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1.
Br J Nutr ; : 1-18, 2020 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-31959270

RESUMO

Early malnutrition, the first environmental cause of intrauterine growth restriction, impairs development of the thymus. Alterations of the thymic structure and function are reported at young ages in murine and ovine models. However, descriptions of thymic consequences of fetal malnutrition at adulthood are scarce. This study investigates thymic structure, protein expression and cell selection process observed at postnatal day 180 (PND180) in male offspring of rats exposed to maternal low protein diet (mLPD) compared to control diet during gestation. The thymic index was lower in adult offspring exposed to mLPD (p<0.05). The thymic cortico-medullar ratio was lower in adult offspring exposed to mLPD (p<0.05). At PND180, the protein expression of the lymphotoxin ß receptor (p<0.05), the autoimmune regulator (p<0.05) and Forkhead box P3 (FoxP3; p<0.05) were all significantly lower in mLPD group. The CD4+/CD8+ single positive thymocyte subpopulations ratio and CD4+/CD8+ lymphocyte subpopulations ratio were increased in mLPD group (p<0.05). Among CD3+ lymphocytes, the proportions of CD4+CD8+ double positive lymphocytes, CD31+ recent thymic emigrants and CD4+ FoxP3+ lymphocytes were not significantly different between mLPD and control groups. These findings suggest mLPD during gestation induced long lasting alterations in the development of thymic structure and thymic cell maturation and selection process in adult male rat offspring.

2.
Dis Model Mech ; 12(12)2019 12 20.
Artigo em Inglês | MEDLINE | ID: mdl-31727854

RESUMO

Mutations in the gene AK2 are responsible for reticular dysgenesis (RD), a rare and severe form of primary immunodeficiency in children. RD patients have a severely shortened life expectancy and without treatment die, generally from sepsis soon after birth. The only available therapeutic option for RD is hematopoietic stem cell transplantation (HSCT). To gain insight into the pathophysiology of RD, we previously created zebrafish models for Ak2 deficiencies. One of the clinical features of RD is hearing loss, but its pathophysiology and causes have not been determined. In adult mammals, sensory hair cells of the inner ear do not regenerate; however, their regeneration has been observed in several non-mammalian vertebrates, including zebrafish. Therefore, we used our RD zebrafish models to determine whether Ak2 deficiency affects sensory organ development and/or hair cell regeneration. Our studies indicated that Ak2 is required for the correct development, survival and regeneration of sensory hair cells. Interestingly, Ak2 deficiency induces the expression of several oxidative stress markers and it triggers an increased level of cell death in the hair cells. Finally, we show that glutathione treatment can partially rescue hair cell development in the sensory organs in our RD models, pointing to the potential use of antioxidants as a therapeutic treatment supplementing HSCT to prevent or ameliorate sensorineural hearing deficits in RD patients.

3.
J Clin Immunol ; 39(5): 476-485, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31144250

RESUMO

OBJECTIVES: Mutations affecting the TMEM173 gene cause STING-associated vasculopathy with onset in infancy (SAVI). No standard immunosuppressive treatment approach is able to control disease progression in patients with SAVI. We studied the efficacy and safety of targeting type I IFN signaling with the Janus kinase inhibitor, ruxolitinib. METHODS: We used DNA sequencing to identify mutations in TMEM173 in patients with peripheral blood type I IFN signature. The JAK1/2 inhibitor ruxolitinib was administered on an off-label basis. RESULTS: We identified three patients with SAVI presenting with skin involvement and progressive severe interstitial lung disease. Indirect echocardiographic signs of pulmonary hypertension were present in one case. Following treatment with ruxolitinib, we observed improvements of respiratory function including increased forced vital capacity in two patients, with discontinuation of oxygen therapy and resolution of echocardiographic abnormalities in one case. Efficacy was persistent in one patient and only transitory in the other two patients. Clinical control of skin complications was obtained, and one patient discontinued steroid treatment. One patient, who presented with kidney involvement, showed resolution of hematuria. One patient experienced increased recurrence of severe viral respiratory infections. Monitoring of peripheral blood type I interferon signature during ruxolitinib treatment did not show a stable decrease. CONCLUSIONS: We conclude that targeting type I IFN receptor signaling may represent a promising therapeutic option for a subset of patients with SAVI syndrome and severe lung involvement. However, the occurrence of viral respiratory infection might represent an important cautionary note for the application of such form of treatment.

5.
J Clin Immunol ; 38(1): 13-27, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29086100

RESUMO

The Wiskott-Aldrich syndrome (WAS) is a rare X-linked disorder originally described by Dr. Alfred Wiskott in 1937 and Dr. Robert Aldrich in 1954 as a familial disease characterized by infections, bleeding tendency, and eczema. Today, it is well recognized that the syndrome has a wide clinical spectrum ranging from mild, isolated thrombocytopenia to full-blown presentation that can be complicated by life-threatening hemorrhages, immunodeficiency, atopy, autoimmunity, and cancer. The pathophysiology of classic and emerging features is being elucidated by clinical studies, but remains incompletely defined, which hinders the application of targeted therapies. At the same time, progress of hematopoietic stem cell transplantation and gene therapy offer optimistic prospects for treatment options aimed at the replacement of the defective lymphohematopoietic system that have the potential to provide a cure for this rare and polymorphic disease.


Assuntos
Genes Ligados ao Cromossomo X/genética , Transplante de Células-Tronco Hematopoéticas , Mutação/genética , Proteína da Síndrome de Wiskott-Aldrich/genética , Síndrome de Wiskott-Aldrich/fisiopatologia , Autoimunidade , Eczema , Terapia Genética , Humanos , Neoplasias , Trombocitopenia , Síndrome de Wiskott-Aldrich/genética , Síndrome de Wiskott-Aldrich/terapia
6.
Rev Med Suisse ; 13(557): 739-742, 2017 Apr 05.
Artigo em Francês | MEDLINE | ID: mdl-28722362

RESUMO

Transient hypogammaglobulinemia of infancy is characterized as a reduction of one or more classes of immunoglobulins with a response to vaccines and normal subpopulations of lymphocytes B presenting in the first years of life. The diagnosis is made a posteriori, once the levels of immunoglobulins are normalized, in general between 2 and 4 years of age. Clinical presentation varies : the child may be either asymptomatic or present with recurrent infections, atopy and / or auto-immunity. There are no clinical or immunological features that distinguish this condition from a common variable immunodeficiency (CVID). Because of the risk of severe infections, it is necessary a follow up by a paediatric immunologist. Depending on the presentation and evolution, a prophylaxis with antibiotics or a substitution with immunoglobulins might be indicated.


Assuntos
Agamaglobulinemia/diagnóstico , Imunodeficiência de Variável Comum/diagnóstico , Imunoglobulinas/imunologia , Agamaglobulinemia/imunologia , Agamaglobulinemia/terapia , Linfócitos B/imunologia , Pré-Escolar , Humanos , Lactente
7.
Rev Med Suisse ; 13(557): 763-766, 2017 Apr 05.
Artigo em Francês | MEDLINE | ID: mdl-28722367

RESUMO

Establishing the definitive diagnosis in the case of inherited immune defects (IID) is often challenging because the clinical features can be heterogeneous, atypical and overlapping different disease entities. The next generation sequencing technology (NGS) allows identifying genetic variants that are responsible for the observed clinical presentations. The use of NGS applied to the genes mutated in IIDs or known to be involved in the development, differentiation and regulation of the immune system allows to target hundreds of relevant genes in well characterized patients suspected of carrying inherited immune defects. This approach answers both diagnostic and research needs, facilitates the understanding of the mechanisms that underlie IIDs, and ultimately leads to the discovery of new therapeutic targets.


Assuntos
Sequenciamento de Nucleotídeos em Larga Escala/métodos , Doenças do Sistema Imunitário/diagnóstico , Síndromes de Imunodeficiência/diagnóstico , Humanos , Doenças do Sistema Imunitário/genética , Síndromes de Imunodeficiência/genética , Mutação
8.
J Clin Invest ; 127(5): 1689-1699, 2017 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-28346229

RESUMO

BACKGROUND: Autologous hematopoietic stem cell transplantation (HSCT) of gene-modified cells is an alternative to enzyme replacement therapy (ERT) and allogeneic HSCT that has shown clinical benefit for adenosine deaminase-deficient (ADA-deficient) SCID when combined with reduced intensity conditioning (RIC) and ERT cessation. Clinical safety and therapeutic efficacy were evaluated in a phase II study. METHODS: Ten subjects with confirmed ADA-deficient SCID and no available matched sibling or family donor were enrolled between 2009 and 2012 and received transplantation with autologous hematopoietic CD34+ cells that were modified with the human ADA cDNA (MND-ADA) γ-retroviral vector after conditioning with busulfan (90 mg/m2) and ERT cessation. Subjects were followed from 33 to 84 months at the time of data analysis. Safety of the procedure was assessed by recording the number of adverse events. Efficacy was assessed by measuring engraftment of gene-modified hematopoietic stem/progenitor cells, ADA gene expression, and immune reconstitution. RESULTS: With the exception of the oldest subject (15 years old at enrollment), all subjects remained off ERT with normalized peripheral blood mononuclear cell (PBMC) ADA activity, improved lymphocyte numbers, and normal proliferative responses to mitogens. Three of nine subjects were able to discontinue intravenous immunoglobulin replacement therapy. The MND-ADA vector was persistently detected in PBMCs (vector copy number [VCN] = 0.1-2.6) and granulocytes (VCN = 0.01-0.3) through the most recent visits at the time of this writing. No patient has developed a leukoproliferative disorder or other vector-related clinical complication since transplant. CONCLUSION: These results demonstrate clinical therapeutic efficacy from gene therapy for ADA-deficient SCID, with an excellent clinical safety profile. TRIAL REGISTRATION: ClinicalTrials.gov NCT00794508. FUNDING: Food and Drug Administration Office of Orphan Product Development award, RO1 FD003005; NHLBI awards, PO1 HL73104 and Z01 HG000122; UCLA Clinical and Translational Science Institute awards, UL1RR033176 and UL1TR000124.


Assuntos
Adenosina Desaminase/deficiência , Agamaglobulinemia , Regulação Enzimológica da Expressão Gênica , Terapia Genética , Transplante de Células-Tronco Hematopoéticas , Imunodeficiência Combinada Severa , Transdução Genética , Adenosina Desaminase/biossíntese , Adenosina Desaminase/genética , Adolescente , Agamaglobulinemia/enzimologia , Agamaglobulinemia/genética , Agamaglobulinemia/terapia , Autoenxertos , Criança , Pré-Escolar , Feminino , Vetores Genéticos , Humanos , Lactente , Masculino , Retroviridae , Imunodeficiência Combinada Severa/enzimologia , Imunodeficiência Combinada Severa/genética , Imunodeficiência Combinada Severa/terapia
9.
Blood ; 129(19): 2624-2635, 2017 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-28351939

RESUMO

Retroviral gene therapy has proved efficacious for multiple genetic diseases of the hematopoietic system, but roughly half of clinical gene therapy trial protocols using gammaretroviral vectors have reported leukemias in some of the patients treated. In dramatic contrast, 39 adenosine deaminase-deficient severe combined immunodeficiency (ADA-SCID) patients have been treated with 4 distinct gammaretroviral vectors without oncogenic consequence. We investigated clonal dynamics and diversity in a cohort of 15 ADA-SCID children treated with gammaretroviral vectors and found clear evidence of genotoxicity, indicated by numerous common integration sites near proto-oncogenes and by increased abundance of clones with integrations near MECOM and LMO2 These clones showed stable behavior over multiple years and never expanded to the point of dominance or dysplasia. One patient developed a benign clonal dominance that could not be attributed to insertional mutagenesis and instead likely resulted from expansion of a transduced natural killer clone in response to chronic Epstein-Barr virus viremia. Clonal diversity and T-cell repertoire, measured by vector integration site sequencing and T-cell receptor ß-chain rearrangement sequencing, correlated significantly with the amount of busulfan preconditioning delivered to patients and to CD34+ cell dose. These data, in combination with results of other ADA-SCID gene therapy trials, suggest that disease background may be a crucial factor in leukemogenic potential of retroviral gene therapy and underscore the importance of cytoreductive conditioning in this type of gene therapy approach.


Assuntos
Adenosina Desaminase/deficiência , Agamaglobulinemia/genética , Agamaglobulinemia/terapia , Antineoplásicos Alquilantes/uso terapêutico , Bussulfano/uso terapêutico , Gammaretrovirus/genética , Terapia Genética/métodos , Vetores Genéticos/uso terapêutico , Imunodeficiência Combinada Severa/genética , Imunodeficiência Combinada Severa/terapia , Proteínas Adaptadoras de Transdução de Sinal/genética , Adenosina Desaminase/genética , Agamaglobulinemia/patologia , Criança , Proteínas de Ligação a DNA/genética , Vetores Genéticos/genética , Humanos , Proteínas com Domínio LIM/genética , Proteína do Locus do Complexo MDS1 e EVI1 , Proteínas Proto-Oncogênicas/genética , Proto-Oncogenes/genética , Imunodeficiência Combinada Severa/patologia , Linfócitos T/citologia , Linfócitos T/efeitos dos fármacos , Linfócitos T/metabolismo , Linfócitos T/patologia , Fatores de Transcrição/genética
10.
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
11.
F1000Res ; 52016.
Artigo em Inglês | MEDLINE | ID: mdl-27508076

RESUMO

In the recent past, the gene therapy field has witnessed a remarkable series of successes, many of which have involved primary immunodeficiency diseases, such as X-linked severe combined immunodeficiency, adenosine deaminase deficiency, chronic granulomatous disease, and Wiskott-Aldrich syndrome. While such progress has widened the choice of therapeutic options in some specific cases of primary immunodeficiency, much remains to be done to extend the geographical availability of such an advanced approach and to increase the number of diseases that can be targeted. At the same time, emerging technologies are stimulating intensive investigations that may lead to the application of precise genetic editing as the next form of gene therapy for these and other human genetic diseases.

12.
Pediatr Rheumatol Online J ; 14(1): 35, 2016 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-27260006

RESUMO

Defective regulation of type I interferon response is associated with severe inflammatory phenotypes and autoimmunity. Type I interferonopathies are a clinically heterogenic group of Mendelian diseases with a constitutive activation of this pathway that might present as atypical, severe, early onset rheumatic diseases. Skin vasculopathy with chilblains and livedo reticularis, interstitial lung disease, and panniculitis are common. Recent studies have implicated abnormal responses to nucleic acid stimuli or defective regulation of downstream effector molecules in disease pathogenesis. As observed for IL1-ß and autoinflammatory diseases, knowledge of the defects responsible for type I interferonopathies will likely promote the development of targeted therapy.


Assuntos
Artrite Juvenil/imunologia , Doenças Autoimunes/imunologia , Interferon Tipo I/imunologia , Doenças da Aorta/genética , Doenças da Aorta/imunologia , Artrite Juvenil/diagnóstico , Doenças Autoimunes/diagnóstico , Doenças Autoimunes/genética , Doenças Autoimunes/terapia , Doenças Autoimunes do Sistema Nervoso/diagnóstico , Doenças Autoimunes do Sistema Nervoso/imunologia , Hipoplasia do Esmalte Dentário/genética , Hipoplasia do Esmalte Dentário/imunologia , Homozigoto , Humanos , Interferon Tipo I/genética , Lúpus Eritematoso Sistêmico/diagnóstico , Lúpus Eritematoso Sistêmico/genética , Lúpus Eritematoso Sistêmico/imunologia , Metacarpo/anormalidades , Metacarpo/imunologia , Doenças Musculares/genética , Doenças Musculares/imunologia , Mutação/genética , Mutação/imunologia , Malformações do Sistema Nervoso/diagnóstico , Malformações do Sistema Nervoso/imunologia , Odontodisplasia/genética , Odontodisplasia/imunologia , Osteocondrodisplasias/genética , Osteocondrodisplasias/imunologia , Osteoporose/genética , Osteoporose/imunologia , Proteoma/genética , Proteoma/imunologia , Doenças Raras/diagnóstico , Doenças Raras/imunologia , Doenças Raras/terapia , Transdução de Sinais , Calcificação Vascular/genética , Calcificação Vascular/imunologia
13.
Blood ; 127(2): 216-20, 2016 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-26468226

RESUMO

Mutations of the Wiskott-Aldrich syndrome gene (WAS) are responsible for Wiskott-Aldrich syndrome (WAS), a disease characterized by thrombocytopenia, eczema, immunodeficiency, and autoimmunity. Mice with conditional deficiency of Was in B lymphocytes (B/WcKO) have revealed a critical role for WAS protein (WASP) expression in B lymphocytes in the maintenance of immune homeostasis. Neural WASP (N-WASP) is a broadly expressed homolog of WASP, and regulates B-cell signaling by modulating B-cell receptor (BCR) clustering and internalization. We have generated a double conditional mouse lacking both WASP and N-WASP selectively in B lymphocytes (B/DcKO). Compared with B/WcKO mice, B/DcKO mice showed defective B-lymphocyte proliferation and impaired antibody responses to T-cell-dependent antigens, associated with decreased autoantibody production and lack of autoimmune kidney disease. These results demonstrate that N-WASP expression in B lymphocytes is required for the development of autoimmunity of WAS and may represent a novel therapeutic target in WAS.


Assuntos
Autoimunidade/genética , Linfócitos B/imunologia , Proteína Neuronal da Síndrome de Wiskott-Aldrich/fisiologia , Síndrome de Wiskott-Aldrich/genética , Síndrome de Wiskott-Aldrich/imunologia , Animais , Linfócitos B/metabolismo , Linfócitos B/patologia , Diferenciação Celular/genética , Diferenciação Celular/imunologia , Deleção de Genes , Camundongos , Camundongos Knockout , Receptores de Antígenos de Linfócitos B/metabolismo , Transdução de Sinais/imunologia , Síndrome de Wiskott-Aldrich/patologia , Proteína Neuronal da Síndrome de Wiskott-Aldrich/genética
14.
Orphanet J Rare Dis ; 10: 159, 2015 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-26682746

RESUMO

Adenosine deaminase-deficient severe combined immunodeficiency (ADA-SCID) is characterized by impaired T-, B- and NK-cell function. Affected children, in addition to early onset of infections, manifest non-immunologic symptoms including pulmonary dysfunction likely attributable to elevated systemic adenosine levels. Lung disease assessment has primarily employed repetitive radiography and effort-dependent functional studies. Through impulse oscillometry (IOS), which is effort-independent, we prospectively obtained objective measures of lung dysfunction in 10 children with ADA-SCID. These results support the use of IOS in the identification and monitoring of lung function abnormalities in children with primary immunodeficiencies.


Assuntos
Adenosina Desaminase/deficiência , Agamaglobulinemia/diagnóstico , Pneumopatias/diagnóstico , Pulmão/fisiologia , Oscilometria/métodos , Imunodeficiência Combinada Severa/diagnóstico , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Estudos Prospectivos , Espirometria
15.
PLoS One ; 10(10): e0139729, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26448644

RESUMO

The Wiskott-Aldrich syndrome (WAS) is a rare X-linked primary immunodeficiency characterized by recurrent infections, thrombocytopenia, eczema, and high incidence of malignancy and autoimmunity. The cellular mechanisms underlying autoimmune complications in WAS have been extensively studied; however, they remain incompletely defined. We investigated the characteristics of IL-10-producing CD19+CD1dhighCD5+ B cells (CD1dhighCD5+ Breg) obtained from Was gene knockout (WKO) mice and found that their numbers were significantly lower in these mice compared to wild type (WT) controls. Moreover, we found a significant age-dependent reduction of the percentage of IL-10-expressing cells in WKO CD1dhighCD5+ Breg cells as compared to age-matched WT control mice. CD1dhighCD5+ Breg cells from older WKO mice did not suppress the in vitro production of inflammatory cytokines from activated CD4+ T cells. Interestingly, CD1dhighCD5+ Breg cells from older WKO mice displayed a basal activated phenotype which may prevent normal cellular responses, among which is the expression of IL-10. These defects may contribute to the susceptibility to autoimmunity with age in patients with WAS.


Assuntos
Envelhecimento , Linfócitos B Reguladores/imunologia , Síndrome de Wiskott-Aldrich/patologia , Animais , Antígenos CD19/metabolismo , Antígenos CD1d/metabolismo , Linfócitos B Reguladores/citologia , Linfócitos B Reguladores/metabolismo , Linfócitos T CD4-Positivos/citologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Antígenos CD5/metabolismo , Técnicas de Cocultura , Citocinas/metabolismo , Ensaio de Imunoadsorção Enzimática , Interleucina-10/análise , Masculino , Camundongos , Camundongos Knockout , Síndrome de Wiskott-Aldrich/metabolismo
17.
J Exp Med ; 212(10): 1663-77, 2015 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-26371186

RESUMO

Wiskott-Aldrich syndrome (WAS) is an X-linked immunodeficiency disorder frequently associated with systemic autoimmunity, including autoantibody-mediated cytopenias. WAS protein (WASp)-deficient B cells have increased B cell receptor (BCR) and Toll-like receptor (TLR) signaling, suggesting that these pathways might impact establishment of the mature, naive BCR repertoire. To directly investigate this possibility, we evaluated naive B cell specificity and composition in WASp-deficient mice and WAS subjects (n = 12). High-throughput sequencing and single-cell cloning analysis of the BCR repertoire revealed altered heavy chain usage and enrichment for low-affinity self-reactive specificities in murine marginal zone and human naive B cells. Although negative selection mechanisms including deletion, anergy, and receptor editing were relatively unperturbed, WASp-deficient transitional B cells showed enhanced proliferation in vivo mediated by antigen- and Myd88-dependent signals. Finally, using both BCR sequencing and cell surface analysis with a monoclonal antibody recognizing an intrinsically autoreactive heavy chain, we show enrichment in self-reactive cells specifically at the transitional to naive mature B cell stage in WAS subjects. Our combined data support a model wherein modest alterations in B cell-intrinsic, BCR, and TLR signals in WAS, and likely other autoimmune disorders, are sufficient to alter B cell tolerance via positive selection of self-reactive transitional B cells.


Assuntos
Linfócitos B/metabolismo , Linfócitos B/patologia , Receptores de Antígenos de Linfócitos B/metabolismo , Receptores Toll-Like/metabolismo , Síndrome de Wiskott-Aldrich/metabolismo , Adolescente , Adulto , Animais , Fator Ativador de Células B/sangue , Linfócitos B/imunologia , Estudos de Casos e Controles , Criança , Pré-Escolar , Citoproteção , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Lactente , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Fator 88 de Diferenciação Mieloide/metabolismo , Síndrome de Wiskott-Aldrich/imunologia , Síndrome de Wiskott-Aldrich/patologia , Proteína da Síndrome de Wiskott-Aldrich/genética , Proteína da Síndrome de Wiskott-Aldrich/metabolismo , Adulto Jovem
18.
J Clin Invest ; 125(10): 3941-51, 2015 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-26368308

RESUMO

Wiskott-Aldrich syndrome (WAS) is an X-linked immunodeficiency characterized by microthrombocytopenia, eczema, and high susceptibility to developing tumors and autoimmunity. Recent evidence suggests that B cells may be key players in the pathogenesis of autoimmunity in WAS. Here, we assessed whether WAS protein deficiency (WASp deficiency) affects the establishment of B cell tolerance by testing the reactivity of recombinant antibodies isolated from single B cells from 4 WAS patients before and after gene therapy (GT). We found that pre-GT WASp-deficient B cells were hyperreactive to B cell receptor stimulation (BCR stimulation). This hyperreactivity correlated with decreased frequency of autoreactive new emigrant/transitional B cells exiting the BM, indicating that the BCR signaling threshold plays a major role in the regulation of central B cell tolerance. In contrast, mature naive B cells from WAS patients were enriched in self-reactive clones, revealing that peripheral B cell tolerance checkpoint dysfunction is associated with impaired suppressive function of WAS regulatory T cells. The introduction of functional WASp by GT corrected the alterations of both central and peripheral B cell tolerance checkpoints. We conclude that WASp plays an important role in the establishment and maintenance of B cell tolerance in humans and that restoration of WASp by GT is able to restore B cell tolerance in WAS patients.


Assuntos
Linfócitos B/imunologia , Terapia Genética , Vetores Genéticos/uso terapêutico , Tolerância Imunológica , Proteína da Síndrome de Wiskott-Aldrich/uso terapêutico , Síndrome de Wiskott-Aldrich/terapia , Adulto , Sequência de Aminoácidos , Medula Óssea/patologia , Criança , Pré-Escolar , Deleção Clonal , Células Clonais/imunologia , Humanos , Lentivirus/genética , Masculino , Dados de Sequência Molecular , Receptores de Antígenos de Linfócitos B/imunologia , Proteínas Recombinantes de Fusão , Linfócitos T Reguladores/imunologia , Síndrome de Wiskott-Aldrich/imunologia , Proteína da Síndrome de Wiskott-Aldrich/deficiência , Proteína da Síndrome de Wiskott-Aldrich/genética
19.
Am J Med Genet A ; 167A(12): 2902-12, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26286438

RESUMO

We report two unrelated patients with a multisystem disease involving liver, eye, immune system, connective tissue, and bone, caused by biallelic mutations in the neuroblastoma amplified sequence (NBAS) gene. Both presented as infants with recurrent episodes triggered by fever with vomiting, dehydration, and elevated transaminases. They had frequent infections, hypogammaglobulinemia, reduced natural killer cells, and the Pelger-Huët anomaly of their granulocytes. Their facial features were similar with a pointed chin and proptosis; loose skin and reduced subcutaneous fat gave them a progeroid appearance. Skeletal features included short stature, slender bones, epiphyseal dysplasia with multiple phalangeal pseudo-epiphyses, and small C1-C2 vertebrae causing cervical instability and myelopathy. Retinal dystrophy and optic atrophy were present in one patient. NBAS is a component of the synthaxin-18 complex and is involved in nonsense-mediated mRNA decay control. Putative loss-of-function mutations in NBAS are already known to cause disease in humans. A specific founder mutation has been associated with short stature, optic nerve atrophy and Pelger-Huët anomaly of granulocytes (SOPH) in the Siberian Yakut population. A more recent report associates NBAS mutations with recurrent acute liver failure in infancy in a group of patients of European descent. Our observations indicate that the phenotypic spectrum of NBAS deficiency is wider than previously known and includes skeletal, hepatic, metabolic, and immunologic aspects. Early recognition of the skeletal phenotype is important for preventive management of cervical instability.


Assuntos
Anormalidades Múltiplas/genética , Mutação , Proteínas de Neoplasias/genética , Anormalidades Múltiplas/etiologia , Criança , Pré-Escolar , Feminino , Humanos , Sistema Imunitário/fisiopatologia , Lactente , Hepatopatias/genética , Masculino , Atrofia Óptica/genética , Anomalia de Pelger-Huët/etiologia , Gravidez , Retina/patologia , Pele/patologia
20.
J Exp Med ; 212(8): 1185-202, 2015 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-26150473

RESUMO

Adenylate kinases (AKs) are phosphotransferases that regulate the cellular adenine nucleotide composition and play a critical role in the energy homeostasis of all tissues. The AK2 isoenzyme is expressed in the mitochondrial intermembrane space and is mutated in reticular dysgenesis (RD), a rare form of severe combined immunodeficiency (SCID) in humans. RD is characterized by a maturation arrest in the myeloid and lymphoid lineages, leading to early onset, recurrent, and overwhelming infections. To gain insight into the pathophysiology of RD, we studied the effects of AK2 deficiency using the zebrafish model and induced pluripotent stem cells (iPSCs) derived from fibroblasts of an RD patient. In zebrafish, Ak2 deficiency affected hematopoietic stem and progenitor cell (HSPC) development with increased oxidative stress and apoptosis. AK2-deficient iPSCs recapitulated the characteristic myeloid maturation arrest at the promyelocyte stage and demonstrated an increased AMP/ADP ratio, indicative of an energy-depleted adenine nucleotide profile. Antioxidant treatment rescued the hematopoietic phenotypes in vivo in ak2 mutant zebrafish and restored differentiation of AK2-deficient iPSCs into mature granulocytes. Our results link hematopoietic cell fate in AK2 deficiency to cellular energy depletion and increased oxidative stress. This points to the potential use of antioxidants as a supportive therapeutic modality for patients with RD.


Assuntos
Adenilato Quinase/metabolismo , Células-Tronco Hematopoéticas/fisiologia , Leucopenia/enzimologia , Leucopenia/fisiopatologia , Estresse Oxidativo/fisiologia , Células-Tronco Pluripotentes/fisiologia , Imunodeficiência Combinada Severa/enzimologia , Imunodeficiência Combinada Severa/fisiopatologia , Laranja Acridina , Adenilato Quinase/deficiência , Animais , Antioxidantes/farmacologia , Apoptose/fisiologia , Compostos Azo , Sequência de Bases , Diferenciação Celular/efeitos dos fármacos , Biologia Computacional , Primers do DNA/genética , Imuno-Histoquímica , Marcação In Situ das Extremidades Cortadas , Dados de Sequência Molecular , Naftalenos , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sequência de DNA , Peixe-Zebra
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