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1.
Front Immunol ; 10: 2659, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31798588

RESUMO

Background: Goodpasture's disease (GP) is mediated by autoantibodies that bind the glomerular and alveolar basement membrane, causing rapidly progressive glomerulonephritis with or without pulmonary hemorrhage. The autoantibodies bind neoepitopes formed upon disruption of the quaternary structure of α345NC1 hexamer, a critical structural domain of α345 collagen IV scaffolds. Hexamer disruption leads to a conformational changes that transitions α3 and α5NC1 subunits into immunogens, however, the trigger remains unknown. This contrasts with another anti-GBM disease, Alports' post-transplant nephritis (APTN), where the pathogenic alloantibody binds directly to native NC1 hexamer. The current report includes the first study of antigenic specificity and allo-incompatability in anti-GBM disease occurring after allogeneic haematopoietic stem cell transplant (HSCT). Results: The anti-GBM antibodies were found to be directed predominantly against the EA epitope of the α3 NC1 monomer of collagen IV and developed rapidly in patient serum reaching peak level within 5 weeks. Autoantibody binding to native α345NC1 hexamer was minimal; however, binding was greatly increased upon dissociation of the native hexamer. There were no polymorphic genetic differences between donor and recipient collagen IV genes which would be predicted to cause a significant NC1 conformational change or to provide a target for antibody binding. Both patient and donor possessed the Goodpasture's susceptibility HLA-allele DRB1 * 1501. Conclusions: The current report includes the first in-depth study of allo-incompatability and antigenic specificity in anti-GBM disease occurring after allogeneic haematopoietic stem cell transplant (HSCT). No polymorphic genetic differences were identified between donor and recipient collagen IV genes which would be predicted to provide a target for antibody binding. Furthermore, autoantibody binding to native α345NC1 hexamer was minimal, increasing greatly upon dissociation of the native hexamer, resembling wild-type GP diseases and marking this as the first example of a post-HSCT conformeropathy.

2.
Nat Immunol ; 20(10): 1299-1310, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31534238

RESUMO

Resisting and tolerating microbes are alternative strategies to survive infection, but little is known about the evolutionary mechanisms controlling this balance. Here genomic analyses of anatomically modern humans, extinct Denisovan hominins and mice revealed a TNFAIP3 allelic series with alterations in the encoded immune response inhibitor A20. Each TNFAIP3 allele encoded substitutions at non-catalytic residues of the ubiquitin protease OTU domain that diminished IκB kinase-dependent phosphorylation and activation of A20. Two TNFAIP3 alleles encoding A20 proteins with partial phosphorylation deficits seemed to be beneficial by increasing immunity without causing spontaneous inflammatory disease: A20 T108A;I207L, originating in Denisovans and introgressed in modern humans throughout Oceania, and A20 I325N, from an N-ethyl-N-nitrosourea (ENU)-mutagenized mouse strain. By contrast, a rare human TNFAIP3 allele encoding an A20 protein with 95% loss of phosphorylation, C243Y, caused spontaneous inflammatory disease in humans and mice. Analysis of the partial-phosphorylation A20 I325N allele in mice revealed diminished tolerance of bacterial lipopolysaccharide and poxvirus inoculation as tradeoffs for enhanced immunity.

3.
Pediatr Infect Dis J ; 38(6): 643-650, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31116180

RESUMO

BACKGROUND: We assessed immunogenicity, antibody persistence and safety of the meningococcal serogroups A, C, W and Y-tetanus toxoid (TT) conjugate vaccine (MenACWY-TT) in children primed as toddlers with MenC vaccine. METHODS: This open, multicenter extension study enrolled children 84-95 months of age who had received one dose of the combined Haemophilus influenzae type b (Hib)-MenC-TT conjugate vaccine (HibMenC group) or Hib-TT and monovalent MenC (MCC)-CRM197 vaccines (Hib+MCC group) at 12-18 months of age, in the primary study. All participants received one dose of MenACWY-TT. We assessed immunogenicity against MenA, MenC, MenW and MenY at 1 month and 2 years postvaccination by serum bactericidal assay using baby rabbit complement (rSBA). Safety and reactogenicity were evaluated. RESULTS: Six years post-MenC vaccination, <20% of children retained rSBA-MenC titers ≥1:8. At 1 month post-MenACWY-TT vaccination, vaccine response rates against all serogroups were high for both groups with ≥97.1% of children having rSBA ≥1:8. Two years postvaccination, ≥63.6% of children retained rSBA-MenA ≥1:8, and ≥87.9% for other serogroups. Geometric mean titers for all serogroups declined at 2 years post-MenACWY-TT vaccination, but remained ≥13 times higher than prevaccination levels. For both groups, pain (≤58.5%), redness (≤51.4%) and fatigue (≤27.0%) were the most frequently reported adverse events. No serious adverse events were reported. CONCLUSIONS: One dose of MenACWY-TT boosts protection against MenC in primed children, is safe and extends protection against MenA, MenW and MenY. Immunogenicity and safety were comparable in infants vaccinated with conjugated vaccine (HibMenC-TT) or the separate vaccines (Hib-TT and MCC-CRM197).

4.
JCI Insight ; 52019 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-31021819

RESUMO

Bi-allelic inactivating mutations in DOCK8 cause a combined immunodeficiency characterised by severe pathogen infections, eczema, allergies, malignancy and impaired humoral responses. These clinical features result from functional defects in most lymphocyte lineages. Thus, DOCK8 plays a key role in immune cell function. Hematopoietic stem cell transplantation (HSCT) is curative for DOCK8 deficiency. While previous reports have described clinical outcomes for DOCK8 deficiency following HSCT, the effect on lymphocyte reconstitution and function has not been investigated. Our study determined whether defects in lymphocyte differentiation and function in DOCK8-deficient patients were restored following HSCT. DOCK8-deficient T and B lymphocytes exhibited aberrant activation and effector function in vivo and in vitro. Frequencies of αß T and MAIT cells were reduced while γδT cells were increased in DOCK8-deficient patients. HSCT improved, abnormal lymphocyte function in DOCK8-deficient patients. Elevated total and allergen-specific IgE in DOCK8-deficient patients decreased over time following HSCT. Our results document the extensive catalogue of cellular defects in DOCK8-deficient patients, and the efficacy of HSCT to correct these defects, concurrent with improvements in clinical phenotypes. Overall, our findings provide mechanisms at a functional cellular level for improvements in clinical features of DOCK8 deficiency post-HSCT, identify biomarkers that correlate with improved clinical outcomes, and inform the general dynamics of immune reconstitution in patients with monogenic immune disorders following HSCT.

6.
J Allergy Clin Immunol Pract ; 7(3): 848-855, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30391550

RESUMO

BACKGROUND: Biallelic variations in the dedicator of cytokinesis 8 (DOCK8) gene cause a combined immunodeficiency with eczema, recurrent bacterial and viral infections, and malignancy. Natural disease outcome is dismal, but allogeneic hematopoietic stem cell transplantation (HSCT) can cure the disease. OBJECTIVE: To determine outcome of HSCT for DOCK8 deficiency and define possible outcome variables. METHODS: We performed a retrospective study of the results of HSCT in a large international cohort of DOCK8-deficient patients. RESULTS: We identified 81 patients from 22 centers transplanted at a median age of 9.7 years (range, 0.7-27.2 years) between 1995 and 2015. After median follow-up of 26 months (range, 3-135 months), 68 (84%) patients are alive. Severe acute (III-IV) or chronic graft versus host disease occurred in 11% and 10%, respectively. Causes of death were infections (n = 5), graft versus host disease (5), multiorgan failure (2), and preexistent lymphoma (1). Survival after matched related (n = 40) or unrelated (35) HSCT was 89% and 81%, respectively. Reduced-toxicity conditioning based on either treosulfan or reduced-dose busulfan resulted in superior survival compared with fully myeloablative busulfan-based regimens (97% vs 78%; P = .049). Ninety-six percent of patients younger than 8 years at HSCT survived, compared with 78% of those 8 years and older (P = .06). Of the 73 patients with chimerism data available, 65 (89%) had more than 90% donor T-cell chimerism at last follow-up. Not all disease manifestations responded equally well to HSCT: eczema, infections, and mollusca resolved quicker than food allergies or failure to thrive. CONCLUSIONS: HSCT is curative in most DOCK8-deficient patients, confirming this approach as the treatment of choice. HSCT using a reduced-toxicity regimen may offer the best chance for survival.

7.
Innate Immun ; 23(7): 578-583, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28836875

RESUMO

Mutations in the nucleotide binding domain of the PRR, NOD2, are associated with the autoinflammatory diseases Blau syndrome and early-onset sarcoidosis. Current theories suggest that constitutive activation of the NOD2 pathway may be responsible for pathogenesis of these diseases. Here, we report the phenotype of a kindred with Blau syndrome caused by a novel NOD2 mutation (p.E383D). Signaling protein and cytokine expression were examined, and the results of these experiments challenge current theories of constitutive NOD2 activation in the pathophysiology of Blau syndrome.


Assuntos
Artrite/genética , Inflamassomos/metabolismo , Mutação/genética , Proteína Adaptadora de Sinalização NOD2/genética , Sarcoidose/genética , Sinovite/genética , Uveíte/genética , Adolescente , Adulto , Artrite/diagnóstico , Autoimunidade/genética , Pré-Escolar , Citocinas/genética , Citocinas/metabolismo , Feminino , Genótipo , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Proteína Adaptadora de Sinalização NOD2/metabolismo , Linhagem , Fenótipo , Sarcoidose/diagnóstico , Transdução de Sinais , Sinovite/diagnóstico , Uveíte/diagnóstico , Adulto Jovem
8.
J Paediatr Child Health ; 53(10): 988-994, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28752571

RESUMO

AIM: Haematopoietic stem cell transplantation (HSCT) is a central therapy in the treatment of primary immunodeficiency diseases (PIDs). Over the past 5 years, outcomes have been greatly improved due to earlier diagnosis, improved donor availability, advancements in graft manipulation and the use of less toxic preparative regimens. We present a 5-year audit of HSCT for PID at a single Australian tertiary hospital. METHODS: Retrospective case note review identified diagnosis, pre-transplant medical morbidity, transplant protocol, engraftment, adverse events, post-transplant immune reconstitution and general health. RESULTS: A total of 22 patients with PID underwent 24 HSCTs at our institution between 2012 and 2016. The most common indications were severe combined immunodeficiency, chronic granulomatous disease and familial haemophagocytic lymphohistiocytosis, with a genetic diagnosis in all but two patients. Reduced intensity or reduced toxicity conditioning was used in 91% of cases, and 75% of the donors were unrelated. Transplant-related mortality at day +100 was 9.5%, and cumulative overall survival was 86%. There were three mortalities, all secondary to viral infection, one of which occurred in the context of graft failure. Two patients remained on immune support, with the remainder achieving adequate immune reconstitution. CONCLUSIONS: The outcomes for HSCT for PIDs performed at Sydney Children's Hospital were in line with the world's best practice. HSCT should be considered a potential therapeutic option for all Australian PID patients with a valid disease indication.


Assuntos
Transplante de Células-Tronco Hematopoéticas , Síndromes de Imunodeficiência/terapia , Centros de Atenção Terciária , Adolescente , Austrália , Criança , Pré-Escolar , Feminino , Doença Enxerto-Hospedeiro , Humanos , Lactente , Masculino , Auditoria Médica , Estudos Retrospectivos
9.
J Paediatr Child Health ; 53(8): 766-770, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28513891

RESUMO

AIM: To examine the long-term follow-up and health outcomes of patients who have undergone haematopoietic stem cell transplant (HSCT) for severe combined immunodeficiency (SCID). METHODS: Through a structured questionnaire, we examined follow-up arrangements and long-term health outcomes in 22 children who have had a successful HSCT for SCID during the period of 1984-2012 at the Sydney Children's Hospital, Sydney, Australia. RESULTS: Most children considered themselves healthy and 'cured' from SCID. Whilst many children enjoy relatively good bio-social health outcomes, specific negative health outcomes and absenteeism from school were perceived negatively. Two-thirds of children see their general practitioner or specialist regularly; however, there did not appear to be consistency with the nature of this follow-up. CONCLUSION: The findings from our study highlight the complex bio-psychosocial health needs of post-HSCT SCID children and encourage SCID centres to consider a multidisciplinary approach to their follow-up. Further studies into the determinants of patients' perceptions of their health are needed.


Assuntos
Transplante de Células-Tronco Hematopoéticas , Avaliação de Resultados da Assistência ao Paciente , Imunodeficiência Combinada Severa/cirurgia , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , New South Wales , Imunodeficiência Combinada Severa/diagnóstico , Inquéritos e Questionários
10.
World J Clin Pediatr ; 6(1): 89-102, 2017 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-28224100

RESUMO

AIM: To determine whether recent evidence-based United States policies on male circumcision (MC) apply to comparable Anglophone countries, Australia and New Zealand. METHODS: Articles in 2005 through 2015 were retrieved from PubMed using the keyword "circumcision" together with 36 relevant subtopics. A further PubMed search was performed for articles published in 2016. Searches of the EMBASE and Cochrane databases did not yield additional citable articles. Articles were assessed for quality and those rated 2+ and above according to the Scottish Intercollegiate Grading System were studied further. The most relevant and representative of the topic were included. Bibliographies were examined to retrieve further key references. Randomized controlled trials, recent high quality systematic reviews or meta-analyses (level 1++ or 1+ evidence) were prioritized for inclusion. A risk-benefit analysis of articles rated for quality was performed. For efficiency and reliability, recent randomized controlled trials, meta-analyses, high quality systematic reviews and large well-designed studies were used if available. Internet searches were conducted for other relevant information, including policies and Australian data on claims under Medicare for MC. RESULTS: Evidence-based policy statements by the American Academy of Pediatrics (AAP) and the Centers for Disease Control and Prevention (CDC) support infant and later age male circumcision (MC) as a desirable public health measure. Our systematic review of relevant literature over the past decade yielded 140 journal articles that met our inclusion criteria. Together, these showed that early infant MC confers immediate and lifelong benefits by protecting against urinary tract infections having potential adverse long-term renal effects, phimosis that causes difficult and painful erections and "ballooning" during urination, inflammatory skin conditions, inferior penile hygiene, candidiasis, various sexually transmissible infections in both sexes, genital ulcers, and penile, prostate and cervical cancer. Our risk-benefit analysis showed that benefits exceeded procedural risks, which are predominantly minor, by up to 200 to 1. We estimated that more than 1 in 2 uncircumcised males will experience an adverse foreskin-related medical condition over their lifetime. Wide-ranging evidence from surveys, physiological measurements, and the anatomical location of penile sensory receptors responsible for sexual sensation strongly and consistently suggested that MC has no detrimental effect on sexual function, sensitivity or pleasure. United States studies showed that early infant MC is cost saving. The evidence supporting early infant MC has further strengthened since the positive AAP and CDC reviews. CONCLUSION: Affirmative MC policies are needed in Australia and New Zealand. Routine provision of accurate, unbiased education, and access in public hospitals, will maximize health and financial benefits.

12.
J Allergy Clin Immunol ; 139(3): 933-949, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27554822

RESUMO

BACKGROUND: Dedicator of cytokinesis 8 (DOCK8) deficiency is a combined immunodeficiency caused by autosomal recessive loss-of-function mutations in DOCK8. This disorder is characterized by recurrent cutaneous infections, increased serum IgE levels, and severe atopic disease, including food-induced anaphylaxis. However, the contribution of defects in CD4+ T cells to disease pathogenesis in these patients has not been thoroughly investigated. OBJECTIVE: We sought to investigate the phenotype and function of DOCK8-deficient CD4+ T cells to determine (1) intrinsic and extrinsic CD4+ T-cell defects and (2) how defects account for the clinical features of DOCK8 deficiency. METHODS: We performed in-depth analysis of the CD4+ T-cell compartment of DOCK8-deficient patients. We enumerated subsets of CD4+ T helper cells and assessed cytokine production and transcription factor expression. Finally, we determined the levels of IgE specific for staple foods and house dust mite allergens in DOCK8-deficient patients and healthy control subjects. RESULTS: DOCK8-deficient memory CD4+ T cells were biased toward a TH2 type, and this was at the expense of TH1 and TH17 cells. In vitro polarization of DOCK8-deficient naive CD4+ T cells revealed the TH2 bias and TH17 defect to be T-cell intrinsic. Examination of allergen-specific IgE revealed plasma IgE from DOCK8-deficient patients is directed against staple food antigens but not house dust mites. CONCLUSION: Investigations into the DOCK8-deficient CD4+ T cells provided an explanation for some of the clinical features of this disorder: the TH2 bias is likely to contribute to atopic disease, whereas defects in TH1 and TH17 cells compromise antiviral and antifungal immunity, respectively, explaining the infectious susceptibility of DOCK8-deficient patients.


Assuntos
Fatores de Troca do Nucleotídeo Guanina/deficiência , Síndromes de Imunodeficiência/imunologia , Linfócitos T/imunologia , Adolescente , Adulto , Alérgenos/imunologia , Criança , Pré-Escolar , Citocinas/imunologia , Feminino , Fatores de Troca do Nucleotídeo Guanina/imunologia , Humanos , Imunoglobulina E/sangue , Leucócitos Mononucleares/imunologia , Masculino , Adulto Jovem
13.
Immunol Cell Biol ; 94(10): 994-999, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27377765

RESUMO

Mevalonate kinase deficiency (MKD) is caused by mutations in a key enzyme of the mevalonate-cholesterol biosynthesis pathway, leading to recurrent autoinflammatory disease characterised by enhanced release of interleukin-1ß (IL-1ß). It is currently believed that the inflammatory phenotype of MKD is triggered by temperature-sensitive loss of mevalonate kinase activity and reduced biosynthesis of isoprenoid lipids required for the prenylation of small GTPase proteins. However, previous studies have not clearly shown any change in protein prenylation in patient cells under normal conditions. With lymphoblast cell lines from two compound heterozygous MKD patients, we used a highly sensitive in vitro prenylation assay, together with quantitative mass spectrometry, to reveal a subtle accumulation of unprenylated Rab GTPases in cells cultured for 3 days or more at 40 °C compared with 37 °C. This included a 200% increase in unprenylated Rab7A, Rab14 and Rab1A. Inhibition of sterol regulatory element-binding protein (SREBP) activation by fatostatin led to more pronounced accumulation of unprenylated Rab proteins in MKD cells but not parent cells, suggesting that cultured MKD cells may partially overcome the loss of isoprenoid lipids by SREBP-mediated upregulation of enzymes required for isoprenoid biosynthesis. Furthermore, while inhibition of Rho/Rac/Rap prenylation promoted the release of IL-1ß, specific inhibition of Rab prenylation by NE10790 had no effect in human peripheral blood mononuclear cells or human THP-1 monocytic cells. These studies demonstrate for the first time that mutations in mevalonate kinase can lead to a mild, temperature-induced defect in the prenylation of small GTPases, but that loss of prenylated Rab GTPases is not the cause of enhanced IL-1ß release in MKD.


Assuntos
Deficiência de Mevalonato Quinase/enzimologia , Prenilação de Proteína , Proteínas rab de Ligação ao GTP/metabolismo , Linhagem Celular , Criança , Pré-Escolar , Feminino , Humanos , Interleucina-1beta/metabolismo , Marcação por Isótopo , Leucócitos Mononucleares/metabolismo , Masculino , Deficiência de Mevalonato Quinase/patologia , Piridinas/farmacologia , Proteína de Ligação a Elemento Regulador de Esterol 1/metabolismo , Temperatura Ambiente , Tiazóis/farmacologia
14.
J Exp Med ; 213(8): 1589-608, 2016 07 25.
Artigo em Inglês | MEDLINE | ID: mdl-27401342

RESUMO

Naive CD4(+) T cells differentiate into specific effector subsets-Th1, Th2, Th17, and T follicular helper (Tfh)-that provide immunity against pathogen infection. The signaling pathways involved in generating these effector cells are partially known. However, the effects of mutations underlying human primary immunodeficiencies on these processes, and how they compromise specific immune responses, remain unresolved. By studying individuals with mutations in key signaling pathways, we identified nonredundant pathways regulating human CD4(+) T cell differentiation in vitro. IL12Rß1/TYK2 and IFN-γR/STAT1 function in a feed-forward loop to induce Th1 cells, whereas IL-21/IL-21R/STAT3 signaling is required for Th17, Tfh, and IL-10-secreting cells. IL12Rß1/TYK2 and NEMO are also required for Th17 induction. Strikingly, gain-of-function STAT1 mutations recapitulated the impact of dominant-negative STAT3 mutations on Tfh and Th17 cells, revealing a putative inhibitory effect of hypermorphic STAT1 over STAT3. These findings provide mechanistic insight into the requirements for human T cell effector function, and explain clinical manifestations of these immunodeficient conditions. Furthermore, they identify molecules that could be targeted to modulate CD4(+) T cell effector function in the settings of infection, vaccination, or immune dysregulation.


Assuntos
Diferenciação Celular/imunologia , Células Th1/imunologia , Células Th17/imunologia , Células Th2/imunologia , Antígenos de Diferenciação/genética , Antígenos de Diferenciação/imunologia , Diferenciação Celular/genética , Feminino , Humanos , Interleucina-10/genética , Interleucina-10/imunologia , Masculino , Mutação , Fator de Transcrição STAT1/genética , Fator de Transcrição STAT1/imunologia , Fator de Transcrição STAT3/genética , Fator de Transcrição STAT3/imunologia , Células Th1/citologia , Células Th17/citologia
16.
J Clin Immunol ; 35(7): 604-9, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26433589

RESUMO

UNLABELLED: Vasculitis occurs rarely in association with X-linked lymphoproliferative disease (XLP). There are four published cases of non-EBV XLP-associated cerebral vasculitis reported, none of whom have survived without major cognitive impairment. CASE: A 9-year old boy initially presented aged 5 years with a restrictive joint disease. He subsequently developed dysgammaglobulinemia, episodic severe pneumonitis, aplastic anaemia, gastritis and cerebral vasculitis. A diagnosis of XLP was made, based on flow cytometric analysis and the identification of a novel mutation in SH2D1A, c.96G>C. No peripheral blood lymphocyte clonal proliferation was identified and he was EBV negative, although human herpes virus-7 (HHV7) was detected repeatedly in his cerebrospinal fluid. He underwent a reduced intensity unrelated umbilical cord blood transplant, but failed to engraft. A second 5/6 matched cord gave 100 % donor engraftment. Complications included BK virus-associated haemorrhagic cystitis, a possible NK-cell mediated immune reconstitution syndrome and post-transplant anti-glomerular basement membrane disease, the latter treated with cyclophosphamide and rituximab. At +450 days post-transplant he is in remission from his vasculitis and anti-glomerular basement membrane disease, and HHV-7 has remained undetectable. CONCLUSION: This is the second published description of joint disease in XLP, and only the fourth case of non-EBV associated cerebral vasculitis in XLP, as well as being the first to be successfully treated for this manifestation. This case raises specific questions about vasculitis in XLP, in particular the potential relevance of HHV-7 to the pathogenesis.


Assuntos
Transplante de Células-Tronco de Sangue do Cordão Umbilical , Herpesvirus Humano 7/imunologia , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Artropatias/terapia , Células Matadoras Naturais/fisiologia , Transtornos Linfoproliferativos/terapia , Complicações Pós-Operatórias/tratamento farmacológico , Infecções por Roseolovirus/terapia , Vasculite do Sistema Nervoso Central/terapia , Austrália , Criança , Ciclofosfamida/administração & dosagem , Antígenos HLA/imunologia , Herpesvirus Humano 7/isolamento & purificação , Humanos , Imunidade/genética , Peptídeos e Proteínas de Sinalização Intracelular/genética , Artropatias/diagnóstico , Artropatias/etiologia , Células Matadoras Naturais/transplante , Células Matadoras Naturais/virologia , Transtornos Linfoproliferativos/complicações , Transtornos Linfoproliferativos/diagnóstico , Masculino , Mutação de Sentido Incorreto/genética , Linhagem , Indução de Remissão , Rituximab/administração & dosagem , Infecções por Roseolovirus/complicações , Infecções por Roseolovirus/diagnóstico , Proteína Associada à Molécula de Sinalização da Ativação Linfocitária , Vasculite do Sistema Nervoso Central/diagnóstico , Vasculite do Sistema Nervoso Central/etiologia
17.
J Allergy Clin Immunol ; 136(4): 993-1006.e1, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26162572

RESUMO

BACKGROUND: Follicular helper T (TFH) cells underpin T cell-dependent humoral immunity and the success of most vaccines. TFH cells also contribute to human immune disorders, such as autoimmunity, immunodeficiency, and malignancy. Understanding the molecular requirements for the generation and function of TFH cells will provide strategies for targeting these cells to modulate their behavior in the setting of these immunologic abnormalities. OBJECTIVE: We sought to determine the signaling pathways and cellular interactions required for the development and function of TFH cells in human subjects. METHODS: Human primary immunodeficiencies (PIDs) resulting from monogenic mutations provide a unique opportunity to assess the requirement for particular molecules in regulating human lymphocyte function. Circulating follicular helper T (cTFH) cell subsets, memory B cells, and serum immunoglobulin levels were quantified and functionally assessed in healthy control subjects, as well as in patients with PIDs resulting from mutations in STAT3, STAT1, TYK2, IL21, IL21R, IL10R, IFNGR1/2, IL12RB1, CD40LG, NEMO, ICOS, or BTK. RESULTS: Loss-of-function (LOF) mutations in STAT3, IL10R, CD40LG, NEMO, ICOS, or BTK reduced cTFH cell frequencies. STAT3 and IL21/R LOF and STAT1 gain-of-function mutations skewed cTFH cell differentiation toward a phenotype characterized by overexpression of IFN-γ and programmed death 1. IFN-γ inhibited cTFH cell function in vitro and in vivo, as corroborated by hypergammaglobulinemia in patients with IFNGR1/2, STAT1, and IL12RB1 LOF mutations. CONCLUSION: Specific mutations affect the quantity and quality of cTFH cells, highlighting the need to assess TFH cells in patients by using multiple criteria, including phenotype and function. Furthermore, IFN-γ functions in vivo to restrain TFH cell-induced B-cell differentiation. These findings shed new light on TFH cell biology and the integrated signaling pathways required for their generation, maintenance, and effector function and explain the compromised humoral immunity seen in patients with some PIDs.


Assuntos
Síndromes de Imunodeficiência/imunologia , Subpopulações de Linfócitos T/imunologia , Linfócitos T Auxiliares-Indutores/imunologia , Tirosina Quinase da Agamaglobulinemia , Linfócitos B/imunologia , Ligante de CD40/genética , Diferenciação Celular/genética , Proliferação de Células/genética , Células Cultivadas , Humanos , Quinase I-kappa B/genética , Imunidade Humoral/genética , Síndromes de Imunodeficiência/genética , Memória Imunológica , Proteína Coestimuladora de Linfócitos T Induzíveis/genética , Interferon gama/genética , Interferon gama/metabolismo , Ativação Linfocitária , Mutação/genética , Proteínas Tirosina Quinases/genética , Receptores de Citocinas/genética , Fator de Transcrição STAT1/genética , Fator de Transcrição STAT3/genética , Transdução de Sinais/genética , Transdução de Sinais/imunologia
18.
Blood ; 122(24): 3940-50, 2013 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-24159173

RESUMO

B-cell responses are guided by the integration of signals through the B-cell receptor (BCR), CD40, and cytokine receptors. The common γ chain (γc)-binding cytokine interleukin (IL)-21 drives humoral immune responses via STAT3-dependent induction of transcription factors required for plasma cell generation. We investigated additional mechanisms by which IL-21/STAT3 signaling modulates human B-cell responses by studying patients with STAT3 mutations. IL-21 strongly induced CD25 (IL-2Rα) in normal, but not STAT3-deficient, CD40L-stimulated naïve B cells. Chromatin immunoprecipitation confirmed IL2RA as a direct target of STAT3. IL-21-induced CD25 expression was also impaired on B cells from patients with IL2RG or IL21R mutations, confirming a requirement for intact IL-21R signaling in this process. IL-2 increased plasmablast generation and immunoglobulin secretion from normal, but not CD25-deficient, naïve B cells stimulated with CD40L/IL-21. IL-2 and IL-21 were produced by T follicular helper cells, and neutralizing both cytokines abolished the B-cell helper capacity of these cells. Our results demonstrate that IL-21, via STAT3, sensitizes B cells to the stimulatory effects of IL-2. Thus, IL-2 may play an adjunctive role in IL-21-induced B-cell differentiation. Lack of this secondary effect of IL-21 may amplify the humoral immunodeficiency in patients with mutations in STAT3, IL2RG, or IL21R due to impaired responsiveness to IL-21.


Assuntos
Linfócitos B/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Interleucina-2/farmacologia , Interleucinas/farmacologia , Plasmócitos/efeitos dos fármacos , Fator de Transcrição STAT3/genética , Linfócitos B/citologia , Linfócitos B/metabolismo , Ligante de CD40/farmacologia , Diferenciação Celular/genética , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Expressão Gênica/efeitos dos fármacos , Humanos , Interleucina-10/farmacologia , Subunidade alfa de Receptor de Interleucina-2/genética , Subunidade alfa de Receptor de Interleucina-2/metabolismo , Mutação , Análise de Sequência com Séries de Oligonucleotídeos , Plasmócitos/citologia , Plasmócitos/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Transcriptoma/efeitos dos fármacos
19.
BMC Pediatr ; 13: 136, 2013 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-24010685

RESUMO

BACKGROUND: Recent attempts in the USA and Europe to ban the circumcision of male children have been unsuccessful. Of current concern is a report by the Tasmanian Law Reform Institute (TLRI) recommending that non-therapeutic circumcision be prohibited, with parents and doctors risking criminal sanctions except where the parents have strong religious and ethnic ties to circumcision. The acceptance of this recommendation would create a precedent for legislation elsewhere in the world, thereby posing a threat to pediatric practice, parental responsibilities and freedoms, and public health. DISCUSSION: The TLRI report ignores the scientific consensus within medical literature about circumcision. It contains legal and ethical arguments that are seriously flawed. Dispassionate ethical arguments and the United Nations Convention on the Rights of the Child are consistent with parents being permitted to authorize circumcision for their male child. Uncritical acceptance of the TLRI report's recommendations would strengthen and legitimize efforts to ban childhood male circumcision not just in Australia, but in other countries as well. The medical profession should be concerned about any attempt to criminalize a well-accepted and evidence-based medical procedure. The recommendations are illogical, pose potential dangers and seem unworkable in practice. There is no explanation of how the State could impose criminal charges against doctors and parents, nor of how such a punitive apparatus could be structured, nor how strength of ethnic or religious ties could be determined. The proposal could easily be used inappropriately, and discriminates against parents not tied to the religions specified. With time, religious exemptions could subsequently be overturned. The law, governments and the medical profession should reject the TLRI recommendations, especially since the recent affirmative infant male circumcision policy statement by the American Academy of Pediatrics attests to the significant individual and public health benefits and low risk of infant male circumcision. SUMMARY: Doctors should be allowed to perform medical procedures based on sound evidence of effectiveness and safety with guaranteed protection. Parents should be free to act in the best interests of the health of their infant son by having him circumcised should they choose.


Assuntos
Circuncisão Masculina/legislação & jurisprudência , Direitos Humanos/legislação & jurisprudência , Pediatria/normas , Religião e Medicina , Circuncisão Masculina/economia , Circuncisão Masculina/ética , Análise Custo-Benefício , Medicina Baseada em Evidências , Humanos , Lactente , Recém-Nascido , Internacionalidade , Masculino , Saúde Pública/tendências , Tasmânia
20.
Med J Aust ; 198(11): 600-2, 2013 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-23919705

RESUMO

A review of case notes from our Sydney-based paediatric allergy services, between 1 January 2003 and 31 December 2011, identified 74 children who had been prescribed diets that eliminated foods containing natural salicylates before attending our clinics. The most common indications for starting the diets were eczema (34/74) and behavioural disturbances (17/74) including attention deficit hyperactivity disorder (ADHD). We could find no peer-reviewed evidence to support the efficacy of salicylate elimination diets in managing these diseases. We do not prescribe these diets, and in a survey of European and North American food allergy experts, only 1/23 respondents used a similar diet for eczema, with none of the respondents using salicylate elimination to treat ADHD. A high proportion (31/66) of children suffered adverse outcomes, including nutritional deficiencies and food aversion, with four children developing eating disorders. We could find no published evidence to support the safety of these diets in children. While this uncontrolled study does not prove a causal relationship between salicylate elimination diets and harm, the frequency of adverse events appears high, and in the absence of evidence of safety or efficacy, we cannot recommend the use of these diets in children.


Assuntos
Dieta/métodos , Salicilatos/efeitos adversos , Transtorno do Deficit de Atenção com Hiperatividade/dietoterapia , Criança , Transtornos do Comportamento Infantil/dietoterapia , Dieta/efeitos adversos , Eczema/dietoterapia , Humanos , Resultado do Tratamento
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