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1.
Sci Immunol ; 4(41)2019 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-31784499

RESUMO

Genetic etiologies of chronic mucocutaneous candidiasis (CMC) disrupt human IL-17A/F-dependent immunity at mucosal surfaces, whereas those of connective tissue disorders (CTDs) often impair the TGF-ß-dependent homeostasis of connective tissues. The signaling pathways involved are incompletely understood. We report a three-generation family with an autosomal dominant (AD) combination of CMC and a previously undescribed form of CTD that clinically overlaps with Ehlers-Danlos syndrome (EDS). The patients are heterozygous for a private splice-site variant of MAPK8, the gene encoding c-Jun N-terminal kinase 1 (JNK1), a component of the MAPK signaling pathway. This variant is loss-of-expression and loss-of-function in the patients' fibroblasts, which display AD JNK1 deficiency by haploinsufficiency. These cells have impaired, but not abolished, responses to IL-17A and IL-17F. Moreover, the development of the patients' TH17 cells was impaired ex vivo and in vitro, probably due to the involvement of JNK1 in the TGF-ß-responsive pathway and further accounting for the patients' CMC. Consistently, the patients' fibroblasts displayed impaired JNK1- and c-Jun/ATF-2-dependent induction of key extracellular matrix (ECM) components and regulators, but not of EDS-causing gene products, in response to TGF-ß. Furthermore, they displayed a transcriptional pattern in response to TGF-ß different from that of fibroblasts from patients with Loeys-Dietz syndrome caused by mutations of TGFBR2 or SMAD3, further accounting for the patients' complex and unusual CTD phenotype. This experiment of nature indicates that the integrity of the human JNK1-dependent MAPK signaling pathway is essential for IL-17A- and IL-17F-dependent mucocutaneous immunity to Candida and for the TGF-ß-dependent homeostasis of connective tissues.

2.
J Exp Med ; 216(8): 1777-1790, 2019 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-31213488

RESUMO

Fulminant viral hepatitis (FVH) is a devastating and unexplained condition that strikes otherwise healthy individuals during primary infection with common liver-tropic viruses. We report a child who died of FVH upon infection with hepatitis A virus (HAV) at age 11 yr and who was homozygous for a private 40-nucleotide deletion in IL18BP, which encodes the IL-18 binding protein (IL-18BP). This mutation is loss-of-function, unlike the variants found in a homozygous state in public databases. We show that human IL-18 and IL-18BP are both secreted mostly by hepatocytes and macrophages in the liver. Moreover, in the absence of IL-18BP, excessive NK cell activation by IL-18 results in uncontrolled killing of human hepatocytes in vitro. Inherited human IL-18BP deficiency thus underlies fulminant HAV hepatitis by unleashing IL-18. These findings provide proof-of-principle that FVH can be caused by single-gene inborn errors that selectively disrupt liver-specific immunity. They also show that human IL-18 is toxic to the liver and that IL-18BP is its antidote.

3.
J Exp Med ; 216(9): 2038-2056, 2019 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-31217193

RESUMO

Autosomal recessive IRF7 and IRF9 deficiencies impair type I and III IFN immunity and underlie severe influenza pneumonitis. We report three unrelated children with influenza A virus (IAV) infection manifesting as acute respiratory distress syndrome (IAV-ARDS), heterozygous for rare TLR3 variants (P554S in two patients and P680L in the third) causing autosomal dominant (AD) TLR3 deficiency. AD TLR3 deficiency can underlie herpes simplex virus-1 (HSV-1) encephalitis (HSE) by impairing cortical neuron-intrinsic type I IFN immunity to HSV-1. TLR3-mutated leukocytes produce normal levels of IFNs in response to IAV. In contrast, TLR3-mutated fibroblasts produce lower levels of IFN-ß and -λ, and display enhanced viral susceptibility, upon IAV infection. Moreover, the patients' iPSC-derived pulmonary epithelial cells (PECs) are susceptible to IAV. Treatment with IFN-α2b or IFN-λ1 rescues this phenotype. AD TLR3 deficiency may thus underlie IAV-ARDS by impairing TLR3-dependent, type I and/or III IFN-mediated, PEC-intrinsic immunity. Its clinical penetrance is incomplete for both IAV-ARDS and HSE, consistent with their typically sporadic nature.

4.
Elife ; 72018 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-29537367

RESUMO

Most humans are exposed to Tropheryma whipplei (Tw). Whipple's disease (WD) strikes only a small minority of individuals infected with Tw (<0.01%), whereas asymptomatic chronic carriage is more common (<25%). We studied a multiplex kindred, containing four WD patients and five healthy Tw chronic carriers. We hypothesized that WD displays autosomal dominant (AD) inheritance, with age-dependent incomplete penetrance. We identified a single very rare non-synonymous mutation in the four patients: the private R98W variant of IRF4, a transcription factor involved in immunity. The five Tw carriers were younger, and also heterozygous for R98W. We found that R98W was loss-of-function, modified the transcriptome of heterozygous leukocytes following Tw stimulation, and was not dominant-negative. We also found that only six of the other 153 known non-synonymous IRF4 variants were loss-of-function. Finally, we found that IRF4 had evolved under purifying selection. AD IRF4 deficiency can underlie WD by haploinsufficiency, with age-dependent incomplete penetrance.

5.
J Clin Invest ; 127(9): 3543-3556, 2017 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-28783042

RESUMO

Varicella zoster virus (VZV) typically causes chickenpox upon primary infection. In rare cases, VZV can give rise to life-threatening disease in otherwise healthy people, but the immunological basis for this remains unexplained. We report 4 cases of acute severe VZV infection affecting the central nervous system or the lungs in unrelated, otherwise healthy children who are heterozygous for rare missense mutations in POLR3A (one patient), POLR3C (one patient), or both (two patients). POLR3A and POLR3C encode subunits of RNA polymerase III. Leukocytes from all 4 patients tested exhibited poor IFN induction in response to synthetic or VZV-derived DNA. Moreover, leukocytes from 3 of the patients displayed defective IFN production upon VZV infection and reduced control of VZV replication. These phenotypes were rescued by transduction with relevant WT alleles. This work demonstrates that monogenic or digenic POLR3A and POLR3C deficiencies confer increased susceptibility to severe VZV disease in otherwise healthy children, providing evidence for an essential role of a DNA sensor in human immunity.


Assuntos
Varicela/genética , Herpes Zoster/genética , Mutação , RNA Polimerase III/genética , RNA Polimerase III/metabolismo , Alelos , Animais , Criança , Análise Mutacional de DNA , Regulação Enzimológica da Expressão Gênica , Células HEK293 , Herpesvirus Humano 3 , Heterozigoto , Humanos , Leucócitos/metabolismo , Camundongos , Mutação de Sentido Incorreto , Fenótipo
6.
J Clin Invest ; 127(5): 1991-2006, 2017 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-28414293

RESUMO

Inborn errors of DNA repair or replication underlie a variety of clinical phenotypes. We studied 5 patients from 4 kindreds, all of whom displayed intrauterine growth retardation, chronic neutropenia, and NK cell deficiency. Four of the 5 patients also had postnatal growth retardation. The association of neutropenia and NK cell deficiency, which is unusual among primary immunodeficiencies and bone marrow failures, was due to a blockade in the bone marrow and was mildly symptomatic. We discovered compound heterozygous rare mutations in Go-Ichi-Ni-San (GINS) complex subunit 1 (GINS1, also known as PSF1) in the 5 patients. The GINS complex is essential for eukaryotic DNA replication, and homozygous null mutations of GINS component-encoding genes are embryonic lethal in mice. The patients' fibroblasts displayed impaired GINS complex assembly, basal replication stress, impaired checkpoint signaling, defective cell cycle control, and genomic instability, which was rescued by WT GINS1. The residual levels of GINS1 activity reached 3% to 16% in patients' cells, depending on their GINS1 genotype, and correlated with the severity of growth retardation and the in vitro cellular phenotype. The levels of GINS1 activity did not influence the immunological phenotype, which was uniform. Autosomal recessive, partial GINS1 deficiency impairs DNA replication and underlies intra-uterine (and postnatal) growth retardation, chronic neutropenia, and NK cell deficiency.


Assuntos
Proteínas de Ligação a DNA/deficiência , Doenças Genéticas Inatas , Transtornos do Crescimento , Síndromes de Imunodeficiência , Células Matadoras Naturais , Neutropenia , Animais , Proteínas de Ligação a DNA/imunologia , Feminino , Retardo do Crescimento Fetal/genética , Retardo do Crescimento Fetal/imunologia , Doenças Genéticas Inatas/genética , Doenças Genéticas Inatas/imunologia , Transtornos do Crescimento/genética , Transtornos do Crescimento/imunologia , Humanos , Síndromes de Imunodeficiência/genética , Síndromes de Imunodeficiência/imunologia , Lactente , Masculino , Camundongos , Neutropenia/genética , Neutropenia/imunologia
7.
J Am Coll Cardiol ; 69(13): 1653-1665, 2017 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-28359509

RESUMO

BACKGROUND: Myocarditis is inflammation of the heart muscle that can follow various viral infections. Why children only rarely develop life-threatening acute viral myocarditis (AVM), given that the causal viral infections are common, is unknown. Genetic lesions might underlie such susceptibilities. Mouse genetic studies demonstrated that interferon (IFN)-α/ß immunity defects increased susceptibility to virus-induced myocarditis. Moreover, variations in human TLR3, a potent inducer of IFNs, were proposed to underlie AVM. OBJECTIVES: This study sought to evaluate the hypothesis that human genetic factors may underlie AVM in previously healthy children. METHODS: We tested the role of TLR3-IFN immunity using human induced pluripotent stem cell-derived cardiomyocytes. We then performed whole-exome sequencing of 42 unrelated children with acute myocarditis (AM), some with proven viral causes. RESULTS: We found that TLR3- and STAT1-deficient cardiomyocytes were not more susceptible to Coxsackie virus B3 (CVB3) infection than control cells. Moreover, CVB3 did not induce IFN-α/ß and IFN-α/ß-stimulated genes in control cardiomyocytes. Finally, exogenous IFN-α did not substantially protect cardiomyocytes against CVB3. We did not observe a significant enrichment of rare variations in TLR3- or IFN-α/ß-related genes. Surprisingly, we found that homozygous but not heterozygous rare variants in genes associated with inherited cardiomyopathies were significantly enriched in AM-AVM patients compared with healthy individuals (p = 2.22E-03) or patients with other diseases (p = 1.08E-04). Seven of 42 patients (16.7%) carried rare biallelic (homozygous or compound heterozygous) nonsynonymous or splice-site variations in 6 cardiomyopathy-associated genes (BAG3, DSP, PKP2, RYR2, SCN5A, or TNNI3). CONCLUSIONS: Previously silent recessive defects of the myocardium may predispose to acute heart failure presenting as AM, notably after common viral infections in children.


Assuntos
Cardiomiopatias/genética , Enterovirus Humano B/fisiologia , Miocardite/genética , Fator de Transcrição STAT1/genética , Receptor 3 Toll-Like/genética , Cardiomiopatias/complicações , Estudos de Casos e Controles , Feminino , Interações Hospedeiro-Patógeno/genética , Humanos , Células-Tronco Pluripotentes Induzidas , Masculino , Miocardite/virologia , Miócitos Cardíacos/virologia
8.
Neurology ; 83(21): 1888-97, 2014 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-25339207

RESUMO

OBJECTIVE: To determine the proportion of children with herpes simplex encephalitis (HSE) displaying TLR3 deficiency, the extent of TLR3 allelic heterogeneity, and the specific clinical features of TLR3 deficiency. METHODS: We determined the sequence of all exons of TLR3 in 110 of the 120 patients with HSE enrolled in our study who do not carry any of the previously described HSE-predisposing mutations of TLR3 pathway genes (TLR3, UNC93B1, TRIF, TRAF3, and TBK1). All the new mutant TLR3 alleles detected were characterized experimentally in-depth to establish the causal relationship between the genotype and phenotype. RESULTS: In addition to the 3 previously reported TLR3-deficient patients from the same cohort, 6 other children or young adults with HSE carry 1 of 5 unique or extremely rare (minor allele frequency <0.001) missense TLR3 alleles. Two alleles (M374T, D592N) heterozygous in 3 patients are not deleterious in vitro. The other 3 are deleterious via different mechanisms: G743D+R811I and L360P heterozygous in 2 patients are loss-of-function due to low levels of expression and lack of cleavage, respectively, and R867Q homozygous in 1 patient is hypomorphic. The 3 patients' fibroblasts display impaired TLR3 responses and enhanced herpes simplex virus 1 susceptibility. Overall, TLR3 deficiency is therefore found in 6 (5%) of the 120 patients studied. There is high allelic heterogeneity, with 3 forms of autosomal dominant partial defect by negative dominance or haploinsufficiency, and 2 forms of autosomal recessive defect with complete or partial deficiency. Finally, 4 (66%) of the 6 TLR3-deficient patients had at least 1 late relapse of HSE, whereas relapse occurred in only 12 (10%) of the total cohort of 120 patients. CONCLUSIONS: Childhood-onset HSE is due to TLR3 deficiency in a traceable fraction of patients, in particular the ones with HSE recurrence. Mutations in TLR3 and TLR3 pathway genes should be searched and experimentally studied in children with HSE, and patients with proven TLR3 deficiency should be followed carefully.


Assuntos
Encefalite por Herpes Simples/diagnóstico , Encefalite por Herpes Simples/genética , Frequência do Gene/genética , Mutação/genética , Receptor 3 Toll-Like/deficiência , Receptor 3 Toll-Like/genética , Adolescente , Células Cultivadas , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Linhagem , Recidiva , Fatores de Risco
9.
J Clin Invest ; 121(12): 4889-902, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22105173

RESUMO

Herpes simplex encephalitis (HSE) is the most common sporadic viral encephalitis of childhood. Autosomal recessive (AR) UNC-93B and TLR3 deficiencies and autosomal dominant (AD) TLR3 and TRAF3 deficiencies underlie HSE in some children. We report here unrelated HSE children with AR or AD TRIF deficiency. The AR form of the disease was found to be due to a homozygous nonsense mutation that resulted in a complete absence of the TRIF protein. Both the TLR3- and the TRIF-dependent TLR4 signaling pathways were abolished. The AD form of disease was found to be due to a heterozygous missense mutation, resulting in a dysfunctional protein. In this form of the disease, the TLR3 signaling pathway was impaired, whereas the TRIF-dependent TLR4 pathway was unaffected. Both patients, however, showed reduced capacity to respond to stimulation of the DExD/H-box helicases pathway. To date, the TRIF-deficient patients with HSE described herein have suffered from no other infections. Moreover, as observed in patients with other genetic etiologies of HSE, clinical penetrance was found to be incomplete, as some HSV-1-infected TRIF-deficient relatives have not developed HSE. Our results provide what we believe to be the first description of human TRIF deficiency and a new genetic etiology for HSE. They suggest that the TRIF-dependent TLR4 and DExD/H-box helicase pathways are largely redundant in host defense. They further demonstrate the importance of TRIF for the TLR3-dependent production of antiviral IFNs in the CNS during primary infection with HSV-1 in childhood.


Assuntos
Proteínas Adaptadoras de Transporte Vesicular/deficiência , Encefalite por Herpes Simples/genética , Herpesvirus Humano 1 , Proteínas Adaptadoras de Transporte Vesicular/genética , Proteínas Adaptadoras de Transporte Vesicular/fisiologia , Sequência de Aminoácidos , Pré-Escolar , Códon sem Sentido , Consanguinidade , RNA Helicases DEAD-box/fisiologia , Feminino , Genes Dominantes , Genes Recessivos , Heterogeneidade Genética , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Genótipo , Humanos , Lactente , Interferon-alfa/biossíntese , Interferon-alfa/genética , Masculino , Dados de Sequência Molecular , Mutação de Sentido Incorreto , Linhagem , Arábia Saudita , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Transdução de Sinais/fisiologia , Receptor 3 Toll-Like/fisiologia , Receptor 4 Toll-Like/fisiologia
10.
J Pediatr ; 157(4): 623-9, 629.e1, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20553844

RESUMO

OBJECTIVE: To test the hypothesis that predisposition to childhood herpes simplex virus (HSV) type 1 encephalitis (HSE) may be determined in part by human genetic factors. STUDY DESIGN: A genetic epidemiologic survey of childhood HSE (onset at age 3 months to 15 years) over a 20-year period (1985-2004) was conducted throughout France (comprising 29 university hospital neuropediatric centers). A total of 85 children fulfilled the diagnostic criteria for inclusion. Family and personal histories were obtained by face-to-face interview for 51 patients. RESULTS: No familial cases of HSE were identified in our survey; however, a high proportion (20%) of the children interviewed had a relevant family history: parental consanguinity (12% of patients), early-onset herpetic keratitis in a first-degree relative (6%), or both (2%). The narrow window of high susceptibility to HSE before age 3 years (62% of patients) further indicates that predisposition to HSE is tightly age-dependent. CONCLUSIONS: This survey suggests that childhood HSE, although sporadic, may result from Mendelian predisposition (from autosomal recessive susceptibility in particular), at least in some children. There likely is incomplete penetrance, however, which may reflect, at least in part, the impact of age at the time of HSV-1 infection.


Assuntos
Encefalite por Herpes Simples/genética , Encefalite por Herpes Simples/virologia , Variação Genética , Receptor 3 Toll-Like/genética , Aciclovir/uso terapêutico , Adolescente , Fatores Etários , Idade de Início , Antivirais/uso terapêutico , Criança , Pré-Escolar , Encefalite por Herpes Simples/tratamento farmacológico , Feminino , Predisposição Genética para Doença , Variação Genética/genética , Humanos , Lactente , Masculino , Fatores de Risco , Simplexvirus , Adulto Jovem
11.
J Acquir Immune Defic Syndr ; 50(1): 19-26, 2009 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-19295331

RESUMO

BACKGROUND: To clarify early correlates and natural history of HIV long-term nonprogressors (LTNPs) since HIV diagnosis. METHODS: Patients enrolled in the French ANRS SEROCO/HEMOCO cohort with CD4 count >500 cells/mm3 at HIV diagnosis. LTNP status was defined as being asymptomatic, antiretroviral free, and with CD4 cell count >500 cells/mm3 for >8 years after HIV diagnosis. In LTNPs, we modeled the biological markers' progression through a joint model. Factors associated with loss of LTNP status were identified through a Cox model. RESULTS: Sixty (9%) of 664 patients were identified as LTNPs during follow-up. At enrollment, HIV RNA was 1.85 log copies/10(6) PBMCs and high HIV DNA increase were associated with an increased risk of losing LTNP status [adjusted hazard ratio: 2.8 (1.2-6.8) and 2.2 (1.0-4.8), respectively]. CONCLUSIONS: LTNP status is established in the first years of HIV infection, low HIV DNA level at enrollment and slow increase of HIV DNA being associated with maintained LTNP status.


Assuntos
Fármacos Anti-HIV/uso terapêutico , Infecções por HIV/tratamento farmacológico , HIV-1 , Adulto , Contagem de Linfócito CD4 , Estudos de Coortes , DNA Viral/sangue , Progressão da Doença , Feminino , França/epidemiologia , Infecções por HIV/epidemiologia , HIV-1/genética , Humanos , Masculino , RNA Viral/sangue , Fatores de Tempo , Adulto Jovem
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