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1.
J Allergy Clin Immunol ; 143(4): 1482-1495, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30170123

RESUMO

BACKGROUND: Caspase activation and recruitment domain 11 (CARD11) encodes a scaffold protein in lymphocytes that links antigen receptor engagement with downstream signaling to nuclear factor κB, c-Jun N-terminal kinase, and mechanistic target of rapamycin complex 1. Germline CARD11 mutations cause several distinct primary immune disorders in human subjects, including severe combined immune deficiency (biallelic null mutations), B-cell expansion with nuclear factor κB and T-cell anergy (heterozygous, gain-of-function mutations), and severe atopic disease (loss-of-function, heterozygous, dominant interfering mutations), which has focused attention on CARD11 mutations discovered by using whole-exome sequencing. OBJECTIVES: We sought to determine the molecular actions of an extended allelic series of CARD11 and to characterize the expanding range of clinical phenotypes associated with heterozygous CARD11 loss-of-function alleles. METHODS: Cell transfections and primary T-cell assays were used to evaluate signaling and function of CARD11 variants. RESULTS: Here we report on an expanded cohort of patients harboring novel heterozygous CARD11 mutations that extend beyond atopy to include other immunologic phenotypes not previously associated with CARD11 mutations. In addition to (and sometimes excluding) severe atopy, heterozygous missense and indel mutations in CARD11 presented with immunologic phenotypes similar to those observed in signal transducer and activator of transcription 3 loss of function, dedicator of cytokinesis 8 deficiency, common variable immunodeficiency, neutropenia, and immune dysregulation, polyendocrinopathy, enteropathy, X-linked-like syndrome. Pathogenic variants exhibited dominant negative activity and were largely confined to the CARD or coiled-coil domains of the CARD11 protein. CONCLUSION: These results illuminate a broader phenotypic spectrum associated with CARD11 mutations in human subjects and underscore the need for functional studies to demonstrate that rare gene variants encountered in expected and unexpected phenotypes must nonetheless be validated for pathogenic activity.

2.
Genet Med ; 20(5): 503-512, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-28933792

RESUMO

PurposeCaV3.2 signaling contributes to nociception, pruritus, gastrointestinal motility, anxiety, and blood pressure homeostasis. This calcium channel, encoded by CACNA1H, overlaps the human tryptase locus, wherein increased TPSAB1 copy number causes hereditary α-tryptasemia. Germ-line CACNA1H variants may contribute to the variable expressivity observed with this genetic trait.MethodsTryptase-encoding sequences at TPSAB1 and TPSB2, and TPSG1 and CACNA1H variants were genotyped in 46 families with hereditary α-tryptasemia syndrome. Electrophysiology was performed on tsA201 HEK cells transfected with wild-type or variant CACNA1H constructs. Effects on clinical phenotypes were interrogated in families with TPSAB1 duplications and in volunteers from the ClinSeq cohort.ResultsThree nonsynonymous variants in CACNA1H (rs3751664, rs58124832, and rs72552056) cosegregated with TPSAB1 duplications in 32/46 families and were confirmed to be in linkage disequilibrium (LD). In vitro, variant CaV3.2 had functional effects: reducing current densities, and altering inactivation and deactivation properties. No clinical differences were observed in association with the CACNA1H haplotype.ConclusionA previously unrecognized haplotype containing three functional CACNA1H variants is relatively common among Caucasians, and is frequently coinherited on the same allele as additional TPSAB1 copies. The variant CACNA1H haplotype, which in vitro imparts partial gain of function, does not result in detectable phenotypic differences in the heterozygous state.


Assuntos
Canais de Cálcio Tipo T/genética , Variações do Número de Cópias de DNA , Frequência do Gene , Haplótipos , Padrões de Herança , Triptases/genética , Canais de Cálcio Tipo T/metabolismo , Linhagem Celular , Duplicação Gênica , Estudos de Associação Genética , Loci Gênicos , Técnicas de Genotipagem , Humanos , Desequilíbrio de Ligação , Mutação , Fenótipo , Análise de Sequência de DNA , Triptases/metabolismo
4.
Nat Genet ; 49(8): 1192-1201, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28628108

RESUMO

Few monogenic causes for severe manifestations of common allergic diseases have been identified. Through next-generation sequencing on a cohort of patients with severe atopic dermatitis with and without comorbid infections, we found eight individuals, from four families, with novel heterozygous mutations in CARD11, which encodes a scaffolding protein involved in lymphocyte receptor signaling. Disease improved over time in most patients. Transfection of mutant CARD11 expression constructs into T cell lines demonstrated both loss-of-function and dominant-interfering activity upon antigen receptor-induced activation of nuclear factor-κB and mammalian target of rapamycin complex 1 (mTORC1). Patient T cells had similar defects, as well as low production of the cytokine interferon-γ (IFN-γ). The mTORC1 and IFN-γ production defects were partially rescued by supplementation with glutamine, which requires CARD11 for import into T cells. Our findings indicate that a single hypomorphic mutation in CARD11 can cause potentially correctable cellular defects that lead to atopic dermatitis.


Assuntos
Proteínas Adaptadoras de Sinalização CARD/genética , Dermatite Atópica/genética , Mutação em Linhagem Germinativa , Guanilato Ciclase/genética , Sistema ASC de Transporte de Aminoácidos/metabolismo , Estudos de Coortes , Análise Mutacional de DNA , Dermatite Atópica/imunologia , Feminino , Genes Dominantes , Glutamina/metabolismo , Humanos , Células Jurkat , Ativação Linfocitária , Masculino , Alvo Mecanístico do Complexo 1 de Rapamicina , Antígenos de Histocompatibilidade Menor/metabolismo , Complexos Multiproteicos/metabolismo , NF-kappa B/metabolismo , Linhagem , Linfócitos T/imunologia , Linfócitos T/metabolismo , Serina-Treonina Quinases TOR/metabolismo
6.
Nat Genet ; 48(12): 1564-1569, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27749843

RESUMO

Elevated basal serum tryptase levels are present in 4-6% of the general population, but the cause and relevance of such increases are unknown. Previously, we described subjects with dominantly inherited elevated basal serum tryptase levels associated with multisystem complaints including cutaneous flushing and pruritus, dysautonomia, functional gastrointestinal symptoms, chronic pain, and connective tissue abnormalities, including joint hypermobility. Here we report the identification of germline duplications and triplications in the TPSAB1 gene encoding α-tryptase that segregate with inherited increases in basal serum tryptase levels in 35 families presenting with associated multisystem complaints. Individuals harboring alleles encoding three copies of α-tryptase had higher basal serum levels of tryptase and were more symptomatic than those with alleles encoding two copies, suggesting a gene-dose effect. Further, we found in two additional cohorts (172 individuals) that elevated basal serum tryptase levels were exclusively associated with duplication of α-tryptase-encoding sequence in TPSAB1, and affected individuals reported symptom complexes seen in our initial familial cohort. Thus, our findings link duplications in TPSAB1 with irritable bowel syndrome, cutaneous complaints, connective tissue abnormalities, and dysautonomia.


Assuntos
Dor Crônica/genética , Doenças do Tecido Conjuntivo/genética , Variações do Número de Cópias de DNA/genética , Disautonomia Familiar/genética , Gastroenteropatias/genética , Prurido/genética , Dermatopatias/genética , Triptases/sangue , Triptases/genética , Adolescente , Adulto , Idoso , Criança , Dor Crônica/sangue , Dor Crônica/enzimologia , Doenças do Tecido Conjuntivo/sangue , Doenças do Tecido Conjuntivo/enzimologia , Disautonomia Familiar/sangue , Disautonomia Familiar/enzimologia , Feminino , Gastroenteropatias/sangue , Gastroenteropatias/enzimologia , Humanos , Masculino , Pessoa de Meia-Idade , Prurido/sangue , Prurido/enzimologia , Dermatopatias/sangue , Dermatopatias/enzimologia , Adulto Jovem
7.
J Clin Invest ; 126(10): 4030-4044, 2016 10 03.
Artigo em Inglês | MEDLINE | ID: mdl-27643438

RESUMO

In addition to the infectious consequences of immunodeficiency, patients with Wiskott-Aldrich syndrome (WAS) often suffer from poorly understood exaggerated immune responses that result in autoimmunity and elevated levels of serum IgE. Here, we have shown that WAS patients and mice deficient in WAS protein (WASP) frequently develop IgE-mediated reactions to common food allergens. WASP-deficient animals displayed an adjuvant-free IgE-sensitization to chow antigens that was most pronounced for wheat and soy and occurred under specific pathogen-free as well as germ-free housing conditions. Conditional deletion of Was in FOXP3+ Tregs resulted in more severe Th2-type intestinal inflammation than that observed in mice with global WASP deficiency, indicating that allergic responses to food allergens are dependent upon loss of WASP expression in this immune compartment. While WASP-deficient Tregs efficiently contained Th1- and Th17-type effector differentiation in vivo, they failed to restrain Th2 effector responses that drive allergic intestinal inflammation. Loss of WASP was phenotypically associated with increased GATA3 expression in effector memory FOXP3+ Tregs, but not in naive-like FOXP3+ Tregs, an effect that occurred independently of increased IL-4 signaling. Our results reveal a Treg-specific role for WASP that is required for prevention of Th2 effector cell differentiation and allergic sensitization to dietary antigens.


Assuntos
Hipersensibilidade Alimentar/metabolismo , Fatores de Transcrição Forkhead/fisiologia , Linfócitos T Reguladores/metabolismo , Células Th2/imunologia , Proteína da Síndrome de Wiskott-Aldrich/genética , Animais , Diferenciação Celular/imunologia , Feminino , Hipersensibilidade Alimentar/imunologia , Humanos , Imunoglobulina E/fisiologia , Masculino , Camundongos da Linhagem 129 , Camundongos Knockout , Mutação , Linfócitos T Reguladores/imunologia , Transcriptoma , Proteína da Síndrome de Wiskott-Aldrich/metabolismo
8.
J Allergy Clin Immunol ; 133(5): 1400-9, 1409.e1-5, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24589341

RESUMO

BACKGROUND: Identifying genetic syndromes that lead to significant atopic disease can open new pathways for investigation and intervention in allergy. OBJECTIVE: We sought to define a genetic syndrome of severe atopy, increased serum IgE levels, immune deficiency, autoimmunity, and motor and neurocognitive impairment. METHODS: Eight patients from 2 families with similar syndromic features were studied. Thorough clinical evaluations, including brain magnetic resonance imaging and sensory evoked potentials, were performed. Peripheral lymphocyte flow cytometry, antibody responses, and T-cell cytokine production were measured. Whole-exome sequencing was performed to identify disease-causing mutations. Immunoblotting, quantitative RT-PCR, enzymatic assays, nucleotide sugar, and sugar phosphate analyses, along with matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry of glycans, were used to determine the molecular consequences of the mutations. RESULTS: Marked atopy and autoimmunity were associated with increased T(H)2 and T(H)17 cytokine production by CD4(+) T cells. Bacterial and viral infection susceptibility were noted along with T-cell lymphopenia, particularly of CD8(+) T cells, and reduced memory B-cell numbers. Apparent brain hypomyelination resulted in markedly delayed evoked potentials and likely contributed to neurologic abnormalities. Disease segregated with novel autosomal recessive mutations in a single gene, phosphoglucomutase 3 (PGM3). Although PGM3 protein expression was variably diminished, impaired function was demonstrated by decreased enzyme activity and reduced uridine diphosphate-N-acetyl-D-glucosamine, along with decreased O- and N-linked protein glycosylation in patients' cells. These results define a new congenital disorder of glycosylation. CONCLUSIONS: Autosomal recessive hypomorphic PGM3 mutations underlie a disorder of severe atopy, immune deficiency, autoimmunity, intellectual disability, and hypomyelination.


Assuntos
Doenças Autoimunes/genética , Transtornos Cognitivos/genética , Imunodeficiência de Variável Comum/genética , Doenças Genéticas Inatas/genética , Hipersensibilidade/genética , Mutação , Fosfoglucomutase/genética , Doenças Autoimunes/enzimologia , Doenças Autoimunes/imunologia , Doenças Autoimunes/patologia , Linfócitos B/enzimologia , Linfócitos B/imunologia , Linfócitos B/patologia , Linfócitos T CD8-Positivos/enzimologia , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/patologia , Criança , Pré-Escolar , Transtornos Cognitivos/enzimologia , Transtornos Cognitivos/imunologia , Transtornos Cognitivos/patologia , Imunodeficiência de Variável Comum/enzimologia , Imunodeficiência de Variável Comum/imunologia , Imunodeficiência de Variável Comum/patologia , Família , Feminino , Doenças Genéticas Inatas/enzimologia , Doenças Genéticas Inatas/imunologia , Doenças Genéticas Inatas/patologia , Humanos , Hipersensibilidade/enzimologia , Hipersensibilidade/imunologia , Hipersensibilidade/patologia , Imunoglobulina E/genética , Imunoglobulina E/imunologia , Masculino , Linhagem , Fosfoglucomutase/imunologia , Fosfoglucomutase/metabolismo , Células Th17/enzimologia , Células Th17/imunologia , Células Th17/patologia , Células Th2/enzimologia , Células Th2/imunologia , Células Th2/patologia , Adulto Jovem
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