipo I/metabolismo , Masculino , Monocitos/virología , Regiones Promotoras Genéticas/genética , Receptor alfa de Ácido Retinoico/metabolismo , Factores de Transcripción/metabolismo , Transcriptoma/genéticaRESUMEN
Influenza A virus (IAV) infection perturbs metabolic pathways such as autophagy, a stress-induced catabolic pathway that crosstalks with cellular inflammatory responses. However, the impact of autophagy perturbation on IAV gene expression or host cell responses remains disputed. Discrepant results may be a reflection of in vivo studies using cell-specific autophagy-related (Atg) gene-deficient mouse strains, which do not delineate modification of developmental programmes from more proximal effects on inflammatory response. In vitro experiments can be confounded by gene expression divergence in wild-type cultivated cell lines, as compared to those experiencing long-term absence of autophagy. With the goal to investigate cellular processes within cells that are competent or incompetent for autophagy, we generated a novel experimental cell line in which autophagy can be restored by ATG5 protein stabilization in an otherwise Atg5-deficient background. We confirmed that IAV induced autophagosome formation and p62 accumulation in infected cells and demonstrated that perturbation of autophagy did not impact viral infection or replication in ATG5-stablized cells. Notably, the induction of interferon-stimulated genes (ISGs) by IAV was diminished when cells were autophagy competent. We further demonstrated that, in the absence of ATG5, IAV-induced interferon-ß (IFN-ß) expression was increased as compared to levels in autophagy-competent lines, a mechanism that was independent of IAV non-structural protein 1. In sum, we report that induction of autophagy by IAV infection reduces ISG expression in infected cells by limiting IFN-ß expression, which may benefit viral replication and spread.
Asunto(s)
Autofagosomas/inmunología , Proteína 5 Relacionada con la Autofagia/inmunología , Regulación de la Expresión Génica/inmunología , Virus de la Influenza A/inmunología , Interferón beta/inmunología , Infecciones por Orthomyxoviridae/inmunología , Animales , Proteína 5 Relacionada con la Autofagia/genética , Línea Celular , Virus de la Influenza A/genética , Interferón beta/genética , Ratones , Ratones Noqueados , Infecciones por Orthomyxoviridae/genética , Infecciones por Orthomyxoviridae/patologíaAsunto(s)
Autofagia/fisiología , Virus de la Influenza A/fisiología , Gripe Humana , Interferón beta/metabolismo , Animales , Autofagia/genética , Proteína 5 Relacionada con la Autofagia/genética , Células Cultivadas , Humanos , Gripe Humana/genética , Gripe Humana/metabolismo , Gripe Humana/patología , Ratones , Infecciones por Orthomyxoviridae/genética , Infecciones por Orthomyxoviridae/metabolismo , Infecciones por Orthomyxoviridae/patología , Factores de Tiempo , Regulación hacia Arriba/genéticaRESUMEN
Chronic infection perturbs immune homeostasis. While prior studies have reported dysregulation of effector and memory cells, little is known about the effects on naïve T cell populations. We performed a cross-sectional study of chronic hepatitis C (cHCV) patients using tetramer-associated magnetic enrichment to study antigen-specific inexperienced CD8(+) T cells (i.e., tumor or unrelated virus-specific populations in tumor-free and sero-negative individuals). cHCV showed normal precursor frequencies, but increased proportions of memory-phenotype inexperienced cells, as compared to healthy donors or cured HCV patients. These observations could be explained by low surface expression of CD5, a negative regulator of TCR signaling. Accordingly, we demonstrated TCR hyperactivation and generation of potent CD8(+) T cell responses from the altered T cell repertoire of cHCV patients. In sum, we provide the first evidence that naïve CD8(+) T cells are dysregulated during cHCV infection, and establish a new mechanism of immune perturbation secondary to chronic infection.
Asunto(s)
Linfocitos T CD8-positivos/inmunología , Hepacivirus/inmunología , Hepatitis C Crónica/patología , Activación de Linfocitos , Antígenos CD5/metabolismo , Estudios Transversales , Humanos , Receptores de Antígenos de Linfocitos T/metabolismo , Transducción de SeñalRESUMEN
Macroautophagy is a catabolic recycling pathway, which can be induced by various stress stimuli. Viruses are able to manipulate autophagy in the cells that they infect. The impact of autophagy on the innate immune response to viruses and its stimulatory role in antigen presentation to CD4(+) T cells are well documented. Herein, we present the impact of autophagy on the activation of cytotoxic T lymphocyte (CTL)-mediated antiviral immune responses, which are required for the eradication or control of multiple viruses. We first discuss the general mechanisms by which viruses can either induce or block autophagy in cells. We then explore the cross-talk between autophagy and innate immune processes, which are both first line defenses against viruses; and constitute crucial steps for the initiation of potent adaptive immune responses. We describe the impact of autophagy on the presentation of viral peptide antigens on class I major histocompatibility complex (MHC I), a prerequisite for the priming of CTL responses. In sum, our review highlights the interplay between viruses and three integrated host response pathways - autophagy, innate and adaptive immunity - providing a framework for future mechanistic and pathogenesis-based research.