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1.
Artigo em Inglês | MEDLINE | ID: mdl-31669435

RESUMO

BACKGROUND: Food allergy (FA) affects an increasing proportion of children for reasons that remain obscure. Novel disease biomarkers and curative treatment options are strongly needed. OBJECTIVE: We sought to apply untargeted metabolomic profiling to identify pathogenic mechanisms and candidate disease biomarkers in patients with FA. METHODS: Mass spectrometry-based untargeted metabolomic profiling was performed on serum samples of children with either FA alone, asthma alone, or both FA and asthma, as well as healthy pediatric control subjects. RESULTS: In this pilot study patients with FA exhibited a disease-specific metabolomic signature compared with both control subjects and asthmatic patients. In particular, FA was uniquely associated with a marked decrease in sphingolipid levels, as well as levels of a number of other lipid metabolites, in the face of normal frequencies of circulating natural killer T cells. Specific comparison of patients with FA and asthmatic patients revealed differences in the microbiota-sensitive aromatic amino acid and secondary bile acid metabolism. Children with both FA and asthma exhibited a metabolomic profile that aligned with that of FA alone but not asthma. Among children with FA, the history of severe systemic reactions and the presence of multiple FAs were associated with changes in levels of tryptophan metabolites, eicosanoids, plasmalogens, and fatty acids. CONCLUSIONS: Children with FA have a disease-specific metabolomic profile that is informative of disease mechanisms and severity and that dominates in the presence of asthma. Lower levels of sphingolipids and ceramides and other metabolomic alterations observed in children with FA might reflect the interplay between an altered microbiota and immune cell subsets in the gut.

2.
Artigo em Inglês | MEDLINE | ID: mdl-31629014

RESUMO

BACKGROUND: Mutations affecting DNA polymerases have been implicated in genomic instability and cancer development, but the mechanisms by which they can affect the immune system remain largely unexplored. OBJECTIVE: We sought to establish the role of DNA polymerase δ1 catalytic subunit (POLD1) as the cause of a primary immunodeficiency in an extended kindred. METHODS: We performed whole-exome and targeted gene sequencing, lymphocyte characterization, molecular and functional analyses of the DNA polymerase δ (Polδ) complex, and T- and B-cell antigen receptor repertoire analysis. RESULTS: We identified a missense mutation (c. 3178C>T; p.R1060C) in POLD1 in 3 related subjects who presented with recurrent, especially herpetic, infections and T-cell lymphopenia with impaired T-cell but not B-cell proliferation. The mutation destabilizes the Polδ complex, leading to ineffective recruitment of replication factor C to initiate DNA replication. Molecular dynamics simulation revealed that the R1060C mutation disrupts the intramolecular interaction between the POLD1 CysB motif and the catalytic domain and also between POLD1 and the Polδ subunit POLD2. The patients exhibited decreased numbers of naive CD4 and especially CD8 T cells in favor of effector memory subpopulations. This skewing was associated with oligoclonality and restricted T-cell receptor ß-chain V-J pairing in CD8+ but not CD4+ T cells, suggesting that POLD1R1060C differentially affects peripheral CD8+ T-cell expansion and possibly thymic selection. CONCLUSION: These results identify gene defects in POLD1 as a novel cause of T-cell immunodeficiency.

3.
J Clin Immunol ; 39(7): 623-640, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31478130

RESUMO

Regulatory T (Treg) cells expressing the transcription factor forkhead box P3 (Foxp3) play a requisite role in the maintenance of immunological homeostasis and prevention of peripheral self-tolerance breakdown. Although Foxp3 by itself is neither necessary nor sufficient to specify many aspects of the Treg cell phenotype, its sustained expression in Treg cells is indispensable for their phenotypic stability, metabolic fitness, and regulatory function. In this review, we summarize recent advances in Treg cell biology, with a particular emphasis on the role of Foxp3 as a transcriptional modulator and metabolic gatekeeper essential to an effective immune regulatory response. We discuss these findings in the context of human inborn errors of immune dysregulation, with a focus on FOXP3 mutations, leading to Treg cell deficiency. We also highlight emerging concepts of therapeutic Treg cell reprogramming to restore tolerance in the settings of immune dysregulatory disorders.

4.
Nat Immunol ; 20(9): 1208-1219, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31384057

RESUMO

Regulatory T cells (Treg cells) deficient in the transcription factor Foxp3 lack suppressor function and manifest an effector T (Teff) cell-like phenotype. We demonstrate that Foxp3 deficiency dysregulates metabolic checkpoint kinase mammalian target of rapamycin (mTOR) complex 2 (mTORC2) signaling and gives rise to augmented aerobic glycolysis and oxidative phosphorylation. Specific deletion of the mTORC2 adaptor gene Rictor in Foxp3-deficient Treg cells ameliorated disease in a Foxo1 transcription factor-dependent manner. Rictor deficiency re-established a subset of Treg cell genetic circuits and suppressed the Teff cell-like glycolytic and respiratory programs, which contributed to immune dysregulation. Treatment of Treg cells from patients with FOXP3 deficiency with mTOR inhibitors similarly antagonized their Teff cell-like program and restored suppressive function. Thus, regulatory function can be re-established in Foxp3-deficient Treg cells by targeting their metabolic pathways, providing opportunities to restore tolerance in Treg cell disorders.


Assuntos
Reprogramação Celular/imunologia , Fatores de Transcrição Forkhead/genética , Alvo Mecanístico do Complexo 2 de Rapamicina/metabolismo , Proteína Companheira de mTOR Insensível à Rapamicina/genética , Linfócitos T Reguladores/imunologia , Animais , Células Cultivadas , Feminino , Regulação da Expressão Gênica , Glicólise/fisiologia , Humanos , Masculino , Alvo Mecanístico do Complexo 2 de Rapamicina/antagonistas & inibidores , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fosforilação Oxidativa , Transdução de Sinais , Linfócitos T Reguladores/citologia
5.
Circulation ; 140(10): 846-863, 2019 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-31266349

RESUMO

BACKGROUND: Transplantation is the treatment of choice for many patients with end-stage organ disease. Despite advances in immunosuppression, long-term outcomes remain suboptimal, hampered by drug toxicity and immune-mediated injury, the leading cause of late graft loss. The development of therapies that promote regulation while suppressing effector immunity is imperative to improve graft survival and minimize conventional immunosuppression. Notch signaling is a highly conserved pathway pivotal to T-cell differentiation and function, rendering it a target of interest in efforts to manipulate T cell-mediated immunity. METHODS: We investigated the pattern of Notch-1 expression in effector and regulatory T cells (Tregs) in both murine and human recipients of a solid-organ transplant. Using a selective human anti-Notch-1 antibody (aNotch-1), we examined the effect of Notch-1 receptor inhibition in full major histocompatibility complex-mismatch murine cardiac and lung transplant models, and in a humanized skin transplant model. On the basis of our findings, we further used a genetic approach to investigate the effect of selective Notch-1 inhibition in Tregs. RESULTS: We observed an increased proportion of Tregs expressing surface and intracellular (activated) Notch-1 in comparison with conventional T cells, both in mice with transplants and in the peripheral blood of patients with transplants. In the murine cardiac transplant model, peritransplant administration of aNotch-1 (days 0, 2, 4, 6, 8, and 10) significantly prolonged allograft survival in comparison with immunoglobulin G-treated controls. Similarly, aNotch-1 treatment improved both histological and functional outcomes in the murine lung transplant model. The use of aNotch-1 resulted in a reduced proportion of both splenic and intragraft conventional T cells, while increasing the proportion of Tregs. Furthermore, Tregs isolated from aNotch-1-treated mice showed enhanced suppressive function on a per-cell basis, confirmed with selective Notch-1 deletion in Tregs (Foxp3EGFPCreNotch1fl/fl). Notch-1 blockade inhibited the mammalian target of rapamycin pathway and increased the phosphorylation of STAT5 (signal transducer and activator of transcription 5) in murine Tregs. Notch-1low Tregs isolated from human peripheral blood exhibited more potent suppressive capacity than Notch-1high Tregs. Last, the combination of aNotch-1 with costimulation blockade induced long-term tolerance in a cardiac transplant model, and this tolerance was dependent on CTLA-4 (cytotoxic T-lymphocyte-associated antigen-4) signaling. CONCLUSIONS: Our data reveal a promising, clinically relevant approach for immune modulation in transplantation by selectively targeting Notch-1.

6.
J Allergy Clin Immunol Pract ; 7(8): 2790-2800.e15, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31238161

RESUMO

BACKGROUND: LPS-responsive beige-like anchor (LRBA) deficiency presents with susceptibility to infections, autoimmunity, and lymphoproliferation. The long-term efficacy of cytotoxic T-lymphocyte-associated antigen 4-immunoglobulin (abatacept) as targeted therapy for its immune dysregulatory features remains to be established. OBJECTIVE: To determine the clinical and immunologic features of LRBA deficiency and long-term efficacy of abatacept treatment in controlling the different disease manifestations. METHODS: Twenty-two LRBA-deficient patients were recruited from different immunology centers and followed prospectively. Eighteen patients on abatacept were evaluated every 3 months for long-term clinical and immunologic responses. LRBA expression, lymphocyte subpopulations, and circulating T follicular helper cells were determined by flow cytometry. RESULTS: The mean age of the patients was 13.4 ± 7.9 years, and the follow-up period was 3.4 ± 2.3 years. Recurrent infections (n = 19 [86.4%]), immune dysregulation (n = 18 [81.8%]), and lymphoproliferation (n = 16 [72.7%]) were common clinical features. The long-term benefits of abatacept in 16 patients were demonstrated by complete control of lymphoproliferation and chronic diarrhea followed by immune dysregulation, most notably autoimmune cytopenias. Weekly or every other week administration of abatacept gave better disease control compared with every 4 weeks. There were no serious side effects related to the abatacept therapy. Circulating T follicular helper cell frequencies were found to be a reliable biomarker of disease activity, which decreased on abatacept therapy in most subjects. However, high circulating T follicular helper cell frequencies persisted in 2 patients who had a more severe disease phenotype that was relatively resistant to abatacept therapy. CONCLUSIONS: Long-term abatacept therapy is effective in most patients with LRBA deficiency.

7.
J Clin Immunol ; 39(1): 37-44, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30543054

RESUMO

PURPOSE: Human signal transducer and activator of transcription 1 (STAT1) gain-of-function (GOF) mutations present with a broad range of manifestations ranging from chronic mucocutaneous candidiasis and autoimmunity to combined immunodeficiency (CID). So far, there is very limited experience with hematopoietic stem cell transplantation (HSCT) as a therapeutic modality in this disorder. Here, we describe two patients with heterozygous STAT1 GOF mutations mimicking CID who were treated with HSCT. METHODS: Data on the HSC sources, conditioning regimen, graft-versus-host disease (GvHD) and antimicrobial prophylaxis, and the post-transplant course including engraftment, GvHD, transplant-related complications, infections, chimerism, and survival were evaluated. Pre- and post-transplant immunological studies included enumeration of circulating interferon gamma (IFN-γ)- and interleukin 17 (IL-17)-expressing CD4+ T cells and analysis of IFN-ß-induced STAT1 phosphorylation in patient 1 (P1)'s T cells. RESULTS: P1 was transplanted with cord blood from an HLA-identical sibling, and P2 with bone marrow from a fully matched unrelated donor using a reduced toxicity conditioning regimen. While P1 completely recovered from her disease, P2 suffered from systemic CMV disease and secondary graft failure and died due to severe pulmonary involvement and hemorrhage. The dysregulated IFN-γ production, suppressed IL-17 response, and enhanced STAT1 phosphorylation previously found in the CD4+ T cells of P1 were normalized following transplantation. CONCLUSION: HSCT could be an alternative and curative therapeutic option for selected STAT1 GOF mutant patients with progressive life-threatening disease unresponsive to conventional therapy. Morbidity and mortality-causing complications included secondary graft failure, infections, and bleeding.


Assuntos
Mutação com Ganho de Função/genética , Doença Enxerto-Hospedeiro/genética , Fator de Transcrição STAT1/genética , Autoimunidade/genética , Linfócitos T CD4-Positivos/metabolismo , Pré-Escolar , Feminino , Transplante de Células-Tronco Hematopoéticas/métodos , Heterozigoto , Humanos , Masculino , Condicionamento Pré-Transplante/métodos
9.
J Allergy Clin Immunol ; 141(3): 1050-1059.e10, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28601686

RESUMO

BACKGROUND: LPS-responsive beige-like anchor protein (LRBA) and cytotoxic T lymphocyte-associated antigen 4 (CTLA4) deficiencies give rise to overlapping phenotypes of immune dysregulation and autoimmunity, with dramatically increased frequencies of circulating follicular helper T (cTFH) cells. OBJECTIVE: We sought to determine the mechanisms of cTFH cell dysregulation in patients with LRBA deficiency and the utility of monitoring cTFH cells as a correlate of clinical response to CTLA4-Ig therapy. METHODS: cTFH cells and other lymphocyte subpopulations were characterized. Functional analyses included in vitro follicular helper T (TFH) cell differentiation and cTFH/naive B-cell cocultures. Serum soluble IL-2 receptor α chain levels and in vitro immunoglobulin production by cultured B cells were quantified by using ELISA. RESULTS: cTFH cell frequencies in patients with LRBA or CTLA4 deficiency sharply decreased with CTLA4-Ig therapy in parallel with other markers of immune dysregulation, including soluble IL-2 receptor α chain, CD45RO+CD4+ effector T cells, and autoantibodies, and this was predictive of favorable clinical responses. cTFH cells in patients with LRBA deficiency were biased toward a TH1-like cell phenotype, which was partially reversed by CTLA4-Ig therapy. LRBA-sufficient but not LRBA-deficient regulatory T cells suppressed in vitro TFH cell differentiation in a CTLA4-dependent manner. LRBA-deficient TFH cells supported in vitro antibody production by naive LRBA-sufficient B cells. CONCLUSIONS: cTFH cell dysregulation in patients with LRBA deficiency reflects impaired control of TFH cell differentiation because of profoundly decreased CTLA4 expression on regulatory T cells and probably contributes to autoimmunity in patients with this disease. Serial monitoring of cTFH cell frequencies is highly useful in gauging the clinical response of LRBA-deficient patients to CTLA4-Ig therapy.

10.
J Clin Immunol ; 37(8): 811-819, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29058101

RESUMO

PURPOSE: The dedicator of cytokinesis 8 (DOCK8) deficiency is an autosomal recessive-combined immunodeficiency whose clinical spectra include recurrent infections, autoimmunity, malignancies, elevated serum IgE, eczema, and food allergies. Here, we report on patients with loss of function DOCK8 mutations with profound immune dysregulation suggestive of an immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX)-like disorder. METHODS: Immunophenotyping of lymphocyte subpopulations and analysis of DOCK8 protein expression were evaluated by flow cytometry. T regulatory (Treg) cells were isolated by cell sorting, and their suppressive activity was analyzed by flow cytometry. Gene mutational analysis was performed by whole-exome and Sanger sequencing. RESULTS: Patient 1 (P1) presented at 10 months of age with chronic severe diarrhea and active colitis in the absence of an infectious trigger, severe eczema with elevated serum IgE, and autoimmune hemolytic anemia, suggestive of an IPEX-related disorder. Whole-exome sequencing revealed a homozygous nonsense mutation in DOCK8 at the DOCK-homology region (DHR)-1 (c.1498C>T; p. R500X). Patient P2, a cousin of P1 who carries the same DOCK8 nonsense mutation, presented with eczema and recurrent ear infections in early infancy, and she developed persistent diarrhea by 3 years of age. Patient P3 presented with lymphoproliferation, severe eczema with allergic dysregulation, and chronic diarrhea with colitis. She harbored a homozygous loss of function DOCK8 mutation (c.2402 -1G→A). Treg cell function was severely compromised by both DOCK8 mutations. CONCLUSION: DOCK8 deficiency may present severe immune dysregulation with features that may overlap with those of IPEX and other IPEX-like disorders.


Assuntos
Transtornos Cromossômicos/diagnóstico , Diabetes Mellitus Tipo 1/congênito , Diarreia/diagnóstico , Doenças Genéticas Ligadas ao Cromossomo X/diagnóstico , Fatores de Troca do Nucleotídeo Guanina/genética , Hipersensibilidade/diagnóstico , Doenças do Sistema Imunitário/congênito , Infecção/diagnóstico , Mutação/genética , Linfócitos T Reguladores/imunologia , Anemia Hemolítica , Pré-Escolar , Diabetes Mellitus Tipo 1/diagnóstico , Feminino , Genes Recessivos/genética , Humanos , Doenças do Sistema Imunitário/diagnóstico , Imunoglobulina E/metabolismo , Imunofenotipagem , Lactente
12.
J Allergy Clin Immunol ; 139(5): 1629-1640.e2, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28139313

RESUMO

BACKGROUND: Gain-of-function (GOF) mutations in the human signal transducer and activator of transcription 1 (STAT1) manifest in immunodeficiency and autoimmunity with impaired TH17 cell differentiation and exaggerated responsiveness to type I and II interferons. Allogeneic bone marrow transplantation has been attempted in severely affected patients, but outcomes have been poor. OBJECTIVE: We sought to define the effect of increased STAT1 activity on T helper cell polarization and to investigate the therapeutic potential of ruxolitinib in treating autoimmunity secondary to STAT1 GOF mutations. METHODS: We used in vitro polarization assays, as well as phenotypic and functional analysis of STAT1-mutated patient cells. RESULTS: We report a child with a novel mutation in the linker domain of STAT1 who had life-threatening autoimmune cytopenias and chronic mucocutaneous candidiasis. Naive lymphocytes from the affected patient displayed increased TH1 and follicular T helper cell and suppressed TH17 cell responses. The mutation augmented cytokine-induced STAT1 phosphorylation without affecting dephosphorylation kinetics. Treatment with the Janus kinase 1/2 inhibitor ruxolitinib reduced hyperresponsiveness to type I and II interferons, normalized TH1 and follicular T helper cell responses, improved TH17 differentiation, cured mucocutaneous candidiasis, and maintained remission of immune-mediated cytopenias. CONCLUSIONS: Autoimmunity and infection caused by STAT1 GOF mutations are the result of dysregulated T helper cell responses. Janus kinase inhibitor therapy could represent an effective targeted treatment for long-term disease control in severely affected patients for whom hematopoietic stem cell transplantation is not available.


Assuntos
Anemia Hemolítica Autoimune/genética , Inibidores de Proteínas Quinases/farmacologia , Púrpura Trombocitopênica Idiopática/genética , Pirazóis/farmacologia , Fator de Transcrição STAT1/genética , Células Th1/efeitos dos fármacos , Células Th17/efeitos dos fármacos , Anemia Hemolítica Autoimune/imunologia , Autoimunidade/efeitos dos fármacos , Candidíase Mucocutânea Crônica/genética , Candidíase Mucocutânea Crônica/imunologia , Criança , Citocinas/imunologia , Feminino , Humanos , Janus Quinases/antagonistas & inibidores , Mutação , Púrpura Trombocitopênica Idiopática/imunologia , Fator de Transcrição STAT1/imunologia , Células Th1/imunologia , Células Th17/imunologia
13.
Nat Med ; 22(9): 1013-22, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27479084

RESUMO

Mechanisms by which regulatory T (Treg) cells fail to control inflammation in asthma remain poorly understood. We show that a severe asthma-associated polymorphism in the gene encoding the interleukin (IL)-4 receptor alpha chain (Il4ra(R576)) promotes conversion of induced Treg (iTreg) cells toward a T helper 17 (TH17) cell fate. This skewing is mediated by the recruitment by IL-4Rα(R576) of the growth-factor-receptor-bound protein 2 (GRB2) adaptor protein, which drives IL-17 expression by activating a pathway that involves extracellular-signal-regulated kinase, IL-6 and the transcription factor STAT3. Treg cell-specific deletion of genes that regulate TH17 cell differentiation, including Il6ra and RAR-related orphan receptor gamma (Rorc), but not of Il4 or Il13, prevented exacerbated airway inflammation in mice expressing Il4ra(R576) (hereafter referred to as Il4ra(R576) mice). Furthermore, treatment of Il4ra(R576) mice with a neutralizing IL-6-specific antibody prevented iTreg cell reprogramming into TH17-like cells and protected against severe airway inflammation. These findings identify a previously unknown mechanism for the development of mixed TH2-TH17 cell inflammation in genetically prone individuals and point to interventions that stabilize iTreg cells as potentially effective therapeutic strategies.


Assuntos
Asma/genética , Subunidade alfa de Receptor de Interleucina-4/genética , Pulmão/imunologia , Receptores de Superfície Celular/genética , Hipersensibilidade Respiratória/imunologia , Linfócitos T Reguladores/imunologia , Células Th17/imunologia , Adolescente , Adulto , Animais , Anticorpos Neutralizantes/farmacologia , Asma/imunologia , Estudos de Casos e Controles , Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/imunologia , Criança , Modelos Animais de Doenças , Feminino , Citometria de Fluxo , Proteína Adaptadora GRB2/imunologia , Perfilação da Expressão Gênica , Humanos , Immunoblotting , Imunoprecipitação , Inflamação/imunologia , Interleucina-13/imunologia , Interleucina-17/imunologia , Subunidade alfa de Receptor de Interleucina-4/imunologia , Interleucina-6/imunologia , Masculino , Camundongos , Pessoa de Meia-Idade , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/genética , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/imunologia , Polimorfismo Genético , Reação em Cadeia da Polimerase em Tempo Real , Receptores de Interleucina-6/genética , Receptores de Interleucina-6/imunologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fator de Transcrição STAT3/imunologia , Linfócitos T Reguladores/efeitos dos fármacos , Células Th17/efeitos dos fármacos , Adulto Jovem
14.
J Clin Immunol ; 36(7): 641-8, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27379765

RESUMO

PURPOSE: Loss and gain-of-function (GOF) mutations in human signal transducer and activator of transcription 1 (STAT1) lead to distinct phenotypes. Although recurrent infections are common to both types of STAT1 mutations, GOF mutations are distinguished by chronic mucocutaneous candidiasis and autoimmunity. However, the clinical spectra of STAT1 GOF mutations continue to expand. We here describe two patients with STAT1 GOF mutations presenting early in life with combined immunodeficiency (CID). METHODS: Clinical data and laboratory findings including immunophenotyping, level of interferon (IFN)-γ/IL-17(+) T cells, interferon-induced STAT1 phosphorylation, and JAK inhibitor assays were evaluated. Sequencing of STAT1 gene was performed by Sanger sequencer. RESULTS: Patient 1 (P1) had persistent oral candidiasis and cytomegalovirus (CMV) infection since 2 months of age and later developed cavitary lung lesions due to Mycobacterium tuberculosis. Patient 2 (P2) presented with oral candidiasis and recurrent pneumonia at 4 months of age and subsequently developed CMV pneumonitis. Both patients suffered heterozygous missense mutations in STAT1, leading to deleterious amino acid substitutions in the DNA binding domain (P1: c.1154C > T; p.T385M; P2. c.971G > T; p.C324F). Circulating CD4(+) T cells of both patients exhibited increased interferon-γ and decreased IL-17 expression as compared to controls. They also exhibited increased IFN-ß and -γ-induced STAT1 phosphorylation that was reversed upon treatment with the JAK kinase inhibitor ruxolitinib. CONCLUSION: STAT1 GOF mutations may present early in life with CID, consistent with the clinical heterogeneity of the disease. JAK kinase inhibitors may potentially be useful in some patients as adjunct therapy pending definitive treatment with bone marrow transplantation.


Assuntos
Mutação com Ganho de Função , Heterozigoto , Fator de Transcrição STAT1/genética , Imunodeficiência Combinada Severa/genética , Imunodeficiência Combinada Severa/imunologia , Idade de Início , Autoimunidade/genética , Biomarcadores , Citocinas/genética , Citocinas/metabolismo , Análise Mutacional de DNA , Feminino , Expressão Gênica , Genes Dominantes , Humanos , Isotipos de Imunoglobulinas/sangue , Isotipos de Imunoglobulinas/imunologia , Imunofenotipagem , Lactente , Infecção/diagnóstico , Infecção/etiologia , Interferon beta/metabolismo , Interferon beta/farmacologia , Janus Quinases/antagonistas & inibidores , Janus Quinases/metabolismo , Masculino , Linhagem , Fosforilação , Pirazóis/farmacologia , Fator de Transcrição STAT1/metabolismo , Imunodeficiência Combinada Severa/complicações , Imunodeficiência Combinada Severa/diagnóstico , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , Tomografia Computadorizada por Raios X , Turquia
15.
J Allergy Clin Immunol ; 138(5): 1384-1394.e2, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27350570

RESUMO

BACKGROUND: The autosomal recessive hyper-IgE syndrome (HIES) caused by dedicator of cytokinesis 8 (DOCK8) deficiency shares clinical features with autosomal dominant HIES because of signal transducer and activator of transcription 3 (STAT3) mutations, including recurrent infections and mucocutaneous candidiasis, which are suggestive of TH17 cell dysfunction. The mechanisms underlying this phenotypic overlap are unclear. OBJECTIVE: We sought to elucidate common mechanisms operating in the different forms of HIES. METHODS: We analyzed the differentiation of CD4+ TH cell subsets in control and DOCK8-deficient subjects. We also examined the role of DOCK8 in regulating STAT3 activation in T cells. TH cell differentiation was analyzed by ELISA, flow cytometry, and real-time PCR measurements of cytokines and TH cell transcription factors. The interaction of DOCK8 and STAT3 signaling pathways was examined by using flow cytometry, immunofluorescence, coimmunoprecipitation, and gene expression analysis. RESULTS: There was a profound block in the differentiation of DOCK8-deficient naive CD4+ T cells into TH17 cells. A missense mutation that disrupts DOCK8 guanine nucleotide exchange factor (GEF) activity while sparing protein expression also impaired TH17 cell differentiation. DOCK8 constitutively associated with STAT3 independent of GEF activity, whereas it regulated STAT3 phosphorylation in a GEF activity-dependent manner. DOCK8 also promoted STAT3 translocation to the nucleus and induction of STAT3-dependent gene expression. CONCLUSION: DOCK8 interacts with STAT3 and regulates its activation and the outcome of STAT3-dependent TH17 differentiation. These findings might explain the phenotypic overlap between DOCK8 deficiency and autosomal dominant HIES.


Assuntos
Fatores de Troca do Nucleotídeo Guanina/deficiência , Fatores de Troca do Nucleotídeo Guanina/imunologia , Síndromes de Imunodeficiência/imunologia , Fator de Transcrição STAT3/imunologia , Células Th17/imunologia , Autoanticorpos/imunologia , Diferenciação Celular , Criança , Pré-Escolar , Feminino , Fatores de Troca do Nucleotídeo Guanina/genética , Fatores de Troca do Nucleotídeo Guanina/metabolismo , Humanos , Síndromes de Imunodeficiência/genética , Síndromes de Imunodeficiência/metabolismo , Lactente , Células Jurkat , Masculino , Mutação , Fosforilação , Transporte Proteico , Fator de Transcrição STAT3/metabolismo
16.
Nat Immunol ; 16(11): 1162-73, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26437242

RESUMO

Receptors of the Notch family direct the differentiation of helper T cell subsets, but their influence on regulatory T cell (T(reg) cell) responses is obscure. We found here that lineage-specific deletion of components of the Notch pathway enhanced T(reg) cell-mediated suppression of type 1 helper T cell (T(H)1 cell) responses and protected against their T(H)1 skewing and apoptosis. In contrast, expression in T(reg) cells of a gain-of-function transgene encoding the Notch1 intracellular domain resulted in lymphoproliferation, exacerbated T(H)1 responses and autoimmunity. Cell-intrinsic canonical Notch signaling impaired T(reg) cell fitness and promoted the acquisition by T(reg) cells of a T(H)1 cell-like phenotype, whereas non-canonical Notch signaling dependent on the adaptor Rictor activated the kinase AKT-transcription factor Foxo1 axis and impaired the epigenetic stability of Foxp3. Our findings establish a critical role for Notch signaling in controlling peripheral T(reg) cell function.


Assuntos
Tolerância Periférica , Receptor Notch1/imunologia , Linfócitos T Reguladores/imunologia , Animais , Proteínas de Transporte/genética , Proteínas de Transporte/imunologia , Epigênese Genética , Feminino , Fatores de Transcrição Forkhead/genética , Fatores de Transcrição Forkhead/imunologia , Doença Enxerto-Hospedeiro/imunologia , Doença Enxerto-Hospedeiro/prevenção & controle , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Mutação , Proteína Companheira de mTOR Insensível à Rapamicina , Receptor Notch1/deficiência , Receptor Notch1/genética , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/imunologia , Transdução de Sinais/imunologia , Células Th1/imunologia , Transcriptoma
17.
Immunity ; 43(2): 289-303, 2015 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-26231118

RESUMO

Commensal microbiota promote mucosal tolerance in part by engaging regulatory T (Treg) cells via Toll-like receptors (TLRs). We report that Treg-cell-specific deletion of the TLR adaptor MyD88 resulted in deficiency of intestinal Treg cells, a reciprocal increase in T helper 17 (Th17) cells and heightened interleukin-17 (IL-17)-dependent inflammation in experimental colitis. It also precipitated dysbiosis with overgrowth of segmented filamentous bacteria (SFB) and increased microbial loads in deep tissues. The Th17 cell dysregulation and bacterial dysbiosis were linked to impaired anti-microbial intestinal IgA responses, related to defective MyD88 adaptor- and Stat3 transcription factor-dependent T follicular regulatory and helper cell differentiation in the Peyer's patches. These findings establish an essential role for MyD88-dependent microbial sensing by Treg cells in enforcing mucosal tolerance and maintaining commensalism by promoting intestinal Treg cell formation and anti-commensal IgA responses.


Assuntos
Colite/imunologia , Infecções por Escherichia coli/imunologia , Escherichia coli/imunologia , Intestinos/imunologia , Fator 88 de Diferenciação Mieloide/metabolismo , Linfócitos T Reguladores/imunologia , Células Th17/imunologia , Animais , Anticorpos Antibacterianos/metabolismo , Diferenciação Celular , Células Cultivadas , Tolerância Imunológica , Imunidade nas Mucosas , Imunoglobulina A/metabolismo , Intestinos/microbiologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Modelos Animais , Fator 88 de Diferenciação Mieloide/genética , Fator de Transcrição STAT3/metabolismo , Simbiose/imunologia , Receptores Toll-Like/metabolismo
18.
Pediatr Nephrol ; 30(7): 1197-202, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25911531

RESUMO

BACKGROUND: Immunodysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) disorder is an autoimmune disease caused by loss-of-function mutations in the gene encoding the forkhead box P3 (FOXP3) transcription factor. These mutations affect the normal function of circulating regulatory T cells. IPEX is characterized by profound immune dysregulation leading to dermatitis, enteropathy, multiple endocrinopathies and failure to thrive. Different forms of renal injury have also been noted in these patients but these have been described to a very limited extent. CASE-DIAGNOSIS: Three patients with IPEX with characteristic renal findings and mutations in FOXP3, including one novel mutation, are described. Case presentations are followed by a review of the renal manifestations noted in IPEX and the range of therapeutic options for this disorder. CONCLUSIONS: We recommend that IPEX be considered in the differential diagnosis of young children who present with signs of immune dysregulation with a concomitant renal biopsy demonstrating immune complex deposition in a membranous-like pattern and/or interstitial nephritis.


Assuntos
Doenças Genéticas Ligadas ao Cromossomo X/patologia , Rim/patologia , Adolescente , Doenças Autoimunes/genética , Doenças Autoimunes/imunologia , Biópsia , Criança , Pré-Escolar , Evolução Fatal , Fatores de Transcrição Forkhead/genética , Doenças Genéticas Ligadas ao Cromossomo X/genética , Doenças Genéticas Ligadas ao Cromossomo X/imunologia , Testes Genéticos , Humanos , Lactente , Masculino , Mutação/genética , Pele/patologia , Transplante de Células-Tronco , Síndrome , Linfócitos T Reguladores/imunologia
19.
Immunity ; 42(3): 512-23, 2015 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-25769611

RESUMO

Oral immunotherapy has had limited success in establishing tolerance in food allergy, reflecting failure to elicit an effective regulatory T (Treg) cell response. We show that disease-susceptible (Il4ra(F709)) mice with enhanced interleukin-4 receptor (IL-4R) signaling exhibited STAT6-dependent impaired generation and function of mucosal allergen-specific Treg cells. This failure was associated with the acquisition by Treg cells of a T helper 2 (Th2)-cell-like phenotype, also found in peripheral-blood allergen-specific Treg cells of food-allergic children. Selective augmentation of IL-4R signaling in Treg cells induced their reprogramming into Th2-like cells and disease susceptibility, whereas Treg-cell-lineage-specific deletion of Il4 and Il13 was protective. IL-4R signaling impaired the capacity of Treg cells to suppress mast cell activation and expansion, which in turn drove Th2 cell reprogramming of Treg cells. Interruption of Th2 cell reprogramming of Treg cells might thus provide candidate therapeutic strategies in food allergy.


Assuntos
Hipersensibilidade Alimentar/imunologia , Predisposição Genética para Doença , Imunidade nas Mucosas , Receptores de Superfície Celular/imunologia , Linfócitos T Reguladores/imunologia , Células Th2/imunologia , Adolescente , Alérgenos/imunologia , Animais , Reprogramação Celular/imunologia , Criança , Pré-Escolar , Feminino , Hipersensibilidade Alimentar/genética , Hipersensibilidade Alimentar/patologia , Mucosa Gástrica/imunologia , Mucosa Gástrica/patologia , Regulação da Expressão Gênica , Humanos , Tolerância Imunológica , Lactente , Interleucina-13/deficiência , Interleucina-13/genética , Interleucina-13/imunologia , Interleucina-4/deficiência , Interleucina-4/genética , Interleucina-4/imunologia , Masculino , Mastócitos/imunologia , Mastócitos/patologia , Camundongos , Camundongos Transgênicos , Receptores de Superfície Celular/genética , Fator de Transcrição STAT6/genética , Fator de Transcrição STAT6/imunologia , Transdução de Sinais , Linfócitos T Reguladores/patologia , Células Th2/patologia , Fator de Crescimento Transformador beta/genética , Fator de Crescimento Transformador beta/imunologia
20.
J Allergy Clin Immunol ; 135(1): 217-27, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25468195

RESUMO

BACKGROUND: A number of heritable immune dysregulatory diseases result from defects affecting regulatory T (Treg) cell development, function, or both. They include immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome, which is caused by mutations in forkhead box P3 (FOXP3), and IPEX-like disorders caused by mutations in IL-2 receptor α (IL2RA), signal transducer and activator of transcription 5b (STAT5b), and signal transducer and activator of transcription 1 (STAT1). However, the genetic defects underlying many cases of IPEX-like disorders remain unknown. OBJECTIVE: We sought to identify the genetic abnormalities in patients with idiopathic IPEX-like disorders. METHODS: We performed whole-exome and targeted gene sequencing and phenotypic and functional analyses of Treg cells. RESULTS: A child who presented with an IPEX-like syndrome and severe Treg cell deficiency was found to harbor a nonsense mutation in the gene encoding LPS-responsive beige-like anchor (LRBA), which was previously implicated as a cause of common variable immunodeficiency with autoimmunity. Analysis of subjects with LRBA deficiency revealed marked Treg cell depletion; profoundly decreased expression of canonical Treg cell markers, including FOXP3, CD25, Helios, and cytotoxic T lymphocyte-associated antigen 4; and impaired Treg cell-mediated suppression. There was skewing in favor of memory T cells and intense autoantibody production, with marked expansion of T follicular helper and contraction of T follicular regulatory cells. Whereas the frequency of recent thymic emigrants and the differentiation of induced Treg cells were normal, LRBA-deficient T cells exhibited increased apoptosis and reduced activities of the metabolic sensors mammalian target of rapamycin complexes 1 and 2. CONCLUSION: LRBA deficiency is a novel cause of IPEX-like syndrome and Treg cell deficiency associated with metabolic dysfunction and increased apoptosis of Treg cells.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/deficiência , Proteínas Adaptadoras de Transdução de Sinal/genética , Linfócitos T Reguladores/imunologia , Adolescente , Autoanticorpos/imunologia , Pré-Escolar , Diabetes Mellitus Tipo 1/congênito , Diarreia , Feminino , Doenças Genéticas Ligadas ao Cromossomo X/genética , Doenças Genéticas Ligadas ao Cromossomo X/imunologia , Humanos , Doenças do Sistema Imunitário/congênito , Interleucina-10/imunologia , Masculino , Mutação
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