Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 179
Filtrar
1.
Am J Hum Genet ; 108(9): 1611-1630, 2021 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-34343493

RESUMO

Genome-wide association studies (GWASs) have identified a melanoma-associated locus on chromosome band 7p21.1 with rs117132860 as the lead SNP and a secondary independent signal marked by rs73069846. rs117132860 is also associated with tanning ability and cutaneous squamous cell carcinoma (cSCC). Because ultraviolet radiation (UVR) is a key environmental exposure for all three traits, we investigated the mechanisms by which this locus contributes to melanoma risk, focusing on cellular response to UVR. Fine-mapping of melanoma GWASs identified four independent sets of candidate causal variants. A GWAS region-focused Capture-C study of primary melanocytes identified physical interactions between two causal sets and the promoter of the aryl hydrocarbon receptor (AHR). Subsequent chromatin state annotation, eQTL, and luciferase assays identified rs117132860 as a functional variant and reinforced AHR as a likely causal gene. Because AHR plays critical roles in cellular response to dioxin and UVR, we explored links between this SNP and AHR expression after both 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and ultraviolet B (UVB) exposure. Allele-specific AHR binding to rs117132860-G was enhanced following both, consistent with predicted weakened AHR binding to the risk/poor-tanning rs117132860-A allele, and allele-preferential AHR expression driven from the protective rs117132860-G allele was observed following UVB exposure. Small deletions surrounding rs117132860 introduced via CRISPR abrogates AHR binding, reduces melanocyte cell growth, and prolongs growth arrest following UVB exposure. These data suggest AHR is a melanoma susceptibility gene at the 7p21.1 risk locus and rs117132860 is a functional variant within a UVB-responsive element, leading to allelic AHR expression and altering melanocyte growth phenotypes upon exposure.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Carcinoma de Células Escamosas/genética , Cromossomos Humanos Par 7 , Loci Gênicos , Melanócitos/metabolismo , Melanoma/genética , Receptores de Hidrocarboneto Arílico/genética , Neoplasias Cutâneas/genética , Alelos , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Carcinogênese/genética , Carcinogênese/metabolismo , Carcinogênese/patologia , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/patologia , Cromatina/química , Cromatina/metabolismo , Regulação da Expressão Gênica , Predisposição Genética para Doença , Genoma Humano , Estudo de Associação Genômica Ampla , Humanos , Melanócitos/efeitos dos fármacos , Melanócitos/patologia , Melanócitos/efeitos da radiação , Melanoma/metabolismo , Melanoma/patologia , Dibenzodioxinas Policloradas/toxicidade , Polimorfismo de Nucleotídeo Único , Cultura Primária de Células , Regiões Promotoras Genéticas , Receptores de Hidrocarboneto Arílico/metabolismo , Neoplasias Cutâneas/metabolismo , Neoplasias Cutâneas/patologia , Banho de Sol , Raios Ultravioleta/efeitos adversos
2.
J Med Chem ; 64(17): 12790-12807, 2021 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-34414766

RESUMO

Phenotypic whole cell high-throughput screening of a ∼150,000 diverse set of compounds against Mycobacterium tuberculosis (Mtb) in cholesterol-containing media identified 1,3-diarylpyrazolyl-acylsulfonamide 1 as a moderately active hit. Structure-activity relationship (SAR) studies demonstrated a clear scope to improve whole cell potency to MIC values of <0.5 µM, and a plausible pharmacophore model was developed to describe the chemical space of active compounds. Compounds are bactericidal in vitro against replicating Mtb and retained activity against multidrug-resistant clinical isolates. Initial biology triage assays indicated cell wall biosynthesis as a plausible mode-of-action for the series. However, no cross-resistance with known cell wall targets such as MmpL3, DprE1, InhA, and EthA was detected, suggesting a potentially novel mode-of-action or inhibition. The in vitro and in vivo drug metabolism and pharmacokinetics profiles of several active compounds from the series were established leading to the identification of a compound for in vivo efficacy proof-of-concept studies.

3.
Am J Hum Genet ; 108(9): 1590-1610, 2021 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-34390653

RESUMO

Our study investigated the underlying mechanism for the 14q24 renal cell carcinoma (RCC) susceptibility risk locus identified by a genome-wide association study (GWAS). The sentinel single-nucleotide polymorphism (SNP), rs4903064, at 14q24 confers an allele-specific effect on expression of the double PHD fingers 3 (DPF3) of the BAF SWI/SNF complex as assessed by massively parallel reporter assay, confirmatory luciferase assays, and eQTL analyses. Overexpression of DPF3 in renal cell lines increases growth rates and alters chromatin accessibility and gene expression, leading to inhibition of apoptosis and activation of oncogenic pathways. siRNA interference of multiple DPF3-deregulated genes reduces growth. Our results indicate that germline variation in DPF3, a component of the BAF complex, part of the SWI/SNF complexes, can lead to reduced apoptosis and activation of the STAT3 pathway, both critical in RCC carcinogenesis. In addition, we show that altered DPF3 expression in the 14q24 RCC locus could influence the effectiveness of immunotherapy treatment for RCC by regulating tumor cytokine secretion and immune cell activation.


Assuntos
Carcinoma de Células Renais/genética , Cromossomos Humanos Par 14 , Proteínas de Ligação a DNA/genética , Loci Gênicos , Neoplasias Renais/genética , Fator de Transcrição STAT3/genética , Fatores de Transcrição/genética , Carcinogênese/genética , Carcinogênese/imunologia , Carcinogênese/patologia , Carcinoma de Células Renais/imunologia , Carcinoma de Células Renais/patologia , Carcinoma de Células Renais/terapia , Linhagem Celular Tumoral , Cromatina/química , Cromatina/imunologia , Montagem e Desmontagem da Cromatina/imunologia , Citocinas/genética , Citocinas/imunologia , Proteínas de Ligação a DNA/imunologia , Regulação da Expressão Gênica , Predisposição Genética para Doença , Genoma Humano , Estudo de Associação Genômica Ampla , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Imunoterapia/métodos , Neoplasias Renais/imunologia , Neoplasias Renais/patologia , Neoplasias Renais/terapia , Polimorfismo de Nucleotídeo Único , Fator de Transcrição STAT3/imunologia , Linfócitos T Citotóxicos , Fatores de Transcrição/imunologia
4.
Int J Health Geogr ; 20(1): 13, 2021 03 18.
Artigo em Inglês | MEDLINE | ID: mdl-33736677

RESUMO

BACKGROUND: Cancer epidemiology studies require sufficient power to assess spatial relationships between exposures and cancer incidence accurately. However, methods for power calculations of spatial statistics are complicated and underdeveloped, and therefore underutilized by investigators. The spatial relative risk function, a cluster detection technique that detects spatial clusters of point-level data for two groups (e.g., cancer cases and controls, two exposure groups), is a commonly used spatial statistic but does not have a readily available power calculation for study design. RESULTS: We developed sparrpowR as an open-source R package to estimate the statistical power of the spatial relative risk function. sparrpowR generates simulated data applying user-defined parameters (e.g., sample size, locations) to detect spatial clusters with high statistical power. We present applications of sparrpowR that perform a power calculation for a study designed to detect a spatial cluster of incident cancer in relation to a point source of numerous environmental emissions. The conducted power calculations demonstrate the functionality and utility of sparrpowR to calculate the local power for spatial cluster detection. CONCLUSIONS: sparrpowR improves the current capacity of investigators to calculate the statistical power of spatial clusters, which assists in designing more efficient studies. This newly developed R package addresses a critically underdeveloped gap in cancer epidemiology by estimating statistical power for a common spatial cluster detection technique.


Assuntos
Neoplasias , Análise por Conglomerados , Humanos , Incidência , Análise Espacial
5.
J Med Chem ; 64(1): 719-740, 2021 01 14.
Artigo em Inglês | MEDLINE | ID: mdl-33395287

RESUMO

Phenotypic screening of a Medicines for Malaria Venture compound library against Mycobacterium tuberculosis (Mtb) identified a cluster of pan-active 2-pyrazolylpyrimidinones. The biology triage of these actives using various tool strains of Mtb suggested a novel mechanism of action. The compounds were bactericidal against replicating Mtb and retained potency against clinical isolates of Mtb. Although selected MmpL3 mutant strains of Mtb showed resistance to these compounds, there was no shift in the minimum inhibitory concentration (MIC) against a mmpL3 hypomorph, suggesting mutations in MmpL3 as a possible resistance mechanism for the compounds but not necessarily as the target. RNA transcriptional profiling and the checkerboard board 2D-MIC assay in the presence of varying concentrations of ferrous salt indicated perturbation of the Fe-homeostasis by the compounds. Structure-activity relationship studies identified potent compounds with good physicochemical properties and in vitro microsomal metabolic stability with moderate selectivity over cytotoxicity against mammalian cell lines.


Assuntos
Antituberculosos/química , Pirimidinonas/química , Animais , Antituberculosos/metabolismo , Antituberculosos/farmacologia , Proteínas de Bactérias/antagonistas & inibidores , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Meia-Vida , Humanos , Ferro/metabolismo , Masculino , Proteínas de Membrana Transportadoras/genética , Proteínas de Membrana Transportadoras/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Testes de Sensibilidade Microbiana , Microssomos/metabolismo , Mutação , Mycobacterium tuberculosis/efeitos dos fármacos , Mycobacterium tuberculosis/isolamento & purificação , Pirazóis/química , Pirimidinonas/metabolismo , Pirimidinonas/farmacologia , Ratos , Relação Estrutura-Atividade
6.
Bioinformatics ; 37(8): 1178-1181, 2021 05 23.
Artigo em Inglês | MEDLINE | ID: mdl-32926120

RESUMO

SUMMARY: A concern when conducting genome-wide association studies (GWAS) is the potential for population stratification, i.e. ancestry-based genetic differences between cases and controls, that if not properly accounted for, could lead to biased association results. We developed PCAmatchR as an open source R package for performing optimal case-control matching using principal component analysis (PCA) to aid in selecting controls that are well matched by ancestry to cases. PCAmatchR takes user supplied PCA outputs and selects matching controls for cases by utilizing a weighted Mahalanobis distance metric which weights each principal component by the percentage of genetic variation explained. Results from the 1000 Genomes Project data demonstrate both the functionality and performance of PCAmatchR for selecting matching controls for case populations as well as reducing inflation of association test statistics. PCAmatchR improves genomic similarity between matched cases and controls, which minimizes the effects of population stratification in GWAS analyses. AVAILABILITY AND IMPLEMENTATION: PCAmatchR is freely available for download on GitHub (https://github.com/machiela-lab/PCAmatchR) or through CRAN (https://CRAN.R-project.org/package=PCAmatchR). SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.


Assuntos
Estudo de Associação Genômica Ampla , Software , Estudos de Casos e Controles , Genômica , Análise de Componente Principal
7.
Hepatology ; 73(1): 247-267, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32222998

RESUMO

BACKGROUND AND AIMS: Organoids provide a powerful system to study epithelia in vitro. Recently, this approach was applied successfully to the biliary tree, a series of ductular tissues responsible for the drainage of bile and pancreatic secretions. More precisely, organoids have been derived from ductal tissue located outside (extrahepatic bile ducts; EHBDs) or inside the liver (intrahepatic bile ducts; IHBDs). These organoids share many characteristics, including expression of cholangiocyte markers such as keratin (KRT) 19. However, the relationship between these organoids and their tissues of origin, and to each other, is largely unknown. APPROACH AND RESULTS: Organoids were derived from human gallbladder, common bile duct, pancreatic duct, and IHBDs using culture conditions promoting WNT signaling. The resulting IHBD and EHBD organoids expressed stem/progenitor markers leucine-rich repeat-containing G-protein-coupled receptor 5/prominin 1 and ductal markers KRT19/KRT7. However, RNA sequencing revealed that organoids conserve only a limited number of regional-specific markers corresponding to their location of origin. Of particular interest, down-regulation of biliary markers and up-regulation of cell-cycle genes were observed in organoids. IHBD and EHBD organoids diverged in their response to WNT signaling, and only IHBDs were able to express a low level of hepatocyte markers under differentiation conditions. CONCLUSIONS: Taken together, our results demonstrate that differences exist not only between extrahepatic biliary organoids and their tissue of origin, but also between IHBD and EHBD organoids. This information may help to understand the tissue specificity of cholangiopathies and also to identify targets for therapeutic development.


Assuntos
Ductos Biliares Extra-Hepáticos/citologia , Ductos Biliares Intra-Hepáticos/citologia , Células Epiteliais/citologia , Organoides/fisiologia , Animais , Bile , Ductos Biliares Extra-Hepáticos/fisiologia , Ductos Biliares Intra-Hepáticos/fisiologia , Diferenciação Celular , Ducto Colédoco/citologia , Células Epiteliais/fisiologia , Vesícula Biliar/citologia , Regulação da Expressão Gênica , Humanos , Queratina-19/análise , Fígado/fisiologia , Camundongos , RNA-Seq , Obtenção de Tecidos e Órgãos
8.
Sci Transl Med ; 12(560)2020 09 09.
Artigo em Inglês | MEDLINE | ID: mdl-32908007

RESUMO

Dysbiosis of the skin microbiota is increasingly implicated as a contributor to the pathogenesis of atopic dermatitis (AD). We previously reported first-in-human safety and clinical activity results from topical application of the commensal skin bacterium Roseomonas mucosa for the treatment of AD in 10 adults and 5 children older than 9 years of age. Here, we examined the potential mechanism of action of R. mucosa treatment and its impact on children with AD less than 7 years of age, the most common age group for children with AD. In 15 children with AD, R. mucosa treatment was associated with amelioration of disease severity, improvement in epithelial barrier function, reduced Staphylococcus aureus burden on the skin, and a reduction in topical steroid requirements without severe adverse events. Our observed response rates to R. mucosa treatment were greater than those seen in historical placebo control groups in prior AD studies. Skin improvements and colonization by R. mucosa persisted for up to 8 months after cessation of treatment. Analyses of cellular scratch assays and the MC903 mouse model of AD suggested that production of sphingolipids by R. mucosa, cholinergic signaling, and flagellin expression may have contributed to therapeutic impact through induction of a TNFR2-mediated epithelial-to-mesenchymal transition. These results suggest that a randomized, placebo-controlled trial of R. mucosa treatment in individuals with AD is warranted and implicate commensals in the maintenance of the skin epithelial barrier.


Assuntos
Dermatite Atópica , Eczema , Methylobacteriaceae , Adulto , Criança , Dermatite Atópica/tratamento farmacológico , Humanos , Lipídeos , Pele
9.
Proc Natl Acad Sci U S A ; 117(32): 19465-19474, 2020 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-32709745

RESUMO

Infection by malaria parasites triggers dynamic immune responses leading to diverse symptoms and pathologies; however, the molecular mechanisms responsible for these reactions are largely unknown. We performed Trans-species Expression Quantitative Trait Locus analysis to identify a large number of host genes that respond to malaria parasite infections. Here we functionally characterize one of the host genes called receptor transporter protein 4 (RTP4) in responses to malaria parasite and virus infections. RTP4 is induced by type I IFN (IFN-I) and binds to the TANK-binding kinase (TBK1) complex where it negatively regulates TBK1 signaling by interfering with expression and phosphorylation of both TBK1 and IFN regulatory factor 3. Rtp4 -/- mice were generated and infected with malaria parasite Plasmodiun berghei ANKA. Significantly higher levels of IFN-I response in microglia, lower parasitemia, fewer neurologic symptoms, and better survival rates were observed in Rtp4 -/- than in wild-type mice. Similarly, RTP4 deficiency significantly reduced West Nile virus titers in the brain, but not in the heart and the spleen, of infected mice, suggesting a specific role for RTP4 in brain infection and pathology. This study reveals functions of RTP4 in IFN-I response and a potential target for therapy in diseases with neuropathology.


Assuntos
Encéfalo/patologia , Interferon Tipo I/metabolismo , Malária Cerebral/patologia , Chaperonas Moleculares/metabolismo , Animais , Encéfalo/parasitologia , Encéfalo/virologia , Células HEK293 , Interações Hospedeiro-Patógeno , Humanos , Fator Regulador 3 de Interferon , Malária Cerebral/metabolismo , Malária Cerebral/parasitologia , Proteínas de Membrana , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Microglia/metabolismo , Chaperonas Moleculares/genética , Fosforilação , Plasmodium berghei/fisiologia , Plasmodium yoelii/fisiologia , Ligação Proteica , Proteínas Serina-Treonina Quinases/metabolismo , Transdução de Sinais , Febre do Nilo Ocidental/metabolismo , Febre do Nilo Ocidental/patologia , Febre do Nilo Ocidental/virologia , Vírus do Nilo Ocidental/fisiologia
10.
Proc Natl Acad Sci U S A ; 117(28): 16567-16578, 2020 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-32606244

RESUMO

Malaria infection induces complex and diverse immune responses. To elucidate the mechanisms underlying host-parasite interaction, we performed a genetic screen during early (24 h) Plasmodium yoelii infection in mice and identified a large number of interacting host and parasite genes/loci after transspecies expression quantitative trait locus (Ts-eQTL) analysis. We next investigated a host E3 ubiquitin ligase gene (March1) that was clustered with interferon (IFN)-stimulated genes (ISGs) based on the similarity of the genome-wide pattern of logarithm of the odds (LOD) scores (GPLS). March1 inhibits MAVS/STING/TRIF-induced type I IFN (IFN-I) signaling in vitro and in vivo. However, in malaria-infected hosts, deficiency of March1 reduces IFN-I production by activating inhibitors such as SOCS1, USP18, and TRIM24 and by altering immune cell populations. March1 deficiency increases CD86+DC (dendritic cell) populations and levels of IFN-γ and interleukin 10 (IL-10) at day 4 post infection, leading to improved host survival. T cell depletion reduces IFN-γ level and reverse the protective effects of March1 deficiency, which can also be achieved by antibody neutralization of IFN-γ. This study reveals functions of MARCH1 (membrane-associated ring-CH-type finger 1) in innate immune responses and provides potential avenues for activating antimalaria immunity and enhancing vaccine efficacy.


Assuntos
Malária/imunologia , Plasmodium yoelii/fisiologia , Linfócitos T/imunologia , Ubiquitina-Proteína Ligases/imunologia , Animais , Modelos Animais de Doenças , Feminino , Interações Hospedeiro-Parasita , Humanos , Imunidade Inata , Interferon Tipo I/genética , Interferon Tipo I/imunologia , Interferon gama/genética , Interferon gama/imunologia , Interleucina-10/genética , Interleucina-10/imunologia , Malária/enzimologia , Malária/genética , Malária/parasitologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Plasmodium yoelii/imunologia , Ubiquitina-Proteína Ligases/genética
11.
Front Genet ; 11: 157, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32180801

RESUMO

Genomic research involving human genetics and evolutionary biology relies heavily on linkage disequilibrium (LD) to investigate population-specific genetic structure, functionally map regions of disease susceptibility and uncover evolutionary history. Interactive and powerful tools are needed to calculate population-specific LD estimates for integrative genomics research. LDlink is an interactive suite of web-based tools developed to query germline variants in 1000 Genomes Project population groups of interest and generate interactive tables and plots of LD estimates. As an expansion to this resource, we have developed an R package, LDlinkR, designed to rapidly calculate statistics for large lists of variants and LD attributes that eliminates the time needed to perform repetitive requests from the web-based LDlink tool. LDlinkR accelerates genomic research by providing efficient and user-friendly functions to programmatically interrogate and download pairwise LD estimates from expansive lists of genetic variants. LDlinkR is a free and publicly available R package that can be installed from the Comprehensive R Archive Network (CRAN) or downloaded from https://github.com/CBIIT/LDlinkR.

12.
Sci Immunol ; 5(44)2020 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-32111619

RESUMO

We investigated the molecular and cellular basis of severe combined immunodeficiency (SCID) in six patients with otofaciocervical syndrome type 2 who failed to attain T cell reconstitution after allogeneic hematopoietic stem cell transplantation, despite successful engraftment in three of them. We identified rare biallelic PAX1 rare variants in all patients. We demonstrated that these mutant PAX1 proteins have an altered conformation and flexibility of the paired box domain and reduced transcriptional activity. We generated patient-derived induced pluripotent stem cells and differentiated them into thymic epithelial progenitor cells and found that they have an altered transcriptional profile, including for genes involved in the development of the thymus and other tissues derived from pharyngeal pouches. These results identify biallelic, loss-of-function PAX1 mutations as the cause of a syndromic form of SCID due to altered thymus development.


Assuntos
Fatores de Transcrição Box Pareados/imunologia , Timo/imunologia , Síndrome Brânquio-Otorrenal/genética , Síndrome Brânquio-Otorrenal/imunologia , Síndrome Brânquio-Otorrenal/patologia , Células Epiteliais/imunologia , Células Epiteliais/patologia , Humanos , Lactente , Masculino , Fatores de Transcrição Box Pareados/genética , Imunodeficiência Combinada Severa/genética , Imunodeficiência Combinada Severa/imunologia , Imunodeficiência Combinada Severa/patologia , Timo/patologia
13.
Tuberculosis (Edinb) ; 120: 101895, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-32090856

RESUMO

New vaccines are needed to combat the public health threat posed by M. tuberculosis (M. tb), but no correlates have been defined to aid vaccine development. Using mouse models, we previously developed an in vitro system that measures the ability of M. tb-immune lymphocytes to control bacterial replication during co-culture with M. tb-infected macrophages. We demonstrated that the degree of in vitro growth control by lymphocytes from mice given vaccines of varying efficacy reflected the relative degree of in vivo protection against lethal challenge. Further, using targeted analyses of gene expression in lymphocytes recovered from co-cultures, we found mediators whose relative expression also correlated with in vitro and in vivo outcomes. Here we advanced those findings by employing genome-wide expression analyses. We first screened splenocytes recovered from co-cultures by microarray, revealing additional genes whose expression correlated with protection. After applying pathway analyses to down-select gene candidates, we used both splenocytes and peripheral blood lymphocytes to validate microarray findings by qRT-PCR. We then subjected data from top candidates to rigorous statistical analyses. Resulting correlate candidates, including CXCL9, IFN-γ, and CCL5, significantly predicted protection with high specificity. These findings therefore refine and extend a panel of relevant immune correlates to advance vaccine development.

14.
mBio ; 11(1)2020 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-31911494

RESUMO

Erythrocyte-binding-like (EBL) proteins are known to play an important role in malaria parasite invasion of red blood cells (RBCs); however, any roles of EBL proteins in regulating host immune responses remain unknown. Here, we show that Plasmodium yoelii EBL (PyEBL) can shape disease severity by modulating the surface structure of infected RBCs (iRBCs) and host immune responses. We identified an amino acid substitution (a change of C to Y at position 741 [C741Y]) in the protein trafficking domain of PyEBL between isogenic P. yoellii nigeriensis strain N67 and N67C parasites that produce different disease phenotypes in C57BL/6 mice. Exchanges of the C741Y alleles altered parasite growth and host survival accordingly. The C741Y substitution also changed protein processing and trafficking in merozoites and in the cytoplasm of iRBCs, reduced PyEBL binding to band 3, increased phosphatidylserine (PS) surface exposure, and elevated the osmotic fragility of iRBCs, but it did not affect invasion of RBCs in vitro The modified iRBC surface triggered PS-CD36-mediated phagocytosis of iRBCs, host type I interferon (IFN-I) signaling, and T cell differentiation, leading to improved host survival. This study reveals a previously unknown role of PyEBL in regulating host-pathogen interaction and innate immune responses, which may be explored for developing disease control strategies.IMPORTANCE Malaria is a deadly parasitic disease that continues to afflict hundreds of millions of people every year. Infections with malaria parasites can be asymptomatic, with mild symptoms, or fatal, depending on a delicate balance of host immune responses. Malaria parasites enter host red blood cells (RBCs) through interactions between parasite ligands and host receptors, such as erythrocyte-binding-like (EBL) proteins and host Duffy antigen receptor for chemokines (DARC). Plasmodium yoelii EBL (PyEBL) is known to play a role in parasite invasion of RBCs. Here, we show that PyEBL also affects disease severity through modulation of host immune responses, particularly type I interferon (IFN-I) signaling. This discovery assigns a new function to PyEBL and provides a mechanism for developing disease control strategies.


Assuntos
Antígenos de Protozoários/imunologia , Eritrócitos/imunologia , Eritrócitos/parasitologia , Malária/imunologia , Malária/parasitologia , Proteínas de Membrana/metabolismo , Plasmodium yoelii/fisiologia , Proteínas de Protozoários/metabolismo , Alelos , Antígenos de Protozoários/metabolismo , Biomarcadores , Citocinas/metabolismo , Imunofluorescência , Interações Hospedeiro-Parasita , Imuno-Histoquímica , Malária/diagnóstico , Malária/metabolismo , Proteínas de Membrana/imunologia , Fragilidade Osmótica , Fagocitose/imunologia , Proteínas de Protozoários/genética , Proteínas de Protozoários/imunologia , Índice de Gravidade de Doença , Baço/imunologia , Baço/metabolismo , Baço/patologia , Linfócitos T Auxiliares-Indutores/imunologia , Linfócitos T Auxiliares-Indutores/metabolismo
16.
Curr Protoc Immunol ; 126(1): e78, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31483103

RESUMO

MicroRNAs (miRNAs) are short (19- to 25-nucleotide) noncoding RNA molecules that target mRNAs to repress gene expression and that play important roles in regulating many fundamental biological functions including cell differentiation, development, growth, and metabolism. They are well conserved in eukaryotic cells and are considered essential ancient elements of gene regulation. miRNA genes are transcribed by RNA polymerase II to generate primary miRNAs (pri-miRNAs), which are cleaved by microprocessor complex in the nucleus to generate stem-loop structures known as pre-miRNAs. Pre-miRNAs are translocated to the cytoplasm and cleaved by Dicer to form the mature miRNAs, which mediate mRNA degradation through their loading to the RNA-induced silencing complex (RISC) and binding to complementary sequences within target mRNAs to repress their translation by mRNA degradation and/or translation inhibition. Because ∼1900 miRNA genes are reported in the human genome, many associated with disease, appropriate methods to study miRNA expression and regulation under physiological and pathological conditions have become increasingly important to the study of many aspects of human biology, including immune regulation. As with small interfering RNA (siRNA), the mechanism of miRNA-mediated targeting has been used to develop miRNA-based therapeutics. For a complete and systematic analysis, it is critical to utilize a variety of different tools to analyze the expression of pri-mRNAs, pre-miRNAs, and mature miRNAs and characterize their targets both in vitro and in vivo. Such studies will facilitate future novel drug design and development. This unit provides six basic protocols for miRNA analysis, covering next-generation sequencing, quantitative real-time PCR (qRT-PCR), and digoxigenin-based expression analysis of pri-mRNAs, pre-miRNAs, and mature miRNAs; mapping of pri-miRNA and their cleavage sites by rapid amplification of cDNA ends (RACE); electrophoretic mobility shift assays (EMSAs) or biotin-based nonradioactive detection of miRNA-protein complexes (miRNPs); and functional analysis of miRNAs using miRNA mimics and inhibitors. © 2019 by John Wiley & Sons, Inc.


Assuntos
Biomimética/métodos , MicroRNAs/genética , RNA Mensageiro/genética , Ensaio de Desvio de Mobilidade Eletroforética , Expressão Gênica , Regulação da Expressão Gênica , Inativação Gênica , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Mimetismo Molecular
17.
Blood ; 133(26): 2753-2764, 2019 06 27.
Artigo em Inglês | MEDLINE | ID: mdl-31064750

RESUMO

Patients with classic hydroa vacciniforme-like lymphoproliferative disorder (HVLPD) typically have high levels of Epstein-Barr virus (EBV) DNA in T cells and/or natural killer (NK) cells in blood and skin lesions induced by sun exposure that are infiltrated with EBV-infected lymphocytes. HVLPD is very rare in the United States and Europe but more common in Asia and South America. The disease can progress to a systemic form that may result in fatal lymphoma. We report our 11-year experience with 16 HVLPD patients from the United States and England and found that whites were less likely to develop systemic EBV disease (1/10) than nonwhites (5/6). All (10/10) of the white patients were generally in good health at last follow-up, while two-thirds (4/6) of the nonwhite patients required hematopoietic stem cell transplantation. Nonwhite patients had later age of onset of HVLPD than white patients (median age, 8 vs 5 years) and higher levels of EBV DNA (median, 1 515 000 vs 250 000 copies/ml) and more often had low numbers of NK cells (83% vs 50% of patients) and T-cell clones in the blood (83% vs 30% of patients). RNA-sequencing analysis of an HVLPD skin lesion in a white patient compared with his normal skin showed increased expression of interferon-γ and chemokines that attract T cells and NK cells. Thus, white patients with HVLPD were less likely to have systemic disease with EBV and had a much better prognosis than nonwhite patients. This trial was registered at www.clinicaltrials.gov as #NCT00369421 and #NCT00032513.


Assuntos
Infecções por Vírus Epstein-Barr/patologia , Hidroa Vaciniforme/virologia , Transtornos Linfoproliferativos/patologia , Transtornos Linfoproliferativos/virologia , Criança , Pré-Escolar , Infecções por Vírus Epstein-Barr/etnologia , Infecções por Vírus Epstein-Barr/imunologia , Grupo com Ancestrais do Continente Europeu , Feminino , Humanos , Transtornos Linfoproliferativos/etnologia , Masculino
18.
J Hum Genet ; 64(6): 545-550, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30850729

RESUMO

Mosaic protein truncating variants (PTVs) in the phosphatase, Mg2+/Mn2+dependent 1D (PPM1D) gene in blood-derived DNA have been associated with increased risk of breast cancer. We analyzed PPM1D PTVs in blood from 3817 breast cancer cases and 3058 controls by deep sequencing of a previously defined region in exon 6 of PPM1D. We identified 50 of 6875 (0.73%) participants having a mosaic PPM1D PTV. We observed a higher frequency of mosaic PPM1D PTVs with increasing age (Ptrend = 2.9 × 10-6). We did not observe an overall association between PPM1D PTVs and increased breast cancer risk (OR = 1.51, 95% CI = 0.84-2.71). Evidence for an association was observed in a subset of cases with DNA collected 1-year or more before breast cancer diagnosis (OR = 3.44, 95% CI = 1.62-7.30, P-value = 0.001); however, no significant association was observed for the larger series of cases with DNA collected post diagnosis (OR = 1.01, 95% CI = 0.51-2.01, P-value = 0.98). Our study indicates that the PPM1D PTVs are present at higher rates than previously reported and the frequency of PPM1D PTVs increases with age. We observed limited evidence for an association between mosaic PPM1D PTVs and breast cancer risk, suggesting mosaic PPM1D PTVs in the blood likely do not influence risk of breast cancer.


Assuntos
Envelhecimento/genética , Neoplasias da Mama/genética , Predisposição Genética para Doença , Proteína Fosfatase 2C/genética , Idoso , Envelhecimento/patologia , Neoplasias da Mama/patologia , Éxons , Feminino , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Pessoa de Meia-Idade , Mutação , Fatores de Risco
19.
Mucosal Immunol ; 12(1): 85-96, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30087442

RESUMO

Despite studies indicating the effects of IL-21 signaling in intestinal inflammation, its roles in intestinal homeostasis and infection are not yet clear. Here, we report potent effects of commensal microbiota on the phenotypic manifestations of IL-21 receptor deficiency. IL-21 is produced highly in the small intestine and appears to be critical for mounting an IgA response against atypical commensals such as segmented filamentous bacteria and Helicobacter, but not to the majority of commensals. In the presence of these atypical commensals, IL-21R-deficient mice exhibit reduced numbers of germinal center and IgA+ B cells and expression of activation-induced cytidine deaminase in Peyer's patches as well as a significant decrease in small intestine IgA+ plasmablasts and plasma cells, leading to higher bacterial burdens and subsequent expansion of Th17 and Treg cells. These microbiota-mediated secondary changes in turn enhance T cell responses to an oral antigen and strikingly dampen Citrobacter rodentium-induced immunopathology, demonstrating a complex interplay between IL-21-mediated mucosal immunity, microbiota, and pathogens.


Assuntos
Formas Bacterianas Atípicas/fisiologia , Linfócitos B/fisiologia , Citrobacter rodentium/fisiologia , Infecções por Enterobacteriaceae/imunologia , Helicobacter/fisiologia , Imunoglobulina A/metabolismo , Mucosa Intestinal/imunologia , Intestino Delgado/imunologia , Receptores de Interleucina-21/genética , Animais , Carga Bacteriana , Diferenciação Celular , Células Cultivadas , Citidina Desaminase/genética , Citidina Desaminase/metabolismo , Homeostase , Humanos , Imunidade Humoral , Imunidade nas Mucosas , Mucosa Intestinal/microbiologia , Intestino Delgado/microbiologia , Camundongos , Camundongos Knockout , Receptores de Interleucina-21/metabolismo , Linfócitos T Reguladores/imunologia , Células Th17/imunologia
20.
mBio ; 9(6)2018 12 18.
Artigo em Inglês | MEDLINE | ID: mdl-30563896

RESUMO

Human infection with Cryptococcus causes up to a quarter of a million AIDS-related deaths annually and is the most common cause of nonviral meningitis in the United States. As an opportunistic fungal pathogen, Cryptococcus neoformans is distinguished by its ability to adapt to diverse host environments, including plants, amoebae, and mammals. In the present study, comparative transcriptomics of the fungus within human cerebrospinal fluid identified expression profiles representative of low-nutrient adaptive responses. Transcriptomics of fungal isolates from a cohort of HIV/AIDS patients identified high expression levels of an alternative carbon nutrient transporter gene, STL1, to be associated with poor early fungicidal activity, an important clinical prognostic marker. Mouse modeling and pathway analysis demonstrated a role for STL1 in mammalian pathogenesis and revealed that STL1 expression is regulated by a novel multigene regulatory mechanism involving the CAC2 subunit of the chromatin assembly complex 1, CAF-1. In this pathway, the global regulator of virulence gene VAD1 was found to transcriptionally regulate a cryptococcal homolog of a cytosolic protein, Ecm15, in turn required for nuclear transport of the Cac2 protein. Derepression of STL1 by the CAC2-containing CAF-1 complex was mediated by Cac2 and modulated binding and suppression of the STL1 enhancer element. Derepression of STL1 resulted in enhanced survival and growth of the fungus in the presence of low-nutrient, alternative carbon sources, facilitating virulence in mice. This study underscores the utility of ex vivo expression profiling of fungal clinical isolates and provides fundamental genetic understanding of saprophyte adaption to the human host.IMPORTANCE Cryptococcus is a fungal pathogen that kills an estimated quarter of a million individuals yearly and is the most common cause of nonviral meningitis in the United States. The fungus is carried in about 10% of the adult population and, after reactivation, causes disease in a wide variety of immunosuppressed individuals, including the HIV infected and patients receiving transplant conditioning, cancer therapy, or corticosteroid therapy for autoimmune diseases. The fungus is widely carried in the soil but can also cause infections in plants and mammals. However, the mechanisms for this widespread ability to infect a variety of hosts are poorly understood. The present study identified adaptation to low nutrients as a key property that allows the fungus to inhabit these diverse environments. Further studies identified a nutrient transporter gene, STL1, to be upregulated under low nutrients and to be associated with early fungicidal activity, a marker of poor clinical outcome in a cohort of HIV/AIDS patients. Understanding molecular mechanisms involved in adaptation to the human host may help to design better methods of control and treatment of widely dispersed fungal pathogens such as Cryptococcus.


Assuntos
Cryptococcus neoformans/genética , Cryptococcus neoformans/patogenicidade , Redes e Vias Metabólicas/genética , Serina-Treonina Quinases TOR/genética , Fatores de Virulência/genética , Adulto , Animais , Modelos Animais de Doenças , Feminino , Perfilação da Expressão Gênica , Genes Reguladores , Infecções por HIV/microbiologia , Interações Hospedeiro-Patógeno/genética , Humanos , Masculino , Proteínas de Membrana Transportadoras/genética , Meningite Criptocócica/líquido cefalorraquidiano , Camundongos , Camundongos Endogâmicos CBA , Pessoa de Meia-Idade , Ensaios Clínicos Controlados Aleatórios como Assunto , Virulência , Adulto Jovem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...