Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 836
Filtrar
Mais filtros

Intervalo de ano de publicação
1.
Immunity ; 54(5): 850-852, 2021 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-33979582

RESUMO

In this issue of Immunity, Schiller et al. report that local sympathetic nerve activation decreases endothelial expression of the adhesion molecule MAdCAM-1, reducing immune cell infiltration and colitis-induced inflammation. These findings suggest that local sympathetic stimulation provides a key gateway for regulating organ homeostasis.


Assuntos
Colite , Mucoproteínas , Moléculas de Adesão Celular , Endotélio , Humanos , Neuroimunomodulação
2.
Immunol Rev ; 2024 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-39037230

RESUMO

Irritable bowel syndrome (IBS) is a chronic gastrointestinal condition associated with altered bowel habits and recurrent abdominal pain, often triggered by food intake. Current treatments focus on improving stool pattern, but effective treatments for pain in IBS are still lacking due to our limited understanding of pathophysiological mechanisms. Visceral hypersensitivity (VHS), or abnormal visceral pain perception, underlies abdominal pain development in IBS, and mast cell activation has been shown to play an important role in the development of VHS. Our work recently revealed that abdominal pain in response to food intake is induced by the sensitization of colonic pain-sensing neurons by histamine produced by activated mast cells following a local IgE response to food. In this review, we summarize the current knowledge on abdominal pain and VHS pathophysiology in IBS, we outline the work leading to the discovery of the role of histamine in abdominal pain, and we introduce antihistamines as a novel treatment option to manage chronic abdominal pain in patients with IBS.

3.
EMBO J ; 42(2): e112372, 2023 01 16.
Artigo em Inglês | MEDLINE | ID: mdl-36472247

RESUMO

Protein synthesis is crucial for cell growth and survival yet one of the most energy-consuming cellular processes. How, then, do cells sustain protein synthesis under starvation conditions when energy is limited? To accelerate the translocation of mRNA-tRNAs through the ribosome, bacterial elongation factor G (EF-G) hydrolyzes energy-rich guanosine triphosphate (GTP) for every amino acid incorporated into a protein. Here, we identify an EF-G paralog-EF-G2-that supports translocation without hydrolyzing GTP in the gut commensal bacterium Bacteroides thetaiotaomicron. EF-G2's singular ability to sustain protein synthesis, albeit at slow rates, is crucial for bacterial gut colonization. EF-G2 is ~10-fold more abundant than canonical EF-G1 in bacteria harvested from murine ceca and, unlike EF-G1, specifically accumulates during carbon starvation. Moreover, we uncover a 26-residue region unique to EF-G2 that is essential for protein synthesis, EF-G2 dissociation from the ribosome, and responsible for the absence of GTPase activity. Our findings reveal how cells curb energy consumption while maintaining protein synthesis to advance fitness in nutrient-fluctuating environments.


Assuntos
Bacteroides , Fator G para Elongação de Peptídeos , Animais , Camundongos , Bacteroides/genética , Bacteroides/metabolismo , Guanosina Trifosfato/metabolismo , Hidrólise , Fator G para Elongação de Peptídeos/genética , Fator G para Elongação de Peptídeos/química , Ribossomos/metabolismo , RNA de Transferência/metabolismo
4.
Cell ; 148(3): 434-46, 2012 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-22304914

RESUMO

Susceptibility to tuberculosis is historically ascribed to an inadequate immune response that fails to control infecting mycobacteria. In zebrafish, we find that susceptibility to Mycobacterium marinum can result from either inadequate or excessive acute inflammation. Modulation of the leukotriene A(4) hydrolase (LTA4H) locus, which controls the balance of pro- and anti-inflammatory eicosanoids, reveals two distinct molecular routes to mycobacterial susceptibility converging on dysregulated TNF levels: inadequate inflammation caused by excess lipoxins and hyperinflammation driven by excess leukotriene B(4). We identify therapies that specifically target each of these extremes. In humans, we identify a single nucleotide polymorphism in the LTA4H promoter that regulates its transcriptional activity. In tuberculous meningitis, the polymorphism is associated with inflammatory cell recruitment, patient survival and response to adjunctive anti-inflammatory therapy. Together, our findings suggest that host-directed therapies tailored to patient LTA4H genotypes may counter detrimental effects of either extreme of inflammation.


Assuntos
Infecções por Mycobacterium/tratamento farmacológico , Infecções por Mycobacterium/imunologia , Tuberculose Meníngea/tratamento farmacológico , Tuberculose Meníngea/imunologia , Animais , Modelos Animais de Doenças , Humanos , Inflamação/imunologia , Leucotrieno A4/genética , Leucotrieno A4/imunologia , Leucotrieno B4/genética , Leucotrieno B4/imunologia , Lipoxinas/imunologia , Mitocôndrias/metabolismo , Infecções por Mycobacterium/genética , Mycobacterium marinum , Polimorfismo Genético , Polimorfismo de Nucleotídeo Único , Regiões Promotoras Genéticas , Transdução de Sinais , Transcrição Gênica , Tuberculose Meníngea/genética , Fator de Necrose Tumoral alfa/metabolismo , Peixe-Zebra/embriologia , Peixe-Zebra/imunologia
5.
Nature ; 590(7844): 151-156, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33442055

RESUMO

Up to 20% of people worldwide develop gastrointestinal symptoms following a meal1, leading to decreased quality of life, substantial morbidity and high medical costs. Although the interest of both the scientific and lay communities in this issue has increased markedly in recent years, with the worldwide introduction of gluten-free and other diets, the underlying mechanisms of food-induced abdominal complaints remain largely unknown. Here we show that a bacterial infection and bacterial toxins can trigger an immune response that leads to the production of dietary-antigen-specific IgE antibodies in mice, which are limited to the intestine. Following subsequent oral ingestion of the respective dietary antigen, an IgE- and mast-cell-dependent mechanism induced increased visceral pain. This aberrant pain signalling resulted from histamine receptor H1-mediated sensitization of visceral afferents. Moreover, injection of food antigens (gluten, wheat, soy and milk) into the rectosigmoid mucosa of patients with irritable bowel syndrome induced local oedema and mast cell activation. Our results identify and characterize a peripheral mechanism that underlies food-induced abdominal pain, thereby creating new possibilities for the treatment of irritable bowel syndrome and related abdominal pain disorders.


Assuntos
Dor Abdominal/imunologia , Dor Abdominal/patologia , Alérgenos/imunologia , Hipersensibilidade Alimentar/imunologia , Alimentos/efeitos adversos , Intestinos/imunologia , Síndrome do Intestino Irritável/imunologia , Dor Abdominal/etiologia , Dor Abdominal/microbiologia , Adulto , Animais , Citrobacter rodentium/imunologia , Diarreia/imunologia , Diarreia/microbiologia , Diarreia/patologia , Infecções por Enterobacteriaceae/complicações , Infecções por Enterobacteriaceae/imunologia , Infecções por Enterobacteriaceae/microbiologia , Feminino , Hipersensibilidade Alimentar/complicações , Hipersensibilidade Alimentar/microbiologia , Hipersensibilidade Alimentar/patologia , Glutens/imunologia , Humanos , Imunoglobulina E/imunologia , Mucosa Intestinal/imunologia , Mucosa Intestinal/microbiologia , Mucosa Intestinal/patologia , Intestinos/microbiologia , Intestinos/patologia , Síndrome do Intestino Irritável/etiologia , Síndrome do Intestino Irritável/microbiologia , Síndrome do Intestino Irritável/patologia , Masculino , Mastócitos/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Pessoa de Meia-Idade , Leite/imunologia , Ovalbumina/imunologia , Qualidade de Vida , Receptores Histamínicos H1/metabolismo , Proteínas de Soja/imunologia , Triticum/imunologia
6.
N Engl J Med ; 389(15): 1357-1367, 2023 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-37819954

RESUMO

BACKGROUND: Adjunctive glucocorticoids are widely used to treat human immunodeficiency virus (HIV)-associated tuberculous meningitis despite limited data supporting their safety and efficacy. METHODS: We conducted a double-blind, randomized, placebo-controlled trial involving HIV-positive adults (≥18 years of age) with tuberculous meningitis in Vietnam and Indonesia. Participants were randomly assigned to receive a 6-to-8-week tapering course of either dexamethasone or placebo in addition to 12 months of antituberculosis chemotherapy. The primary end point was death from any cause during the 12 months after randomization. RESULTS: A total of 520 adults were randomly assigned to receive either dexamethasone (263 participants) or placebo (257 participants). The median age was 36 years; 255 of 520 participants (49.0%) had never received antiretroviral therapy, and 251 of 484 participants (51.9%) with available data had a baseline CD4 count of 50 cells per cubic millimeter or less. Six participants withdrew from the trial, and five were lost to follow-up. During the 12 months of follow-up, death occurred in 116 of 263 participants (44.1%) in the dexamethasone group and in 126 of 257 participants (49.0%) in the placebo group (hazard ratio, 0.85; 95% confidence interval, 0.66 to 1.10; P = 0.22). Prespecified analyses did not reveal a subgroup that clearly benefited from dexamethasone. The incidence of secondary end-point events, including cases of immune reconstitution inflammatory syndrome during the first 6 months, was similar in the two trial groups. The numbers of participants with at least one serious adverse event were similar in the dexamethasone group (192 of 263 participants [73.0%]) and the placebo group (194 of 257 participants [75.5%]) (P = 0.52). CONCLUSIONS: Among HIV-positive adults with tuberculous meningitis, adjunctive dexamethasone, as compared with placebo, did not confer a benefit with respect to survival or any secondary end point. (Funded by the Wellcome Trust; ACT HIV ClinicalTrials.gov number, NCT03092817.).


Assuntos
Antirretrovirais , Antituberculosos , Dexametasona , Glucocorticoides , Infecções por HIV , Tuberculose Meníngea , Adulto , Humanos , Dexametasona/efeitos adversos , Dexametasona/uso terapêutico , Método Duplo-Cego , Glucocorticoides/efeitos adversos , Glucocorticoides/uso terapêutico , HIV , Infecções por HIV/complicações , Infecções por HIV/tratamento farmacológico , Soropositividade para HIV/complicações , Soropositividade para HIV/tratamento farmacológico , Tuberculose Meníngea/complicações , Tuberculose Meníngea/tratamento farmacológico , Antituberculosos/efeitos adversos , Antituberculosos/uso terapêutico , Quimioterapia Combinada/efeitos adversos , Antirretrovirais/efeitos adversos , Antirretrovirais/uso terapêutico
7.
Nature ; 575(7783): 535-539, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31723268

RESUMO

The cytochrome b6 f (cytb6 f ) complex has a central role in oxygenic photosynthesis, linking electron transfer between photosystems I and II and converting solar energy into a transmembrane proton gradient for ATP synthesis1-3. Electron transfer within cytb6 f occurs via the quinol (Q) cycle, which catalyses the oxidation of plastoquinol (PQH2) and the reduction of both plastocyanin (PC) and plastoquinone (PQ) at two separate sites via electron bifurcation2. In higher plants, cytb6 f also acts as a redox-sensing hub, pivotal to the regulation of light harvesting and cyclic electron transfer that protect against metabolic and environmental stresses3. Here we present a 3.6 Å resolution cryo-electron microscopy (cryo-EM) structure of the dimeric cytb6 f complex from spinach, which reveals the structural basis for operation of the Q cycle and its redox-sensing function. The complex contains up to three natively bound PQ molecules. The first, PQ1, is located in one cytb6 f monomer near the PQ oxidation site (Qp) adjacent to haem bp and chlorophyll a. Two conformations of the chlorophyll a phytyl tail were resolved, one that prevents access to the Qp site and another that permits it, supporting a gating function for the chlorophyll a involved in redox sensing. PQ2 straddles the intermonomer cavity, partially obstructing the PQ reduction site (Qn) on the PQ1 side and committing the electron transfer network to turnover at the occupied Qn site in the neighbouring monomer. A conformational switch involving the haem cn propionate promotes two-electron, two-proton reduction at the Qn site and avoids formation of the reactive intermediate semiquinone. The location of a tentatively assigned third PQ molecule is consistent with a transition between the Qp and Qn sites in opposite monomers during the Q cycle. The spinach cytb6 f structure therefore provides new insights into how the complex fulfils its catalytic and regulatory roles in photosynthesis.


Assuntos
Microscopia Crioeletrônica , Complexo Citocromos b6f/química , Complexo Citocromos b6f/ultraestrutura , Spinacia oleracea/química , Spinacia oleracea/ultraestrutura , Sítios de Ligação , Clorofila/química , Heme/química , Lipídeos/química , Modelos Moleculares , Oxirredução , Fotossíntese , Plastoquinona/química , Relação Estrutura-Atividade
8.
Clin Infect Dis ; 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38916975

RESUMO

BACKGROUND: Staphylococcus aureus bacteraemia (SAB) is a clinically heterogeneous disease. The ability to identify sub-groups of patients with shared traits (sub-phenotypes) is an unmet need that could allow patient stratification for clinical management and research. We aimed to test the hypothesis that clinically-relevant sub-phenotypes can be reproducibly identified amongst patients with SAB. METHODS: We studied three cohorts of hospitalised adults with monomicrobial SAB: a UK retrospective observational study (Edinburgh cohort, n=458), the UK ARREST randomised trial (n=758), and the Spanish SAFO randomised trial (n=214). Latent class analysis was used to identify sub-phenotypes using routinely-collected clinical data, without considering outcomes. Mortality and microbiologic outcomes were then compared between sub-phenotypes. RESULTS: Included patients had predominantly methicillin-susceptible SAB (1366/1430,95.5%). We identified five distinct, reproducible clinical sub-phenotypes: (A) SAB associated with older age and comorbidity, (B) nosocomial intravenous catheter-associated SAB in younger people without comorbidity, (C) community-acquired metastatic SAB, (D) SAB associated with chronic kidney disease, and (E) SAB associated with injection drug use. Survival and microbiologic outcomes differed between the sub-phenotypes. 84-day mortality was highest in sub-phenotype A, and lowest in B and E. Microbiologic outcomes were worse in sub-phenotype C. In a secondary analysis of the ARREST trial, adjunctive rifampicin was associated with increased 84-day mortality in sub-phenotype B and improved microbiologic outcomes in sub-phenotype C. CONCLUSIONS: We have identified reproducible and clinically-relevant sub-phenotypes within SAB, and provide proof-of-principle of differential treatment effects. Through clinical trial enrichment and patient stratification, these sub-phenotypes could contribute to a personalised medicine approach to SAB.

9.
J Am Chem Soc ; 2024 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-38991108

RESUMO

Small, diffusible redox proteins play an essential role in electron transfer (ET) in respiration and photosynthesis, sustaining life on Earth by shuttling electrons between membrane-bound complexes via finely tuned and reversible interactions. Ensemble kinetic studies show transient ET complexes form in two distinct stages: an "encounter" complex largely mediated by electrostatic interactions, which subsequently, through subtle reorganization of the binding interface, forms a "productive" ET complex stabilized by additional hydrophobic interactions around the redox-active cofactors. Here, using single-molecule force spectroscopy (SMFS) we dissected the transient ET complexes formed between the photosynthetic reaction center-light harvesting complex 1 (RC-LH1) of Rhodobacter sphaeroides and its native electron donor cytochrome c2 (cyt c2). Importantly, SMFS resolves the distribution of interaction forces into low (∼150 pN) and high (∼330 pN) components, with the former more susceptible to salt concentration and to alteration of key charged residues on the RC. Thus, the low force component is suggested to reflect the contribution of electrostatic interactions in forming the initial encounter complex, whereas the high force component reflects the additional stabilization provided by hydrophobic interactions to the productive ET complex. Employing molecular dynamics simulations, we resolve five intermediate states that comprise the encounter, productive ET and leaving complexes, predicting a weak interaction between cyt c2 and the LH1 ring near the RC-L subunit that could lie along the exit path for oxidized cyt c2. The multimodal nature of the interactions of ET complexes captured here may have wider implications for ET in all domains of life.

10.
Emerg Infect Dis ; 30(3): 499-509, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38407176

RESUMO

We characterized the spatial distribution of drug-susceptible (DS) and multidrug-resistant (MDR) tuberculosis (TB) cases in Ho Chi Minh City, Vietnam, a major metropolis in southeastern Asia, and explored demographic and socioeconomic factors associated with local TB burden. Hot spots of DS and MDR TB incidence were observed in the central parts of Ho Chi Minh City, and substantial heterogeneity was observed across wards. Positive spatial autocorrelation was observed for both DS TB and MDR TB. Ward-level TB incidence was associated with HIV prevalence and the male proportion of the population. No ward-level demographic and socioeconomic indicators were associated with MDR TB case count relative to total TB case count. Our findings might inform spatially targeted TB control strategies and provide insights for generating hypotheses about the nature of the relationship between DS and MDR TB in Ho Chi Minh City and the wider southeastern region of Asia.


Assuntos
Tuberculose Resistente a Múltiplos Medicamentos , Tuberculose , Masculino , Humanos , Vietnã/epidemiologia , Tuberculose Resistente a Múltiplos Medicamentos/epidemiologia , Ásia , Análise Espacial
11.
J Clin Microbiol ; 62(4): e0128723, 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38466092

RESUMO

Mortality from tuberculous meningitis (TBM) remains around 30%, with most deaths occurring within 2 months of starting treatment. Mortality from drug-resistant strains is higher still, making early detection of drug resistance (DR) essential. Targeted next-generation sequencing (tNGS) produces high read depths, allowing the detection of DR-associated alleles with low frequencies. We applied Deeplex Myc-TB-a tNGS assay-to cerebrospinal fluid (CSF) samples from 72 adults with microbiologically confirmed TBM and compared its genomic drug susceptibility predictions to a composite reference standard of phenotypic susceptibility testing (pDST) and whole genome sequencing, as well as to clinical outcomes. Deeplex detected Mycobacterium tuberculosis complex DNA in 24/72 (33.3%) CSF samples and generated full DR reports for 22/24 (91.7%). The read depth generated by Deeplex correlated with semi-quantitative results from MTB/RIF Xpert. Alleles with <20% frequency were seen at canonical loci associated with first-line DR. Disregarding these low-frequency alleles, Deeplex had 100% concordance with the composite reference standard for all drugs except pyrazinamide and streptomycin. Three patients had positive CSF cultures after 30 days of treatment; reference tests and Deeplex identified isoniazid resistance in two, and Deeplex alone identified low-frequency rifampin resistance alleles in one. Five patients died, of whom one had pDST-identified pyrazinamide resistance. tNGS on CSF can rapidly and accurately detect drug-resistant TBM, but its application is limited to those with higher bacterial loads. In those with lower bacterial burdens, alternative approaches need to be developed for both diagnosis and resistance detection.


Assuntos
Mycobacterium tuberculosis , Tuberculose Meníngea , Tuberculose Resistente a Múltiplos Medicamentos , Adulto , Humanos , Tuberculose Meníngea/diagnóstico , Tuberculose Meníngea/tratamento farmacológico , Tuberculose Meníngea/líquido cefalorraquidiano , Mycobacterium tuberculosis/genética , Pirazinamida , Sensibilidade e Especificidade , Rifampina/farmacologia , Rifampina/uso terapêutico , Tuberculose Resistente a Múltiplos Medicamentos/microbiologia , Líquido Cefalorraquidiano , Testes de Sensibilidade Microbiana
12.
BMC Infect Dis ; 24(1): 163, 2024 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-38321395

RESUMO

BACKGROUND: Diagnosis of tuberculous meningitis (TBM) is hampered by the lack of a gold standard. Current microbiological tests lack sensitivity and clinical diagnostic approaches are subjective. We therefore built a diagnostic model that can be used before microbiological test results are known. METHODS: We included 659 individuals aged [Formula: see text] years with suspected brain infections from a prospective observational study conducted in Vietnam. We fitted a logistic regression diagnostic model for TBM status, with unknown values estimated via a latent class model on three mycobacterial tests: Ziehl-Neelsen smear, Mycobacterial culture, and GeneXpert. We additionally re-evaluated mycobacterial test performance, estimated individual mycobacillary burden, and quantified the reduction in TBM risk after confirmatory tests were negative. We also fitted a simplified model and developed a scoring table for early screening. All models were compared and validated internally. RESULTS: Participants with HIV, miliary TB, long symptom duration, and high cerebrospinal fluid (CSF) lymphocyte count were more likely to have TBM. HIV and higher CSF protein were associated with higher mycobacillary burden. In the simplified model, HIV infection, clinical symptoms with long duration, and clinical or radiological evidence of extra-neural TB were associated with TBM At the cutpoints based on Youden's Index, the sensitivity and specificity in diagnosing TBM for our full and simplified models were 86.0% and 79.0%, and 88.0% and 75.0% respectively. CONCLUSION: Our diagnostic model shows reliable performance and can be developed as a decision assistant for clinicians to detect patients at high risk of TBM. Diagnosis of tuberculous meningitis is hampered by the lack of gold standard. We developed a diagnostic model using latent class analysis, combining confirmatory test results and risk factors. Models were accurate, well-calibrated, and can support both clinical practice and research.


Assuntos
Infecções por HIV , Mycobacterium tuberculosis , Tuberculose Meníngea , Humanos , Idoso , Tuberculose Meníngea/diagnóstico , Análise de Classes Latentes , Teorema de Bayes , Sensibilidade e Especificidade , Convulsões
13.
J Immunol ; 208(6): 1352-1361, 2022 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-35217585

RESUMO

The major human genes regulating Mycobacterium tuberculosis-induced immune responses and tuberculosis (TB) susceptibility are poorly understood. Although IL-12 and IL-10 are critical for TB pathogenesis, the genetic factors that regulate their expression in humans are unknown. CNBP, REL, and BHLHE40 are master regulators of IL-12 and IL-10 signaling. We hypothesized that common variants in CNBP, REL, and BHLHE40 were associated with IL-12 and IL-10 production from dendritic cells, and that these variants also influence adaptive immune responses to bacillus Calmette-Guérin (BCG) vaccination and TB susceptibility. We characterized the association between common variants in CNBP, REL, and BHLHE40, innate immune responses in dendritic cells and monocyte-derived macrophages, BCG-specific T cell responses, and susceptibility to pediatric and adult TB in human populations. BHLHE40 single-nucleotide polymorphism (SNP) rs4496464 was associated with increased BHLHE40 expression in monocyte-derived macrophages and increased IL-10 from peripheral blood dendritic cells and monocyte-derived macrophages after LPS and TB whole-cell lysate stimulation. SNP BHLHE40 rs11130215, in linkage disequilibrium with rs4496464, was associated with increased BCG-specific IL-2+CD4+ T cell responses and decreased risk for pediatric TB in South Africa. SNPs REL rs842634 and rs842618 were associated with increased IL-12 production from dendritic cells, and SNP REL rs842618 was associated with increased risk for TB meningitis. In summary, we found that genetic variations in REL and BHLHE40 are associated with IL-12 and IL-10 cytokine responses and TB clinical outcomes. Common human genetic regulation of well-defined intermediate cellular traits provides insights into mechanisms of TB pathogenesis.


Assuntos
Mycobacterium bovis , Mycobacterium tuberculosis , Proteínas Proto-Oncogênicas c-rel/genética , Tuberculose , Adulto , Vacina BCG , Fatores de Transcrição Hélice-Alça-Hélice Básicos , Criança , Proteínas de Homeodomínio , Humanos , Interleucina-10/genética , Interleucina-12/genética , Tuberculose/genética
14.
J Immunol ; 208(1): 169-180, 2022 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-34853077

RESUMO

Adoptive T cell therapy with T cells expressing affinity-enhanced TCRs has shown promising results in phase 1/2 clinical trials for solid and hematological tumors. However, depth and durability of responses to adoptive T cell therapy can suffer from an inhibitory tumor microenvironment. A common immune-suppressive agent is TGF-ß, which is secreted by tumor cells and cells recruited to the tumor. We investigated whether human T cells could be engineered to be resistant to inhibition by TGF-ß. Truncating the intracellular signaling domain from TGF-ß receptor (TGFßR) II produces a dominant-negative receptor (dnTGFßRII) that dimerizes with endogenous TGFßRI to form a receptor that can bind TGF-ß but cannot signal. We previously generated specific peptide enhanced affinity receptor TCRs recognizing the HLA-A*02-restricted peptides New York esophageal squamous cell carcinoma 1 (NY-ESO-1)157-165/l-Ag family member-1A (TCR: GSK3377794, formerly NY-ESO-1c259) and melanoma Ag gene A10254-262 (TCR: ADP-A2M10, formerly melanoma Ag gene A10c796). In this article, we show that exogenous TGF-ß inhibited in vitro proliferation and effector functions of human T cells expressing these first-generation high-affinity TCRs, whereas inhibition was reduced or abolished in the case of second-generation TCRs coexpressed with dnTGFßRII (e.g., GSK3845097). TGF-ß isoforms and a panel of TGF-ß-associated genes are overexpressed in a range of cancer indications in which NY-ESO-1 is commonly expressed, particularly in synovial sarcoma. As an example, immunohistochemistry/RNAscope identified TGF-ß-positive cells close to T cells in tumor nests and stroma, which had low frequencies of cells expressing IFN-γ in a non-small cell lung cancer setting. Coexpression of dnTGFßRII may therefore improve the efficacy of TCR-transduced T cells.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Carcinoma de Células Escamosas/terapia , Neoplasias Hematológicas/terapia , Imunoterapia Adotiva/métodos , Melanoma/terapia , Receptor do Fator de Crescimento Transformador beta Tipo II/metabolismo , Receptores de Antígenos de Linfócitos T/metabolismo , Receptores de Antígenos Quiméricos/metabolismo , Sarcoma Sinovial/terapia , Fator de Crescimento Transformador beta/metabolismo , Antígenos de Neoplasias/imunologia , Carcinoma de Células Escamosas/imunologia , Linhagem Celular Tumoral , Engenharia Genética , Antígeno HLA-A2/metabolismo , Neoplasias Hematológicas/imunologia , Humanos , Tolerância Imunológica , Melanoma/imunologia , Proteínas de Membrana/imunologia , Proteínas de Neoplasias/imunologia , Fragmentos de Peptídeos/imunologia , Receptor do Fator de Crescimento Transformador beta Tipo II/genética , Receptores de Antígenos de Linfócitos T/genética , Receptores de Antígenos Quiméricos/genética , Sarcoma Sinovial/imunologia , Especificidade do Receptor de Antígeno de Linfócitos T , Microambiente Tumoral
15.
Proc Natl Acad Sci U S A ; 118(10)2021 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-33658385

RESUMO

Adjunctive treatment with antiinflammatory corticosteroids like dexamethasone increases survival in tuberculosis meningitis. Dexamethasone responsiveness associates with a C/T variant in Leukotriene A4 Hydrolase (LTA4H), which regulates expression of the proinflammatory mediator leukotriene B4 (LTB4). TT homozygotes, with increased expression of LTA4H, have the highest survival when treated with dexamethasone and the lowest survival without. While the T allele is present in only a minority of the world's population, corticosteroids confer modest survival benefit worldwide. Using Bayesian methods, we examined how pretreatment levels of cerebrospinal fluid proinflammatory cytokines affect survival in dexamethasone-treated tuberculous meningitis. LTA4H TT homozygosity was associated with global cytokine increases, including tumor necrosis factor. Association between higher cytokine levels and survival extended to non-TT patients, suggesting that other genetic variants may also induce dexamethasone-responsive pathological inflammation. These findings warrant studies that tailor dexamethasone therapy to pretreatment cerebrospinal fluid cytokine concentrations, while searching for additional genetic loci shaping the inflammatory milieu.


Assuntos
Citocinas/líquido cefalorraquidiano , Dexametasona/administração & dosagem , Epóxido Hidrolases/genética , Variação Genética , Tuberculose Meníngea , Intervalo Livre de Doença , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Taxa de Sobrevida , Tuberculose Meníngea/líquido cefalorraquidiano , Tuberculose Meníngea/tratamento farmacológico , Tuberculose Meníngea/genética , Tuberculose Meníngea/mortalidade
16.
J Infect Dis ; 228(3): 343-352, 2023 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-36823694

RESUMO

BACKGROUND: The purpose of this study was to assess if single nucleotide polymorphisms (SNPs) in lung mucins MUC5B and MUC5AC are associated with Mycobacterium tuberculosis outcomes. METHODS: Independent SNPs in MUC5B and MUC5AC (genotyped by Illumina HumanOmniExpress array) were assessed for associations with tumor necrosis factor (TNF) concentrations (measured by immunoassay) in cerebral spinal fluid (CSF) from tuberculous meningitis (TBM) patients. SNPs associated with CSF TNF concentrations were carried forward for analyses of pulmonary and meningeal tuberculosis susceptibility and TBM mortality. RESULTS: MUC5AC SNP rs28737416 T allele was associated with lower CSF concentrations of TNF (P = 1.8 × 10-8) and IFN-γ (P = 2.3 × 10-6). In an additive genetic model, rs28737416 T/T genotype was associated with higher susceptibility to TBM (odds ratio [OR], 1.24; 95% confidence interval [CI], 1.03-1.49; P = .02), but not pulmonary tuberculosis (OR, 1.11, 95% CI, .98-1.25; P = .10). TBM mortality was higher among participants with the rs28737416 T/T and T/C genotypes (35/119, 30.4%) versus the C/C genotype (11/89, 12.4%; log-rank P = .005) in a Vietnam discovery cohort (n = 210), an independent Vietnam validation cohort (n = 87; 9/87, 19.1% vs 1/20, 2.5%; log-rank P = .02), and an Indonesia validation cohort (n = 468, 127/287, 44.3% vs 65/181, 35.9%; log-rank P = .06). CONCLUSIONS: MUC5AC variants may contribute to immune changes that influence TBM outcomes.


Assuntos
Mycobacterium tuberculosis , Tuberculose Meníngea , Humanos , Tuberculose Meníngea/genética , Tuberculose Meníngea/complicações , Citocinas/genética , Genótipo , Fator de Necrose Tumoral alfa/genética , Polimorfismo de Nucleotídeo Único , Mucina-5AC/genética
17.
J Clin Microbiol ; 61(4): e0163422, 2023 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-37010411

RESUMO

Offering patients with tuberculosis (TB) an optimal and timely treatment regimen depends on the rapid detection of Mycobacterium tuberculosis (Mtb) drug resistance from clinical samples. Finding Low Abundance Sequences by Hybridization (FLASH) is a technique that harnesses the efficiency, specificity, and flexibility of the Cas9 enzyme to enrich targeted sequences. Here, we used FLASH to amplify 52 candidate genes probably associated with resistance to first- and second-line drugs in the Mtb reference strain (H37Rv), then detect drug resistance mutations in cultured Mtb isolates, and in sputum samples. 92% of H37Rv reads mapped to Mtb targets, with 97.8% of target regions covered at a depth ≥ 10X. Among cultured isolates, FLASH-TB detected the same 17 drug resistance mutations as whole genome sequencing (WGS) did, but with much greater depth. Among the 16 sputum samples, FLASH-TB increased recovery of Mtb DNA compared with WGS (from 1.4% [IQR 0.5-7.5] to 33% [IQR 4.6-66.3]) and average depth reads of targets (from 6.3 [IQR 3.8-10.5] to 1991 [IQR 254.4-3623.7]). FLASH-TB identified Mtb complex in all 16 samples based on IS1081 and IS6110 copies. Drug resistance predictions for 15/16 (93.7%) clinical samples were highly concordant with phenotypic DST for isoniazid, rifampicin, amikacin, and kanamycin [15/15 (100%)], ethambutol [12/15 (80%)] and moxifloxacin [14/15 (93.3%)]. These results highlighted the potential of FLASH-TB for detecting Mtb drug resistance from sputum samples.


Assuntos
Mycobacterium tuberculosis , Tuberculose Resistente a Múltiplos Medicamentos , Tuberculose , Humanos , Antituberculosos/farmacologia , Antituberculosos/uso terapêutico , Escarro/microbiologia , Tuberculose Resistente a Múltiplos Medicamentos/microbiologia , Tuberculose/tratamento farmacológico , Mycobacterium tuberculosis/genética , Testes de Sensibilidade Microbiana
18.
Stat Med ; 42(8): 1156-1170, 2023 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-36732886

RESUMO

In some clinical scenarios, for example, severe sepsis caused by extensively drug resistant bacteria, there is uncertainty between many common treatments, but a conventional multiarm randomized trial is not possible because individual participants may not be eligible to receive certain treatments. The Personalised Randomized Controlled Trial design allows each participant to be randomized between a "personalised randomization list" of treatments that are suitable for them. The primary aim is to produce treatment rankings that can guide choice of treatment, rather than focusing on the estimates of relative treatment effects. Here we use simulation to assess several novel analysis approaches for this innovative trial design. One of the approaches is like a network meta-analysis, where participants with the same personalised randomization list are like a trial, and both direct and indirect evidence are used. We evaluate this proposed analysis and compare it with analyses making less use of indirect evidence. We also propose new performance measures including the expected improvement in outcome if the trial's rankings are used to inform future treatment rather than random choice. We conclude that analysis of a personalized randomized controlled trial can be performed by pooling data from different types of participants and is robust to moderate subgroup-by-intervention interactions based on the parameters of our simulation. The proposed approach performs well with respect to estimation bias and coverage. It provides an overall treatment ranking list with reasonable precision, and is likely to improve outcome on average if used to determine intervention policies and guide individual clinical decisions.


Assuntos
Ensaios Clínicos Controlados Aleatórios como Assunto , Projetos de Pesquisa , Humanos , Medicina de Precisão , Participação do Paciente
19.
Health Promot Int ; 38(3)2023 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-35362520

RESUMO

With an increasing number of children attending regular early childhood education and care (ECEC), this setting presents an opportunity to develop physical activity habits and movement skills of children. These behaviours play an important role in the development and well-being of children. In 2017, an Active Play Standard was introduced in British Columbia, Canada, to mandate practices related to physical activity, screen time and movement skill development in licensed ECEC. A capacity-building initiative including training and online resources was released alongside these guidelines to support implementation. The purpose of this study was to qualitatively examine the barriers and facilitators ECEC practitioners faced in implementing the standard, and to explore the role of the capacity-building initiative. Data were collected via semi-structured telephone interviews with educators (n = 23). Data were coded using thematic analysis and sorted into three major themes influencing provision of physical activity opportunities: attributes and impact of the Active Play standard and capacity-building workshop, characteristics of providers and characteristics of ECEC settings. Future studies should consider targeting factors including organizational culture and climate, and provider capacity to provide physical activity and fundamental movement skill programming, and support for facility level policies and collaborative planning processes that create a positive physical activity culture.


Assuntos
Cuidado da Criança , Creches , Criança , Pré-Escolar , Humanos , Colúmbia Britânica , Exercício Físico , Saúde da Criança
20.
J Infect Dis ; 225(9): 1653-1662, 2022 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-33104201

RESUMO

BACKGROUND: Helminth infections may modulate the inflammatory response to Mycobacterium tuberculosis and influence disease presentation and outcome. Strongyloides stercoralis is common among populations with high tuberculosis prevalence. Our aim was to determine whether S. stercoralis coinfection influenced clinical presentation, cerebrospinal fluid (CSF) inflammation, and outcome from tuberculous meningitis (TBM). METHODS: From June 2017 to December 2019, 668 Vietnamese adults with TBM, enrolled in the ACT HIV or LAST ACT trials (NCT03092817 and NCT03100786), underwent pretreatment S. stercoralis testing by serology, stool microscopy, and/or stool polymerase chain reaction. Comparisons of pretreatment TBM severity, CSF inflammation (including cytokines), and 3-month clinical end points were performed in groups with or without active S. stercoralis infection. RESULTS: Overall, 9.4% participants (63 of 668) tested positive for S. stercoralis. Active S. stercoralis infection was significantly associated with reduced pretreatment CSF neutrophil counts (median [interquartile range], 3/µL [0-25/µL] vs 14 /µL [1-83/µL]; P = .04), and with reduced CSF interferon É£, interleukin 2, and tumor necrosis factor α concentrations (11.4 vs 56.0 pg/mL [P = .01], 33.1 vs 54.5 pg/mL [P = .03], and 4.5 vs 11.9 pg/mL [P = .02], respectively), compared with uninfected participants. Neurological complications by 3 months were significantly reduced in participants with active S. stercoralis infection compared with uninfected participants (3.8% [1 of 26] vs 30.0% [33 of 110], respectively; P = .01). CONCLUSIONS: S. stercoralis coinfection may modulate the intracerebral inflammatory response to M. tuberculosis and improve TBM clinical outcomes.


Assuntos
Coinfecção , Mycobacterium tuberculosis , Strongyloides stercoralis , Tuberculose Meníngea , Adulto , Animais , Coinfecção/complicações , Humanos , Inflamação/complicações , Tuberculose Meníngea/complicações
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA