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3.
Proc Natl Acad Sci U S A ; 116(3): 970-975, 2019 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-30591564

RESUMO

Receptor-interacting serine/threonine-protein kinase 1 (RIPK1) is a critical regulator of cell death and inflammation, but its relevance for human disease pathogenesis remains elusive. Studies of monogenic disorders might provide critical insights into disease mechanisms and therapeutic targeting of RIPK1 for common diseases. Here, we report on eight patients from six unrelated pedigrees with biallelic loss-of-function mutations in RIPK1 presenting with primary immunodeficiency and/or intestinal inflammation. Mutations in RIPK1 were associated with reduced NF-κB activity, defective differentiation of T and B cells, increased inflammasome activity, and impaired response to TNFR1-mediated cell death in intestinal epithelial cells. The characterization of RIPK1-deficient patients highlights the essential role of RIPK1 in controlling human immune and intestinal homeostasis, and might have critical implications for therapies targeting RIPK1.


Assuntos
Diferenciação Celular , Imunidade nas Mucosas/genética , Doenças Inflamatórias Intestinais , Mucosa Intestinal , Proteína Serina-Treonina Quinases de Interação com Receptores , Imunodeficiência Combinada Severa , Linfócitos B/imunologia , Linfócitos B/patologia , Diferenciação Celular/genética , Diferenciação Celular/imunologia , Células Epiteliais/imunologia , Células Epiteliais/patologia , Feminino , Células HCT116 , Células HEK293 , Humanos , Doenças Inflamatórias Intestinais/genética , Doenças Inflamatórias Intestinais/imunologia , Doenças Inflamatórias Intestinais/patologia , Mucosa Intestinal/imunologia , Mucosa Intestinal/patologia , Masculino , Mutação , NF-kappa B/genética , NF-kappa B/imunologia , Proteína Serina-Treonina Quinases de Interação com Receptores/deficiência , Proteína Serina-Treonina Quinases de Interação com Receptores/imunologia , Imunodeficiência Combinada Severa/genética , Imunodeficiência Combinada Severa/imunologia , Imunodeficiência Combinada Severa/patologia , Linfócitos T/imunologia , Linfócitos T/patologia
4.
Br J Haematol ; 180(5): 644-653, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29270983

RESUMO

Reticular Dysgenesis is a rare immunodeficiency which is clinically characterized by the combination of Severe Combined Immunodeficiency (SCID) with agranulocytosis and sensorineural deafness. Mutations in the gene encoding adenylate kinase 2 (AK2) were identified to cause this phenotype. In this review, we will demonstrate important clinical differences between reticular dysgenesis and other SCID entities and summarize recent concepts in the understanding of the pathophysiology of the disease and the management strategies for this difficult condition.

6.
Blood ; 130(7): 875-880, 2017 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-28559357

RESUMO

We report 5 individuals in 3 unrelated families with severe thrombocytopenia progressing to trilineage bone marrow failure (BMF). Four of the children received hematopoietic stem cell transplants and all showed poor graft function with persistent severe cytopenias even after repeated transplants with different donors. Exome and targeted sequencing identified mutations in the gene encoding thrombopoietin (THPO): THPO R99W, homozygous in affected children in 2 families, and THPO R157X, homozygous in the affected child in the third family. Both mutations result in a lack of THPO in the patients' serum. For the 2 surviving patients, improvement in trilineage hematopoiesis was achieved following treatment with a THPO receptor agonist. These studies demonstrate that biallelic loss-of-function mutations in THPO cause BMF, which is unresponsive to transplant due to a hematopoietic cell-extrinsic mechanism. These studies provide further support for the critical role of the MPL-THPO pathway in hematopoiesis and highlight the importance of accurate genetic diagnosis to inform treatment decisions for BMF.


Assuntos
Transplante de Medula Óssea , Medula Óssea/patologia , Mutação/genética , Trombopoetina/genética , Sequência de Bases , Criança , Pré-Escolar , Feminino , Células HEK293 , Humanos , Lactente , Masculino , Linhagem , Receptores Fc/uso terapêutico , Proteínas Recombinantes de Fusão/uso terapêutico , Trombopoetina/uso terapêutico , Resultado do Tratamento
7.
Front Immunol ; 8: 449, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28507545

RESUMO

Typical features of dyskeratosis congenita (DC) resulting from excessive telomere shortening include bone marrow failure (BMF), mucosal fragility, and pulmonary or liver fibrosis. In more severe cases, immune deficiency and recurring infections can add to disease severity. RTEL1 deficiency has recently been described as a major genetic etiology, but the molecular basis and clinical consequences of RTEL1-associated DC are incompletely characterized. We report our observations in a cohort of six patients: five with novel biallelic RTEL1 mutations p.Trp456Cys, p.Ile425Thr, p.Cys1244ProfsX17, p.Pro884_Gln885ins53X13, and one with novel heterozygous mutation p.Val796AlafsX4. The most unifying features were hypocellular BMF in 6/6 and B-/NK-cell lymphopenia in 5/6 patients. In addition, three patients with homozygous mutations p.Trp456Cys or p.Ile425Thr also suffered from immunodeficiency, cerebellar hypoplasia, and enteropathy, consistent with Hoyeraal-Hreidarsson syndrome. Chromosomal breakage resembling a homologous recombination defect was detected in patient-derived fibroblasts but not in hematopoietic compartment. Notably, in both cellular compartments, differential expression of 1243aa and 1219/1300aa RTEL1 isoforms was observed. In fibroblasts, response to ionizing irradiation and non-homologous end joining were not impaired. Telomeric circles did not accumulate in patient-derived primary cells and lymphoblastoid cell lines, implying alternative pathomechanisms for telomeric loss. Overall, RTEL1-deficient cells exhibited a phenotype of replicative exhaustion, spontaneous apoptosis and senescence. Specifically, CD34+ cells failed to expand in vitro, B-cell development was compromised, and T-cells did not proliferate in long-term culture. Finally, we report on the natural history and outcome of our patients. While two patients died from infections, hematopoietic stem cell transplantation (HSCT) resulted in sustained engraftment in two patients. Whether chemotherapy negatively impacts on the course and onset of other DC-related symptoms remains open at present. Early-onset lung disease occurred in one of our patients after HSCT. In conclusion, RTEL deficiency can show a heterogeneous clinical picture ranging from mild hypocellular BMF with B/NK cell lymphopenia to early-onset, very severe, and rapidly progressing cellular deficiency.

8.
Blood ; 129(21): 2928-2938, 2017 05 25.
Artigo em Inglês | MEDLINE | ID: mdl-28331055

RESUMO

Reticular dysgenesis (RD) is a rare congenital disorder defined clinically by the combination of severe combined immunodeficiency (SCID), agranulocytosis, and sensorineural deafness. Mutations in the gene encoding adenylate kinase 2 were identified to cause the disorder. Hematopoietic stem cell transplantation (HSCT) is the only option to cure this otherwise fatal disease. Retrospective data on clinical presentation, genetics, and outcome of HSCT were collected from centers in Europe, Asia, and North America for a total of 32 patients born between 1982 and 2011. Age at presentation was <4 weeks in 30 of 32 patients (94%). Grafts originated from mismatched family donors in 17 patients (55%), from matched family donors in 6 patients (19%), and from unrelated marrow or umbilical cord blood donors in 8 patients (26%). Thirteen patients received secondary or tertiary transplants. After transplantation, 21 of 31 patients were reported alive at a mean follow-up of 7.9 years (range: 0.6-23.6 years). All patients who died beyond 6 months after HSCT had persistent or recurrent agranulocytosis due to failure of donor myeloid engraftment. In the absence of conditioning, HSCT was ineffective to overcome agranulocytosis, and inclusion of myeloablative components in the conditioning regimens was required to achieve stable lymphomyeloid engraftment. In comparison with other SCID entities, considerable differences were noted regarding age at presentation, onset, and type of infectious complications, as well as the requirement of conditioning prior to HSCT. Although long-term survival is possible in the presence of mixed chimerism, high-level donor myeloid engraftment should be targeted to avoid posttransplant neutropenia.


Assuntos
Transplante de Células-Tronco de Sangue do Cordão Umbilical , Transplante de Células-Tronco Hematopoéticas , Leucopenia/mortalidade , Leucopenia/terapia , Imunodeficiência Combinada Severa/mortalidade , Imunodeficiência Combinada Severa/terapia , Condicionamento Pré-Transplante , Doadores não Relacionados , Adenilil Ciclases/genética , Adenilil Ciclases/metabolismo , Adolescente , Adulto , Idade de Início , Aloenxertos , Criança , Intervalo Livre de Doença , Feminino , Humanos , Leucopenia/enzimologia , Leucopenia/genética , Masculino , Imunodeficiência Combinada Severa/enzimologia , Imunodeficiência Combinada Severa/genética , Taxa de Sobrevida
9.
Clin Immunol ; 179: 1-7, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28216420

RESUMO

Here we describe novel mutations in recombination activation gene 1 (RAG1) in a compound heterozygous male patient with combined T and B cell immunodeficiency (CID). Clinical manifestations besides antibody deficiency included airway infections, granulomatosis and autoimmune features. He died at the age of 37 due to PML caused by JC virus infection. By targeted next-generation sequencing we detected post mortem in this patient three mutations in RAG1. One allele harbored two novel mutations (c.1123C>G, p.H375D and c.1430delC, p.F478Sfs*14), namely a missense variant and a frameshift deletion, of which the latter leads to a truncated RAG1 protein. The other allele revealed a previously described missense mutation (c.1420C>T, p.R474C, rs199474678). Functional analysis of the p.R474C variant in an in vitro V(D)J recombination assay exhibited reduced recombination activity compared to a wild-type control. Our findings suggest that mutations in RAG1, specifically the p.R474C variant, can be associated with relatively mild clinical symptoms or delayed occurrence of T cell and B cell deficiencies but may predispose to PML.


Assuntos
Proteínas de Homeodomínio/genética , Síndromes de Imunodeficiência/genética , Leucoencefalopatia Multifocal Progressiva/genética , Adulto , Linfócitos B/imunologia , Biópsia , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Proliferação de Células , Humanos , Imunoglobulinas/sangue , Síndromes de Imunodeficiência/sangue , Síndromes de Imunodeficiência/diagnóstico por imagem , Síndromes de Imunodeficiência/imunologia , Leucoencefalopatia Multifocal Progressiva/sangue , Leucoencefalopatia Multifocal Progressiva/diagnóstico por imagem , Leucoencefalopatia Multifocal Progressiva/imunologia , Contagem de Linfócitos , Imagem por Ressonância Magnética , Masculino , Mutação , Receptores de Antígenos de Linfócitos T/imunologia , Linfócitos T/imunologia , Recombinação V(D)J
10.
Clin Immunol ; 164: 52-6, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26812624

RESUMO

NF-κB essential modulator (NEMO) deficiency causes ectodermal dysplasia with immunodeficiency in males, while manifesting as incontinentia pigmenti in heterozygous females. We report a family with NEMO deficiency, in which a female carrier displayed skewed X-inactivation favoring the mutant NEMO allele associated with symptoms of Behçet's disease. Hematopoietic stem cell transplantation of an affected boy from this donor reconstituted an immune system with retained skewed X-inactivation. After transplantation no more severe infections occurred, indicating that an active wild-type NEMO allele in only 10% of immune cells restores host defense. Yet he developed inflammatory bowel disease (IBD). While gut infiltrating immune cells stained strongly for nuclear p65 indicating restored NEMO function, this was not the case in intestinal epithelial cells - in contrast to cells from conventional IBD patients. These results extend murine observations that epithelial NEMO-deficiency suffices to cause IBD. High anti-TNF doses controlled the intestinal inflammation and symptoms of Behçet's disease.


Assuntos
Transplante de Células-Tronco Hematopoéticas , Quinase I-kappa B , Doenças Inflamatórias Intestinais/imunologia , Alelos , Síndrome de Behçet/diagnóstico , Síndrome de Behçet/genética , Síndrome de Behçet/imunologia , Feminino , Humanos , Quinase I-kappa B/deficiência , Quinase I-kappa B/genética , Quinase I-kappa B/imunologia , Masculino , Irmãos
11.
Hum Mutat ; 37(3): 257-68, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26615982

RESUMO

Immunodeficiency patients with DNA repair defects exhibit radiosensitivity and proneness to leukemia/lymphoma formation. Though progress has been made in identifying the underlying mutations, in most patients the genetic basis is unknown. Two de novo mutated candidate genes, MCM3AP encoding germinal center-associated nuclear protein (GANP) and POMP encoding proteasome maturation protein (POMP), were identified by whole-exome sequencing (WES) and confirmed by Sanger sequencing in a child with complex phenotype displaying immunodeficiency, genomic instability, skin changes, and myelodysplasia. GANP was previously described to promote B-cell maturation by nuclear targeting of activation-induced cytidine deaminase (AID) and to control AID-dependent hyperrecombination. POMP is required for 20S proteasome assembly and, thus, for efficient NF-κB signaling. Patient-derived cells were characterized by impaired homologous recombination, moderate radio- and cross-linker sensitivity associated with accumulation of damage, impaired DNA damage-induced NF-κB signaling, and reduced nuclear AID levels. Complementation by wild-type (WT)-GANP normalized DNA repair and WT-POMP rescued defective NF-κB signaling. In conclusion, we identified for the first time mutations in MCM3AP and POMP in an immunodeficiency patient. These mutations lead to cooperative effects on DNA recombination and damage signaling. Digenic/polygenic mutations may constitute a novel genetic basis in immunodeficiency patients with DNA repair defects.


Assuntos
Acetiltransferases/genética , Dano ao DNA/genética , Reparo do DNA/genética , Síndromes de Imunodeficiência/genética , Peptídeos e Proteínas de Sinalização Intracelular/genética , Chaperonas Moleculares/genética , Dano ao DNA/fisiologia , Reparo do DNA/fisiologia , Humanos , Mutação/genética , Transdução de Sinais/genética , Transdução de Sinais/fisiologia
12.
Hum Mol Genet ; 24(25): 7361-72, 2015 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-26476407

RESUMO

Null mutations in genes involved in V(D)J recombination cause a block in B- and T-cell development, clinically presenting as severe combined immunodeficiency (SCID). Hypomorphic mutations in the non-homologous end-joining gene DCLRE1C (encoding ARTEMIS) have been described to cause atypical SCID, Omenn syndrome, Hyper IgM syndrome and inflammatory bowel disease-all with severely impaired T-cell immunity. By whole-exome sequencing, we investigated the molecular defect in a consanguineous family with three children clinically diagnosed with antibody deficiency. We identified perfectly segregating homozygous variants in DCLRE1C in three index patients with recurrent respiratory tract infections, very low B-cell numbers and serum IgA levels. In patients, decreased colony survival after irradiation, impaired proliferative response and reduced counts of naïve T cells were observed in addition to a restricted T-cell receptor repertoire, increased palindromic nucleotides in the complementarity determining regions 3 and long stretches of microhomology at switch junctions. Defective V(D)J recombination was complemented by wild-type ARTEMIS protein in vitro. Subsequently, homozygous or compound heterozygous DCLRE1C mutations were identified in nine patients from the same geographic region. We demonstrate that DCLRE1C mutations can cause a phenotype presenting as only antibody deficiency. This novel association broadens the clinical spectrum associated with ARTEMIS mutations. Clinicians should consider the possibility that an immunodeficiency with a clinically mild initial presentation could be a combined immunodeficiency, so as to provide appropriate care for affected patients.


Assuntos
Proteínas Nucleares/genética , Imunodeficiência Combinada Severa/genética , Linfócitos B/metabolismo , Criança , Pré-Escolar , Endonucleases , Feminino , Humanos , Imunoglobulina A/metabolismo , Masculino , Mutação/genética
14.
Blood ; 126(14): 1658-69, 2015 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-26289640

RESUMO

Omenn syndrome (OS) is a severe immunodeficiency associated with erythroderma, lymphoproliferation, elevated IgE, and hyperactive oligoclonal T cells. A restricted T-cell repertoire caused by defective thymic T-cell development and selection, lymphopenia with homeostatic proliferation, and lack of regulatory T cells are considered key factors in OS pathogenesis. We report 2 siblings presenting with cytomegalovirus (CMV) and Pneumocystis jirovecii infections and recurrent sepsis; one developed all clinical features of OS. Both carried homozygous germline mutations in CARD11 (p.Cys150*), impairing NF-κB signaling and IL-2 production. A somatic second-site mutation reverting the stop codon to a missense mutation (p.Cys150Leu) was detected in tissue-infiltrating T cells of the OS patient. Expression of p.Cys150Leu in CARD11-deficient T cells largely reconstituted NF-κB signaling. The reversion likely occurred in a prethymic T-cell precursor, leading to a chimeric T-cell repertoire. We speculate that in our patient the functional advantage of the revertant T cells in the context of persistent CMV infection, combined with lack of regulatory T cells, may have been sufficient to favor OS. This first observation of OS in a patient with a T-cell activation defect suggests that severely defective T-cell development or homeostatic proliferation in a lymphopenic environment are not required for this severe immunopathology.


Assuntos
Proteínas Adaptadoras de Sinalização CARD/genética , Guanilato Ciclase/genética , Ativação Linfocitária/genética , Mutação , Imunodeficiência Combinada Severa/genética , Linfócitos T Reguladores/imunologia , Animais , Proteínas Adaptadoras de Sinalização CARD/deficiência , Proteínas Adaptadoras de Sinalização CARD/imunologia , Feminino , Citometria de Fluxo , Guanilato Ciclase/deficiência , Guanilato Ciclase/imunologia , Humanos , Immunoblotting , Imuno-Histoquímica , Imunofenotipagem , Lactente , Ativação Linfocitária/imunologia , Masculino , Camundongos , Reação em Cadeia da Polimerase em Tempo Real , Imunodeficiência Combinada Severa/imunologia , Irmãos
16.
Blood ; 123(2): 281-9, 2014 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-24144642

RESUMO

A subgroup of severe combined immunodeficiencies (SCID) is characterized by lack of T and B cells and is caused by defects in genes required for T- and B-cell receptor gene rearrangement. Several of these genes are also involved in nonhomologous end joining of DNA double-strand break repair, the largest subgroup consisting of patients with T(-)B(-)NK(+)SCID due to DCLRE1C/ARTEMIS defects. We postulated that in patients with ARTEMIS deficiency, early and late complications following hematopoietic cell transplantation might be more prominent compared with patients with T(-)B(-)NK(+)SCID caused by recombination activating gene 1/2 (RAG1/2) deficiencies. We analyzed 69 patients with ARTEMIS and 76 patients with RAG1/2 deficiencies who received transplants from either HLA-identical donors without conditioning or from HLA-nonidentical donors without or with conditioning. There was no difference in survival or in the incidence or severity of acute graft-versus-host disease regardless of exposure to alkylating agents. Secondary malignancies were not observed. Immune reconstitution was comparable in both groups, however, ARTEMIS-deficient patients had a significantly higher occurrence of infections in long-term follow-up. There is a highly significant association between poor growth in ARTEMIS deficiency and use of alkylating agents. Furthermore, abnormalities in dental development and endocrine late effects were associated with alkylation therapy in ARTEMIS deficiency.


Assuntos
Proteínas de Ligação a DNA/deficiência , Proteínas de Homeodomínio/genética , Proteínas Nucleares/deficiência , Imunodeficiência Combinada Severa/genética , Imunodeficiência Combinada Severa/imunologia , Linfócitos B/imunologia , Endonucleases , Feminino , Seguimentos , Doença Enxerto-Hospedeiro/etiologia , Antígenos HLA/imunologia , Transplante de Células-Tronco Hematopoéticas , Humanos , Depleção Linfocítica , Masculino , Mutação , Fatores de Risco , Imunodeficiência Combinada Severa/complicações , Imunodeficiência Combinada Severa/mortalidade , Imunodeficiência Combinada Severa/terapia , Linfócitos T/imunologia , Linfócitos T/metabolismo , Condicionamento Pré-Transplante , Resultado do Tratamento
18.
N Engl J Med ; 369(26): 2504-14, 2013 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-24369075

RESUMO

BACKGROUND: Severe combined immunodeficiency (SCID) comprises a heterogeneous group of heritable deficiencies of humoral and cell-mediated immunity. Many patients with SCID have lymphocyte-activation defects that remain uncharacterized. METHODS: We performed genetic studies in four patients, from four families of Northern Cree ancestry, who had clinical characteristics of SCID, including early onset of severe viral, bacterial, and fungal infections despite normal B-cell and T-cell counts. Genomewide homozygosity mapping was used to identify a candidate region, which was found on chromosome 8; all genes within this interval were sequenced. Immune-cell populations, signal transduction on activation, and effector functions were studied. RESULTS: The patients had hypogammaglobulinemia or agammaglobulinemia, and their peripheral-blood B cells and T cells were almost exclusively of naive phenotype. Regulatory T cells and γδ T cells were absent. All patients carried a homozygous duplication--c.1292dupG in exon 13 of IKBKB, which encodes IκB kinase 2 (IKK2, also known as IKKß)--leading to loss of expression of IKK2, a component of the IKK-nuclear factor κB (NF-κB) pathway. Immune cells from the patients had impaired responses to stimulation through T-cell receptors, B-cell receptors, toll-like receptors, inflammatory cytokine receptors, and mitogens. CONCLUSIONS: A form of human SCID is characterized by normal lymphocyte development despite a loss of IKK2 function. IKK2 deficiency results in an impaired response to activation stimuli in a variety of immune cells, leading to clinically relevant impairment of adaptive and innate immunity. Although Ikk2 deficiency is lethal in mouse embryos, our observations suggest a more restricted, unique role of IKK2-NF-κB signaling in humans. (Funded by the German Federal Ministry of Education and Research and others.).


Assuntos
Agamaglobulinemia/genética , Quinase I-kappa B/genética , Mutação , Imunodeficiência Combinada Severa/genética , Imunidade Adaptativa/genética , Linfócitos B/fisiologia , Evolução Fatal , Feminino , Genes Recessivos , Humanos , Quinase I-kappa B/deficiência , Imunidade Inata/genética , Índios Norte-Americanos , Lactente , Recém-Nascido , Ativação Linfocitária , Contagem de Linfócitos , Masculino , Linhagem , Análise de Sequência de DNA , Linfócitos T/fisiologia
19.
Am J Hum Genet ; 88(2): 226-31, 2011 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-21310277

RESUMO

The importance of intracellular folate metabolism is illustrated by the severity of symptoms and complications caused by inborn disorders of folate metabolism or by folate deficiency. We examined three children of healthy, distantly related parents presenting with megaloblastic anemia and cerebral folate deficiency causing neurologic disease with atypical childhood absence epilepsy. Genome-wide homozygosity mapping revealed a candidate region on chromosome 5 including the dihydrofolate reductase (DHFR) locus. DHFR sequencing revealed a homozygous DHFR mutation, c.458A>T (p.Asp153Val), in all siblings. The patients' folate profile in red blood cells (RBC), plasma, and cerebrospinal fluid (CSF), analyzed by liquid chromatography tandem mass spectrometry, was compatible with DHFR deficiency. DHFR activity and fluorescein-labeled methotrexate (FMTX) binding were severely reduced in EBV-immortalized lymphoblastoid cells of all patients. Heterozygous cells displayed intermediate DHFR activity and FMTX binding. RT-PCR of DHFR mRNA revealed no differences between wild-type and DHFR mutation-carrying cells, whereas protein expression was reduced in cells with the DHFR mutation. Treatment with folinic acid resulted in the resolution of hematological abnormalities, normalization of CSF folate levels, and improvement of neurological symptoms. In conclusion, the homozygous DHFR mutation p.Asp153Val causes DHFR deficiency and leads to a complex hematological and neurological disease that can be successfully treated with folinic acid. DHFR is necessary for maintaining sufficient CSF and RBC folate levels, even in the presence of adequate nutritional folate supply and normal plasma folate.


Assuntos
Anemia Megaloblástica/genética , Deficiência de Ácido Fólico/diagnóstico , Mutação/genética , Doenças do Sistema Nervoso/genética , Tetra-Hidrofolato Desidrogenase/deficiência , Tetra-Hidrofolato Desidrogenase/genética , Anemia Megaloblástica/diagnóstico , Criança , Pré-Escolar , Eritrócitos/metabolismo , Feminino , Fluoresceínas/metabolismo , Ácido Fólico/sangue , Ácido Fólico/líquido cefalorraquidiano , Deficiência de Ácido Fólico/sangue , Deficiência de Ácido Fólico/líquido cefalorraquidiano , Homozigoto , Humanos , Masculino , Metotrexato/análogos & derivados , Metotrexato/metabolismo , Modelos Moleculares , Doenças do Sistema Nervoso/diagnóstico , Linhagem , Conformação Proteica , Tetra-Hidrofolato Desidrogenase/química
20.
Immunity ; 33(5): 736-51, 2010 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-21093318

RESUMO

Whether the recently identified innate lymphocyte population coexpressing natural killer cell receptors (NKRs) and the nuclear receptor RORγt is part of the NK or lymphoid tissue inducer (LTi) cell lineage remains unclear. By using adoptive transfer of genetically tagged LTi-like cells, we demonstrate that NKR⁻RORγt(+) innate lymphocytes but not NK cells were direct progenitors to NKR(+)RORγt(+) cells in vivo. Genetic lineage tracing revealed that the differentiation of LTi-like cells was characterized by the stable upregulation of NKRs and a progressive loss of RORγt expression. Whereas interleukin-7 (IL-7) and intestinal microbiota stabilized RORγt expression within such NKR-LTi cells, IL-12 and IL-15 accelerated RORγt loss. RORγt(+) NKR-LTi cells produced IL-22, whereas RORγt⁻ NKR-LTi cells released IFN-γ and were potent inducers of colitis. Thus, the RORγt gradient in NKR-LTi cells serves as a tunable rheostat for their functional program. Our data also define a previously unappreciated role of RORγt⁻ NKR-LTi cells for the onset or maintenance of inflammatory bowel diseases.


Assuntos
Células Matadoras Naturais/imunologia , Tecido Linfoide/imunologia , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/metabolismo , Animais , Linhagem da Célula/imunologia , Regulação para Baixo , Doenças Inflamatórias Intestinais/imunologia , Interferon gama/imunologia , Interferon gama/metabolismo , Interleucina-12/imunologia , Interleucina-12/metabolismo , Interleucina-15/imunologia , Interleucina-15/metabolismo , Interleucina-7/genética , Interleucina-7/imunologia , Interleucina-7/metabolismo , Interleucinas/imunologia , Interleucinas/metabolismo , Intestinos/imunologia , Intestinos/microbiologia , Ativação Linfocitária , Camundongos , Camundongos Endogâmicos C57BL , Linfócitos T Auxiliares-Indutores/imunologia , Linfócitos T Auxiliares-Indutores/metabolismo , Regulação para Cima
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