Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 45
Filtrar
1.
J Clin Immunol ; 44(1): 38, 2024 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-38165470

RESUMO

BACKGROUND: X-linked reticular pigmentary disorder (XLPDR) is a rare condition characterized by skin hyperpigmentation, ectodermal features, multiorgan inflammation, and recurrent infections. All probands identified to date share the same intronic hemizygous POLA1 hypomorphic variant (NM_001330360.2(POLA1):c.1393-354A > G) on the X chromosome. Previous studies have supported excessive type 1 interferon (IFN) inflammation and natural killer (NK) cell dysfunction in disease pathogenesis. Common null polymorphisms in filaggrin (FLG) gene underlie ichthyosis vulgaris and atopic predisposition. CASE: A 9-year-old boy born to non-consanguineous parents developed eczema with reticular skin hyperpigmentation in early infancy. He suffered recurrent chest infections with chronic cough, clubbing, and asthma, moderate allergic rhinoconjunctivitis with keratitis, multiple food allergies, and vomiting with growth failure. Imaging demonstrated bronchiectasis, while gastroscopy identified chronic eosinophilic gastroduodenitis. Interestingly, growth failure and bronchiectasis improved over time without specific treatment. METHODS: Whole-genome sequencing (WGS) using Illumina short-read sequencing was followed by both manual and orthogonal automated bioinformatic analyses for single-nucleotide variants, small insertions/deletions (indels), and larger copy number variations. NK cell cytotoxic function was assessed using 51Cr release and degranulation assays. The presence of an interferon signature was investigated using a panel of six interferon-stimulated genes (ISGs) by QPCR. RESULTS: WGS identified a de novo hemizygous intronic variant in POLA1 (NM_001330360.2(POLA1):c.1393-354A > G) giving a diagnosis of XLPDR, as well as a heterozygous nonsense FLG variant (NM_002016.2(FLG):c.441del, NP_0020.1:p.(Arg151Glyfs*43)). Compared to healthy controls, the IFN signature was elevated although the degree moderated over time with the improvement in his chest disease. NK cell functional studies showed normal cytotoxicity and degranulation. CONCLUSION: This patient had multiple atopic manifestations affecting eye, skin, chest, and gut, complicating the presentation of XLPDR. This highlights that common FLG polymorphisms should always be considered when assessing genotype-phenotype correlations of other genetic variation in patients with atopic symptoms. Additionally, while the patient exhibited an enhanced IFN signature, he does not have an NK cell defect, suggesting this may not be a constant feature of XLPDR.


Assuntos
Bronquiectasia , Dermatite Atópica , Hiperpigmentação , Masculino , Humanos , Criança , Variações do Número de Cópias de DNA , Proteínas Filagrinas , Inflamação , Interferons
2.
Blood ; 141(19): 2330-2342, 2023 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-36706356

RESUMO

Familial forms of the severe immunoregulatory disease hemophagocytic lymphohistiocytosis (HLH) arise from biallelic mutations in the PRF1, UNC13D, STXBP2, and STX11 genes. Early and accurate diagnosis of the disease is important to determine the most appropriate treatment option, including potentially curative stem cell transplantation. The diagnosis of familial HLH (FHL) is traditionally based on finding biallelic mutations in patients with HLH symptoms and reduced natural killer (NK)-cell cytotoxicity. However, patients often have a low NK-cell count or receive immunosuppressive therapies that may render the NK-cell cytotoxicity assay unreliable. Furthermore, to fully understand the nature of a disease it is critical to directly assess the effect of mutations on cellular function; this will help to avoid instances in which carriers of innocuous mutations may be recommended for invasive procedures including transplantation. To overcome this diagnostic problem, we have developed a rapid and robust method that takes advantage of the functional equivalence of the human and mouse orthologues of PRF1, UNC13D, STX11, and STXBP2 proteins. By knocking out endogenous mouse genes in CD8+ T cells and simultaneously replacing them with their mutated human orthologues, we can accurately assess the effect of mutations on cell function. The wide dynamic range of this novel system allowed us to understand the basis of, otherwise cryptic, cases of FHL or HLH and, in some instances, to demonstrate that previously reported mutations are unlikely to cause FHL. This novel approach provides valuable new information to enable more accurate diagnosis and treatment of patients with HLH or FHL who inherit mutations of undetermined pathogenicity.


Assuntos
Linfo-Histiocitose Hemofagocítica , Humanos , Animais , Camundongos , Linfo-Histiocitose Hemofagocítica/diagnóstico , Linfo-Histiocitose Hemofagocítica/genética , Proteínas Citotóxicas Formadoras de Poros , Perforina/genética , Genótipo , Mutação , Fenótipo , Proteínas de Membrana/genética , Proteínas Munc18/genética
3.
Ocul Immunol Inflamm ; 31(5): 1097-1100, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35622932

RESUMO

BACKGROUND: Orbital myositis is a rare sporadic eye disease associated with extraocular eye muscle inflammation. To date, there have been two reports of familial orbital myositis (FOM), which demonstrate partially penetrant autosomal dominant inheritance. CASES: We report six new Australian cases of FOM, four of whom extend one of the reported pedigrees, as well as a separate mother and daughter manifesting orbital myositis, which constitutes a third report of familial occurrence. We can confirm that the disease has onset in childhood, appearing to go into remission in adult life, and that the inflammation is corticosteroid-responsive. However, one patient went on to develop permanent diplopia in upgaze. We also report two children suffering chronic pain and diplopia who demonstrated complete resolution of symptoms with the anti-TNF-α monoclonal infliximab. CONCLUSION: Uncontrolled FOM in childhood may result in permanent extraocular eye muscle damage, while TNF-α blockade provides an excellent steroid-sparing effect.


Assuntos
Doenças Orbitárias , Miosite Orbital , Adulto , Humanos , Criança , Miosite Orbital/diagnóstico , Miosite Orbital/tratamento farmacológico , Miosite Orbital/etiologia , Infliximab/uso terapêutico , Diplopia/complicações , Inibidores do Fator de Necrose Tumoral , Austrália , Doenças Orbitárias/diagnóstico , Inflamação/complicações
4.
J Clin Immunol ; 42(1): 119-129, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34657245

RESUMO

Rare, biallelic loss-of-function mutations in DOCK8 result in a combined immune deficiency characterized by severe and recurrent cutaneous infections, eczema, allergies, and susceptibility to malignancy, as well as impaired humoral and cellular immunity and hyper-IgE. The advent of next-generation sequencing technologies has enabled the rapid molecular diagnosis of rare monogenic diseases, including inborn errors of immunity. These advances have resulted in the implementation of gene-guided treatments, such as hematopoietic stem cell transplant for DOCK8 deficiency. However, putative disease-causing variants revealed by next-generation sequencing need rigorous validation to demonstrate pathogenicity. Here, we report the eventual diagnosis of DOCK8 deficiency in a consanguineous family due to a novel homozygous intronic deletion variant that caused aberrant exon splicing and subsequent loss of expression of DOCK8 protein. Remarkably, the causative variant was not initially detected by clinical whole-genome sequencing but was subsequently identified and validated by combining advanced genomic analysis, RNA-seq, and flow cytometry. This case highlights the need to adopt multipronged confirmatory approaches to definitively solve complex genetic cases that result from variants outside protein-coding exons and conventional splice sites.


Assuntos
Síndrome de Job , Consanguinidade , Fatores de Troca do Nucleotídeo Guanina/genética , Homozigoto , Humanos , Síndrome de Job/diagnóstico , Síndrome de Job/genética , Mutação/genética , Sequenciamento do Exoma
5.
J Clin Immunol ; 41(8): 1915-1935, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34657246

RESUMO

PURPOSE: Deficiency of adenosine deaminase type 2 (ADA2) (DADA2) is a rare inborn error of immunity caused by deleterious biallelic mutations in ADA2. Clinical manifestations are diverse, ranging from severe vasculopathy with lacunar strokes to immunodeficiency with viral infections, hypogammaglobulinemia and bone marrow failure. Limited data are available on the phenotype and function of leukocytes from DADA2 patients. The aim of this study was to perform in-depth immunophenotyping and functional analysis of the impact of DADA2 on human lymphocytes. METHODS: In-depth immunophenotyping and functional analyses were performed on ten patients with confirmed DADA2 and compared to heterozygous carriers of pathogenic ADA2 mutations and normal healthy controls. RESULTS: The median age of the patients was 10 years (mean 20.7 years, range 1-44 years). Four out of ten patients were on treatment with steroids and/or etanercept or other immunosuppressives. We confirmed a defect in terminal B cell differentiation in DADA2 and reveal a block in B cell development in the bone marrow at the pro-B to pre-B cell stage. We also show impaired differentiation of CD4+ and CD8+ memory T cells, accelerated exhaustion/senescence, and impaired survival and granzyme production by ADA2 deficient CD8+ T cells. Unconventional T cells (i.e. iNKT, MAIT, Vδ2+ γδT) were diminished whereas pro-inflammatory monocytes and CD56bright immature NK cells were increased. Expression of the IFN-induced lectin SIGLEC1 was increased on all monocyte subsets in DADA2 patients compared to healthy donors. Interestingly, the phenotype and function of lymphocytes from healthy heterozygous carriers were often intermediate to that of healthy donors and ADA2-deficient patients. CONCLUSION: Extended immunophenotyping in DADA2 patients shows a complex immunophenotype. Our findings provide insight into the cellular mechanisms underlying some of the complex and heterogenous clinical features of DADA2. More research is needed to design targeted therapy to prevent viral infections in these patients with excessive inflammation as the overarching phenotype.


Assuntos
Agamaglobulinemia/imunologia , Linfócitos B/imunologia , Imunodeficiência Combinada Severa/imunologia , Linfócitos T/imunologia , Adenosina Desaminase/sangue , Adenosina Desaminase/deficiência , Adenosina Desaminase/genética , Adolescente , Adulto , Agamaglobulinemia/sangue , Agamaglobulinemia/genética , Idoso , Diferenciação Celular , Criança , Pré-Escolar , Células Dendríticas/imunologia , Humanos , Lactente , Peptídeos e Proteínas de Sinalização Intercelular/sangue , Peptídeos e Proteínas de Sinalização Intercelular/deficiência , Peptídeos e Proteínas de Sinalização Intercelular/genética , Células Matadoras Naturais/imunologia , Pessoa de Meia-Idade , Imunodeficiência Combinada Severa/sangue , Imunodeficiência Combinada Severa/genética , Adulto Jovem
6.
Proc Natl Acad Sci U S A ; 118(34)2021 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-34417303

RESUMO

Sterile α motif domain-containing protein 9-like (SAMD9L) is encoded by a hallmark interferon-induced gene with a role in controlling virus replication that is not well understood. Here, we analyze SAMD9L function from the perspective of human mutations causing neonatal-onset severe autoinflammatory disease. Whole-genome sequencing of two children with leukocytoclastic panniculitis, basal ganglia calcifications, raised blood inflammatory markers, neutrophilia, anemia, thrombocytopaenia, and almost no B cells revealed heterozygous de novo SAMD9L mutations, p.Asn885Thrfs*6 and p.Lys878Serfs*13. These frameshift mutations truncate the SAMD9L protein within a domain a region of homology to the nucleotide-binding and oligomerization domain (NOD) of APAF1, ∼80 amino acids C-terminal to the Walker B motif. Single-cell analysis of human cells expressing green fluorescent protein (GFP)-SAMD9L fusion proteins revealed that enforced expression of wild-type SAMD9L repressed translation of red fluorescent protein messenger RNA and globally repressed endogenous protein translation, cell autonomously and in proportion to the level of GFP-SAMD9L in each cell. The children's truncating mutations dramatically exaggerated translational repression even at low levels of GFP-SAMD9L per cell, as did a missense Arg986Cys mutation reported recurrently as causing ataxia pancytopenia syndrome. Autoinflammatory disease associated with SAMD9L truncating mutations appears to result from an interferon-induced translational repressor whose activity goes unchecked by the loss of C-terminal domains that may normally sense virus infection.


Assuntos
Ataxia/patologia , Regulação da Expressão Gênica , Mutação de Sentido Incorreto , Síndromes Mielodisplásicas/patologia , Pancitopenia/patologia , Biossíntese de Proteínas , Proteínas Supressoras de Tumor/genética , Ataxia/genética , Criança , Feminino , Heterozigoto , Humanos , Recém-Nascido , Masculino , Síndromes Mielodisplásicas/genética , Pancitopenia/genética
7.
Sci Immunol ; 6(60)2021 06 18.
Artigo em Inglês | MEDLINE | ID: mdl-34145065

RESUMO

Analysis of autoinflammatory and immunodeficiency disorders elucidates human immunity and fosters the development of targeted therapies. Oligoadenylate synthetase 1 is a type I interferon-induced, intracellular double-stranded RNA (dsRNA) sensor that generates 2'-5'-oligoadenylate to activate ribonuclease L (RNase L) as a means of antiviral defense. We identified four de novo heterozygous OAS1 gain-of-function variants in six patients with a polymorphic autoinflammatory immunodeficiency characterized by recurrent fever, dermatitis, inflammatory bowel disease, pulmonary alveolar proteinosis, and hypogammaglobulinemia. To establish causality, we applied genetic, molecular dynamics simulation, biochemical, and cellular functional analyses in heterologous, autologous, and inducible pluripotent stem cell-derived macrophages and/or monocytes and B cells. We found that upon interferon-induced expression, OAS1 variant proteins displayed dsRNA-independent activity, which resulted in RNase L-mediated RNA cleavage, transcriptomic alteration, translational arrest, and dysfunction and apoptosis of monocytes, macrophages, and B cells. RNase L inhibition with curcumin modulated and allogeneic hematopoietic cell transplantation cured the disorder. Together, these data suggest that human OAS1 is a regulator of interferon-induced hyperinflammatory monocyte, macrophage, and B cell pathophysiology.


Assuntos
2',5'-Oligoadenilato Sintetase/genética , Doenças Hereditárias Autoinflamatórias/genética , Doenças da Imunodeficiência Primária/genética , 2',5'-Oligoadenilato Sintetase/imunologia , 2',5'-Oligoadenilato Sintetase/isolamento & purificação , 2',5'-Oligoadenilato Sintetase/metabolismo , Linfócitos B/imunologia , Células Cultivadas , Análise Mutacional de DNA , Endorribonucleases/genética , Endorribonucleases/metabolismo , Ensaios Enzimáticos , Mutação com Ganho de Função/imunologia , Técnicas de Inativação de Genes , Transplante de Células-Tronco Hematopoéticas , Doenças Hereditárias Autoinflamatórias/diagnóstico , Doenças Hereditárias Autoinflamatórias/imunologia , Doenças Hereditárias Autoinflamatórias/terapia , Heterozigoto , Humanos , Lactente , Recém-Nascido , Interferon Tipo I/metabolismo , Macrófagos/imunologia , Simulação de Dinâmica Molecular , Monócitos/imunologia , Cultura Primária de Células , Doenças da Imunodeficiência Primária/diagnóstico , Doenças da Imunodeficiência Primária/imunologia , Doenças da Imunodeficiência Primária/terapia , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Transdução de Sinais/genética , Transdução de Sinais/imunologia
8.
J Clin Invest ; 131(3)2021 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-33290277

RESUMO

Inborn errors of immunity cause monogenic immune dysregulatory conditions such as severe and recurrent pathogen infection, inflammation, allergy, and malignancy. Somatic reversion refers to the spontaneous repair of a pathogenic germline genetic variant and has been reported to occur in a number of inborn errors of immunity, with a range of impacts on clinical outcomes of these conditions. DOCK8 deficiency due to biallelic inactivating mutations in DOCK8 causes a combined immunodeficiency characterized by severe bacterial, viral, and fungal infections, as well as allergic disease and some cancers. Here, we describe the clinical, genetic, and cellular features of 3 patients with biallelic DOCK8 variants who, following somatic reversion in multiple lymphocyte subsets, exhibited improved clinical features, including complete resolution of infection and allergic disease, and cure over time. Acquisition of DOCK8 expression restored defective lymphocyte signalling, survival and proliferation, as well as CD8+ T cell cytotoxicity, CD4+ T cell cytokine production, and memory B cell generation compared with typical DOCK8-deficient patients. Our temporal analysis of DOCK8-revertant and DOCK8-deficient cells within the same individual established mechanisms of clinical improvement in these patients following somatic reversion and revealed further nonredundant functions of DOCK8 in human lymphocyte biology. Last, our findings have significant implications for future therapeutic options for the treatment of DOCK8 deficiency.


Assuntos
Diferenciação Celular , Fatores de Troca do Nucleotídeo Guanina/deficiência , Memória Imunológica/genética , Ativação Linfocitária/genética , Linfócitos/imunologia , Imunodeficiência Combinada Severa , Adulto , Diferenciação Celular/genética , Diferenciação Celular/imunologia , Feminino , Humanos , Masculino , Imunodeficiência Combinada Severa/genética , Imunodeficiência Combinada Severa/imunologia
9.
J Paediatr Child Health ; 56(10): 1508-1513, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-33099818

RESUMO

This consensus document outlines the recommendations from the Australasian Society of Clinical Immunology and Allergy Transplantation and Primary Immunodeficiency group for the diagnosis and management of patients with severe combined immunodeficiency. It also provides a proposed framework for the early investigation, management and supportive care prior to haematopoietic stem cell transplantation.


Assuntos
Transplante de Células-Tronco Hematopoéticas , Síndromes de Imunodeficiência , Imunodeficiência Combinada Severa , Austrália , Humanos , Síndromes de Imunodeficiência/diagnóstico , Síndromes de Imunodeficiência/terapia , Nova Zelândia , Imunodeficiência Combinada Severa/diagnóstico , Imunodeficiência Combinada Severa/terapia
10.
Dalton Trans ; 49(45): 16175-16183, 2020 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-32301445

RESUMO

Pseudo-octahedral iron complexes supported by tridentate N^N^N-binding, redox 'non-innocent' diiminepyridine (DIP) ligands exhibit multiple reversible ligand-based reductions that suggest the potential application of these complexes as anolytes in redox flow batteries (RFBs). When bearing aryl groups at the imine nitrogens, substitution at the 4-position can be used to tune these redox potentials and impact other properties relevant to RFB applications, such as solubility and stability over extended cycling. DIP ligands bearing electron-withdrawing groups (EWGs) in this position, however, can be challenging to isolate via typical condensation routes involving para-substituted anilines and 2,6-diacetylpyridine. In this work, we demonstrate a high-yielding Zn-templated synthesis of DIP ligands bearing strong EWGs. The synthesis and electrochemical characterization of iron(ii) complexes of these ligands is also described, along with properties relevant to their potential application as RFB anolytes.

11.
J Clin Immunol ; 40(2): 299-309, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31865525

RESUMO

Variants in MAGT1 have been identified as the cause of an immune deficiency termed X-linked immunodeficiency with magnesium defect, Epstein-Barr virus (EBV) infection and neoplasia (XMEN) disease. Here, we describe 2 cases of XMEN disease due to novel mutations in MAGT1, one of whom presented with classical features of XMEN disease and another who presented with a novel phenotype including probable CNS vasculitis, HHV-8 negative multicentric Castelman disease and severe molluscum contagiosum, thus highlighting the clinical diversity that may be seen in this condition. Peripheral blood immunophenotyping of these 2 patients, together with an additional 4 XMEN patients, revealed reduced NKG2D expression, impaired CD28 expression on CD8+ T cells, CD4+ T cell lymphopenia, an inverted CD4:CD8 ratio and decreased memory B cells. In addition, we showed for the first time alterations to the CD8+ T cell memory compartment, reduced CD56hi NK cells, MAIT and iNKT cells, as well as compromised differentiation of naïve CD4+ T cells into IL-21-producing Tfh-type cells in vitro. Both patients were treated with supplemental magnesium with limited benefit. However, one patient has undergone allogeneic haematopoietic stem cell transplant, with full donor chimerism and immune reconstitution. These results expand our understanding of the clinical and immunological phenotype in XMEN disease, adding to the current literature, which we further discuss here.


Assuntos
Proteínas de Transporte de Cátions/genética , Infecções por Vírus Epstein-Barr/genética , Herpesvirus Humano 4/fisiologia , Leucócitos Mononucleares/imunologia , Neoplasias/genética , Doenças por Imunodeficiência Combinada Ligada ao Cromossomo X/genética , Adulto , Diferenciação Celular , Criança , Quimerismo , Infecções por Vírus Epstein-Barr/imunologia , Transplante de Células-Tronco Hematopoéticas , Humanos , Memória Imunológica , Imunofenotipagem , Linfopenia , Magnésio/metabolismo , Masculino , Subfamília K de Receptores Semelhantes a Lectina de Células NK/metabolismo , Neoplasias/imunologia , Doenças por Imunodeficiência Combinada Ligada ao Cromossomo X/imunologia
12.
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.


Assuntos
Doença Antimembrana Basal Glomerular/imunologia , Autoanticorpos/imunologia , Autoantígenos/imunologia , Colágeno Tipo IV/imunologia , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Aloenxertos , Doença Antimembrana Basal Glomerular/etiologia , Criança , Colágeno Tipo IV/genética , Epitopos/imunologia , Humanos , Isoanticorpos/imunologia , Transtornos Linfoproliferativos/terapia , Masculino , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/imunologia
13.
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.


Assuntos
Infecções por Poxviridae/imunologia , Poxviridae/fisiologia , Domínios Proteicos/genética , Proteína 3 Induzida por Fator de Necrose Tumoral alfa/genética , Alelos , Animais , Extinção Biológica , Humanos , Imunidade , Inflamação , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Mutação de Sentido Incorreto/genética , Fosforilação
14.
JCI Insight ; 52019 04 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.


Assuntos
Linfócitos B/imunologia , Fatores de Troca do Nucleotídeo Guanina/deficiência , Transplante de Células-Tronco Hematopoéticas , Síndrome de Job/terapia , Linfócitos T/imunologia , Adolescente , Adulto , Diferenciação Celular/genética , Diferenciação Celular/imunologia , Criança , Pré-Escolar , Humanos , Imunoglobulina E/sangue , Imunoglobulina E/imunologia , Síndrome de Job/sangue , Síndrome de Job/genética , Síndrome de Job/imunologia , Ativação Linfocitária/genética , Resultado do Tratamento , Adulto Jovem
15.
J Pediatric Infect Dis Soc ; 8(1): 73-76, 2019 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-29415165

RESUMO

Single gene defects that impair lymphocyte cytotoxicity can predispose to severe viral infection that normally remains subclinical. The classic severe presentation is hemophagocytic lymphohistiocytosis. Here, we report the case of a neonate who presented with cytomegalovirus palatal ulceration and bocavirus pneumonitis secondary to impaired cytotoxicity caused by biallelic mutations in the UNC13D gene.


Assuntos
Infecções por Citomegalovirus/imunologia , Citotoxicidade Imunológica , Bocavirus Humano/isolamento & purificação , Linfócitos/imunologia , Proteínas de Membrana/genética , Palato Duro/imunologia , Infecções por Parvoviridae/imunologia , Pneumonia Viral/imunologia , Úlcera/imunologia , Infecções por Citomegalovirus/patologia , Humanos , Recém-Nascido , Masculino , Mutação , Palato Duro/patologia , Palato Duro/virologia , Infecções por Parvoviridae/genética , Infecções por Parvoviridae/patologia , Pneumonia Viral/genética , Pneumonia Viral/patologia , Úlcera/patologia , Úlcera/virologia
16.
J Allergy Clin Immunol ; 143(1): 276-291.e6, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-29800648

RESUMO

BACKGROUND: Germline gain-of function (GOF) mutations in PIK3CD, encoding the catalytic p110δ subunit of phosphoinositide 3-kinase (PI3K), result in hyperactivation of the PI3K-AKT-mechanistic target of rapamycin pathway and underlie a novel inborn error of immunity. Affected subjects exhibit perturbed humoral and cellular immunity, manifesting as recurrent infections, autoimmunity, hepatosplenomegaly, uncontrolled EBV and/or cytomegalovirus infection, and increased incidence of B-cell lymphoproliferation, lymphoma, or both. Mechanisms underlying disease pathogenesis remain unknown. OBJECTIVE: Understanding the cellular and molecular mechanisms underpinning inefficient surveillance of EBV-infected B cells is required to understand disease in patients with PIK3CD GOF mutations, identify key molecules required for cell-mediated immunity against EBV, and develop immunotherapeutic interventions for the treatment of this and other EBV-opathies. METHODS: We studied the consequences of PIK3CD GOF mutations on the generation, differentiation, and function of CD8+ T cells and natural killer (NK) cells, which are implicated in host defense against infection with herpesviruses, including EBV. RESULTS: PIK3CD GOF total and EBV-specific CD8+ T cells were skewed toward an effector phenotype, with exaggerated expression of markers associated with premature immunosenescence/exhaustion and increased susceptibility to reactivation-induced cell death. These findings were recapitulated in a novel mouse model of PI3K GOF mutations. NK cells in patients with PIK3CD GOF mutations also exhibited perturbed expression of differentiation-associated molecules. Both CD8+ T and NK cells had reduced capacity to kill EBV-infected B cells. PIK3CD GOF B cells had increased expression of CD48, programmed death ligand 1/2, and CD70. CONCLUSIONS: PIK3CD GOF mutations aberrantly induce exhaustion, senescence, or both and impair cytotoxicity of CD8+ T and NK cells. These defects might contribute to clinical features of affected subjects, such as impaired immunity to herpesviruses and tumor surveillance.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Diferenciação Celular/imunologia , Classe I de Fosfatidilinositol 3-Quinases , Infecções por Vírus Epstein-Barr , Mutação com Ganho de Função , Doenças Genéticas Inatas/imunologia , Herpesvirus Humano 4/imunologia , Células Matadoras Naturais/imunologia , Adolescente , Adulto , Idoso , Linfócitos B/imunologia , Linfócitos T CD8-Positivos/patologia , Diferenciação Celular/genética , Senescência Celular/genética , Senescência Celular/imunologia , Criança , Pré-Escolar , Classe I de Fosfatidilinositol 3-Quinases/genética , Classe I de Fosfatidilinositol 3-Quinases/imunologia , Infecções por Vírus Epstein-Barr/genética , Infecções por Vírus Epstein-Barr/imunologia , Infecções por Vírus Epstein-Barr/patologia , Doenças Genéticas Inatas/genética , Doenças Genéticas Inatas/patologia , Humanos , Vigilância Imunológica/genética , Células Matadoras Naturais/patologia , Masculino , Pessoa de Meia-Idade
17.
J Exp Med ; 215(8): 2073-2095, 2018 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-30018075

RESUMO

Gain-of-function (GOF) mutations in PIK3CD, encoding the p110δ subunit of phosphatidylinositide 3-kinase (PI3K), cause a primary immunodeficiency. Affected individuals display impaired humoral immune responses following infection or immunization. To establish mechanisms underlying these immune defects, we studied a large cohort of patients with PIK3CD GOF mutations and established a novel mouse model using CRISPR/Cas9-mediated gene editing to introduce a common pathogenic mutation in Pik3cd In both species, hyperactive PI3K severely affected B cell development and differentiation in the bone marrow and the periphery. Furthermore, PI3K GOF B cells exhibited intrinsic defects in class-switch recombination (CSR) due to impaired induction of activation-induced cytidine deaminase (AID) and failure to acquire a plasmablast gene signature and phenotype. Importantly, defects in CSR, AID expression, and Ig secretion were restored by leniolisib, a specific p110δ inhibitor. Our findings reveal key roles for balanced PI3K signaling in B cell development and long-lived humoral immunity and memory and establish the validity of treating affected individuals with p110δ inhibitors.


Assuntos
Linfócitos B/citologia , Linfócitos B/imunologia , Classe I de Fosfatidilinositol 3-Quinases/genética , Mutação em Linhagem Germinativa/genética , Fosfatidilinositol 3-Quinases/genética , Animais , Afinidade de Anticorpos/imunologia , Células da Medula Óssea/citologia , Diferenciação Celular , Proliferação de Células , Criança , Mutação com Ganho de Função/genética , Humanos , Switching de Imunoglobulina , Imunoglobulinas/metabolismo , Interleucinas/farmacologia , Camundongos , Modelos Animais , Fenótipo , Fosfatidilinositol 3-Quinases/metabolismo , Plasmócitos/metabolismo , Transdução de Sinais
18.
Sci Immunol ; 3(24)2018 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-29907691

RESUMO

Heterozygosity for human signal transducer and activator of transcription 3 (STAT3) dominant-negative (DN) mutations underlies an autosomal dominant form of hyper-immunoglobulin E syndrome (HIES). We describe patients with an autosomal recessive form of HIES due to loss-of-function mutations of a previously uncharacterized gene, ZNF341 ZNF341 is a transcription factor that resides in the nucleus, where it binds a specific DNA motif present in various genes, including the STAT3 promoter. The patients' cells have low basal levels of STAT3 mRNA and protein. The autoinduction of STAT3 production, activation, and function by STAT3-activating cytokines is strongly impaired. Like patients with STAT3 DN mutations, ZNF341-deficient patients lack T helper 17 (TH17) cells, have an excess of TH2 cells, and have low memory B cells due to the tight dependence of STAT3 activity on ZNF341 in lymphocytes. Their milder extra-hematopoietic manifestations and stronger inflammatory responses reflect the lower ZNF341 dependence of STAT3 activity in other cell types. Human ZNF341 is essential for the STAT3 transcription-dependent autoinduction and sustained activity of STAT3.


Assuntos
Regulação da Expressão Gênica/imunologia , Síndrome de Job/genética , Fator de Transcrição STAT3/genética , Fatores de Transcrição/genética , Transcrição Gênica/imunologia , Adolescente , Adulto , Diferenciação Celular/genética , Diferenciação Celular/imunologia , Núcleo Celular/metabolismo , Consanguinidade , Citocinas/imunologia , Citocinas/metabolismo , Éxons/genética , Feminino , Genes Recessivos/genética , Genes Recessivos/imunologia , Homozigoto , Humanos , Imunoglobulina E/sangue , Imunoglobulina E/imunologia , Síndrome de Job/sangue , Síndrome de Job/imunologia , Mutação com Perda de Função , Contagem de Linfócitos , Masculino , Pessoa de Meia-Idade , Linhagem , Regiões Promotoras Genéticas/genética , RNA Mensageiro/metabolismo , Fator de Transcrição STAT3/imunologia , Fator de Transcrição STAT3/metabolismo , Células Th17/imunologia , Células Th17/metabolismo , Células Th2/imunologia , Células Th2/metabolismo , Fatores de Transcrição/imunologia , Fatores de Transcrição/metabolismo , Sequenciamento do Exoma , Adulto Jovem , Dedos de Zinco/genética
19.
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
20.
Peptides ; 90: 48-54, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28219695

RESUMO

Dynorphin 1-17 (DYN 1-17) is biotransformed rapidly to a range of fragments in rodent inflamed tissue with dynorphin 3-14 (DYN 3-14) being the most stable and prevalent. DYN 1-17 has been shown previously to be involved in the regulation of inflammatory response following tissue injury, in which the biotransformation fragments of DYN 1-17 may possess similar features. This study investigated the effects of DYN 3-14 on lipopolysaccharide (LPS)-induced nuclear factor-kappaB/p65 (NF-κB/p65) nuclear translocation and the release of pro-inflammatory cytokines interleukin-1beta (IL-1ß) and tumor necrosis factor-alpha (TNF-α) in differentiated THP-1 cells. Treatment with DYN 3-14 (10nM) resulted in 35% inhibition of the LPS-induced nuclear translocation of NF-κB/p65. Furthermore, DYN 3-14 modulated both IL-1ß and TNF-α release; inhibiting IL-1ß and paradoxically augmenting TNF-α release in a concentration-independent manner. A number of opioids have been implicated in the modulation of the toll-like receptor 4 (TLR4), highlighting the complexity of their immunomodulatory effects. To determine whether DYN 3-14 modulates TLR4, HEK-Blue™-hTLR4 cells were stimulated with LPS in the presence of DYN 3-14. DYN 3-14 (10µM) inhibited TLR4 activation in a concentration-dependent fashion by suppressing the LPS signals around 300-fold lower than LPS-RS, a potent TLR4 antagonist. These findings indicate that DYN 3-14 is a potential TLR4 antagonist that alters cellular signaling in response to LPS and cytokine release, implicating a role for biotransformed endogenous opioid peptides in immunomodulation.


Assuntos
Dinorfinas/administração & dosagem , Inflamação/tratamento farmacológico , Receptor 4 Toll-Like/genética , Fator de Transcrição RelA/genética , Animais , Linhagem Celular , Dinorfinas/imunologia , Humanos , Imunomodulação/efeitos dos fármacos , Inflamação/induzido quimicamente , Inflamação/genética , Interleucina-1beta/genética , Lipopolissacarídeos/toxicidade , NF-kappa B/genética , Transporte Proteico/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Receptor 4 Toll-Like/antagonistas & inibidores , Fator de Necrose Tumoral alfa/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA