Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 117
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Inflamm Bowel Dis ; 2019 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-31833544

RESUMO

Very early onset inflammatory bowel disease (VEO-IBD) is defined as IBD presenting before 6 years of age. When compared with IBD diagnosed in older children, VEO-IBD has some distinct characteristics such as a higher likelihood of an underlying monogenic etiology or primary immune deficiency. In addition, patients with VEO-IBD have a higher incidence of inflammatory bowel disease unclassified (IBD-U) as compared with older-onset IBD. In some populations, VEO-IBD represents the age group with the fastest growing incidence of IBD. There are contradicting reports on whether VEO-IBD is more resistant to conventional medical interventions. There is a strong need for ongoing research in the field of VEO-IBD to provide optimized management of these complex patients. Here, we provide an approach to diagnosis and management of patients with VEO-IBD. These recommendations are based on expert opinion from members of the VEO-IBD Consortium (www.VEOIBD.org). We highlight the importance of monogenic etiologies, underlying immune deficiencies, and provide a comprehensive description of monogenic etiologies identified to date that are responsible for VEO-IBD.

2.
Mol Biol Cell ; : mbcE19070375, 2019 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-31774722

RESUMO

Retrograde membrane trafficking from plasma membrane (PM) to Golgi and endoplasmic reticulum (ER) typifies one of the key sorting steps emerging from the early endosome that affects cell surface and intracellular protein dynamics underlying cell function. While some cell surface proteins and lipids are known to sort retrograde, there are few effective methods to quantitatively measure the extent or kinetics of these events. Here we took advantage of the well-known retrograde trafficking of cholera toxin and newly defined split fluorescent protein technology to develop a quantitative, sensitive, and effectively real-time single-cell flow cytometry assay for retrograde membrane transport. The approach can be applied in high throughput to elucidate the underlying biology of membrane traffic, and how endosomes adapt to the physiologic needs of different cell types and cell states.

3.
Gastroenterology ; 2019 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-31743734

RESUMO

BACKGROUND & AIMS: Mutations in the tetratricopeptide repeat domain 7A gene (TTC7A) cause intestinal epithelial and immune defects. Patients can become immune deficient and develop apoptotic enterocolitis, multiple intestinal atresia, and recurrent intestinal stenosis. The intestinal disease in patients with TTC7A deficiency is severe, untreatable, and recurs despite resection or allogeneic hematopoietic stem cell transplant. We screened drugs for those that prevent apoptosis of in cells with TTC7A deficiency and tested their effects in an animal model of the disease. METHODS: We developed a high-throughput screen to identify compounds approved by the Food and Drug Administration that reduce activity of caspases 3 and 7 in TTC7A-knockout HAP1 (human haploid) cells and reduce the susceptibility to apoptosis. We validated the effects of identified agents in HeLa cells that stably express TTC7A with point mutations found in patients. Signaling pathways in cells were analyzed by immunoblots. We tested the effects of identified agents in zebrafish with disruption of ttc7a, which develop intestinal defects, and colonoids derived from biopsies of patients with and without mutations in TTC7A. We performed real-time imaging of intestinal peristalsis in zebrafish and histologic analyses of intestinal tissues from patients and zebrafish. Colonoids were analyzed by immunofluorescence and for ion transport. RESULTS: TTC7A-knockout HAP1 cells have abnormal morphology and undergo apoptosis, due to increased levels of active caspases 3 and 7. We identified drugs that increased cell viability; leflunomide (used to treat patients with inflammatory conditions) reduced caspase 3 and 7 activity in cells by 96%. TTC7A-knockout cells contained cleaved caspase 3 and had reduced levels of phosphorylated AKT and XIAP; incubation of these cells with leflunomide increased levels of phosphorylated AKT and XIAP and reduced levels of cleaved caspase 3. Administration of leflunomide to ttc7a-/- zebrafish increased gut motility, reduced intestinal tract narrowing, increased intestinal cell survival, increased sizes of intestinal luminal spaces, and restored villi and goblet cell morphology. Exposure of patient-derived colonoids to leflunomide increased cell survival, polarity, and transport function. CONCLUSIONS: In a drug screen, we identified leflunomide as an agent that reduces apoptosis and levels of caspase 3 and activates AKT signaling and in TTC7A-knockout cells. In zebrafish with disruption of ttc7a, leflunomide restores gut motility, reduces intestinal tract narrowing, and increases intestinal cell survival. This drug might be repurposed for treatment of TTC7A deficiency.

4.
Biochem Pharmacol ; : 113671, 2019 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-31634456

RESUMO

The immune system is quite remarkable having both the ability to tolerate innocuous and self-antigens while possessing a robust capacity to recognize and eradicate infectious pathogens and foreign entities. The genetics that encode this delicate balancing act include multiple genes and specialized cell types. Over the past several years, whole exome and whole genome sequencing has uncovered the genetics driving many human immune-mediated diseases including monogenic disorders and hematological malignancies. With the advent of genome editing technologies, the ability to correct genetic immune defects in autologous cells holds great promise for a number of conditions. Since assessment of novel therapeutic strategies have been difficult in mice, in recent years, immunodeficient mice capable of engrafting human cells and tissue have been developed and utilized for a variety of research applications. In this review, we discuss immune-humanized mice as a research tool to study human immunobiology and genetic immune disorders in vivo and the promise of future applications.

5.
Crohns Colitis 360 ; 1(2): otz009, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31423487

RESUMO

Aim: The aim of this study was to determine the immunologic effects and safety of oral anti-CD3 in patients with ulcerative colitis (UC). Methods: An open-label pilot study of orally delivered anti-CD3 was performed in patients with moderate-to-severe UC. The primary end points were changes in immunologic parameters and evaluation for safety. Results: Six subjects received oral OKT3. Biologic effects of oral anti-CD3 included significantly increased proliferation in response to anti-CD3 and anti-inflammatory gene expression profile in peripheral blood mononuclear cells. No serious treatment-related adverse events occurred. Conclusion: Orally delivered anti-CD3 resulted in immunologic changes in patients with UC.

6.
Inflamm Bowel Dis ; 25(12): 1927-1938, 2019 11 14.
Artigo em Inglês | MEDLINE | ID: mdl-31276165

RESUMO

BACKGROUND: The beneficial effects of antibiotics in Crohn's disease (CD) depend in part on the gut microbiota but are inadequately understood. We investigated the impact of metronidazole (MET) and metronidazole plus azithromycin (MET+AZ) on the microbiota in pediatric CD and the use of microbiota features as classifiers or predictors of disease remission. METHODS: 16S rRNA-based microbiota profiling was performed on stool samples from 67 patients in a multinational, randomized, controlled, longitudinal, 12-week trial of MET vs MET+AZ in children with mild to moderate CD. Profiles were analyzed together with disease activity, and then used to construct random forest models to classify remission or predict treatment response. RESULTS: Both MET and MET+AZ significantly decreased diversity of the microbiota and caused large treatment-specific shifts in microbiota structure at week 4. Disease remission was associated with a treatment-specific microbiota configuration. Random forest models constructed from microbiota profiles before and during antibiotic treatment with metronidazole accurately classified disease remission in this treatment group (area under the curve [AUC], 0.879; 95% confidence interval, 0.683-0.9877; sensitivity, 0.7778; specificity, 1.000; P < 0.001). A random forest model trained on pre-antibiotic microbiota profiles predicted disease remission at week 4 with modest accuracy (AUC, 0.8; P = 0.24). CONCLUSIONS: MET and MET+AZ antibiotic regimens in pediatric CD lead to distinct gut microbiota structures at remission. It may be possible to classify and predict remission based in part on microbiota profiles, but larger cohorts will be needed to realize this goal.

7.
J Pediatr Gastroenterol Nutr ; 69(1): e13-e18, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31232887

RESUMO

Very early onset inflammatory bowel disease (VEO-IBD) represents a diagnostic and treatment challenge. Here we present a case of VEO-IBD secondary to a mutation in BIRC4 gene, which encodes X-linked inhibitor of apoptosis protein (XIAP), in a 17-month-old boy with severe failure to thrive, intractable diarrhea, and hepatosplenomegaly. Endoscopy and histology identified only mild duodenitis and ileitis, but severe pancolitis with crypt abscesses and epithelium apoptosis. Minimal improvement in symptoms was achieved with total parenteral nutrition (TPN), intravenous (IV) corticosteroids, and tacrolimus, whereas induction and maintenance therapy with adalimumab led to complete remission. After 6 months, the patient developed hemophagocytic lymphohistiocytosis and eventually died due to multisystem organ failure. A review of the literature revealed that some patients with VEO-IBD secondary to XIAP deficiency develop symptoms that are refractory to medical and surgical management, while initial reports suggest that allogeneic hematopoietic stem cell transplantation (HSCT), with reduced intensity conditioning, can successfully induce long-lasting remission and may even be curative. We propose that in patients with XIAP deficiency a constellation of symptoms including colitis at an early age, severe failure to thrive, and splenomegaly/hepatosplenomegaly can identify a subgroup of patients at high risk of experiencing medically refractory IBD phenotype and increased mortality. Hematopoietic stem cell transplant should be considered early in these high-risk patients, as it may resolve both their intestinal inflammation and a risk of developing life threatening hemophagocytic lymphohistiocytosis .

9.
J Clin Immunol ; 39(4): 430-439, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31079270

RESUMO

PURPOSE: This study aimed to characterize the clinical phenotype, genetic basis, and consequent immunological phenotype of a boy with severe infantile-onset colitis and eosinophilic gastrointestinal disease, and no evidence of recurrent or severe infections. METHODS: Trio whole-exome sequencing (WES) was utilized for pathogenic variant discovery. Western blot (WB) and immunohistochemical (IHC) staining were used for protein expression analyses. Immunological workup included in vitro T cell studies, flow cytometry, and CyTOF analysis. RESULTS: WES revealed a homozygous variant in the capping protein regulator and myosin 1 linker 2 (CARMIL2) gene: c.1590C>A; p.Asn530Lys which co-segregated with the disease in the nuclear family. WB and IHC analyses demonstrated reduced protein levels in patient's cells compared with controls. Moreover, comprehensive immunological workup revealed severely diminished blood-borne regulatory T cell (Treg) frequency and impaired in vitro CD4+ T cell proliferation and Treg generation. CyTOF analysis showed significant shifts in the patient's innate and adaptive immune cells compared with healthy controls and ulcerative colitis patients. CONCLUSIONS: Pathogenic variants in CARMIL2 have been implicated in an immunodeficiency syndrome characterized by recurrent infections, occasionally with concurrent chronic diarrhea. We show that CARMIL2-immunodeficiency is associated with significant alterations in the landscape of immune populations in a patient with prominent gastrointestinal disease. This case provides evidence that CARMIL2 should be a candidate gene when diagnosing children with very early onset inflammatory and eosinophilic gastrointestinal disorders, even when signs of immunodeficiency are not observed.

10.
Inflamm Bowel Dis ; 25(Suppl 2): S5-S12, 2019 05 16.
Artigo em Inglês | MEDLINE | ID: mdl-31095706

RESUMO

Preclinical human IBD mechanisms is part of five focus areas of the Challenges in IBD research document, which also include environmental triggers, novel technologies, precision medicine and pragmatic clinical research. The Challenges in IBD research document provides a comprehensive overview of current gaps in inflammatory bowel diseases (IBD) research and delivers actionable approaches to address them. It is the result of a multidisciplinary input from scientists, clinicians, patients, and funders, and represents a valuable resource for patient centric research prioritization. In particular, the preclinical human IBD mechanisms manuscript is focused on highlighting the main research gaps in the pathophysiological understanding of human IBD. These research gap areas include: 1) triggers of immune responses; 2) intestinal epithelial homeostasis and wound repair; 3) age-specific pathophysiology; 4) disease complications; 5) heterogeneous response to treatments; and 6) determination of disease location. As an approach to address these research gaps, the prioritization of reverse translation studies is proposed in which clinical observations are the foundation for experimental IBD research in the lab, and for the identification of new therapeutic targets and biomarkers. The use of human samples in validating basic research findings and development of precision medicine solutions is also proposed. This prioritization aims to put emphasis on relevant biochemical pathways and humanized in vitro and in vivo models that extrapolate meaningfully to human IBD, to eventually yield first-in-class and effective therapies.

11.
Inflamm Bowel Dis ; 25(11): 1788-1795, 2019 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-31115454

RESUMO

BACKGROUND: Children with very early onset inflammatory bowel diseases (VEO-IBD) often have a refractory and severe disease course. A significant number of described VEO-IBD-causing monogenic disorders can be attributed to defects in immune-related genes. The diagnosis of the underlying primary immunodeficiency (PID) often has critical implications for the treatment of patients with IBD-like phenotypes. METHODS: To identify the molecular etiology in 5 patients from 3 unrelated kindred with IBD-like symptoms, we conducted whole exome sequencing. Immune workup confirmed an underlying PID. RESULTS: Whole exome sequencing revealed 3 novel CARMIL2 loss-of-function mutations in our patients. Immunophenotyping of peripheral blood mononuclear cells showed reduction of regulatory and effector memory T cells and impaired B cell class switching. The T cell proliferation and activation assays confirmed defective responses to CD28 costimulation, consistent with CARMIL2 deficiency. CONCLUSION: Our study highlights that human CARMIL2 deficiency can manifest with IBD-like symptoms. This example illustrates that early diagnosis of underlying PID is crucial for the treatment and prognosis of children with VEO-IBD.

12.
Nat Med ; 25(4): 690-700, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30936544

RESUMO

Epithelial barrier loss is a driver of intestinal and systemic diseases. Myosin light chain kinase (MLCK) is a key effector of barrier dysfunction and a potential therapeutic target, but enzymatic inhibition has unacceptable toxicity. Here, we show that a unique domain within the MLCK splice variant MLCK1 directs perijunctional actomyosin ring (PAMR) recruitment. Using the domain structure and multiple screens, we identify a domain-binding small molecule (divertin) that blocks MLCK1 recruitment without inhibiting enzymatic function. Divertin blocks acute, tumor necrosis factor (TNF)-induced MLCK1 recruitment as well as downstream myosin light chain (MLC) phosphorylation, barrier loss, and diarrhea in vitro and in vivo. Divertin corrects barrier dysfunction and prevents disease development and progression in experimental inflammatory bowel disease. Beyond applications of divertin in gastrointestinal disease, this general approach to enzymatic inhibition by preventing access to specific subcellular sites provides a new paradigm for safely and precisely targeting individual properties of enzymes with multiple functions.


Assuntos
Homeostase , Mucosa Intestinal/metabolismo , Espaço Intracelular/enzimologia , Quinase de Cadeia Leve de Miosina/metabolismo , Actomiosina/metabolismo , Animais , Células CACO-2 , Doença Crônica , Homeostase/efeitos dos fármacos , Humanos , Inflamação/patologia , Doenças Inflamatórias Intestinais/patologia , Mucosa Intestinal/efeitos dos fármacos , Jejuno/efeitos dos fármacos , Jejuno/metabolismo , Jejuno/patologia , Camundongos , Cadeias Leves de Miosina/metabolismo , Quinase de Cadeia Leve de Miosina/química , Fosforilação/efeitos dos fármacos , Domínios Proteicos , Bibliotecas de Moléculas Pequenas/farmacologia , Junções Íntimas/efeitos dos fármacos , Junções Íntimas/metabolismo , Fator de Necrose Tumoral alfa/farmacologia
13.
Dev Cell ; 49(1): 10-29, 2019 04 08.
Artigo em Inglês | MEDLINE | ID: mdl-30930166

RESUMO

Single-cell gene expression analyses of mammalian tissues have uncovered profound stage-specific molecular regulatory phenomena that have changed the understanding of unique cell types and signaling pathways critical for lineage determination, morphogenesis, and growth. We discuss here the case for a Pediatric Cell Atlas as part of the Human Cell Atlas consortium to provide single-cell profiles and spatial characterization of gene expression across human tissues and organs. Such data will complement adult and developmentally focused HCA projects to provide a rich cytogenomic framework for understanding not only pediatric health and disease but also environmental and genetic impacts across the human lifespan.


Assuntos
Desenvolvimento Embrionário/genética , Redes Reguladoras de Genes/genética , Pediatria/tendências , Análise de Célula Única/métodos , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento/genética , Humanos , Distribuição Tecidual/genética
14.
Nat Commun ; 10(1): 912, 2019 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-30796216

RESUMO

The JAK-STAT pathway critically regulates T-cell differentiation, and STAT1 is postulated to regulate several immune-mediated diseases by inducing proinflammatory subsets. Here we show that STAT1 enables CD4+ T-cell-mediated intestinal inflammation by protecting them from natural killer (NK) cell-mediated elimination. Stat1-/- T cells fail to expand and establish colitis in lymphopenic mice. This defect is not fully recapitulated by the combinatorial loss of type I and II IFN signaling. Mechanistically, Stat1-/- T cells have reduced expression of Nlrc5 and multiple MHC class I molecules that serve to protect cells from NK cell-mediated killing. Consequently, the depletion of NK cells significantly rescues the survival and spontaneous proliferation of Stat1-/- T cells, and restores their ability to induce colitis in adoptive transfer mouse models. Stat1-/- mice however have normal CD4+ T cell numbers as innate STAT1 signaling is required for their elimination. Overall, our findings reveal a critical perspective on JAK-STAT1 signaling that might apply to multiple inflammatory diseases.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Colite/patologia , Intestinos/patologia , Células Matadoras Naturais/imunologia , Fator de Transcrição STAT1/genética , Fator de Transcrição STAT1/imunologia , Transferência Adotiva , Animais , Linfócitos T CD4-Positivos/citologia , Diferenciação Celular/imunologia , Células Cultivadas , Antígenos de Histocompatibilidade Classe I/imunologia , Intestinos/imunologia , Peptídeos e Proteínas de Sinalização Intracelular/biossíntese , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Transdução de Sinais/genética , Transdução de Sinais/imunologia
16.
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
17.
Nat Commun ; 9(1): 3797, 2018 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-30228258

RESUMO

Inflammatory bowel disease (IBD) are heterogenous disorders of the gastrointestinal tract caused by a spectrum of genetic and environmental factors. In mice, overlapping regions of chromosome 3 have been associated with susceptibility to IBD-like pathology, including a locus called Hiccs. However, the specific gene that controls disease susceptibility remains unknown. Here we identify a Hiccs locus gene, Alpk1 (encoding alpha kinase 1), as a potent regulator of intestinal inflammation. In response to infection with the commensal pathobiont Helicobacter hepaticus (Hh), Alpk1-deficient mice display exacerbated interleukin (IL)-12/IL-23 dependent colitis characterized by an enhanced Th1/interferon(IFN)-γ response. Alpk1 controls intestinal immunity via the hematopoietic system and is highly expressed by mononuclear phagocytes. In response to Hh, Alpk1-/- macrophages produce abnormally high amounts of IL-12, but not IL-23. This study demonstrates that Alpk1 promotes intestinal homoeostasis by regulating the balance of type 1/type 17 immunity following microbial challenge.


Assuntos
Colite/imunologia , Infecções por Helicobacter/imunologia , Doenças Inflamatórias Intestinais/imunologia , Interleucina-12/imunologia , Proteínas Quinases/metabolismo , Células Th1/imunologia , Animais , Células da Medula Óssea , Transplante de Medula Óssea , Colite/microbiologia , Colite/patologia , Colo , Modelos Animais de Doenças , Feminino , Infecções por Helicobacter/microbiologia , Infecções por Helicobacter/patologia , Helicobacter hepaticus/imunologia , Humanos , Doenças Inflamatórias Intestinais/microbiologia , Doenças Inflamatórias Intestinais/patologia , Interleucina-12/metabolismo , Interleucina-23/imunologia , Interleucina-23/metabolismo , Macrófagos/imunologia , Macrófagos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Cultura Primária de Células , Proteínas Quinases/genética , Proteínas Quinases/imunologia , Quimera por Radiação , Células Th1/metabolismo
18.
Mucosal Immunol ; 11(6): 1684-1693, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30111863

RESUMO

Simultaneous analyses of peripheral and mucosal immune compartments can yield insight into the pathogenesis of mucosal-associated diseases. Although methods to preserve peripheral immune cells are well established, studies involving mucosal immune cells have been hampered by lack of simple storage techniques. We provide a cryopreservation protocol allowing for storage of gastrointestinal (GI) tissue with preservation of viability and functionality of both immune and epithelial cells. These methods will facilitate translational studies allowing for batch analysis of mucosal tissue to investigate disease pathogenesis, biomarker discovery and treatment responsiveness.


Assuntos
Criopreservação/métodos , Imunofenotipagem/métodos , Mucosa Intestinal/imunologia , Intestinos/fisiologia , Sobrevivência Celular , Perfilação da Expressão Gênica , Humanos , Intestinos/patologia
19.
NPJ Genom Med ; 3: 21, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30131872

RESUMO

Despite major progress in defining the genetic basis of Mendelian disorders, the molecular etiology of many cases remains unknown. Patients with these undiagnosed disorders often have complex presentations and require treatment by multiple health care specialists. Here, we describe an integrated clinical diagnostic and research program using whole-exome and whole-genome sequencing (WES/WGS) for Mendelian disease gene discovery. This program employs specific case ascertainment parameters, a WES/WGS computational analysis pipeline that is optimized for Mendelian disease gene discovery with variant callers tuned to specific inheritance modes, an interdisciplinary crowdsourcing strategy for genomic sequence analysis, matchmaking for additional cases, and integration of the findings regarding gene causality with the clinical management plan. The interdisciplinary gene discovery team includes clinical, computational, and experimental biomedical specialists who interact to identify the genetic etiology of the disease, and when so warranted, to devise improved or novel treatments for affected patients. This program effectively integrates the clinical and research missions of an academic medical center and affords both diagnostic and therapeutic options for patients suffering from genetic disease. It may therefore be germane to other academic medical institutions engaged in implementing genomic medicine programs.

20.
J Clin Invest ; 128(9): 4115-4131, 2018 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-30124469

RESUMO

Congenital neutropenia is characterized by low absolute neutrophil numbers in blood, leading to recurrent bacterial infections, and patients often require life-long granulocyte CSF (G-CSF) support. X-linked neutropenia (XLN) is caused by gain-of-function mutations in the actin regulator Wiskott-Aldrich syndrome protein (WASp). To understand the pathophysiology in XLN and the role of WASp in neutrophils, we here examined XLN patients and 2 XLN mouse models. XLN patients had reduced myelopoiesis and extremely low blood neutrophil number. However, their neutrophils had a hyperactive phenotype and were present in normal numbers in XLN patient saliva. Murine XLN neutrophils were hyperactivated, with increased actin dynamics and migration into tissues. We provide molecular evidence that the hyperactivity of XLN neutrophils is caused by WASp in a constitutively open conformation due to contingent phosphorylation of the critical tyrosine-293 and plasma membrane localization. This renders WASp activity less dependent on regulation by PI3K. Our data show that the amplitude of WASp activity inside a cell could be enhanced by cell-surface receptor signaling even in the context in which WASp is already in an active conformation. Moreover, these data categorize XLN as an atypical congenital neutropenia in which constitutive activation of WASp in tissue neutrophils compensates for reduced myelopoiesis.


Assuntos
Doenças Genéticas Ligadas ao Cromossomo X/genética , Doenças Genéticas Ligadas ao Cromossomo X/metabolismo , Neutropenia/genética , Neutropenia/metabolismo , Neutrófilos/metabolismo , Proteína da Síndrome de Wiskott-Aldrich/genética , Proteína da Síndrome de Wiskott-Aldrich/metabolismo , Animais , Feminino , Mutação com Ganho de Função , Técnicas de Introdução de Genes , Humanos , Masculino , Camundongos , Camundongos da Linhagem 129 , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Neutropenia/congênito , Neutrófilos/ultraestrutura , Fagocitose , Fosforilação , Conformação Proteica , Proteína da Síndrome de Wiskott-Aldrich/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA