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1.
J Exp Med ; 221(9)2024 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-39028869

RESUMO

An exome sequencing strategy employed to identify pathogenic variants in patients with pediatric-onset systemic lupus or Evans syndrome resulted in the discovery of six novel monoallelic mutations in PTPN2. PTPN2 is a phosphatase that acts as an essential negative regulator of the JAK/STAT pathways. All mutations led to a loss of PTPN2 regulatory function as evidenced by in vitro assays and by hyperproliferation of patients' T cells. Furthermore, patients exhibited high serum levels of inflammatory cytokines, mimicking the profile observed in individuals with gain-of-function mutations in STAT factors. Flow cytometry analysis of patients' blood cells revealed typical alterations associated with autoimmunity and all patients presented with autoantibodies. These findings further supported the notion that a loss of function in negative regulators of cytokine pathways can lead to a broad spectrum of autoimmune manifestations and that PTPN2 along with SOCS1 haploinsufficiency constitute a new group of monogenic autoimmune diseases that can benefit from targeted therapy.


Assuntos
Anemia Hemolítica Autoimune , Autoimunidade , Haploinsuficiência , Lúpus Eritematoso Sistêmico , Proteína Tirosina Fosfatase não Receptora Tipo 2 , Humanos , Haploinsuficiência/genética , Proteína Tirosina Fosfatase não Receptora Tipo 2/genética , Anemia Hemolítica Autoimune/genética , Anemia Hemolítica Autoimune/imunologia , Lúpus Eritematoso Sistêmico/genética , Lúpus Eritematoso Sistêmico/imunologia , Feminino , Masculino , Criança , Autoimunidade/genética , Adolescente , Mutação , Trombocitose/genética , Trombocitose/imunologia , Proteína 1 Supressora da Sinalização de Citocina/genética , Autoanticorpos/imunologia , Citocinas/metabolismo , Pré-Escolar , Linfócitos T/imunologia , Trombocitopenia
3.
medRxiv ; 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38883731

RESUMO

Systemic Lupus Erythematosus (SLE) is an autoimmune disease, the pathophysiology and genetic basis of which are incompletely understood. Using a forward genetic screen in multiplex families with systemic lupus erythematosus (SLE) we identified an association between SLE and compound heterozygous deleterious variants in the non-receptor tyrosine kinases (NRTKs) ACK1 and BRK. Experimental blockade of ACK1 or BRK increased circulating autoantibodies in vivo in mice and exacerbated glomerular IgG deposits in an SLE mouse model. Mechanistically, non-receptor tyrosine kinases (NRTKs) regulate activation, migration, and proliferation of immune cells. We found that the patients' ACK1 and BRK variants impair efferocytosis, the MERTK-mediated anti-inflammatory response to apoptotic cells, in human induced Pluripotent Stem Cell (hiPSC)-derived macrophages, which may contribute to SLE pathogenesis. Overall, our data suggest that ACK1 and BRK deficiencies are associated with human SLE and impair efferocytosis in macrophages.

4.
medRxiv ; 2024 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-38798321

RESUMO

IKKα, encoded by CHUK , is crucial in the non-canonical NF-κB pathway and part of the IKK complex activating the canonical pathway alongside IKKß. Absence of IKKα cause fetal encasement syndrome in human, fatal in utero, while an impaired IKKα-NIK interaction was reported in a single patient and cause combined immunodeficiency. Here, we describe compound heterozygous variants in the kinase domain of IKKα in a female patient with hypogammaglobulinemia, recurrent lung infections, and Hay-Wells syndrome-like features. We showed that both variants were loss-of-function. Non-canonical NF-κB activation was profoundly diminished in stromal and immune cells while the canonical pathway was partially impaired. Reintroducing wild-type CHUK restored non-canonical NF-κB activation. The patient had neutralizing autoantibodies against type I IFN, akin to non-canonical NF-κB pathway deficiencies. Thus, this is the first case of bi-allelic CHUK mutations disrupting IKKα kinase function, broadening non-canonical NF-κB defect understanding and suggesting IKKα's role in canonical NF-κB target gene expression in human.

5.
Cell Death Dis ; 15(5): 315, 2024 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-38704374

RESUMO

Autoimmune lymphoproliferative syndrome (ALPS) is a primary disorder of lymphocyte homeostasis, leading to chronic lymphoproliferation, autoimmune cytopenia, and increased risk of lymphoma. The genetic landscape of ALPS includes mutations in FAS, FASLG, and FADD, all associated with apoptosis deficiency, while the role of CASP10 defect in the disease remains debated. In this study, we aimed to assess the impact of CASP10 variants on ALPS pathogenesis. We benefit from thousands of genetic analysis datasets performed in our Institute's genetic platform to identify individuals carrying CASP10 variants previously suspected to be involved in ALPS outcome: p.C401LfsX15, p.V410I and p.Y446C, both at heterozygous and homozygous state. Clinical and laboratory features of the six included subjects were variable but not consistent with ALPS. Two individuals were healthy. Comprehensive analyses of CASP10 protein expression and FAS-mediated apoptosis were conducted and compared to healthy controls and ALPS patients with FAS mutations. Missense CASP10 variants (p.V410I and p.Y446C), which are common in the general population, did not disrupt CASP10 expression, nor FAS-mediated apoptosis. In contrast, homozygous p.C401LfsX15 CASP10 variant lead to a complete abolished CASP10 expression but had no impact on FAS-mediated apoptosis function. At heterozygous state, this p.C401LfsX15 variant lead to a reduced CASP10 protein levels but remained associated with a normal FAS-mediated apoptosis function. These findings demonstrate that CASPASE 10 is dispensable for FAS-mediated apoptosis. In consequences, CASP10 defect unlikely contribute to ALPS pathogenesis, since they did not result in an impairment of FAS-mediated apoptosis nor in clinical features of ALPS in human. Moreover, the absence of FAS expression up-regulation in subjects with CASP10 variants rule out any compensatory mechanisms possibly involved in the normal apoptosis function observed. In conclusion, this study challenges the notion that CASP10 variants contribute to the development of ALPS.


Assuntos
Apoptose , Síndrome Linfoproliferativa Autoimune , Caspase 10 , Mutação , Receptor fas , Humanos , Caspase 10/genética , Caspase 10/metabolismo , Síndrome Linfoproliferativa Autoimune/genética , Masculino , Feminino , Mutação/genética , Apoptose/genética , Receptor fas/genética , Receptor fas/metabolismo , Adulto , Criança , Adolescente , Pessoa de Meia-Idade
6.
J Clin Immunol ; 44(4): 99, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38619739

RESUMO

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease that is characterized by its large heterogeneity in terms of clinical presentation and severity. The pathophysiology of SLE involves an aberrant autoimmune response against various tissues, an excess of apoptotic bodies, and an overproduction of type-I interferon. The genetic contribution to the disease is supported by studies of monozygotic twins, familial clustering, and genome-wide association studies (GWAS) that have identified numerous risk loci. In the early 70s, complement deficiencies led to the description of familial forms of SLE caused by a single gene defect. High-throughput sequencing has recently identified an increasing number of monogenic defects associated with lupus, shaping the concept of monogenic lupus and enhancing our insights into immune tolerance mechanisms. Monogenic lupus (moSLE) should be suspected in patients with either early-onset lupus or syndromic lupus, in male, or in familial cases of lupus. This review discusses the genetic basis of monogenic SLE and proposes its classification based on disrupted pathways. These pathways include defects in the clearance of apoptotic cells or immune complexes, interferonopathies, JAK-STATopathies, TLRopathies, and T and B cell dysregulations.


Assuntos
Autoimunidade , Lúpus Eritematoso Sistêmico , Humanos , Masculino , Complexo Antígeno-Anticorpo , Autoimunidade/genética , Estudo de Associação Genômica Ampla , Lúpus Eritematoso Sistêmico/genética , Fenótipo , Feminino , Estudos em Gêmeos como Assunto
7.
J Exp Med ; 221(5)2024 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-38530241

RESUMO

NLRP3-associated autoinflammatory disease is a heterogenous group of monogenic conditions caused by NLRP3 gain-of-function mutations. The poor functional characterization of most NLRP3 variants hinders diagnosis despite efficient anti-IL-1 treatments. Additionally, while NLRP3 is controlled by priming and activation signals, gain-of-functions have only been investigated in response to priming. Here, we characterize 34 NLRP3 variants in vitro, evaluating their activity upon induction, priming, and/or activation signals, and their sensitivity to four inhibitors. We highlight the functional diversity of the gain-of-function mutants and describe four groups based on the signals governing their activation, correlating partly with the symptom severity. We identify a new group of NLRP3 mutants responding to the activation signal without priming, associated with frequent misdiagnoses. Our results identify key NLRP3 residues controlling inflammasome activity and sensitivity to inhibitors, and antagonistic mechanisms with broader efficacy for therapeutic strategies. They provide new insights into NLRP3 activation, an explanatory mechanism for NLRP3-AID heterogeneity, and original tools for NLRP3-AID diagnosis and drug development.


Assuntos
Mutação com Ganho de Função , Proteína 3 que Contém Domínio de Pirina da Família NLR , Humanos , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Mutação com Ganho de Função/genética , Inflamassomos/genética , Desenvolvimento de Medicamentos , Síndrome
9.
J Allergy Clin Immunol ; 154(1): 229-236.e2, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38438084

RESUMO

BACKGROUND: Immune dysregulation often presents as autoimmunity, inflammation, and/or lymphoproliferation. Several germline genetic defects have been associated with immune dysregulation; they include heterozygous gain-of-function (GOF) mutations in IKZF1, an essential transcription factor for hematopoiesis containing zinc finger domains (ZFs). However, in a large percentage of patients, the genetic origin of their immunedysregulation remains undetermined. OBJECTIVE: A family with 2 members presenting immune dysregulation signs was studied to identify the genetic cause of their disease. METHODS: Whole exome sequencing, analysis of immunologic parameters, and functional assays (including Western blotting, electrophoretic mobility shift assay during the cell cycle, and TH cell differentiation) were performed. RESULTS: The 2 patients carried a novel heterozygous mutation in IKZF1 (IKZF1T398M). IKZF1 heterozygous mutations have previously been shown to be responsible for several distinct human immunologic diseases by directly affecting the ability of ZFs to bind to DNA or to dimerize. Herein, we showed that the IKZF1T398M, which is outside the ZFs, caused impaired phosphorylation of IKZF1, resulting in enhanced DNA-binding ability at the S phase of the cell cycle, reduction of the G1-S phase transition, and decreased proliferation. Confirming these data, similar functional alterations were observed with IKZF1T398A, but not with IKZF1T398D, mimicking dephosphorylation and phosphorylation, respectively. In T lymphocytes, expression of IKZF1T398M led to TH cell differentiation skewed toward TH2 cells. Thus, our data indicate that IKZF1T398M behaves as a GOF variant underlying immune dysregulation. CONCLUSION: Disturbed IKZF1 phosphorylation represents a novel GOF mechanism (GOF by loss of phosphorylation (termed as GOF-LOP) associated with immune dysregulation, highlighting the regulatory role of IKZF1 during cell cycle progression through phosphorylation.


Assuntos
Mutação com Ganho de Função , Fator de Transcrição Ikaros , Humanos , Fator de Transcrição Ikaros/genética , Fosforilação , Feminino , Masculino , Linhagem , Adulto
10.
Br J Haematol ; 204(5): 1899-1907, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38432067

RESUMO

Kabuki syndrome (KS) is now listed in the Human Inborn Errors of Immunity (IEI) Classification. It is a rare disease caused by KMT2D and KDM6A variants, dominated by intellectual disability and characteristic facial features. Recurrently, pathogenic variants are identified in those genes in patients examined for autoimmune cytopenia (AIC), but interpretation remains challenging. This study aims to describe the genetic diagnosis and the clinical management of patients with paediatric-onset AIC and KS. Among 11 patients with AIC and KS, all had chronic immune thrombocytopenic purpura, and seven had Evans syndrome. All had other associated immunopathological manifestations, mainly symptomatic hypogammaglobinaemia. They had a median of 8 (5-10) KS-associated manifestations. Pathogenic variants were detected in KMT2D gene without clustering, during the immunological work-up of AIC in three cases, and the clinical strategy to validate them is emphasized. Eight patients received second-line treatments, mainly rituximab and mycophenolate mofetil. With a median follow-up of 17 (2-31) years, 8/10 alive patients still needed treatment for AIC. First-line paediatricians should be able to recognize and confirm KS in children with ITP or multiple AIC, to provide early appropriate clinical management and specific long-term follow-up. The epigenetic immune dysregulation in KS opens exciting new perspectives.


Assuntos
Anormalidades Múltiplas , Proteínas de Ligação a DNA , Face , Doenças Hematológicas , Histona Desmetilases , Proteínas de Neoplasias , Doenças Vestibulares , Humanos , Doenças Vestibulares/genética , Doenças Vestibulares/diagnóstico , Criança , Face/anormalidades , Feminino , Masculino , Pré-Escolar , Anormalidades Múltiplas/genética , Adolescente , Histona Desmetilases/genética , Proteínas de Neoplasias/genética , Doenças Hematológicas/genética , Proteínas de Ligação a DNA/genética , Púrpura Trombocitopênica Idiopática/genética , Púrpura Trombocitopênica Idiopática/terapia , Púrpura Trombocitopênica Idiopática/diagnóstico , Lactente , Trombocitopenia/genética , Trombocitopenia/diagnóstico , Trombocitopenia/etiologia , Trombocitopenia/terapia , Anemia Hemolítica Autoimune/genética , Anemia Hemolítica Autoimune/diagnóstico , Anemia Hemolítica Autoimune/terapia , Doenças Autoimunes/genética , Doenças Autoimunes/diagnóstico , Rituximab/uso terapêutico , Mutação , Citopenia
11.
Clin Immunol ; 261: 110165, 2024 04.
Artigo em Inglês | MEDLINE | ID: mdl-38423196

RESUMO

Mutations in NFkB pathway genes can cause inborn errors of immunity (IEI), with NFKB1 haploinsufficiency being a significant etiology for common variable immunodeficiency (CVID). Indeed, mutations in NFKB1 are found in 4 to 5% of in European and United States CVID cohorts, respectively; CVID representing almost » of IEI patients in European countries registries. This case study presents a 49-year-old patient with respiratory infections, chronic diarrhea, immune thrombocytopenia, hypogammaglobulinemia, and secondary lymphoma. Comprehensive genetic analysis, including high-throughput sequencing of 300 IEI-related genes and copy number variation analysis, identified a critical 2.6-kb deletion spanning the first untranslated exon and its upstream region. The region's importance was confirmed through genetic markers indicative of enhancers and promoters. The deletion was also found in the patient's brother, who displayed similar but milder symptoms. Functional analysis supported haploinsufficiency with reduced mRNA and protein expression in both patients. This case underscores the significance of copy number variation (CNV) analysis and targeting noncoding exons within custom gene panels, emphasizing the broader genomic approaches needed in medical genetics.


Assuntos
Imunodeficiência de Variável Comum , Irmãos , Masculino , Adulto , Humanos , Pessoa de Meia-Idade , Haploinsuficiência/genética , Variações do Número de Cópias de DNA , NF-kappa B/genética , Imunodeficiência de Variável Comum/genética , Sequências Reguladoras de Ácido Nucleico , Subunidade p50 de NF-kappa B/genética
12.
Sci Immunol ; 9(91): eadj5948, 2024 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-38215192

RESUMO

Defective FAS (CD95/Apo-1/TNFRSF6) signaling causes autoimmune lymphoproliferative syndrome (ALPS). Hypergammaglobulinemia is a common feature in ALPS with FAS mutations (ALPS-FAS), but paradoxically, fewer conventional memory cells differentiate from FAS-expressing germinal center (GC) B cells. Resistance to FAS-induced apoptosis does not explain this phenotype. We tested the hypothesis that defective non-apoptotic FAS signaling may contribute to impaired B cell differentiation in ALPS. We analyzed secondary lymphoid organs of patients with ALPS-FAS and found low numbers of memory B cells, fewer GC B cells, and an expanded extrafollicular (EF) B cell response. Enhanced mTOR activity has been shown to favor EF versus GC fate decision, and we found enhanced PI3K/mTOR and BCR signaling in ALPS-FAS splenic B cells. Modeling initial T-dependent B cell activation with CD40L in vitro, we showed that FAS competent cells with transient FAS ligation showed specifically decreased mTOR axis activation without apoptosis. Mechanistically, transient FAS engagement with involvement of caspase-8 induced nuclear exclusion of PTEN, leading to mTOR inhibition. In addition, FASL-dependent PTEN nuclear exclusion and mTOR modulation were defective in patients with ALPS-FAS. In the early phase of activation, FAS stimulation promoted expression of genes related to GC initiation at the expense of processes related to the EF response. Hence, our data suggest that non-apoptotic FAS signaling acts as molecular switch between EF versus GC fate decisions via regulation of the mTOR axis and transcription. The defect of this modulatory circuit may explain the observed hypergammaglobulinemia and low memory B cell numbers in ALPS.


Assuntos
Hipergamaglobulinemia , Transtornos Linfoproliferativos , Humanos , Apoptose/genética , Centro Germinativo , Transtornos Linfoproliferativos/genética , Serina-Treonina Quinases TOR
13.
J Invest Dermatol ; 144(6): 1282-1294.e8, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38128752

RESUMO

A20 haploinsufficiency is an autoinflammatory disease caused by defective inactivation of the NF-κB pathway. We conducted a systematic literature review of articles reporting patients with TNFAIP3 sequence variants from 2016 to August 2023 following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Data from 177 patients from 65 articles were retrieved (108 women). The principal features were mucosal ulcers (n = 129); fever (n = 93) followed by gastrointestinal (n = 81); skin features (n = 76); autoimmunity (n = 61), including thyroiditis (n = 25) and lupus (n = 16); and joint involvements (n = 54). Five patients had died at the time of publication. In 54 of 63 patients, CRP was significantly elevated during flares, with a median of 51 mg/l. The most commonly used treatment included corticosteroids and nonsteroidal anti-inflammatory drugs (n = 32), TNF blockers (n = 29), colchicine (n = 28), and methotrexate (n = 14). TNFAIP3 variants impacted the ovarian tumor domain in 92 cases and a Zinc finger domain in 68 cases. Geographic origin, reported sex, and variant type significantly impacted phenotype. A better understanding of the wide A20 haploinsufficiency phenotype could facilitate the diagnosis process. Much remains to be elucidated about pathogenesis and treatment to improve outcome in patients with A20 haploinsufficiency.


Assuntos
Haploinsuficiência , Proteína 3 Induzida por Fator de Necrose Tumoral alfa , Proteína 3 Induzida por Fator de Necrose Tumoral alfa/genética , Humanos , Haploinsuficiência/genética , Feminino , Masculino , Doenças Hereditárias Autoinflamatórias/genética , Doenças Hereditárias Autoinflamatórias/diagnóstico , Doenças Hereditárias Autoinflamatórias/tratamento farmacológico
14.
J Clin Immunol ; 44(1): 2, 2023 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-38099988

RESUMO

The DNA polymerase δ complex (PolD), comprising catalytic subunit POLD1 and accessory subunits POLD2, POLD3, and POLD4, is essential for DNA synthesis and is central to genome integrity. We identified, by whole exome sequencing, a homozygous missense mutation (c.1118A > C; p.K373T) in POLD3 in a patient with Omenn syndrome. The patient exhibited severely decreased numbers of naïve T cells associated with a restricted T-cell receptor repertoire and a defect in the early stages of TCR recombination. The patient received hematopoietic stem cell transplantation at age 6 months. He manifested progressive neurological regression and ultimately died at age 4 years. We performed molecular and functional analysis of the mutant POLD3 and assessed cell cycle progression as well as replication-associated DNA damage. Patient fibroblasts showed a marked defect in S-phase entry and an enhanced number of double-stranded DNA break-associated foci despite normal expression levels of PolD components. The cell cycle defect was rescued by transduction with WT POLD3. This study validates autosomal recessive POLD3 deficiency as a novel cause of profound T-cell deficiency and Omenn syndrome.


Assuntos
DNA Polimerase III , Imunodeficiência Combinada Severa , Masculino , Humanos , Lactente , Pré-Escolar , Imunodeficiência Combinada Severa/diagnóstico , Imunodeficiência Combinada Severa/genética , Imunodeficiência Combinada Severa/terapia , Ciclo Celular , Dano ao DNA , Fibroblastos
15.
Cell Rep Med ; 4(12): 101333, 2023 12 19.
Artigo em Inglês | MEDLINE | ID: mdl-38118407

RESUMO

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.


Assuntos
Interferon Tipo I , Doenças Vasculares , Humanos , Monócitos/metabolismo , Leucócitos Mononucleares/metabolismo , Doenças Vasculares/genética , Doenças Vasculares/metabolismo , Interferon Tipo I/metabolismo , RNA
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