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1.
Rheumatology (Oxford) ; 62(4): 1699-1705, 2023 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-36193988

RESUMO

OBJECTIVES: Inborn errors of immunity manifest with susceptibility to infection but may also present with immune dysregulation only. According to the European Society for Immunodeficiencies Registry about 50% of inborn errors of immunity are classified as common variable immunodeficiencies (CVID). In only few CVID patients are monogenic causes identified. IFN regulatory factor-2 binding protein 2 (IRF2BP2) is one of 20 known genes associated with CVID phenotypes and has only been reported in two families so far. We report another IRF2BP2-deficient patient with a novel pathogenic variant and phenotype and characterize impaired B cell function and immune dysregulation. METHODS: We performed trio whole-exome sequencing, determined B cell subpopulations and intracellular calcium mobilization upon B cell receptor crosslinking in B cells. T cell subpopulations, T cell proliferation and a type I IFN signature were measured. Colonoscopy and gastroduodenoscopy including histopathology were performed. RESULTS: The 33-year-old male presented with recurrent respiratory infections since childhood, colitis and RA beginning at age 25 years. We identified a novel de novo nonsense IRF2BP2 variant c.1618C>T; p.(Q540*). IgG deficiency was detected as consequence of a severe B cell differentiation defect. This was confirmed by impaired plasmablast formation upon stimulation with CpG. No serum autoantibodies were detected. Intracellular cytokine production in CD4+ T cells and CTLA4 expression on FOXP3+ Tregs were impaired. Type I IFN signature was elevated. CONCLUSION: The identified loss-of-function variant in IRF2BP2 severely impairs B cell development and T cell homeostasis, and may be associated with colitis and RA. Our results provide further evidence for association of IRF2BP2 with CVID and contribute to the understanding of the underlying pathomechanisms.


Assuntos
Linfócitos T CD4-Positivos , Fatores de Transcrição , Masculino , Linfócitos B , Mutação , Fenótipo , Humanos , Adulto
2.
Blood Cells Mol Dis ; 92: 102596, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34547651

RESUMO

Chronic granulomatous disease (CGD) is an immunodeficiency disorder affecting about 1 in 250,000 individuals. CGD patients suffer from severe, recurrent bacterial and fungal infections. The disease is caused by mutations in the genes encoding the components of the leukocyte NADPH oxidase. This enzyme produces superoxide, which is subsequently metabolized to hydrogen peroxide and other reactive oxygen species (ROS). These products are essential for intracellular killing of pathogens by phagocytic leukocytes (neutrophils, eosinophils, monocytes and macrophages). The leukocyte NADPH oxidase is composed of five subunits, four of which are encoded by autosomal genes. These are CYBA, encoding p22phox, NCF1, encoding p47phox, NCF2, encoding p67phox and NCF4, encoding p40phox. This article lists all mutations identified in these genes in CGD patients. In addition, cytochrome b558 chaperone-1 (CYBC1), recently recognized as an essential chaperone protein for the expression of the X-linked NADPH oxidase component gp91phox (also called Nox2), is encoded by the autosomal gene CYBC1. Mutations in this gene also lead to CGD. Finally, RAC2, a small GTPase of the Rho family, is needed for activation of the NADPH oxidase, and mutations in the RAC2 gene therefore also induce CGD-like symptoms. Mutations in these last two genes are also listed in this article.


Assuntos
Doença Granulomatosa Crônica/genética , Mutação , Humanos , NADPH Oxidases/genética
3.
Blood Cells Mol Dis ; 90: 102587, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34175765

RESUMO

Chronic granulomatous disease (CGD) is an immunodeficiency disorder affecting about 1 in 250,000 individuals. CGD patients suffer from severe bacterial and fungal infections. The disease is caused by a lack of superoxide production by the leukocyte enzyme NADPH oxidase. Superoxide and subsequently formed other reactive oxygen species (ROS) are instrumental in killing phagocytosed micro-organisms in neutrophils, eosinophils, monocytes and macrophages. The leukocyte NADPH oxidase is composed of five subunits, of which the enzymatic component is gp91phox, also called Nox2. This protein is encoded by the CYBB gene on the X chromosome. Mutations in this gene are found in about 70% of all CGD patients in Europe and in about 20% in countries with a high ratio of parental consanguinity. This article lists all mutations identified in CYBB and should therefore help in genetic counseling of X-CGD patients' families. Moreover, apparently benign polymorphisms in CYBB are also given, which should facilitate the recognition of disease-causing mutations. In addition, we also include some mutations in G6PD, the gene on the X chromosome that encodes glucose-6-phosphate dehydrogenase, because inactivity of this enzyme may lead to shortage of NADPH and thus to insufficient activity of NADPH oxidase. Severe G6PD deficiency can induce CGD-like symptoms.


Assuntos
Cromossomos Humanos X/genética , Doença Granulomatosa Crônica/genética , Mutação , NADPH Oxidase 2/genética , Humanos
4.
Pediatr Allergy Immunol ; 32(3): 576-585, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33118209

RESUMO

BACKGROUND: Hematopoietic stem cell transplantation (HSCT) can cure chronic granulomatous disease (CGD), but it remains debated whether all conventionally treated CGD patients benefit from HSCT. METHODS: We retrospectively analyzed 104 conventionally treated CGD patients, of whom 50 patients underwent HSCT. RESULTS: On conventional treatment, seven patients (13%) died after a median time of 16.2 years (interquartile range [IQR] 7.0-18.0). Survival without severe complications was 10 ± 3% (mean ± SD) at the age of 20 years; 85% of patients developed at least one infection, 76% one non-infectious inflammation. After HSCT, 44 patients (88%) were alive at a median follow-up of 2.3 years (IQR 0.8-4.9): Six patients (12%) died from infections. Survival after HSCT was significantly better for patients transplanted ≤8 years (96 ± 4%) or for patients without active complications at HSCT (100%). Eight patients suffered from graft failure (16%); six (12%) developed acute graft-vs-host disease requiring systemic treatment. Conventionally treated patients developed events that required medical attention at a median frequency of 1.7 (IQR 0.8-3.2) events per year vs 0 (IQR 0.0-0.5) in patients beyond the first year post-HSCT. While most conventionally treated CGD patients failed to thrive, catch-up growth after HSCT in surviving patients reached the individual percentiles at the age of diagnosis of CGD. CONCLUSION: Chronic granulomatous disease patients undergoing HSCT until 8 years of age show excellent survival, but young children need more intense conditioning to avoid graft rejection. Risks and benefits of HSCT for adolescents and adults must still be weighed carefully.


Assuntos
Doença Enxerto-Hospedeiro , Doença Granulomatosa Crônica , Transplante de Células-Tronco Hematopoéticas , Adolescente , Pré-Escolar , Doença Granulomatosa Crônica/terapia , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Humanos , Recém-Nascido , Estudos Retrospectivos , Condicionamento Pré-Transplante , Resultado do Tratamento
5.
Blood ; 127(18): 2193-202, 2016 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-26907631

RESUMO

Fas is a transmembrane receptor involved in the maintenance of tolerance and immune homeostasis. In murine models, it has been shown to be essential for deletion of autoreactive B cells in the germinal center. The role of Fas in human B-cell selection and in development of autoimmunity in patients carrying FAS mutations is unclear. We analyzed patients with either a somatic FAS mutation or a germline FAS mutation and somatic loss-of-heterozygosity, which allows comparing the fate of B cells with impaired vs normal Fas signaling within the same individual. Class-switched memory B cells showed: accumulation of FAS-mutated B cells; failure to enrich single V, D, J genes and single V-D, D-J gene combinations of the B-cell receptor variable region; increased frequency of variable regions with higher content of positively charged amino acids; and longer CDR3 and maintenance of polyreactive specificities. Importantly, Fas-deficient switched memory B cells showed increased rates of somatic hypermutation. Our data uncover a defect in B-cell selection in patients with FAS mutations, which has implications for the understanding of the pathogenesis of autoimmunity and lymphomagenesis of autoimmune lymphoproliferative syndrome.


Assuntos
Síndrome Linfoproliferativa Autoimune/imunologia , Subpopulações de Linfócitos B/imunologia , Seleção Clonal Mediada por Antígeno , Mutação , Receptor fas/fisiologia , Apoptose , Autoimunidade , Linhagem Celular Transformada , Transformação Celular Neoplásica , Criança , Códon sem Sentido , Feminino , Mutação da Fase de Leitura , Mutação em Linhagem Germinativa , Heterozigoto , Humanos , Memória Imunológica , Perda de Heterozigosidade , Masculino , Análise de Sequência de DNA , Hipermutação Somática de Imunoglobulina , Recombinação V(D)J , Receptor fas/deficiência , Receptor fas/genética
6.
Rheumatology (Oxford) ; 56(12): 2102-2108, 2017 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-28968868

RESUMO

Objective: To provide outcome data concerning pregnancies exposed to the Interleukin-1 (IL-1) inhibitors prior to conception in both men and women, during pregnancy and breast feeding. Methods: Retrospective data were collected from members of the International Society for Systemic Autoinflammatory diseases and collated in a single centre. A uniform data collection sheet was used to obtain standardized data including maternal age and diagnosis, type, duration of and response to IL-1 blockade, pregnancy duration, delivery, mode of feeding and neonatal development. Results: There were 31 maternal-exposed pregnancies from seven countries and we report the first data on paternal exposure: six to anakinra and five to canakinumab, with no negative outcomes. We also report the first data on canakinumab-exposed pregnancies: eight pregnancies that resulted in the delivery of seven healthy infants of normal gestational age and birthweight. There were 23 anakinra-exposed pregnancies resulting in the birth of 21 healthy infants, and one baby with unilateral renal agenesis and ectopic neurohypophysis. There were two first trimester miscarriages affecting a mother with active disease. There were no serious neonatal infections. Fourteen infants were breast fed with no complications. There were no reports of developmental delay, with follow-up of up to 10 years (median 18 months). Conclusion: This series substantially increases the published experience of IL-1 blockade and reproduction including the first data on canakinumab and on paternal exposure to these agents. Data are generally reassuring, although the case of renal agenesis is the second reported in an anakinra-exposed pregnancy.


Assuntos
Antirreumáticos/efeitos adversos , Doenças Autoimunes/tratamento farmacológico , Interleucina-1/antagonistas & inibidores , Exposição Materna/efeitos adversos , Exposição Paterna/efeitos adversos , Adulto , Anticorpos Monoclonais/efeitos adversos , Anticorpos Monoclonais Humanizados , Doenças Autoimunes/complicações , Peso ao Nascer , Aleitamento Materno/efeitos adversos , Feminino , Idade Gestacional , Humanos , Recém-Nascido , Proteína Antagonista do Receptor de Interleucina 1/efeitos adversos , Masculino , Gravidez , Resultado da Gravidez , Estudos Retrospectivos , Adulto Jovem
7.
Blood ; 126(26): 2842-51, 2015 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-26491069

RESUMO

Neutrophils play an essential role in the initial stages of inflammation by balancing pro- and antiinflammatory signals. Among these signals are the production of proinflammatory cytokines and the timely initiation of antiinflammatory cell death via constitutive apoptosis. Here we identify ataxia-telangiectasia mutated (ATM) kinase as a modulator of these neutrophil functions. Ataxia-telangiectasia (AT) is a pleiotropic multisystem disorder caused by mutations in the gene-encoding ATM, a master regulator of the DNA damage response. In addition to progressive neurodegeneration and high rates of cancer, AT patients have numerous symptoms that can be linked to chronic inflammation. We report that neutrophils isolated from patients with AT overproduce proinflammatory cytokines and have a prolonged lifespan compared with healthy controls. This effect is partly mediated by increases in activation of p38 MAP kinase. Furthermore, we show that the oxidative burst, catalyzed by nicotinamide adenine dinucleotide phosphate oxidase, can activate ATM in neutrophils. Finally, activation of ATM and DNA damage signaling suppress cytokine production and can abrogate the overproduction of IL-8 in ROS-deficient cells. This reveals a novel mechanism for the regulation of cytokine production and apoptosis, establishing DNA damage as a downstream mediator of immune regulation by reactive oxygen species. We propose that deficiencies in the DNA damage response, like deficiencies in the oxidative burst seen in chronic granulomatous disease, could lead to pathologic inflammation.


Assuntos
Apoptose/fisiologia , Proteínas Mutadas de Ataxia Telangiectasia/metabolismo , Ativação Enzimática/fisiologia , Neutrófilos/metabolismo , Explosão Respiratória/fisiologia , Western Blotting , Separação Celular , Citocinas/biossíntese , Citometria de Fluxo , Imunofluorescência , Humanos , Reação em Cadeia da Polimerase em Tempo Real
8.
Mol Ther ; 24(4): 812-22, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26316390

RESUMO

Chronic granulomatous disease (CGD) is an inherited immunodeficiency, caused by the inability of neutrophils to produce functional NADPH oxidase required for fighting microbial infections. The X-linked form of CGD (X-CGD), which is due to mutations in the CYBB (gp91phox) gene, a component of NADPH oxidase, accounts for about two-thirds of CGD cases. We derived induced pluripotent stem cells (iPSCs) from X-CGD patient keratinocytes using a Flp recombinase excisable lentiviral reprogramming vector. For restoring gp91phox function, we applied two strategies: transposon-mediated bacterial artificial chromosome (BAC) transgenesis and gene targeting using vectors with a fixed 5' homology arm (HA) of 8 kb and 3'HA varying in size from 30 to 80 kb. High efficiency of homologous recombination (up to 22%) was observed with increased size of the 3'HA. Both, BAC transgenesis and gene targeting resulted in functional restoration of the gp91phox measured by an oxidase activity assay in X-CGD iPSCs differentiated into the myeloid lineage. In conclusion, we delivered an important milestone towards the use of genetically corrected autologous cells for the treatment of X-CGD and monogenic diseases in general.


Assuntos
Cromossomos Artificiais Bacterianos/genética , Técnicas de Transferência de Genes , Doença Granulomatosa Crônica/patologia , Células-Tronco Pluripotentes Induzidas/enzimologia , Glicoproteínas de Membrana/genética , NADPH Oxidases/genética , Diferenciação Celular , Células Cultivadas , Marcação de Genes , Terapia Genética , Vetores Genéticos , Doença Granulomatosa Crônica/genética , Doença Granulomatosa Crônica/terapia , Humanos , Queratinócitos/citologia , Glicoproteínas de Membrana/metabolismo , Mutação , NADPH Oxidase 2 , NADPH Oxidases/metabolismo
9.
Klin Padiatr ; 229(3): 113-117, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28561224

RESUMO

Background Heterozygous point mutations in the GT splice donor consensus sequence of exon 11 of the PIK3R1 gene (coding for p85α, p55α, and p50α regulatory subunits of PI3K) lead to exon skipping and thereby to an aberrant protein that leaves PI3K hyperactivated. Several patients with this particular variant of PI3 kinase delta syndrome (APDS) suffering from sinopulmonary infections and lymphoproliferation have been described. Methods (Whole exome) sequencing, evaluation of cellular and clinical phenotypes. Results We here report a family with a new heterozygous mutation in this gene, a 9 bp deletion (c.1418_1425+1del) that, however, leads to the same skipping of exon 11. The clinical phenotypes of their members partly overlap features of patients of other reports. Conclusions We found a new mutation in PIK3R1 and show how broad the resulting clinical spectrum can be.


Assuntos
Variação Genética/genética , Transtornos do Crescimento/genética , Síndromes de Imunodeficiência/genética , Linfoma/genética , Fenótipo , Fosfatidilinositol 3-Quinases/genética , Mutação Puntual , Linfócitos B/imunologia , Criança , Deleção Cromossômica , Classe Ia de Fosfatidilinositol 3-Quinase , Análise Mutacional de DNA , Éxons/genética , Feminino , Triagem de Portadores Genéticos , Marcadores Genéticos/genética , Transtornos do Crescimento/diagnóstico , Transtornos do Crescimento/imunologia , Humanos , Síndromes de Imunodeficiência/diagnóstico , Síndromes de Imunodeficiência/imunologia , Contagem de Linfócitos , Linfoma/diagnóstico , Linfoma/imunologia , Linhagem , Sítios de Splice de RNA/genética , Sequenciamento do Exoma
11.
J Immunol ; 192(9): 4379-85, 2014 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-24706726

RESUMO

The proinflammatory enzyme caspase-1 plays an important role in the innate immune system and is involved in a variety of inflammatory conditions. Rare naturally occurring human variants of the caspase-1 gene (CASP1) lead to different protein expression and structure and to decreased or absent enzymatic activity. Paradoxically, a significant number of patients with such variants suffer from febrile episodes despite decreased IL-1ß production and secretion. In this study, we investigate how variant (pro)caspase-1 can possibly contribute to inflammation. In a transfection model, such variant procaspase-1 binds receptor interacting protein kinase 2 (RIP2) via Caspase activation and recruitment domain (CARD)/CARD interaction and thereby activates NF-κB, whereas wild-type procaspase-1 reduces intracellular RIP2 levels by enzymatic cleavage and release into the supernatant. We approach the protein interactions by coimmunoprecipitation and confocal microscopy and show that NF-κB activation is inhibited by anti-RIP2-short hairpin RNA and by the expression of a RIP2 CARD-only protein. In conclusion, variant procaspase-1 binds RIP2 and thereby activates NF-κB. This pathway could possibly contribute to proinflammatory signaling.


Assuntos
Caspase 1/genética , Febre/genética , Inflamação/genética , NF-kappa B/metabolismo , Proteína Serina-Treonina Quinase 2 de Interação com Receptor/metabolismo , Western Blotting , Caspase 1/metabolismo , Febre/enzimologia , Imunofluorescência , Técnicas de Silenciamento de Genes , Variação Genética , Células HEK293 , Humanos , Imunoprecipitação , Inflamação/imunologia , Inflamação/metabolismo , Transdução de Sinais/fisiologia , Transdução Genética , Transfecção
12.
Curr Rheumatol Rep ; 17(7): 45, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26003867

RESUMO

Caspase-1 is a proinflammatory enzyme that is essential in many inflammatory conditions including infectious, autoimmune, and autoinflammatory disorders. The inflammation is mainly mediated by the generation of inflammasomes that activate caspase-1 and subsequently interleukin (IL)-1ß and IL-18. In addition, homotypic CARD/CARD interaction of procaspase-1 with RIP2 and thereby activation of the NF-κB pathways may play some role in the inflammation. However, normally, this pathway seems to become downregulated rapidly by the cleavage and excretion of RIP2 by active (pro-)caspase-1. In patients with unexplained recurrent systemic inflammation, CASP1 variants were detected, which often destabilized the caspase-1 dimer interface. Obviously, the resulting decreased or abrogated enzymatic activity and IL-1ß production did not prevent the febrile episodes. As an unexpected finding, the inactive procaspase-1 variants significantly enhanced proinflammatory signaling by increasing RIP2 mediated NF-κB activation in an in vitro cell transfection model. A likely reason is the failure of inactive procaspase-1 to cleave bound RIP2 and also to mediate its excretion out of the intracelluar space thereby keeping the RIP2-NF-κB pathway upregulated. Hence, proinflammatory effects of enzymatically inactive procaspase-1 variants may partially explain the inflammatory episodes of the patients.


Assuntos
Doenças Autoimunes/genética , Caspase 1/genética , Febre/genética , Inflamação/genética , Doenças Autoimunes/metabolismo , Caspase 1/metabolismo , Febre/metabolismo , Variação Genética , Humanos , Imunidade Inata , Inflamação/metabolismo , Recidiva
13.
J Allergy Clin Immunol ; 134(1): 116-26, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24582312

RESUMO

BACKGROUND: Common variable immunodeficiency (CVID) is an antibody deficiency with an equal sex distribution and a high variability in clinical presentation. The main features include respiratory tract infections and their associated complications, enteropathy, autoimmunity, and lymphoproliferative disorders. OBJECTIVE: This study analyzes the clinical presentation, association between clinical features, and differences and effects of immunoglobulin treatment in Europe. METHODS: Data on 2212 patients with CVID from 28 medical centers contributing to the European Society for Immunodeficiencies Database were analyzed retrospectively. RESULTS: Early disease onset (<10 years) was very frequent in our cohort (33.7%), especially in male subjects (39.8%). Male subjects with early-onset CVID were more prone to pneumonia and less prone to other complications suggesting a distinct disease entity. The diagnostic delay of CVID ranges between 4 and 5 years in many countries and is particularly high in subjects with early-onset CVID. Enteropathy, autoimmunity, granulomas, and splenomegaly formed a set of interrelated features, whereas bronchiectasis was not associated with any other clinical feature. Patient survival in this cohort was associated with age at onset and age at diagnosis only. There were different treatment strategies in Europe, with considerable differences in immunoglobulin dosing, ranging from 130 up to 750 mg/kg/mo. Patients with very low trough levels of less than 4 g/L had poor clinical outcomes, whereas higher trough levels were associated with a reduced frequency of serious bacterial infections. CONCLUSION: Patients with CVID are being managed differently throughout Europe, affecting various outcome measures. Clinically, CVID is a truly variable antibody deficiency syndrome.


Assuntos
Imunodeficiência de Variável Comum/complicações , Transtornos Linfoproliferativos/complicações , Pneumonia/complicações , Adolescente , Adulto , Idade de Início , Autoimunidade , Bronquiectasia/patologia , Criança , Pré-Escolar , Imunodeficiência de Variável Comum/tratamento farmacológico , Imunodeficiência de Variável Comum/imunologia , Imunodeficiência de Variável Comum/mortalidade , Diagnóstico Tardio , Europa (Continente) , Feminino , Humanos , Imunoglobulinas Intravenosas/uso terapêutico , Transtornos Linfoproliferativos/tratamento farmacológico , Transtornos Linfoproliferativos/imunologia , Transtornos Linfoproliferativos/mortalidade , Masculino , Pneumonia/tratamento farmacológico , Pneumonia/imunologia , Pneumonia/mortalidade , Estudos Retrospectivos , Esplenomegalia/patologia , Análise de Sobrevida
14.
J Allergy Clin Immunol ; 132(2): 400-11.e9, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23830147

RESUMO

BACKGROUND: The capacity of CD8(+) T cells to control infections and mediate antitumor immunity requires the development and survival of effector and memory cells. IL-21 has emerged as a potent inducer of CD8(+) T-cell effector function and memory development in mouse models of infectious disease. However, the role of IL-21 and associated signaling pathways in protective CD8(+) T-cell immunity in human subjects is unknown. OBJECTIVE: We sought to determine which signaling pathways mediate the effects of IL-21 on human CD8(+) T cells and whether defects in these pathways contribute to disease pathogenesis in patients with primary immunodeficiencies caused by mutations in components of the IL-21 signaling cascade. METHODS: Human primary immunodeficiencies resulting from monogenic mutations provide a unique opportunity to assess the requirement for particular molecules in regulating human lymphocyte function. Lymphocytes from patients with loss-of-function mutations in signal transducer and activator of transcription 1 (STAT1), STAT3, or IL-21 receptor (IL21R) were used to assess the respective roles of these genes in human CD8(+) T-cell differentiation in vivo and in vitro. RESULTS: Mutations in STAT3 and IL21R, but not STAT1, led to a decrease in multiple memory CD8(+) T-cell subsets in vivo, indicating that STAT3 signaling, possibly downstream of IL-21R, regulates the memory cell pool. Furthermore, STAT3 was important for inducing the lytic machinery in IL-21-stimulated naive CD8(+) T cells. However, this defect was overcome by T-cell receptor engagement. CONCLUSION: The IL-21R/STAT3 pathway is required for many aspects of human CD8(+) T-cell behavior but in some cases can be compensated by other signals. This helps explain the relatively mild susceptibility to viral disease observed in STAT3- and IL-21R-deficient subjects.


Assuntos
Linfócitos T CD8-Positivos/citologia , Diferenciação Celular , Memória Imunológica , Síndrome de Job/genética , Mutação , Fator de Transcrição STAT3/metabolismo , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Diferenciação Celular/genética , Diferenciação Celular/imunologia , Humanos , Interleucinas/genética , Interleucinas/imunologia , Interleucinas/metabolismo , Síndrome de Job/imunologia , Síndrome de Job/patologia , Receptores de Interleucina-21/genética , Receptores de Interleucina-21/imunologia , Receptores de Interleucina-21/metabolismo , Fator de Transcrição STAT3/genética
15.
Hum Mutat ; 34(1): 122-31, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22833538

RESUMO

Caspase-1 (Interleukin-1 Converting Enzyme, ICE) is a proinflammatory enzyme that plays pivotal roles in innate immunity and many inflammatory conditions such as periodic fever syndromes and gout. Inflammation is often mediated by enzymatic activation of interleukin (IL)-1ß and IL-18. We detected seven naturally occurring human CASP1 variants with different effects on protein structure, expression, and enzymatic activity. Most mutations destabilized the caspase-1 dimer interface as revealed by crystal structure analysis and homology modeling followed by molecular dynamics simulations. All variants demonstrated decreased or absent enzymatic and IL-1ß releasing activity in vitro, in a cell transfection model, and as low as 25% of normal ex vivo in a whole blood assay of samples taken from subjects with variant CASP1, a subset of whom suffered from unclassified autoinflammation. We conclude that decreased enzymatic activity of caspase-1 is compatible with normal life and does not prevent moderate and severe autoinflammation.


Assuntos
Caspase 1/genética , Caspase 1/metabolismo , Variação Genética , Interleucina-1beta/metabolismo , Biocatálise , Caspase 1/química , Linhagem Celular , Cristalografia por Raios X , Citocinas/sangue , Citocinas/metabolismo , Análise Mutacional de DNA , Predisposição Genética para Doença/genética , Células HEK293 , Humanos , Inflamação/enzimologia , Inflamação/genética , Modelos Moleculares , Mutação , Multimerização Proteica , Estrutura Terciária de Proteína
16.
Clin Immunol ; 147(1): 61-68, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23524443

RESUMO

We describe a family with 12 members carrying a heterozygous germline FAS c.3G>T start codon mutation leading to FAS haploinsufficiency. One patient had autoimmune lymphoproliferative syndrome (ALPS), one had recovered from ALPS, and ten mutation-positive relatives (MPRs) were healthy. FAS-mediated apoptosis and surface expression of FAS in single-positive T cells were lower for MPRs but did not discriminate between them and the ALPS patient. However, double-negative (DN) T cells of the ALPS patient had no FAS expression due to somatic loss of heterozygosity. Our results in this kindred suggest that FAS haploinsufficiency does not cause ALPS-FAS, but that modifying genetic events are crucial for its pathogenesis. FAS surface expression on DN T cells should be assessed routinely and FAS haploinsufficient patients should be followed as its potential for lymphomagenesis is not well defined and a second hit might occur later on.


Assuntos
Síndrome Linfoproliferativa Autoimune/genética , Códon de Iniciação/genética , Perda de Heterozigosidade , Mutação , Receptor fas/genética , Idoso , Apoptose/genética , Sequência de Bases , Células Cultivadas , Análise Mutacional de DNA , Saúde da Família , Feminino , Citometria de Fluxo , Haploinsuficiência , Humanos , Leucócitos Mononucleares/metabolismo , Leucócitos Mononucleares/patologia , Masculino , Pessoa de Meia-Idade , Linhagem , Adulto Jovem
17.
Blood ; 117(3): 953-9, 2011 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-20974672

RESUMO

The granule enzyme myeloperoxidase (MPO) plays an important role in neutrophil antimicrobial responses. However, the severity of immunodeficiency in patients carrying mutations in MPO is variable. Serious microbial infections, especially with Candida species, have been observed in a subset of completely MPO-deficient patients. Here we show that neutrophils from donors who are completely deficient in MPO fail to form neutrophil extracellular traps (NETs), indicating that MPO is required for NET formation. In contrast, neutrophils from partially MPO-deficient donors make NETs, and pharmacological inhibition of MPO only delays and reduces NET formation. Extracellular products of MPO do not rescue NET formation, suggesting that MPO acts cell-autonomously. Finally, NET-dependent inhibition of Candida albicans growth is compromised in MPO-deficient neutrophils. The inability to form NETs may contribute in part to the host defense defects observed in completely MPO-deficient individuals.


Assuntos
Doadores de Sangue , Espaço Extracelular/metabolismo , Neutrófilos/metabolismo , Peroxidase/metabolismo , Compostos de Anilina/farmacologia , Western Blotting , Candida albicans/fisiologia , Células Cultivadas , Espaço Extracelular/efeitos dos fármacos , Espaço Extracelular/imunologia , Genótipo , Interações Hospedeiro-Patógeno , Humanos , Imunidade Inata/imunologia , Microscopia de Fluorescência , Mutação , Neutrófilos/imunologia , Neutrófilos/microbiologia , Peroxidase/antagonistas & inibidores , Peroxidase/genética , Acetato de Tetradecanoilforbol/farmacologia
18.
Front Immunol ; 13: 878989, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35651609

RESUMO

Background: Atopic dermatitis (AD) affects up to 25% of children and 10% of adults in Western countries. When severe or recurrent infections and exceedingly elevated serum IgE levels occur in AD patients, an inborn error of immunity (IEI) may be suspected. The International Union of Immunological Societies classification lists variants in different genes responsible for so-called Hyper-IgE syndromes. Diagnosing an underlying IEI may influence treatment strategies. Methods: Clinical and diagnostic workup of family members are presented including a detailed immunological description and histology of the carcinoma. Functional testing of the novel variant in CARD11 underlying 'CARD11-associated atopy with dominant interference of NF-kB signaling' (CADINS) was performed. Results: We report on an 18-year-old patient with a long-standing history of infections, accompanied by hypogammaglobulinemia, intermittent agranulocytosis, atopy, eosinophilia and colitis. The working diagnosis of common variable immunodeficiency was revised when a novel heterozygous CARD11 variant [c.223C>T; p.(Arg75Trp)] was identified. Functional studies confirmed this variant to have a dominant negative (DN) effect, as previously described in patients with CADINS. Five other family members were affected by severe atopy associated with the above variant, but not hypogammaglobulinemia. Malignancies occurred in two generations: an HPV-positive squamous cell carcinoma and a cutaneous T-cell lymphoma. So far, one patient is under treatment with dupilumab, which has shown marked benefit in controlling severe eczema. Conclusion: The phenotypic spectrum associated with heterozygous CARD11 DN mutations is broad. Partial T-cell deficiency, diminished IFN-γ cytokine and increased IL-4 production, were identified as disease-causing mechanisms. Malignant disease associated with germline CARD11 DN variants has only been reported sporadically. HPV vaccination in teenage years, and cytology screening analogous with routine cervical swabs may be recommended. Treatment with dupilumab, a monoclonal antibody blocking interleukin-4- and interleukin-13 signaling, may be of benefit in controlling severe and extended AD for some patients as reported for STAT3 loss-of-function.


Assuntos
Carcinoma , Dermatite Atópica , Síndrome de Job , Infecções por Papillomavirus , Adolescente , Adulto , Criança , Dermatite Atópica/tratamento farmacológico , Dermatite Atópica/genética , Humanos , Imunoglobulina E , Síndrome de Job/diagnóstico , Síndrome de Job/genética
19.
J Allergy Clin Immunol ; 126(3): 611-7.e1, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20816194

RESUMO

BACKGROUND: Hyper-IgE syndromes (HIES) are primary immunodeficiency disorders characterized by Staphylococcus aureus abscesses, recurrent pneumonia, increased serum IgE levels, and eczema. The association of heterozygous signal transducer and activator of transcription 3 (STAT3) mutations with autosomal dominant (AD)-HIES allows the differentiation of AD-HIES from disorders associated with eczema and increased serum IgE levels, such as other primary immunodeficiencies and atopic dermatitis. OBJECTIVE: To facilitate early diagnosis of AD-HIES to initiate appropriate therapy. METHODS: The clinical phenotype (suggested by a National Institutes of Health [NIH] score of >or=40 points), STAT3 genotype, and T(H)17 cell counts were compared in a cohort of 78 patients suspected of having HIES. RESULTS: Heterozygous STAT3 missense mutations and in-frame deletions were identified in 48 patients, all but 2 with an NIH score >or=40 points. Patients with STAT3 mutations with HIES showed significantly lower T(H)17 cell counts compared with patients with wild-type STAT3 and control subjects. Only 1 patient with wild-type STAT3 had both an NIH score >or=40 points and abnormal T(H)17 cell counts (

Assuntos
Dermatite Atópica/diagnóstico , Síndrome de Job/diagnóstico , Adolescente , Adulto , Criança , Pré-Escolar , Dermatite Atópica/genética , Dermatite Atópica/imunologia , Feminino , Deleção de Genes , Humanos , Lactente , Interleucina-17/metabolismo , Síndrome de Job/imunologia , Masculino , Pessoa de Meia-Idade , Fator de Transcrição STAT3/genética , Linfócitos T Auxiliares-Indutores/citologia , Linfócitos T Auxiliares-Indutores/imunologia
20.
Pediatr Infect Dis J ; 40(7): 649-654, 2021 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-34097656

RESUMO

BACKGROUND: Pulmonary invasive aspergillosis is a frequent and life-threatening complication for patients with chronic granulomatous disease (CGD). Despite combined treatment with several groups of antifungal agents, conservative treatment of invasive aspergillosis often remains refractory. Pulmonary invasive aspergillosis is often treated by surgical resection of consolidated lobes or segments, donor granulocyte transfusions and allogeneic hematopoietic stem cell transplantation (HSCT). These options are not mutually exclusive and often combined. METHODS AND RESULTS: We here describe the treatment of 3 patients with CGD who received HSCT upon active pulmonary invasive aspergillosis: Two of them received HSCT as salvage therapy for refractory aspergillosis, and 1 patient received elective HSCT in infancy but developed pulmonary aspergillosis during secondary graft failure. Based on our experience and available literature, we discuss indication as well as timing of HSCT, granulocyte transfusions and surgery in patients with CGD and pulmonary invasive aspergillosis. CONCLUSIONS: Upon diagnosis with invasive aspergillosis in CGD, we propose to start antifungal treatment and preparation for HSCT at the same time. Remission of pulmonary invasive aspergillosis before HSCT remains preferable but is not mandatory. When pulmonary aspergillosis in patients with CGD remains refractory for longer than 3 months on conservative treatment, HSCT without prior surgery or accompanying granulocyte transfusions is a feasible option.


Assuntos
Doença Granulomatosa Crônica/complicações , Transplante de Células-Tronco Hematopoéticas/métodos , Aspergilose Pulmonar Invasiva/terapia , Criança , Pré-Escolar , Doença Granulomatosa Crônica/microbiologia , Humanos , Lactente , Masculino , Terapia de Salvação/métodos , Resultado do Tratamento
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