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1.
PLoS Genet ; 15(2): e1007964, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30817801

RESUMO

Transmission ratio distortion (TRD) by the mouse t-haplotype, a variant region on chromosome 17, is a well-studied model of non-Mendelian inheritance. It is characterized by the high transmission ratio (up to 99%) of the t-haplotype from t/+ males to their offspring. TRD is achieved by the exquisite ability of the responder (Tcr) to trigger non-Mendelian inheritance of homologous chromosomes. Several distorters (Tcd1-Tcd4), which act cumulatively, together promote the high transmission ratio of Tcr and the t-haplotype. Molecularly, TRD is brought about by deregulation of Rho signaling pathways via the distorter products, which impair sperm motility, and the t-sperm specific rescue of sperm motility by the responder. The t-sperm thus can reach the egg cells faster than +-sperm and fertilize them. Previously we have shown that the responder function is accomplished by a dominant negative form of sperm motility kinase (SMOKTCR), while the distorter functions are accomplished by the Rho G protein regulators TAGAP, FGD2 and NME3 proposed to function in two oppositely acting pathways. Here we identify the RAC1-specific guanine nucleotide exchange factor TIAM2 as modifier of t-haplotype TRD. Tiam2 is expressed in two isoforms, the full-length (Tiam2l) and a short transcript (Tiam2s). Tiam2s expression from the t-allele is strongly increased compared to the wild-type allele. By transgenic approaches we show that Tiam2s enhances t-haplotype transmission, while Tiam2l has the opposite effect. Our data show that a single modifier locus can encode different gene products exerting opposite effects on a trait. They also suggest that the expression ratio of the isoforms determines if the outcome is an enhancing or a suppressive effect on the trait.


Assuntos
Fatores de Troca do Nucleotídeo Guanina/genética , Fatores de Troca do Nucleotídeo Guanina/metabolismo , Padrões de Herança , Região do Complexo-t do Genoma , Alelos , Animais , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Fatores de Troca do Nucleotídeo Guanina/deficiência , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Modelos Genéticos , Herança Paterna , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Motilidade Espermática/genética , Motilidade Espermática/fisiologia , Espermatogênese/genética
2.
Scand J Immunol ; 89(6): e12759, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30793341

RESUMO

DOCK8 immunodeficiency syndrome (DIDS) is a combined immunodeficiency characterized by recurrent viral infections, severe atopy and early onset malignancy. Immunological abnormalities include lymphopenia, CD8+ T-cell cytoskeleton dysfunction, defective B cell memory and variable serum immunoglobulin levels. Here, we analyse the B cell receptor repertoire (BCR) characteristics and antibody avidity of four DIDS patients, attempt to understand the dysregulated humoral immunity in DIDS patients with a normal antibody titre and suggest a scientific basis for intravenous immunoglobulin (IVIG) replacement therapy for these patients. We analysed BCR characteristics, including somatic hypermutation (SHM) frequency, using deep sequencing of multiplex PCR products derived from BCR heavy chain CDR3 regions from DIDS patients and controls. The antibody avidity of human tetanus and hemophilus influenza B antibodies was determined by ELISA using thiocyanate elution. IVIG replacement treatment and infection conditions were investigated retrospectively. We found skewing of the BCR repertoire and decreased antibody avidity in patients with DIDS. DIDS patients had fewer negatively charged amino acids than healthy controls. The SHM frequency of the IGHV3 gene was lower in patients with DIDS. Patients received regular IVIG therapy, resulting in fewer and less severe infections. We conclude that although IgG levels are normal in most DIDS patients, IVIG replacement therapy is still necessary.


Assuntos
Afinidade de Anticorpos/imunologia , Linfócitos B/imunologia , Fatores de Troca do Nucleotídeo Guanina/deficiência , Doenças do Sistema Imunitário/genética , Doenças do Sistema Imunitário/terapia , Imunoglobulinas Intravenosas/uso terapêutico , Receptores de Antígenos de Linfócitos B/imunologia , Adolescente , Anticorpos Antibacterianos/imunologia , Linfócitos T CD8-Positivos/imunologia , Pré-Escolar , Clostridium tetani/imunologia , Feminino , Fatores de Troca do Nucleotídeo Guanina/genética , Haemophilus influenzae tipo b/imunologia , Humanos , Imunoglobulina A/sangue , Imunoglobulina E/sangue , Imunoglobulina G/sangue , Cadeias Pesadas de Imunoglobulinas/genética , Imunoglobulina M/sangue , Memória Imunológica/imunologia , Masculino , Receptores de Antígenos de Linfócitos B/genética
3.
Mol Vis ; 24: 727-732, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30581279

RESUMO

Purpose: Inflammation is a key component of retinal disease. We previously reported that exchange protein for cAMP 1 (Epac1) reduced inflammatory mediators, including total levels of high mobility group box 1 (HMGB1) in retinal endothelial cells (RECs) and the mouse retina. The goal of this study was to determine intermediate pathways that allow Epac1 to reduce HMGB1, which could lead to novel targets for therapeutics. Methods: We used endothelial cell-specific conditional knockout mice for Epac1 and RECs to investigate whether Epac1 requires activation of insulin like growth factor binding protein 3 (IGFBP-3) and sirtuin 1 (SIRT1) to reduce acetylated HMGB1 levels with immunoprecipitation, western blot, and enzyme-linked immunosorbent assay (ELISA). Results: Data showed that high glucose reduced IGFBP-3 and SIRT1 levels, and increased acetylation of HMGB1 in RECs. An Epac1 agonist reduced acetylated HMGB1 levels in high glucose. The Epac1 agonist could not reduce HMGB1 or SIRT1 levels when IGFBP-3 siRNA was used. The agonist also could not reduce HMGB1 when SIRT1 siRNA was used. The mouse retina showed that loss of Epac1 increases acetylated HMGB1 levels and reduces IGFBP-3 and SIRT1 levels. Conclusions: Taken together, the data suggest that Epac1 activates IGFBP-3 to increase SIRT1, leading to a significant reduction in acetylated HMGB1. These findings provide novel therapeutic targets for reducing key inflammatory cascades in the retina.


Assuntos
Células Endoteliais/metabolismo , Fatores de Troca do Nucleotídeo Guanina/genética , Proteína HMGB1/genética , Proteína 3 de Ligação a Fator de Crescimento Semelhante à Insulina/genética , Vasos Retinianos/metabolismo , Sirtuína 1/genética , Acetilação/efeitos dos fármacos , Animais , AMP Cíclico/análogos & derivados , AMP Cíclico/farmacologia , Células Endoteliais/citologia , Células Endoteliais/efeitos dos fármacos , Feminino , Regulação da Expressão Gênica , Glucose/farmacologia , Fatores de Troca do Nucleotídeo Guanina/agonistas , Fatores de Troca do Nucleotídeo Guanina/deficiência , Proteína HMGB1/metabolismo , Humanos , Proteína 3 de Ligação a Fator de Crescimento Semelhante à Insulina/antagonistas & inibidores , Proteína 3 de Ligação a Fator de Crescimento Semelhante à Insulina/metabolismo , Masculino , Camundongos , Camundongos Knockout , Cultura Primária de Células , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Retina/citologia , Retina/efeitos dos fármacos , Retina/metabolismo , Vasos Retinianos/citologia , Vasos Retinianos/efeitos dos fármacos , Transdução de Sinais , Sirtuína 1/antagonistas & inibidores , Sirtuína 1/metabolismo , Tionucleotídeos/farmacologia
4.
J Pediatric Infect Dis Soc ; 7(suppl_2): S79-S82, 2018 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-30590619

RESUMO

Hematopoietic stem cell transplantation (HSCT) has been the standard of care for infants with severe combined immunodeficiency (SCID) for several decades due to the dismal prognosis early in life without immune reconstitution. In recent years, as HSCT conditioning regimens and supportive care have greatly improved, HSCT is gaining in acceptance for more non-SCID primary immunodeficiencies (PIDs) and outside the early childhood period. In addition, potential donor options for non-SCID PIDs are expanding with increasing success for haploidentical donor transplants. In this brief report of a presentation at the PIDS-St. Jude 2018 conference, PIDs for which transplants are increasingly performed outside of early childhood will be discussed.


Assuntos
Transplante de Células-Tronco Hematopoéticas , Síndromes de Imunodeficiência/terapia , Criança , Deficiência de GATA2/terapia , Fatores de Troca do Nucleotídeo Guanina/deficiência , Humanos , Lactente , Imunodeficiência Combinada Severa/terapia
5.
Mol Brain ; 11(1): 27, 2018 05 10.
Artigo em Inglês | MEDLINE | ID: mdl-29747665

RESUMO

Rapgef2 and Rapgef6 define a subfamily of guanine nucleotide exchange factors for Rap small GTPases, characterized by the possession of the Ras/Rap-associating domain. Previous genomic analyses suggested their possible involvement in the etiology of schizophrenia. We recently demonstrated the development of an ectopic cortical mass (ECM), which resembles the human subcortical band heterotopia, in the dorsal telencephalon-specific Rapgef2 conditional knockout (Rapgef2-cKO) brains. Additional knockout of Rapgef6 in Rapgef2-cKO mice resulted in gross enlargement of the ECM whereas knockout of Rapgef6 alone (Rapgef6-KO) had no discernible effect on the brain morphology. Here, we performed a battery of behavioral tests to examine the effects of Rapgef2 or Rapgef6 deficiency on higher brain functions. Rapgef2-cKO mice exhibited hyperlocomotion phenotypes. They showed decreased anxiety-like behavior in the elevated plus maze and the open-field tests as well as increased depression-like behavior in the Porsolt forced swim and tail suspension tests. They also exhibited increased sociability especially in novel environments. They showed defects in cognitive function as evidenced by reduced learning ability in the Barnes circular maze test and by impaired working memory in the T maze tests. In contrast, although Rapgef6 and Rapgef2 share similarities in biochemical roles, Rapgef6-KO mice exhibited mild behavioral abnormalities detected with a number of behavioral tests, such as hyperlocomotion phenotype in the open-field test and the social interaction test with a novel environment and working-memory defects in the T-maze test. In conclusion, although there were differences in their brain morphology and the magnitude of the behavioral abnormalities, Rapgef2-cKO mice and Rapgef6-KO mice exhibited hyperlocomotion phenotype and working-memory defect, both of which could be recognized as schizophrenia-like behavior.


Assuntos
Fatores de Troca do Nucleotídeo Guanina/química , Fatores de Troca do Nucleotídeo Guanina/deficiência , Animais , Ansiedade/metabolismo , Ansiedade/fisiopatologia , Comportamento Animal , Cognição , Condicionamento (Psicologia) , Depressão/metabolismo , Depressão/fisiopatologia , Medo , Fatores de Troca do Nucleotídeo Guanina/metabolismo , Aprendizagem em Labirinto , Memória , Camundongos Knockout , Atividade Motora , Inibição Pré-Pulso , Domínios Proteicos , Reflexo de Sobressalto , Comportamento Social
6.
Biochem Biophys Res Commun ; 501(1): 92-99, 2018 06 18.
Artigo em Inglês | MEDLINE | ID: mdl-29702092

RESUMO

Patients with DOCK8 deficiency are at increased susceptibility to develop allergic diseases such as food allergy and asthma. Here, we aimed to analyze the pathogenesis of asthma in DOCK8-deficient patients. In our mouse model, DOCK8-knockout (KO) mice sensitized with low-dose OVA were challenged with 1.5% OVA to induce allergic asthma. As compared to that in WT mice, remarkable airway hyperresponsiveness was observed in KO mice. Increased inflammatory cells and eosinophils infiltrated in airway lumen in KO mice especially around bronchi. KO mice showed higher levels of serum IgE and OVA-specific IgE and significantly elevated IgE-producing B cells in blood and in spleen. Surprisingly, nasal administration with rmIL-21 significantly reduced the airway hyperresponsiveness, inflammatory infiltration, as well as the serum IgE and IgE-producing B cells. DOCK8-knockout mice are susceptible to low-dose OVA induced allergic airway inflammation and airway hyperresponsiveness. Supplementary nasal administration of rmIL-21 alleviates allergic asthma in this mouse model.


Assuntos
Asma/tratamento farmacológico , Fatores de Troca do Nucleotídeo Guanina/deficiência , Interleucinas/uso terapêutico , Administração Intranasal , Animais , Asma/genética , Asma/imunologia , Linfócitos B/imunologia , Modelos Animais de Doenças , Fatores de Troca do Nucleotídeo Guanina/genética , Imunoglobulina E/biossíntese , Imunoglobulina E/sangue , Interleucinas/administração & dosagem , Pulmão/efeitos dos fármacos , Pulmão/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Ovalbumina/administração & dosagem , Ovalbumina/imunologia , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/uso terapêutico , Hipersensibilidade Respiratória/tratamento farmacológico
7.
Dev Neurobiol ; 78(4): 374-390, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29380551

RESUMO

Autosomal recessive disorders such as Fukuyama congenital muscular dystrophy, Walker-Warburg syndrome, and the muscle-eye-brain disease are characterized by defects in the development of patient's brain, eyes, and skeletal muscles. These syndromes are accompanied by brain malformations like type II lissencephaly in the cerebral cortex with characteristic overmigrations of neurons through the breaches of the pial basement membrane. The signaling pathways activated by laminin receptors, dystroglycan and integrins, control the integrity of the basement membrane, and their malfunctioning may underlie the pathologies found in the rise of defects reminiscent of these syndromes. Similar defects in corticogenesis and neuromuscular disorders were found in mice when RIC8A was specifically removed from neural precursor cells. RIC8A regulates a subset of G-protein α subunits and in several model organisms, it has been reported to participate in the control of cell division, signaling, and migration. Here, we studied the role of RIC8A in the development of the brain, muscles, and eyes of the neural precursor-specific conditional Ric8a knockout mice. The absence of RIC8A severely affected the attachment and positioning of radial glial processes, Cajal-Retzius' cells, and the arachnoid trabeculae, and these mice displayed additional defects in the lens, skeletal muscles, and heart development. All the discovered defects might be linked to aberrancies in cell adhesion and migration, suggesting that RIC8A has a crucial role in the regulation of cell-extracellular matrix interactions and that its removal leads to the phenotype characteristic to type II lissencephaly-associated diseases. © 2018 Wiley Periodicals, Inc. Develop Neurobiol 78: 374-390, 2018.


Assuntos
Encéfalo/embriologia , Olho/embriologia , Fatores de Troca do Nucleotídeo Guanina/deficiência , Músculos/embriologia , Células-Tronco Neurais/metabolismo , Animais , Encéfalo/metabolismo , Encéfalo/patologia , Olho/metabolismo , Olho/patologia , Fatores de Troca do Nucleotídeo Guanina/genética , Camundongos Endogâmicos C57BL , Camundongos Knockout , Músculos/metabolismo , Músculos/patologia , Células-Tronco Neurais/patologia
8.
J Neurosci ; 37(50): 12202-12213, 2017 12 13.
Artigo em Inglês | MEDLINE | ID: mdl-29118104

RESUMO

The olfactory system can discriminate a vast number of odorants. This ability derives from the existence of a large family of odorant receptors expressed in the cilia of the olfactory sensory neurons. Odorant receptors signal through the olfactory-specific G-protein subunit, Gαolf. Ric-8b, a guanine nucleotide exchange factor, interacts with Gαolf and can amplify odorant receptor signal transduction in vitro To explore the function of Ric-8b in vivo, we generated a tissue specific knock-out mouse by crossing OMP-Cre transgenic mice to Ric-8b floxed mice. We found that olfactory-specific Ric-8b knock-out mice of mixed sex do not express the Gαolf protein in the olfactory epithelium. We also found that in these mice, the mature olfactory sensory neuron layer is reduced, and that olfactory sensory neurons show increased rate of cell death compared with wild-type mice. Finally, behavioral tests showed that the olfactory-specific Ric-8b knock-out mice show an impaired sense of smell, even though their motivation and mobility behaviors remain normal.SIGNIFICANCE STATEMENT Ric-8b is a guanine nucleotide exchange factor (GEF) expressed in the olfactory epithelium and in the striatum. Ric-8b interacts with the olfactory Gαolf subunit, and can amplify odorant signaling through odorant receptors in vitro However, the functional significance of this GEF in the olfactory neurons in vivo remains unknown. We report that deletion of Ric-8b in olfactory sensory neurons prevents stable expression of Gαolf. In addition, we demonstrate that olfactory neurons lacking Ric-8b (and consequently Gαolf) are more susceptible to cell death. Ric-8b conditional knock-out mice display impaired olfactory guided behavior. Our results reveal that Ric-8b is essential for olfactory function, and suggest that it may also be essential for Gαolf-dependent functions in the brain.


Assuntos
Comportamento Apetitivo/fisiologia , Aprendizagem da Esquiva/fisiologia , Fatores de Troca do Nucleotídeo Guanina/fisiologia , Proteínas do Tecido Nervoso/fisiologia , Neurônios Receptores Olfatórios/fisiologia , Animais , Animais Lactentes , Ácido Butírico , Contagem de Células , Morte Celular , Cruzamentos Genéticos , Feminino , Alimentos , Subunidades alfa de Proteínas de Ligação ao GTP/deficiência , Subunidades alfa de Proteínas de Ligação ao GTP/fisiologia , Fatores de Troca do Nucleotídeo Guanina/deficiência , Fatores de Troca do Nucleotídeo Guanina/genética , Masculino , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Proteínas do Tecido Nervoso/deficiência , Proteínas do Tecido Nervoso/genética , Odorantes , Mucosa Olfatória/patologia , Receptores Odorantes/fisiologia
11.
Pediatr Transplant ; 21(7)2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28664550

RESUMO

DIDS is a unique form of combined immune deficiency characterized by an unusual susceptibility to cutaneous viral infections, severe allergies with eosinophilia and elevated immunoglobulin E titers, autoimmunity, and cancer. HSCT is considered the standard of care for this deadly disease. We have retrospectively analyzed the outcome of allogeneic HSCT from unrelated donors in patients with DIDS. Data from four patients, with five transplants, are presented. All patients received transplants from unrelated donors' BM, except for one patient who received a cord blood transplant. The conditioning regimens were based on myeloablative protocols for BM derived transplants; a NM regimen was pursued for the patient who received a cord blood transplant, which resulted in graft rejection. Although recurrent pneumonia and skin infections resolved immediately after transplantation, all patients subsequently developed human herpesvirus infection, including cutaneous herpetic lesions, cytomegalovirus reactivation, and zona zoster, which could be attributed to the use of ATG. Despite the presence of serious morbidities prior to transplantation, all patients recovered successfully. DIDS can be successfully treated with allogeneic HSCT from unrelated donors following a myeloablative conditioning regimen, with a reasonable safety profile.


Assuntos
Fatores de Troca do Nucleotídeo Guanina/deficiência , Transplante de Células-Tronco Hematopoéticas/métodos , Síndrome de Job/terapia , Adolescente , Criança , Pré-Escolar , Feminino , Seguimentos , Humanos , Estudos Retrospectivos , Resultado do Tratamento , Doadores não Relacionados
12.
Cancer Cell ; 31(5): 621-634.e6, 2017 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-28416184

RESUMO

Aberrant WNT signaling drives colorectal cancer (CRC). Here, we identify TIAM1 as a critical antagonist of CRC progression through inhibiting TAZ and YAP, effectors of WNT signaling. We demonstrate that TIAM1 shuttles between the cytoplasm and nucleus antagonizing TAZ/YAP by distinct mechanisms in the two compartments. In the cytoplasm, TIAM1 localizes to the destruction complex and promotes TAZ degradation by enhancing its interaction with ßTrCP. Nuclear TIAM1 suppresses TAZ/YAP interaction with TEADs, inhibiting expression of TAZ/YAP target genes implicated in epithelial-mesenchymal transition, cell migration, and invasion, and consequently suppresses CRC cell migration and invasion. Importantly, high nuclear TIAM1 in clinical specimens associates with increased CRC patient survival. Together, our findings suggest that in CRC TIAM1 suppresses tumor progression by regulating YAP/TAZ activity.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Movimento Celular , Neoplasias Colorretais/metabolismo , Células Epiteliais/metabolismo , Fatores de Troca do Nucleotídeo Guanina/metabolismo , Mucosa Intestinal/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Fosfoproteínas/metabolismo , Transporte Ativo do Núcleo Celular , Proteínas Adaptadoras de Transdução de Sinal/genética , Animais , Células CACO-2 , Núcleo Celular/metabolismo , Proliferação de Células , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Citoplasma/metabolismo , Células Epiteliais/patologia , Transição Epitelial-Mesenquimal , Regulação Neoplásica da Expressão Gênica , Predisposição Genética para Doença , Fatores de Troca do Nucleotídeo Guanina/deficiência , Fatores de Troca do Nucleotídeo Guanina/genética , Humanos , Mucosa Intestinal/patologia , Camundongos da Linhagem 129 , Camundongos Endogâmicos C57BL , Camundongos Knockout , Invasividade Neoplásica , Fenótipo , Fosfoproteínas/genética , Proteólise , Interferência de RNA , Proteína 1 Indutora de Invasão e Metástase de Linfoma de Células T , Transcrição Genética , Transfecção , Via de Sinalização Wnt , Peixe-Zebra/embriologia , Proteínas Contendo Repetições de beta-Transducina/genética , Proteínas Contendo Repetições de beta-Transducina/metabolismo
13.
Neurobiol Aging ; 54: 59-70, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28319837

RESUMO

Psychosis in Alzheimer's disease (AD+P) represents a distinct clinical and neurobiological AD phenotype and is associated with more rapid cognitive decline, higher rates of abnormal behaviors, and increased caregiver burden compared with AD without psychosis. On a molecular level, AD+P is associated with greater reductions in the protein kalirin, a guanine exchange factor which has also been linked to the psychotic disease, schizophrenia. In this study, we sought to determine the molecular and behavioral consequences of kalirin reduction in APPswe/PSEN1dE9 mice. We evaluated mice with and without kalirin reduction during tasks measuring psychosis-associated behaviors and spatial memory. We found that kalirin reduction in APPswe/PSEN1dE9 mice significantly attenuated psychosis-associated behavior at 12 months of age without changing spatial memory performance. The 12-month-old APPswe/PSEN1dE9 mice with reduced kalirin levels also had increased levels of the active, phosphorylated forms of p21 protein (Cdc42/Rac)-activated kinases (PAKs), which function in signaling pathways for maintenance of dendritic spine density, morphology, and function.


Assuntos
Fatores de Troca do Nucleotídeo Guanina/deficiência , Fatores de Troca do Nucleotídeo Guanina/fisiologia , Transtornos Mentais/genética , Transtornos Psicóticos/genética , Doença de Alzheimer/complicações , Doença de Alzheimer/genética , Doença de Alzheimer/psicologia , Precursor de Proteína beta-Amiloide/genética , Animais , Cognição , Espinhas Dendríticas , Modelos Animais de Doenças , Humanos , Transtornos Mentais/complicações , Transtornos Mentais/psicologia , Camundongos Transgênicos , Fosforilação , Presenilina-1/genética , Transtornos Psicóticos/complicações , Transtornos Psicóticos/psicologia , Transdução de Sinais/genética , Transdução de Sinais/fisiologia , Memória Espacial , Quinases Ativadas por p21/metabolismo , Quinases Ativadas por p21/fisiologia
14.
Biol Blood Marrow Transplant ; 23(6): 980-990, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28288951

RESUMO

Dedicator-of-cytokinesis 8 (DOCK8) deficiency, a primary immunodeficiency disease, can be reversed by allogeneic hematopoietic stem cell transplantation (HSCT); however, there are few reports describing the use of alternative donor sources for HSCT in DOCK8 deficiency. We describe HSCT for patients with DOCK8 deficiency who lack a matched related or unrelated donor using bone marrow from haploidentical related donors and post-transplantation cyclophosphamide (PT/Cy) for graft-versus-host disease (GVHD) prophylaxis. Seven patients with DOCK8 deficiency (median age, 20 years; range, 7 to 25 years) received a haploidentical related donor HSCT. The conditioning regimen included 2 days of low-dose cyclophosphamide, 5 days of fludarabine, 3 days of busulfan, and 200 cGy total body irradiation. GVHD prophylaxis consisted of PT/Cy 50 mg/kg/day on days +3 and +4 and tacrolimus and mycophenolate mofetil starting at day +5. The median times to neutrophil and platelet engraftment were 15 and 19 days, respectively. All patients attained >90% donor engraftment by day +30. Four subjects developed acute GVHD (1 with maximum grade 3). No patient developed chronic GVHD. With a median follow-up time of 20.6 months (range, 9.5 to 31.7 months), 6 of 7 patients are alive and disease free. Haploidentical related donor HSCT with PT/Cy represents an effective therapeutic approach for patients with DOCK8 deficiency who lack a matched related or unrelated donor.


Assuntos
Fatores de Troca do Nucleotídeo Guanina/deficiência , Transplante de Células-Tronco Hematopoéticas/métodos , Síndromes de Imunodeficiência/terapia , Ciclofosfamida/uso terapêutico , Doença Enxerto-Hospedeiro/prevenção & controle , Transplante de Células-Tronco Hematopoéticas/mortalidade , Humanos , Síndromes de Imunodeficiência/mortalidade , Taxa de Sobrevida , Condicionamento Pré-Transplante/métodos , Transplante Haploidêntico/métodos , Transplante Haploidêntico/mortalidade , Resultado do Tratamento
15.
Nat Commun ; 8: 13946, 2017 01 09.
Artigo em Inglês | MEDLINE | ID: mdl-28067314

RESUMO

Mutations of DOCK8 in humans cause a combined immunodeficiency characterized by atopic dermatitis with high serum IgE levels. However, the molecular link between DOCK8 deficiency and atopic skin inflammation is unknown. Here we show that CD4+ T cells from DOCK8-deficient mice produce large amounts of IL-31, a major pruritogen associated with atopic dermatitis. IL-31 induction critically depends on the transcription factor EPAS1, and its conditional deletion in CD4+ T cells abrogates skin disease development in DOCK8-deficient mice. Although EPAS1 is known to form a complex with aryl hydrocarbon receptor nuclear translocator (ARNT) and control hypoxic responses, EPAS1-mediated Il31 promoter activation is independent of ARNT, but in collaboration with SP1. On the other hand, we find that DOCK8 is an adaptor and negative regulator of nuclear translocation of EPAS1. Thus, EPAS1 links DOCK8 deficiency to atopic skin inflammation via IL-31 induction in CD4+ T cells.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Linfócitos T CD4-Positivos/imunologia , Dermatite Atópica/genética , Fatores de Troca do Nucleotídeo Guanina/genética , Interleucinas/genética , Transporte Ativo do Núcleo Celular , Animais , Translocador Nuclear Receptor Aril Hidrocarboneto/genética , Translocador Nuclear Receptor Aril Hidrocarboneto/imunologia , Fatores de Transcrição Hélice-Alça-Hélice Básicos/deficiência , Fatores de Transcrição Hélice-Alça-Hélice Básicos/imunologia , Linfócitos T CD4-Positivos/patologia , Núcleo Celular/imunologia , Núcleo Celular/metabolismo , Citosol/imunologia , Citosol/metabolismo , Dermatite Atópica/imunologia , Dermatite Atópica/patologia , Modelos Animais de Doenças , Feminino , Regulação da Expressão Gênica , Fatores de Troca do Nucleotídeo Guanina/deficiência , Fatores de Troca do Nucleotídeo Guanina/imunologia , Heterozigoto , Imunoglobulina E/genética , Imunoglobulina E/imunologia , Interleucinas/imunologia , Masculino , Camundongos , Camundongos Knockout , Regiões Promotoras Genéticas , Transporte Proteico , Transdução de Sinais , Fator de Transcrição Sp1/genética , Fator de Transcrição Sp1/imunologia
16.
J Immunol ; 198(5): 1887-1899, 2017 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-28130497

RESUMO

In myelodysplastic syndromes (MDS), functional defects of neutrophils result in high mortality because of infections; however, the molecular basis remains unclear. We recently found that miR-34a and miR-155 were significantly increased in MDS neutrophils. To clarify the effects of the aberrant microRNA expression on neutrophil functions, we introduced miR-34a, miR-155, or control microRNA into neutrophil-like differentiated HL60 cells. Ectopically introduced miR-34a and miR-155 significantly attenuated migration toward chemoattractants fMLF and IL-8, but enhanced degranulation. To clarify the mechanisms for inhibition of migration, we studied the effects of miR-34a and miR-155 on the migration-regulating Rho family members, Cdc42 and Rac1. The introduced miR-34a and miR-155 decreased the fMLF-induced active form of Cdc42 to 29.0 ± 15.9 and 39.7 ± 4.8% of that in the control cells, respectively, although Cdc42 protein levels were not altered. miR-34a decreased a Cdc42-specific guanine nucleotide exchange factor (GEF), dedicator of cytokinesis (DOCK) 8, whereas miR-155 reduced another Cdc42-specific GEF, FYVE, RhoGEF, and PH domain-containing (FGD) 4. The knockdown of DOCK8 and FGD4 by small interfering RNA suppressed Cdc42 activation and fMLF/IL-8-induced migration. miR-155, but not miR-34a, decreased Rac1 protein, and introduction of Rac1 small interfering RNA attenuated Rac1 activation and migration. Neutrophils from patients showed significant attenuation in migration compared with healthy cells, and protein levels of DOCK8, FGD4, and Rac1 were well correlated with migration toward fMLF (r = 0.642, 0.686, and 0.436, respectively) and IL-8 (r = 0.778, 0.659, and 0.606, respectively). Our results indicated that reduction of DOCK8, FGD4, and Rac1 contributes to impaired neutrophil migration in MDS.


Assuntos
Quimiotaxia de Leucócito , MicroRNAs/imunologia , Síndromes Mielodisplásicas/imunologia , Ativação de Neutrófilo , Neutrófilos/fisiologia , Idoso , Idoso de 80 Anos ou mais , Proliferação de Células , Quimiotaxia/imunologia , Feminino , Fatores de Troca do Nucleotídeo Guanina/deficiência , Fatores de Troca do Nucleotídeo Guanina/genética , Fatores de Troca do Nucleotídeo Guanina/imunologia , Fatores de Troca do Nucleotídeo Guanina/metabolismo , Células HL-60 , Humanos , Interleucina-8/imunologia , Masculino , MicroRNAs/genética , MicroRNAs/fisiologia , Proteínas dos Microfilamentos/deficiência , Proteínas dos Microfilamentos/genética , Proteínas dos Microfilamentos/metabolismo , Pessoa de Meia-Idade , Neutrófilos/imunologia , RNA Interferente Pequeno , Proteína cdc42 de Ligação ao GTP/genética , Proteína cdc42 de Ligação ao GTP/imunologia , Proteínas rac1 de Ligação ao GTP/genética , Proteínas rac1 de Ligação ao GTP/imunologia
17.
Curr Opin Hematol ; 24(1): 16-22, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27749373

RESUMO

PURPOSE OF REVIEW: Primary immunodeficiencies (PIDs) are inherited conditions where components of the immune system are missing or dysfunctional. Over 300 genes have been causally linked to monogenic forms of PID, including a number that regulate the actin cytoskeleton. The majority of cytoskeletal defects disrupt assembly and disassembly of filamentous actin in multiple immune cell lineages impacting functions such as cell migration and adhesion, pathogen uptake, intercellular communication, intracellular signalling, and cell division. RECENT FINDINGS: In the past 24 months, new actin defects have been identified through next generation sequencing technologies. Substantial progress has also been made in understanding the pathogenic mechanisms that contribute to immunological dysfunction, and also how the cytoskeleton participates in normal physiological immune processes. SUMMARY: This review summarises recent advances in the field, raising awareness of these conditions and our current understanding of their presentation. Description of further cases and new conditions will extend the clinical phenotype of actin-related disorders, and will promote the development of more effective and targeted therapies.


Assuntos
Citoesqueleto de Actina/metabolismo , Síndromes de Imunodeficiência/etiologia , Síndromes de Imunodeficiência/metabolismo , Animais , Adesão Celular , Movimento Celular , Fatores de Troca do Nucleotídeo Guanina/deficiência , Humanos , Leucócitos/imunologia , Leucócitos/metabolismo , Proteínas dos Microfilamentos/deficiência , Ligação Proteica , Multimerização Proteica , Imunodeficiência Combinada Severa/etiologia , Imunodeficiência Combinada Severa/metabolismo , Transdução de Sinais , Transativadores/deficiência
18.
J Allergy Clin Immunol ; 139(3): 933-949, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27554822

RESUMO

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


Assuntos
Fatores de Troca do Nucleotídeo Guanina/deficiência , Síndromes de Imunodeficiência/imunologia , Linfócitos T/imunologia , Adolescente , Adulto , Alérgenos/imunologia , Criança , Pré-Escolar , Citocinas/imunologia , Feminino , Fatores de Troca do Nucleotídeo Guanina/imunologia , Humanos , Imunoglobulina E/sangue , Leucócitos Mononucleares/imunologia , Masculino , Adulto Jovem
19.
Dermatol Clin ; 35(1): 11-19, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27890234

RESUMO

DOCK8 deficiency is an autosomal recessive combined immunodeficiency disease associated with elevated IgE, atopy, recurrent sinopulmonary and cutaneous viral infections, and malignancy. The DOCK8 protein is critical for cytoskeletal organization, and deficiency impairs dendritic cell transmigration, T-cell survival, and NK cell cytotoxicity. Early hematopoietic stem cell transplantation is gaining prominence as a definitive treatment given the potential for severe complications and mortality in this disease. Recently, DOCK2 deficiency has been identified in several patients with early-onset invasive bacterial and viral infections.


Assuntos
Fatores de Troca do Nucleotídeo Guanina/imunologia , Síndromes de Imunodeficiência/imunologia , Dermatopatias Bacterianas/imunologia , Dermatopatias Virais/imunologia , Neoplasias Cutâneas/imunologia , Animais , Linfócitos B/imunologia , Carcinoma de Células Escamosas/imunologia , Carcinoma de Células Escamosas/virologia , Celulite (Flegmão)/imunologia , Dermatite Atópica/imunologia , Infecções por Vírus Epstein-Barr/imunologia , Centro Germinativo/imunologia , Fatores de Troca do Nucleotídeo Guanina/deficiência , Fatores de Troca do Nucleotídeo Guanina/genética , Humanos , Imunoglobulina E/imunologia , Síndromes de Imunodeficiência/genética , Células Matadoras Naturais/imunologia , Linfoma/imunologia , Linfoma/virologia , Linfoma Cutâneo de Células T/imunologia , Linfoma Cutâneo de Células T/virologia , Camundongos , Infecções por Papillomavirus/imunologia , Pneumonia/imunologia , Recidiva , Sinusite/imunologia , Neoplasias Cutâneas/virologia , Linfócitos T/imunologia , Verrugas/imunologia
20.
Skinmed ; 14(4): 315-317, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27784527

RESUMO

An 18-year-old Caucasian man presented with extensive recalcitrant verrucae on his trunk and extremities that were unresponsive to cryotherapy, salicylic acid, topical imiquimod, CO2 laser, candida antigen, and intralesional bleomycin. He had a diagnosis of hyperimmunoglobulin E syndrome until 2011, when he was determined to have DOCK8 immunodeficiency after genetic testing at the National Institutes of Health. In addition to verrucae, he had a personal history of eczematous dermatitis, osteomyelitis, molluscum infections, cutaneous abscesses, recurrent pneumonia, and severe food allergy.


Assuntos
Fatores de Troca do Nucleotídeo Guanina/deficiência , Verrugas/etiologia , Adolescente , Crioterapia , Humanos , Síndrome de Job/diagnóstico , Masculino , Verrugas/diagnóstico , Verrugas/terapia
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