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1.
Nat Commun ; 10(1): 3765, 2019 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-31434886

RESUMO

Of the 1.8 billion people worldwide infected with Mycobacterium tuberculosis, 5-15% will develop active tuberculosis (TB). Approximately half will progress to active TB within the first 18 months after infection, presumably because they fail to mount an effective initial immune response. Here, in a genome-wide genetic study of early TB progression, we genotype 4002 active TB cases and their household contacts in Peru. We quantify genetic heritability ([Formula: see text]) of early TB progression to be 21.2% (standard error 0.08). This suggests TB progression has a strong genetic basis, and is comparable to traits with well-established genetic bases. We identify a novel association between early TB progression and variants located in a putative enhancer region on chromosome 3q23 (rs73226617, OR = 1.18; P = 3.93 × 10-8). With in silico and in vitro analyses we identify rs73226617 or rs148722713 as the likely functional variant and ATP1B3 as a potential causal target gene with monocyte specific function.

2.
J Allergy Clin Immunol ; 144(5): 1364-1376, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31201888

RESUMO

BACKGROUND: CCAAT enhancer-binding protein epsilon (C/EBPε) is a transcription factor involved in late myeloid lineage differentiation and cellular function. The only previously known disorder linked to C/EBPε is autosomal recessive neutrophil-specific granule deficiency leading to severely impaired neutrophil function and early mortality. OBJECTIVE: The aim of this study was to molecularly characterize the effects of C/EBPε transcription factor Arg219His mutation identified in a Finnish family with previously genetically uncharacterized autoinflammatory and immunodeficiency syndrome. METHODS: Genetic analysis, proteomics, genome-wide transcriptional profiling by means of RNA-sequencing, chromatin immunoprecipitation (ChIP) sequencing, and assessment of the inflammasome function of primary macrophages were performed. RESULTS: Studies revealed a novel mechanism of genome-wide gain-of-function that dysregulated transcription of 464 genes. Mechanisms involved dysregulated noncanonical inflammasome activation caused by decreased association with transcriptional repressors, leading to increased chromatin occupancy and considerable changes in transcriptional activity, including increased expression of NLR family, pyrin domain-containing 3 protein (NLRP3) and constitutively expressed caspase-5 in macrophages. CONCLUSION: We describe a novel autoinflammatory disease with defective neutrophil function caused by a homozygous Arg219His mutation in the transcription factor C/EBPε. Mutated C/EBPε acts as a regulator of both the inflammasome and interferome, and the Arg219His mutation causes the first human monogenic neomorphic and noncanonical inflammasomopathy/immunodeficiency. The mechanism, including widely dysregulated transcription, is likely not unique for C/EBPε. Similar multiomics approaches should also be used in studying other transcription factor-associated diseases.

3.
Am J Med Genet B Neuropsychiatr Genet ; 177(7): 641-657, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30325587

RESUMO

Individuals with psychiatric disorders have elevated rates of autoimmune comorbidity and altered immune signaling. It is unclear whether these altered immunological states have a shared genetic basis with those psychiatric disorders. The present study sought to use existing summary-level data from previous genome-wide association studies to determine if commonly varying single nucleotide polymorphisms are shared between psychiatric and immune-related phenotypes. We estimated heritability and examined pair-wise genetic correlations using the linkage disequilibrium score regression (LDSC) and heritability estimation from summary statistics methods. Using LDSC, we observed significant genetic correlations between immune-related disorders and several psychiatric disorders, including anorexia nervosa, attention deficit-hyperactivity disorder, bipolar disorder, major depression, obsessive compulsive disorder, schizophrenia, smoking behavior, and Tourette syndrome. Loci significantly mediating genetic correlations were identified for schizophrenia when analytically paired with Crohn's disease, primary biliary cirrhosis, systemic lupus erythematosus, and ulcerative colitis. We report significantly correlated loci and highlight those containing genome-wide associations and candidate genes for respective disorders. We also used the LDSC method to characterize genetic correlations among the immune-related phenotypes. We discuss our findings in the context of relevant genetic and epidemiological literature, as well as the limitations and caveats of the study.

4.
Artigo em Inglês | MEDLINE | ID: mdl-30170123

RESUMO

BACKGROUND: Caspase activation and recruitment domain 11 (CARD11) encodes a scaffold protein in lymphocytes that links antigen receptor engagement with downstream signaling to nuclear factor κB, c-Jun N-terminal kinase, and mechanistic target of rapamycin complex 1. Germline CARD11 mutations cause several distinct primary immune disorders in human subjects, including severe combined immune deficiency (biallelic null mutations), B-cell expansion with nuclear factor κB and T-cell anergy (heterozygous, gain-of-function mutations), and severe atopic disease (loss-of-function, heterozygous, dominant interfering mutations), which has focused attention on CARD11 mutations discovered by using whole-exome sequencing. OBJECTIVES: We sought to determine the molecular actions of an extended allelic series of CARD11 and to characterize the expanding range of clinical phenotypes associated with heterozygous CARD11 loss-of-function alleles. METHODS: Cell transfections and primary T-cell assays were used to evaluate signaling and function of CARD11 variants. RESULTS: Here we report on an expanded cohort of patients harboring novel heterozygous CARD11 mutations that extend beyond atopy to include other immunologic phenotypes not previously associated with CARD11 mutations. In addition to (and sometimes excluding) severe atopy, heterozygous missense and indel mutations in CARD11 presented with immunologic phenotypes similar to those observed in signal transducer and activator of transcription 3 loss of function, dedicator of cytokinesis 8 deficiency, common variable immunodeficiency, neutropenia, and immune dysregulation, polyendocrinopathy, enteropathy, X-linked-like syndrome. Pathogenic variants exhibited dominant negative activity and were largely confined to the CARD or coiled-coil domains of the CARD11 protein. CONCLUSION: These results illuminate a broader phenotypic spectrum associated with CARD11 mutations in human subjects and underscore the need for functional studies to demonstrate that rare gene variants encountered in expected and unexpected phenotypes must nonetheless be validated for pathogenic activity.

5.
Nat Commun ; 9(1): 3174, 2018 08 09.
Artigo em Inglês | MEDLINE | ID: mdl-30093657

RESUMO

Streptococcus pneumoniae is a major cause of pneumonia and a leading cause of death world-wide. Antibody-mediated immune responses can confer protection against repeated exposure to S. pneumoniae, yet vaccines offer only partial protection. Patients with Activated PI3Kδ Syndrome (APDS) are highly susceptible to S. pneumoniae. We generated a conditional knock-in mouse model of this disease and identify a CD19+B220- B cell subset that is induced by PI3Kδ signaling, resides in the lungs, and is correlated with increased susceptibility to S. pneumoniae during early phases of infection via an antibody-independent mechanism. We show that an inhaled PI3Kδ inhibitor improves survival rates following S. pneumoniae infection in wild-type mice and in mice with activated PI3Kδ. These results suggest that a subset of B cells in the lung can promote the severity of S. pneumoniae infection, representing a potential therapeutic target.

6.
Science ; 361(6404): 810-813, 2018 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-30026316

RESUMO

RIPK1 (receptor-interacting serine/threonine kinase 1) is a master regulator of signaling pathways leading to inflammation and cell death and is of medical interest as a drug target. We report four patients from three unrelated families with complete RIPK1 deficiency caused by rare homozygous mutations. The patients suffered from recurrent infections, early-onset inflammatory bowel disease, and progressive polyarthritis. They had immunodeficiency with lymphopenia and altered production of various cytokines revealed by whole-blood assays. In vitro, RIPK1-deficient cells showed impaired mitogen-activated protein kinase activation and cytokine secretion and were prone to necroptosis. Hematopoietic stem cell transplantation reversed cytokine production defects and resolved clinical symptoms in one patient. Thus, RIPK1 plays a critical role in the human immune system.


Assuntos
Artrite/genética , Doenças Inflamatórias Intestinais/genética , Proteína Serina-Treonina Quinases de Interação com Receptores/genética , Imunodeficiência Combinada Severa/genética , Alelos , Artrite/imunologia , Citocinas/metabolismo , Feminino , Fibroblastos/metabolismo , Fibroblastos/patologia , Humanos , Doenças Inflamatórias Intestinais/imunologia , Linfopenia/genética , Masculino , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Linhagem , Imunodeficiência Combinada Severa/imunologia
7.
Artigo em Inglês | MEDLINE | ID: mdl-29939941

RESUMO

X-linked severe combined immunodeficiency disease (SCID) is caused by mutations in the interleukin (IL)-2 receptor γ (IL2RG) gene and patients usually present with a TBNK SCID phenotype. Nevertheless, a minority of these patients present with a TBNK phenotype, similar to the IL-7R-deficient patients. We report a patient with a novel missense p.Glu297Gly mutation in the IL2RG gene presenting with a leaky TBNK SCID with delayed onset, moderate susceptibility to infections, and nodular regenerative hyperplasia. He presents with preserved STAT5 tyrosine phosphorylation in response to IL-15 stimulation but not in response to IL-2 and IL-7, resulting in the NK phenotype.

8.
Front Immunol ; 9: 369, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29535736

RESUMO

Activated PI3 kinase delta syndrome (APDS) is a primary immunodeficiency caused by dominant mutations that increase activity of phosphoinositide-3-kinase δ (PI3Kδ). APDS can be caused by mutations in the PIK3CD gene that encodes PI3Kδ catalytic subunit p110δ (APDS1) or mutations in the PIK3R1 gene that encodes regulatory subunit p85α (APDS2). APDS research advanced rapidly after the initial discovery in 2013. More than 200 APDS patients have been identified around the world. Multiple novel APDS mutations were reported and molecular mechanisms leading to PI3Kδ activation have been elucidated. The finding of APDS significantly increased our understanding of the role of PI3Kδ in the human immune system. Perhaps most importantly, discovery of the molecular basis of this primary immunodeficiency suggested that APDS patients, who previously received only non-specific therapy, could be treated by a novel class of drugs that inhibits PI3Kδ activity. This led to the ongoing clinical trials of selective PI3Kδ inhibitors in APDS patients. Overall, the APDS story provides an excellent example of translational research, beginning with patients who had an unknown disease cause and leading to a novel specific knowledge-based treatment.

9.
Front Immunol ; 9: 2863, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30619256

RESUMO

Background: The auto-inflammation and phospholipase Cγ2 (PLCγ2)-associated antibody deficiency and immune dysregulation (APLAID) syndrome is a rare primary immunodeficiency caused by a gain-of-function mutation S707Y in the PLCG2 gene previously described in two patients from one family. The APLAID patients presented with early-onset blistering skin lesions, posterior uveitis, inflammatory bowel disease (IBD) and recurrent sinopulmonary infections caused by a humoral defect, but lacked circulating autoantibodies and had no cold-induced urticaria, contrary to the patients with the related PLAID syndrome. Case: We describe a new APLAID patient who presented with vesiculopustular rash in the 1st weeks of life, followed by IBD, posterior uveitis, recurrent chest infections, interstitial pneumonitis, and also had sensorineural deafness and cutis laxa. Her disease has been refractory to most treatments, including IL1 blockers and a trial with ruxolitinib has been attempted. Results: In this patient, we found a unique de novo heterozygous missense L848P mutation in the PLCG2 gene, predicted to affect the PLCγ2 structure. Similarly to S707Y, the L848P mutation led to the increased basal and EGF-stimulated PLCγ2 activity in vitro. Whole blood assays showed reduced production of IFN-γ and IL-17 in response to polyclonal T-cell stimulation and reduced production of IL-10 and IL-1ß after LPS stimulation. Reduced IL-1ß levels and the lack of clinical response to treatment with IL-1 blockers argue against NLRP3 inflammasome hyperactivation being the main mechanism mediating the APLAID pathogenesis. Conclusion: Our findings indicate that L848P is novel a gain-of-function mutation that leads to PLCγ2 activation and suggest cutis laxa as a possible clinical manifestations of the APLAID syndrome.


Assuntos
Cútis Laxa/genética , Doenças Hereditárias Autoinflamatórias/genética , Síndromes de Imunodeficiência/genética , Mutação de Sentido Incorreto , Fosfolipase C gama/genética , Sequência de Aminoácidos , Sequência de Bases , Cútis Laxa/complicações , Cútis Laxa/enzimologia , Análise Mutacional de DNA , Feminino , Doenças Hereditárias Autoinflamatórias/complicações , Doenças Hereditárias Autoinflamatórias/enzimologia , Humanos , Síndromes de Imunodeficiência/complicações , Síndromes de Imunodeficiência/enzimologia , Recém-Nascido , Doenças Inflamatórias Intestinais/complicações , Doenças Inflamatórias Intestinais/genética , Masculino , Linhagem , Fosfolipase C gama/química , Fosfolipase C gama/metabolismo , Homologia de Sequência de Aminoácidos
10.
Nat Genet ; 49(7): 986-992, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28530675

RESUMO

SNP heritability, the proportion of phenotypic variance explained by SNPs, has been reported for many hundreds of traits. Its estimation requires strong prior assumptions about the distribution of heritability across the genome, but current assumptions have not been thoroughly tested. By analyzing imputed data for a large number of human traits, we empirically derive a model that more accurately describes how heritability varies with minor allele frequency (MAF), linkage disequilibrium (LD) and genotype certainty. Across 19 traits, our improved model leads to estimates of common SNP heritability on average 43% (s.d. 3%) higher than those obtained from the widely used software GCTA and 25% (s.d. 2%) higher than those from the recently proposed extension GCTA-LDMS. Previously, DNase I hypersensitivity sites were reported to explain 79% of SNP heritability; using our improved heritability model, their estimated contribution is only 24%.


Assuntos
Estudo de Associação Genômica Ampla/métodos , Modelos Genéticos , Herança Multifatorial/genética , Polimorfismo de Nucleotídeo Único/genética , Alelos , Estudos de Casos e Controles , Sítios Frágeis do Cromossomo , Estudos de Coortes , Simulação por Computador , Desoxirribonuclease I , Frequência do Gene , Estudos de Associação Genética , Humanos , Padrões de Herança , Característica Quantitativa Herdável
11.
Nat Commun ; 7: 13992, 2016 12 23.
Artigo em Inglês | MEDLINE | ID: mdl-28008925

RESUMO

Mutations in genes encoding components of the immune system cause primary immunodeficiencies. Here, we study a patient with recurrent atypical mycobacterial infection and early-onset metastatic bladder carcinoma. Exome sequencing identified two homozygous missense germline mutations, P733L and P832S, in the JAK1 protein that mediates signalling from multiple cytokine receptors. Cells from this patient exhibit reduced JAK1 and STAT phosphorylation following cytokine stimulations, reduced induction of expression of interferon-regulated genes and dysregulated cytokine production; which are indicative of signalling defects in multiple immune response pathways including Interferon-γ production. Reconstitution experiments in the JAK1-deficient cells demonstrate that the impaired JAK1 function is mainly attributable to the effect of the P733L mutation. Further analyses of the mutant protein reveal a phosphorylation-independent role of JAK1 in signal transduction. These findings clarify JAK1 signalling mechanisms and demonstrate a critical function of JAK1 in protection against mycobacterial infection and possibly the immunological surveillance of cancer.


Assuntos
Alelos , Janus Quinase 1/genética , Mutação/genética , Infecções por Mycobacterium/enzimologia , Infecções por Mycobacterium/genética , Sequência de Aminoácidos , Sequência de Bases , Células Sanguíneas/metabolismo , Criança , Pré-Escolar , Citocinas/sangue , Suscetibilidade a Doenças , Feminino , Fibroblastos/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Interferon-alfa/farmacologia , Interferon gama/farmacologia , Janus Quinase 1/química , Masculino , Linhagem , Fosforilação/efeitos dos fármacos , Domínios Proteicos , Fatores de Transcrição STAT/metabolismo , Transdução de Sinais/genética , TYK2 Quinase/metabolismo , Adulto Jovem
12.
Nat Rev Immunol ; 16(11): 702-714, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27616589

RESUMO

Primary immunodeficiencies are inherited disorders of the immune system, often caused by the mutation of genes required for lymphocyte development and activation. Recently, several studies have identified gain-of-function mutations in the phosphoinositide 3-kinase (PI3K) genes PIK3CD (which encodes p110δ) and PIK3R1 (which encodes p85α) that cause a combined immunodeficiency syndrome, referred to as activated PI3Kδ syndrome (APDS; also known as p110δ-activating mutation causing senescent T cells, lymphadenopathy and immunodeficiency (PASLI)). Paradoxically, both loss-of-function and gain-of-function mutations that affect these genes lead to immunosuppression, albeit via different mechanisms. Here, we review the roles of PI3Kδ in adaptive immunity, describe the clinical manifestations and mechanisms of disease in APDS and highlight new insights into PI3Kδ gleaned from these patients, as well as implications of these findings for clinical therapy.


Assuntos
Síndromes de Imunodeficiência/etiologia , Síndromes de Imunodeficiência/metabolismo , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Animais , Diferenciação Celular/genética , Diferenciação Celular/imunologia , Senescência Celular/genética , Senescência Celular/imunologia , Ativação Enzimática , Regulação da Expressão Gênica , Humanos , Sistema Imunitário/citologia , Sistema Imunitário/imunologia , Sistema Imunitário/metabolismo , Imunidade , Síndromes de Imunodeficiência/terapia , Ativação Linfocitária/genética , Ativação Linfocitária/imunologia , Linfócitos/citologia , Linfócitos/imunologia , Linfócitos/metabolismo , Terapia de Alvo Molecular , Mutação , Fosfatidilinositol 3-Quinases/antagonistas & inibidores , Fosfatidilinositol 3-Quinases/química , Subunidades Proteicas/genética , Subunidades Proteicas/metabolismo , Transdução de Sinais
13.
J Allergy Clin Immunol ; 138(1): 210-218.e9, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27221134

RESUMO

BACKGROUND: Activated phosphoinositide 3-kinase δ syndrome (APDS) 2 (p110δ-activating mutations causing senescent T cells, lymphadenopathy, and immunodeficiency [PASLI]-R1), a recently described primary immunodeficiency, results from autosomal dominant mutations in PIK3R1, the gene encoding the regulatory subunit (p85α, p55α, and p50α) of class IA phosphoinositide 3-kinases. OBJECTIVES: We sought to review the clinical, immunologic, and histopathologic phenotypes of APDS2 in a genetically defined international patient cohort. METHODS: The medical and biological records of 36 patients with genetically diagnosed APDS2 were collected and reviewed. RESULTS: Mutations within splice acceptor and donor sites of exon 11 of the PIK3R1 gene lead to APDS2. Recurrent upper respiratory tract infections (100%), pneumonitis (71%), and chronic lymphoproliferation (89%, including adenopathy [75%], splenomegaly [43%], and upper respiratory tract lymphoid hyperplasia [48%]) were the most common features. Growth retardation was frequently noticed (45%). Other complications were mild neurodevelopmental delay (31%); malignant diseases (28%), most of them being B-cell lymphomas; autoimmunity (17%); bronchiectasis (18%); and chronic diarrhea (24%). Decreased serum IgA and IgG levels (87%), increased IgM levels (58%), B-cell lymphopenia (88%) associated with an increased frequency of transitional B cells (93%), and decreased numbers of naive CD4 and naive CD8 cells but increased numbers of CD8 effector/memory T cells were predominant immunologic features. The majority of patients (89%) received immunoglobulin replacement; 3 patients were treated with rituximab, and 6 were treated with rapamycin initiated after diagnosis of APDS2. Five patients died from APDS2-related complications. CONCLUSION: APDS2 is a combined immunodeficiency with a variable clinical phenotype. Complications are frequent, such as severe bacterial and viral infections, lymphoproliferation, and lymphoma similar to APDS1/PASLI-CD. Immunoglobulin replacement therapy, rapamycin, and, likely in the near future, selective phosphoinositide 3-kinase δ inhibitors are possible treatment options.


Assuntos
Classe I de Fosfatidilinositol 3-Quinases/genética , Síndromes de Imunodeficiência/diagnóstico , Síndromes de Imunodeficiência/etiologia , Fenótipo , Adolescente , Adulto , Alelos , Biópsia , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Criança , Pré-Escolar , Estudos de Coortes , Feminino , Frequência do Gene , Genótipo , Humanos , Síndromes de Imunodeficiência/mortalidade , Masculino , Pessoa de Meia-Idade , Mutação , Sítios de Splice de RNA , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , Adulto Jovem
14.
Nat Genet ; 48(3): 318-22, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26829749

RESUMO

Mycobacterium tuberculosis infections cause 9 million new tuberculosis cases and 1.5 million deaths annually. To identify variants conferring risk of tuberculosis, we tested 28.3 million variants identified through whole-genome sequencing of 2,636 Icelanders for association with tuberculosis (8,162 cases and 277,643 controls), pulmonary tuberculosis (PTB) and M. tuberculosis infection. We found association of three variants in the region harboring genes encoding the class II human leukocyte antigens (HLAs): rs557011[T] (minor allele frequency (MAF) = 40.2%), associated with M. tuberculosis infection (odds ratio (OR) = 1.14, P = 3.1 × 10(-13)) and PTB (OR = 1.25, P = 5.8 × 10(-12)), and rs9271378[G] (MAF = 32.5%), associated with PTB (OR = 0.78, P = 2.5 × 10(-12))--both located between HLA-DQA1 and HLA-DRB1--and a missense variant encoding p.Ala210Thr in HLA-DQA1 (MAF = 19.1%, rs9272785), associated with M. tuberculosis infection (P = 9.3 × 10(-9), OR = 1.14). We replicated association of these variants with PTB in samples of European ancestry from Russia and Croatia (P < 5.9 × 10(-4)). These findings show that the HLA class II region contributes to genetic risk of tuberculosis, possibly through reduced presentation of protective M. tuberculosis antigens to T cells.


Assuntos
Cadeias alfa de HLA-DQ/genética , Cadeias HLA-DRB1/genética , Mycobacterium tuberculosis/patogenicidade , Tuberculose Pulmonar/genética , Alelos , Grupo com Ancestrais do Continente Europeu , Frequência do Gene , Predisposição Genética para Doença , Variação Genética , Genoma Humano , Estudo de Associação Genômica Ampla , Cadeias alfa de HLA-DQ/imunologia , Cadeias HLA-DRB1/imunologia , Humanos , Islândia , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/imunologia , Fatores de Risco , Linfócitos T/imunologia , Tuberculose Pulmonar/imunologia , Tuberculose Pulmonar/microbiologia
16.
Infect Genet Evol ; 36: 517-523, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26319998

RESUMO

We conducted a prospective study to establish factors associated with survival in tuberculosis patients in Russia including social, clinical and pathogen-related genetic parameters. Specifically we wished to determine whether different strains/clades of the Beijing lineage exerted a differential effect of survival. HIV-negative culture-confirmed cases were recruited during 2008-2010 across Samara Oblast and censored in December 2011. Molecular characterization was performed by a combination of spoligotyping, multilocus VNTR typing and whole genome sequencing (WGS). We analyzed 2602 strains and detected a high prevalence of Beijing family (n=1933; 74%) represented largely by two highly homogenous dominant clades A (n=794) and B (n=402) and non-A/non-B (n=737). Multivariable analysis of 1366 patients with full clinical and genotyping data showed that multi- and extensive drug resistance (HR=1.86; 95%CI: 1.52, 2.28 and HR=2.19; 95%CI: 1.55, 3.11) had the largest impact on survival. In addition older age, extensive lung damage, shortness of breath, treatment in the past and alcohol abuse reduced survival time. After adjustment for clinical and demographic predictors there was evidence that clades A and B combined were associated with poorer survival than other Beijing strains (HR=0.48; 95%CI 0.34, 0.67). All other pathogen-related factors (polymorphisms in genes plcA, plcB, plcC, lipR, dosT and pks15/1) had no effect on survival. In conclusion, drug resistance exerted the greatest effect on survival of TB patients. Nevertheless we provide evidence for the independent biological effect on survival of different Beijing family strains even within the same defined geographical population. Better understanding of the role of different strain factors in active disease and their influence on outcome is essential.


Assuntos
Genótipo , Soronegatividade para HIV , Mycobacterium tuberculosis/genética , Tuberculose/microbiologia , Tuberculose/mortalidade , Feminino , Ligação Genética , Genoma Bacteriano , Humanos , Estimativa de Kaplan-Meier , Masculino , Mycobacterium tuberculosis/classificação , Mycobacterium tuberculosis/efeitos dos fármacos , Modelos de Riscos Proporcionais , Estudos Prospectivos , Fatores de Risco , Federação Russa/epidemiologia , Tuberculose/epidemiologia
17.
Blood ; 126(13): 1527-35, 2015 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-26224645

RESUMO

Megakaryoblastic leukemia 1 (MKL1), also known as MAL or myocardin-related transcription factor A (MRTF-A), is a coactivator of serum response factor, which regulates transcription of actin and actin cytoskeleton-related genes. MKL1 is known to be important for megakaryocyte differentiation and function in mice, but its role in immune cells is unexplored. Here we report a patient with a homozygous nonsense mutation in the MKL1 gene resulting in immunodeficiency characterized predominantly by susceptibility to severe bacterial infection. We show that loss of MKL1 protein expression causes a dramatic loss of filamentous actin (F-actin) content in lymphoid and myeloid lineage immune cells and widespread cytoskeletal dysfunction. MKL1-deficient neutrophils displayed reduced phagocytosis and almost complete abrogation of migration in vitro. Similarly, primary dendritic cells were unable to spread normally or to form podosomes. Silencing of MKL1 in myeloid cell lines revealed that F-actin assembly was abrogated through reduction of globular actin (G-actin) levels and disturbed expression of multiple actin-regulating genes. Impaired migration of these cells was associated with failure of uropod retraction likely due to altered contractility and adhesion, evidenced by reduced expression of the myosin light chain 9 (MYL9) component of myosin II complex and overexpression of CD11b integrin. Together, our results show that MKL1 is a nonredundant regulator of cytoskeleton-associated functions in immune cells and fibroblasts and that its depletion underlies a novel human primary immunodeficiency.


Assuntos
Códon sem Sentido , Síndromes de Imunodeficiência/genética , Infecções por Pseudomonas/genética , Transativadores/genética , Actinas/metabolismo , Actinas/ultraestrutura , Linhagem Celular , Movimento Celular , Células Cultivadas , Citoesqueleto/metabolismo , Citoesqueleto/ultraestrutura , Células Dendríticas/citologia , Células Dendríticas/metabolismo , Feminino , Fibroblastos/citologia , Fibroblastos/metabolismo , Homozigoto , Humanos , Síndromes de Imunodeficiência/complicações , Síndromes de Imunodeficiência/diagnóstico , Síndromes de Imunodeficiência/metabolismo , Neutrófilos/citologia , Neutrófilos/metabolismo , Pseudomonas/isolamento & purificação , Infecções por Pseudomonas/complicações , Infecções por Pseudomonas/diagnóstico , Infecções por Pseudomonas/metabolismo
18.
Nat Genet ; 47(5): 523-527, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25774636

RESUMO

Human genetic factors predispose to tuberculosis (TB). We studied 7.6 million genetic variants in 5,530 people with pulmonary TB and in 5,607 healthy controls. In the combined analysis of these subjects and the follow-up cohort (15,087 TB patients and controls altogether), we found an association between TB and variants located in introns of the ASAP1 gene on chromosome 8q24 (P = 2.6 × 10(-11) for rs4733781; P = 1.0 × 10(-10) for rs10956514). Dendritic cells (DCs) showed high ASAP1 expression that was reduced after Mycobacterium tuberculosis infection, and rs10956514 was associated with the level of reduction of ASAP1 expression. The ASAP1 protein is involved in actin and membrane remodeling and has been associated with podosomes. The ASAP1-depleted DCs showed impaired matrix degradation and migration. Therefore, genetically determined excessive reduction of ASAP1 expression in M. tuberculosis-infected DCs may lead to their impaired migration, suggesting a potential mechanism of predisposition to TB.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Células Dendríticas/fisiologia , Tuberculose Pulmonar/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Adulto , Estudos de Casos e Controles , Movimento Celular , Células Cultivadas , Feminino , Expressão Gênica , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Humanos , Íntrons , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Transporte Proteico
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