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1.
Cell ; 177(2): 315-325.e14, 2019 04 04.
Artigo em Inglês | MEDLINE | ID: mdl-30929905

RESUMO

Transmission of malaria parasites occurs when a female Anopheles mosquito feeds on an infected host to acquire nutrients for egg development. How parasites are affected by oogenetic processes, principally orchestrated by the steroid hormone 20-hydroxyecdysone (20E), remains largely unknown. Here we show that Plasmodium falciparum development is intimately but not competitively linked to processes shaping Anopheles gambiae reproduction. We unveil a 20E-mediated positive correlation between egg and oocyst numbers; impairing oogenesis by multiple 20E manipulations decreases parasite intensities. These manipulations, however, accelerate Plasmodium growth rates, allowing sporozoites to become infectious sooner. Parasites exploit mosquito lipids for faster growth, but they do so without further affecting egg development. These results suggest that P. falciparum has adopted a non-competitive evolutionary strategy of resource exploitation to optimize transmission while minimizing fitness costs to its mosquito vector. Our findings have profound implications for currently proposed control strategies aimed at suppressing mosquito populations.


Assuntos
Ecdisterona/metabolismo , Interações Hospedeiro-Parasita/fisiologia , Malária Falciparum/parasitologia , Animais , Anopheles/parasitologia , Culicidae , Ecdisterona/fisiologia , Feminino , Células HEK293 , Humanos , Insetos Vetores , Malária/parasitologia , Camundongos , Mosquitos Vetores , Células NIH 3T3 , Oogênese/fisiologia , Plasmodium/metabolismo , Plasmodium falciparum , Esporozoítos , Esteroides/metabolismo
2.
Cell ; 150(4): 842-54, 2012 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-22901813

RESUMO

Due to genome instability, most cancers exhibit loss of regions containing tumor suppressor genes and collateral loss of other genes. To identify cancer-specific vulnerabilities that are the result of copy number losses, we performed integrated analyses of genome-wide copy number and RNAi profiles and identified 56 genes for which gene suppression specifically inhibited the proliferation of cells harboring partial copy number loss of that gene. These CYCLOPS (copy number alterations yielding cancer liabilities owing to partial loss) genes are enriched for spliceosome, proteasome, and ribosome components. One CYCLOPS gene, PSMC2, encodes an essential member of the 19S proteasome. Normal cells express excess PSMC2, which resides in a complex with PSMC1, PSMD2, and PSMD5 and acts as a reservoir protecting cells from PSMC2 suppression. Cells harboring partial PSMC2 copy number loss lack this complex and die after PSMC2 suppression. These observations define a distinct class of cancer-specific liabilities resulting from genome instability.


Assuntos
Genes Essenciais , Instabilidade Genômica , Neoplasias/genética , ATPases Associadas a Diversas Atividades Celulares , Animais , Linhagem Celular Tumoral , Deleção Cromossômica , Dosagem de Genes , Genes Supressores de Tumor , Humanos , Camundongos , Camundongos Nus , Transplante de Neoplasias , Neoplasias/metabolismo , Complexo de Endopeptidases do Proteassoma/genética , Complexo de Endopeptidases do Proteassoma/metabolismo , Transplante Heterólogo
3.
Nature ; 595(7866): 289-294, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34194041

RESUMO

The global decline in malaria has stalled1, emphasizing the need for vaccines that induce durable sterilizing immunity. Here we optimized regimens for chemoprophylaxis vaccination (CVac), for which aseptic, purified, cryopreserved, infectious Plasmodium falciparum sporozoites (PfSPZ) were inoculated under prophylactic cover with pyrimethamine (PYR) (Sanaria PfSPZ-CVac(PYR)) or chloroquine (CQ) (PfSPZ-CVac(CQ))-which kill liver-stage and blood-stage parasites, respectively-and we assessed vaccine efficacy against homologous (that is, the same strain as the vaccine) and heterologous (a different strain) controlled human malaria infection (CHMI) three months after immunization ( https://clinicaltrials.gov/ , NCT02511054 and NCT03083847). We report that a fourfold increase in the dose of PfSPZ-CVac(PYR) from 5.12 × 104 to 2 × 105 PfSPZs transformed a minimal vaccine efficacy (low dose, two out of nine (22.2%) participants protected against homologous CHMI), to a high-level vaccine efficacy with seven out of eight (87.5%) individuals protected against homologous and seven out of nine (77.8%) protected against heterologous CHMI. Increased protection was associated with Vδ2 γδ T cell and antibody responses. At the higher dose, PfSPZ-CVac(CQ) protected six out of six (100%) participants against heterologous CHMI three months after immunization. All homologous (four out of four) and heterologous (eight out of eight) infectivity control participants showed parasitaemia. PfSPZ-CVac(CQ) and PfSPZ-CVac(PYR) induced a durable, sterile vaccine efficacy against a heterologous South American strain of P. falciparum, which has a genome and predicted CD8 T cell immunome that differs more strongly from the African vaccine strain than other analysed African P. falciparum strains.


Assuntos
Anticorpos Neutralizantes/imunologia , Fígado/imunologia , Fígado/parasitologia , Vacinas Antimaláricas/imunologia , Plasmodium falciparum/efeitos dos fármacos , Plasmodium falciparum/imunologia , Vacinas Atenuadas/imunologia , Adulto , Animais , Formação de Anticorpos/imunologia , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Estágios do Ciclo de Vida/imunologia , Malária/sangue , Malária/imunologia , Malária/parasitologia , Malária/prevenção & controle , Vacinas Antimaláricas/administração & dosagem , Vacinas Antimaláricas/efeitos adversos , Vacinas Antimaláricas/química , Masculino , Pessoa de Meia-Idade , Plasmodium falciparum/crescimento & desenvolvimento , Linfócitos T/citologia , Linfócitos T/imunologia , Linfócitos T/metabolismo , Fatores de Tempo , Vacinação/efeitos adversos , Vacinas Atenuadas/administração & dosagem , Vacinas Atenuadas/efeitos adversos , Vacinas Atenuadas/química
4.
Proc Natl Acad Sci U S A ; 121(11): e2307802121, 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38437557

RESUMO

RNA interference (RNAi) therapeutics are an emerging class of medicines that selectively target mRNA transcripts to silence protein production and combat disease. Despite the recent progress, a generalizable approach for monitoring the efficacy of RNAi therapeutics without invasive biopsy remains a challenge. Here, we describe the development of a self-reporting, theranostic nanoparticle that delivers siRNA to silence a protein that drives cancer progression while also monitoring the functional activity of its downstream targets. Our therapeutic target is the transcription factor SMARCE1, which was previously identified as a key driver of invasion in early-stage breast cancer. Using a doxycycline-inducible shRNA knockdown in OVCAR8 ovarian cancer cells both in vitro and in vivo, we demonstrate that SMARCE1 is a master regulator of genes encoding proinvasive proteases in a model of human ovarian cancer. We additionally map the peptide cleavage profiles of SMARCE1-regulated proteases so as to design a readout for downstream enzymatic activity. To demonstrate the therapeutic and diagnostic potential of our approach, we engineered self-assembled layer-by-layer nanoparticles that can encapsulate nucleic acid cargo and be decorated with peptide substrates that release a urinary reporter upon exposure to SMARCE1-related proteases. In an orthotopic ovarian cancer xenograft model, theranostic nanoparticles were able to knockdown SMARCE1 which was in turn reported through a reduction in protease-activated urinary reporters. These LBL nanoparticles both silence gene products by delivering siRNA and noninvasively report on downstream target activity by delivering synthetic biomarkers to sites of disease, enabling dose-finding studies as well as longitudinal assessments of efficacy.


Assuntos
Neoplasias Ovarianas , Peptídeos , Humanos , Feminino , Interferência de RNA , Peptídeos/genética , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/terapia , Peptídeo Hidrolases , RNA Interferente Pequeno/genética , Endopeptidases , Proteínas Cromossômicas não Histona , Proteínas de Ligação a DNA
5.
Annu Rev Cell Dev Biol ; 28: 385-410, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23057744

RESUMO

Efforts in the interdisciplinary field of bioengineering have led to innovative methods for investigating the complexities of cell responses in vitro. These approaches have emphasized the reduction of complex multicomponent cellular microenvironments into distinct individual signals as a means to both (a) better construct mimics of in vivo microenvironments and (b) better deconstruct microenvironments to study them. Microtechnology tools, together with advances in biomaterials, have been fundamental to this progress by enabling the tightly controlled presentation of environmental cues and the improved systematic analysis of cellular perturbations. In this review, we describe bioengineering approaches for controlling and measuring cell-environmental interactions in vitro, including strategies for high-throughput analysis. We also describe the mechanistic insights gained by the use of these novel tools, with associated applications ranging from fundamental biological studies, in vitro modeling of in vivo processes, and cell-based therapies.


Assuntos
Técnicas de Cultura de Células , Engenharia Celular/métodos , Fenômenos Biomecânicos , Materiais Biomiméticos , Reatores Biológicos , Adesão Celular , Humanos , Técnicas Analíticas Microfluídicas , Análise Serial de Tecidos/métodos
6.
Proc Natl Acad Sci U S A ; 119(25): e2121778119, 2022 06 21.
Artigo em Inglês | MEDLINE | ID: mdl-35696579

RESUMO

Community-acquired pneumonia (CAP) has been brought to the forefront of global health priorities due to the COVID-19 pandemic. However, classification of viral versus bacterial pneumonia etiology remains a significant clinical challenge. To this end, we have engineered a panel of activity-based nanosensors that detect the dysregulated activity of pulmonary host proteases implicated in the response to pneumonia-causing pathogens and produce a urinary readout of disease. The nanosensor targets were selected based on a human protease transcriptomic signature for pneumonia etiology generated from 33 unique publicly available study cohorts. Five mouse models of bacterial or viral CAP were developed to assess the ability of the nanosensors to produce etiology-specific urinary signatures. Machine learning algorithms were used to train diagnostic classifiers that could distinguish infected mice from healthy controls and differentiate those with bacterial versus viral pneumonia with high accuracy. This proof-of-concept diagnostic approach demonstrates a way to distinguish pneumonia etiology based solely on the host proteolytic response to infection.


Assuntos
COVID-19 , Infecções Comunitárias Adquiridas , Perfilação da Expressão Gênica , Peptídeo Hidrolases , Pneumonia Bacteriana , Animais , Técnicas Biossensoriais , COVID-19/genética , Infecções Comunitárias Adquiridas/classificação , Infecções Comunitárias Adquiridas/genética , Infecções Comunitárias Adquiridas/virologia , Modelos Animais de Doenças , Humanos , Aprendizado de Máquina , Camundongos , Nanopartículas , Peptídeo Hidrolases/genética , Pneumonia Bacteriana/classificação , Pneumonia Bacteriana/genética
7.
Proc Natl Acad Sci U S A ; 119(28): e2115867119, 2022 07 12.
Artigo em Inglês | MEDLINE | ID: mdl-35763565

RESUMO

Liver regeneration is a well-orchestrated process that is typically studied in animal models. Although previous animal studies have offered many insights into liver regeneration, human biology is less well understood. To this end, we developed a three-dimensional (3D) platform called structurally vascularized hepatic ensembles for analyzing regeneration (SHEAR) to model multiple aspects of human liver regeneration. SHEAR enables control over hemodynamic alterations to mimic those that occur during liver injury and regeneration and supports the administration of biochemical inputs such as cytokines and paracrine interactions with endothelial cells. We found that exposing the endothelium-lined channel to fluid flow led to increased secretion of regeneration-associated factors. Stimulation with relevant cytokines not only amplified the secretory response, but also induced cell-cycle entry of primary human hepatocytes (PHHs) embedded within the device. Further, we identified endothelial-derived mediators that are sufficient to initiate proliferation of PHHs in this context. Collectively, the data presented here underscore the importance of multicellular models that can recapitulate high-level tissue functions and demonstrate that the SHEAR device can be used to discover and validate conditions that promote human liver regeneration.


Assuntos
Células Endoteliais , Hepatócitos , Regeneração Hepática , Fígado , Técnicas de Cultura de Células em Três Dimensões , Citocinas , Humanos , Fígado/irrigação sanguínea , Regeneração Hepática/fisiologia
8.
Gastroenterology ; 162(4): 1210-1225, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-34951993

RESUMO

BACKGROUND & AIMS: There is a major unmet need to assess the prognostic impact of antifibrotics in clinical trials because of the slow rate of liver fibrosis progression. We aimed to develop a surrogate biomarker to predict future fibrosis progression. METHODS: A fibrosis progression signature (FPS) was defined to predict fibrosis progression within 5 years in patients with hepatitis C virus and nonalcoholic fatty liver disease (NAFLD) with no to minimal fibrosis at baseline (n = 421) and was validated in an independent NAFLD cohort (n = 78). The FPS was used to assess response to 13 candidate antifibrotics in organotypic ex vivo cultures of clinical fibrotic liver tissues (n = 78) and cenicriviroc in patients with nonalcoholic steatohepatitis enrolled in a clinical trial (n = 19, NCT02217475). A serum protein-based surrogate FPS was developed and tested in a cohort of compensated cirrhosis patients (n = 122). RESULTS: A 20-gene FPS was defined and validated in an independent NAFLD cohort (adjusted odds ratio, 10.93; area under the receiver operating characteristic curve, 0.86). Among computationally inferred fibrosis-driving FPS genes, BCL2 was confirmed as a potential pharmacologic target using clinical liver tissues. Systematic ex vivo evaluation of 13 candidate antifibrotics identified rational combination therapies based on epigallocatechin gallate, which were validated for enhanced antifibrotic effect in ex vivo culture of clinical liver tissues. In patients with nonalcoholic steatohepatitis treated with cenicriviroc, FPS modulation was associated with 1-year fibrosis improvement accompanied by suppression of the E2F pathway. Induction of the PPARα pathway was absent in patients without fibrosis improvement, suggesting a benefit of combining PPARα agonism to improve the antifibrotic efficacy of cenicriviroc. A 7-protein serum protein-based surrogate FPS was associated with the development of decompensation in cirrhosis patients. CONCLUSION: The FPS predicts long-term fibrosis progression in an etiology-agnostic manner, which can inform antifibrotic drug development.


Assuntos
Hepatopatia Gordurosa não Alcoólica , Progressão da Doença , Desenvolvimento de Medicamentos , Fibrose , Humanos , Fígado/patologia , Cirrose Hepática/complicações , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Hepatopatia Gordurosa não Alcoólica/genética , PPAR alfa/genética
9.
BMC Med ; 21(1): 184, 2023 05 16.
Artigo em Inglês | MEDLINE | ID: mdl-37193989

RESUMO

BACKGROUND: The Emergency Medical Service (EMS) in Germany is increasingly challenged by strongly rising demand. Speculations about a greater utilisation for minor cases have led to intensive media coverage, but empirical evidence is lacking. We investigated the development of low-acuity calls from 2018 to 2021 in the federal state of Berlin and its correlations with sociodemographic characteristics. METHODS: We analysed over 1.5 million call documentations including medical dispatch codes, age, location and time using descriptive and inferential statistics and multivariate binary logistic regression. We defined a code list to classify low-acuity calls and merged the dataset with sociodemographic indicators and data on population density. RESULTS: The number of emergency calls (phone number 112 in Germany) increased by 9.1% from 2018 to 2021; however, the proportion of low-acuity calls did not increase. The regression model shows higher odds of low-acuity for young to medium age groups (especially for age 0-9, OR 1.50 [95% CI 1.45-1.55]; age 10-19, OR 1.77 [95% CI 1.71-1.83]; age 20-29, OR 1.64 [95% CI 1.59-1.68] and age 30-39, OR 1.40 [95% CI 1.37-1.44]; p < 0.001, reference group 80-89) and for females (OR 1.12 [95% CI 1.1-1.13], p < 0.001). Odds were slightly higher for calls from a neighbourhood with lower social status (OR 1.01 per index unit increase [95% CI 1.0-1.01], p < 0.05) and at the weekend (OR 1.02 [95% CI 1.0-1.04, p < 0.05]). No significant association of the call volume with population density was detected. CONCLUSIONS: This analysis provides valuable new insights into pre-hospital emergency care. Low-acuity calls were not the primary driver of increased EMS utilisation in Berlin. Younger age is the strongest predictor for low-acuity calls in the model. The association with female gender is significant, while socially deprived neighbourhoods play a minor role. No statistically significant differences in call volume between densely and less densely populated regions were detected. The results can inform the EMS in future resource planning.


Assuntos
Emergências , Serviços Médicos de Emergência , Humanos , Feminino , Recém-Nascido , Lactente , Pré-Escolar , Criança , Adolescente , Adulto Jovem , Adulto , Berlim/epidemiologia , Serviço Hospitalar de Emergência , Alemanha/epidemiologia , Estudos Retrospectivos
10.
Proc Natl Acad Sci U S A ; 117(24): 13428-13436, 2020 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-32493746

RESUMO

The recent advent of immune checkpoint inhibitor (CPI) antibodies has revolutionized many aspects of cancer therapy, but the efficacy of these breakthrough therapeutics remains limited, as many patients fail to respond for reasons that still largely evade understanding. An array of studies in human patients and animal models has demonstrated that local signaling can generate strongly immunosuppressive microenvironments within tumors, and emerging evidence suggests that delivery of immunostimulatory molecules into tumors can have therapeutic effects. Nanoparticle formulations of these cargoes offer a promising way to maximize their delivery and to enhance the efficacy of checkpoint inhibitors. We developed a modular nanoparticle system capable of encapsulating an array of immunostimulatory oligonucleotides that, in some cases, greatly increase their potency to activate inflammatory signaling within immune cells in vitro. We hypothesized that these immunostimulatory nanoparticles could suppress tumor growth by activating similar signaling in vivo, and thereby also improve responsiveness to immune checkpoint inhibitor antibody therapies. We found that our engineered nanoparticles carrying a CpG DNA ligand of TLR9 can suppress tumor growth in several animal models of various cancers, resulting in an abscopal effect on distant tumors, and improving responsiveness to anti-CTLA4 treatment with combinatorial effects after intratumoral administration. Moreover, by incorporating tumor-homing peptides, immunostimulatory nucleotide-bearing nanoparticles facilitate antitumor efficacy after systemic intravenous (i.v.) administration.


Assuntos
Adjuvantes Imunológicos , Antineoplásicos Imunológicos/uso terapêutico , Imunoterapia/métodos , Nanopartículas , Oligonucleotídeos/uso terapêutico , Animais , Antígeno CTLA-4/antagonistas & inibidores , Linhagem Celular , Sistemas de Liberação de Medicamentos , Quimioterapia Combinada , Inflamação , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Camundongos , Nanopartículas/química , Neoplasias Experimentais/terapia , Oligonucleotídeos/química , Oligonucleotídeos/imunologia
11.
Proc Natl Acad Sci U S A ; 117(3): 1678-1688, 2020 01 21.
Artigo em Inglês | MEDLINE | ID: mdl-31915293

RESUMO

Primary human hepatocytes (PHHs) are an essential tool for modeling drug metabolism and liver disease. However, variable plating efficiencies, short lifespan in culture, and resistance to genetic manipulation have limited their use. Here, we show that the pyrrolizidine alkaloid retrorsine improves PHH repopulation of chimeric mice on average 10-fold and rescues the ability of even poorly plateable donor hepatocytes to provide cells for subsequent ex vivo cultures. These mouse-passaged (mp) PHH cultures overcome the marked donor-to-donor variability of cryopreserved PHH and remain functional for months as demonstrated by metabolic assays and infection with hepatitis B virus and Plasmodium falciparum mpPHH can be efficiently genetically modified in culture, mobilized, and then recultured as spheroids or retransplanted to create highly humanized mice that carry a genetically altered hepatocyte graft. Together, these advances provide flexible tools for the study of human liver disease and evaluation of hepatocyte-targeted gene therapy approaches.


Assuntos
Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Hepatopatias/genética , Alcaloides de Pirrolizidina/farmacologia , Animais , Transplante de Células , Quimera , Modelos Animais de Doenças , Feminino , Terapia Genética , Hepatite B , Vírus da Hepatite B , Hepatócitos/transplante , Proteínas de Homeodomínio/genética , Humanos , Hidrolases/genética , Subunidade gama Comum de Receptores de Interleucina/genética , Fígado/patologia , Hepatopatias/patologia , Malária , Masculino , Camundongos , Camundongos Endogâmicos NOD , Camundongos Knockout , Plasmodium falciparum
12.
Eur Respir J ; 59(4)2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-34561286

RESUMO

BACKGROUND: Biomarkers of disease progression and treatment response are urgently needed for patients with lymphangioleiomyomatosis (LAM). Activity-based nanosensors, an emerging biosensor class, detect dysregulated proteases in vivo and release a reporter to provide a urinary readout of disease. Because proteases are dysregulated in LAM and may directly contribute to lung function decline, activity-based nanosensors may enable quantitative, real-time monitoring of LAM progression and treatment response. We aimed to assess the diagnostic utility of activity-based nanosensors in a pre-clinical model of pulmonary LAM. METHODS: Tsc2-null cells were injected intravenously into female nude mice to establish a mouse model of pulmonary LAM. A library of 14 activity-based nanosensors, designed to detect proteases across multiple catalytic classes, was administered into the lungs of LAM mice and healthy controls, urine was collected, and mass spectrometry was performed to measure nanosensor cleavage products. Mice were then treated with rapamycin and monitored with activity-based nanosensors. Machine learning was performed to distinguish diseased from healthy and treated from untreated mice. RESULTS: Multiple activity-based nanosensors (PP03 (cleaved by metallo, aspartic and cysteine proteases), padjusted<0.0001; PP10 (cleaved by serine, aspartic and cysteine proteases), padjusted=0.017)) were differentially cleaved in diseased and healthy lungs, enabling strong classification with a machine learning model (area under the curve (AUC) 0.95 from healthy). Within 2 days after rapamycin initiation, we observed normalisation of PP03 and PP10 cleavage, and machine learning enabled accurate classification of treatment response (AUC 0.94 from untreated). CONCLUSIONS: Activity-based nanosensors enable noninvasive, real-time monitoring of disease burden and treatment response in a pre-clinical model of LAM.


Assuntos
Cisteína Proteases , Linfangioleiomiomatose , Animais , Cisteína Proteases/uso terapêutico , Feminino , Humanos , Linfangioleiomiomatose/tratamento farmacológico , Camundongos , Camundongos Nus , Peptídeo Hidrolases/uso terapêutico , Sirolimo/uso terapêutico
13.
Nat Mater ; 20(10): 1440-1448, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34267368

RESUMO

Therapeutic outcomes in oncology may be aided by precision diagnostics that offer early detection, localization and the opportunity to monitor response to therapy. Here, we report a multimodal nanosensor engineered to target tumours through acidosis, respond to proteases in the microenvironment to release urinary reporters and (optionally) carry positron emission tomography probes to enable localization of primary and metastatic cancers in mouse models of colorectal cancer. We present a paradigm wherein this multimodal sensor can be employed longitudinally to assess burden of disease non-invasively, including tumour progression and response to chemotherapy. Specifically, we showed that acidosis-mediated tumour insertion enhanced on-target release of matrix metalloproteinase-responsive reporters in urine. Subsequent on-demand loading of the radiotracer 64Cu allowed pH-dependent tumour visualization, enabling enriched microenvironmental characterization when compared with the conventional metabolic tracer 18F-fluorodeoxyglucose. Through tailored target specificities, this modular platform has the capacity to be engineered as a pan-cancer test that may guide treatment decisions for numerous tumour types.


Assuntos
Acidose/diagnóstico , Neoplasias Colorretais/diagnóstico , Imagem Multimodal , Medicina de Precisão , Microambiente Tumoral , Acidose/complicações , Animais , Neoplasias Colorretais/complicações , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/patologia , Progressão da Doença , Feminino , Fluordesoxiglucose F18 , Camundongos , Camundongos Endogâmicos BALB C , Tomografia por Emissão de Pósitrons
14.
BMC Infect Dis ; 22(1): 493, 2022 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-35614394

RESUMO

BACKGROUND: Understanding the characteristics and natural history of novel pathogens is crucial to inform successful control measures. Japan was one of the first affected countries in the COVID-19 pandemic reporting their first case on 14 January 2020. Interventions including airport screening, contact tracing, and cluster investigations were quickly implemented. Here we present insights from the first 3 months of the epidemic in Japan based on detailed case data. METHODS: We conducted descriptive analyses based on information systematically extracted from individual case reports from 13 January to 31 March 2020 including patient demographics, date of report and symptom onset, symptom progression, travel history, and contact type. We analysed symptom progression and estimated the time-varying reproduction number, Rt, correcting for epidemic growth using an established Bayesian framework. Key delays and the age-specific probability of transmission were estimated using data on exposures and transmission pairs. RESULTS: The corrected fitted mean onset-to-reporting delay after the peak was 4 days (standard deviation: ± 2 days). Early transmission was driven primarily by returning travellers with Rt peaking at 2.4 (95% CrI: 1.6, 3.3) nationally. In the final week of the trusted period (16-23 March 2020), Rt accounting for importations diverged from overall Rt at 1.1 (95% CrI: 1.0, 1.2) compared to 1.5 (95% CrI: 1.3, 1.6), respectively. Household (39.0%) and workplace (11.6%) exposures were the most frequently reported potential source of infection. The estimated probability of transmission was assortative by age with individuals more likely to infect, and be infected by, contacts in a similar age group to them. Across all age groups, cases most frequently onset with cough, fever, and fatigue. There were no reported cases of patients < 20 years old developing pneumonia or severe respiratory symptoms. CONCLUSIONS: Information collected in the early phases of an outbreak are important in characterising any novel pathogen. The availability of timely and detailed data and appropriate analyses is critical to estimate and understand a pathogen's transmissibility, high-risk settings for transmission, and key symptoms. These insights can help to inform urgent response strategies.


Assuntos
COVID-19 , Adulto , Teorema de Bayes , COVID-19/epidemiologia , Humanos , Japão/epidemiologia , Pandemias/prevenção & controle , SARS-CoV-2 , Adulto Jovem
15.
Nature ; 536(7614): 81-85, 2016 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-27437587

RESUMO

The widespread view of bacteria as strictly pathogenic has given way to an appreciation of the prevalence of some beneficial microbes within the human body. It is perhaps inevitable that some bacteria would evolve to preferentially grow in environments that harbor disease and thus provide a natural platform for the development of engineered therapies. Such therapies could benefit from bacteria that are programmed to limit bacterial growth while continually producing and releasing cytotoxic agents in situ. Here we engineer a clinically relevant bacterium to lyse synchronously ata threshold population density and to release genetically encoded cargo. Following quorum lysis, a small number of surviving bacteria reseed the growing population, thus leading to pulsatile delivery cycles. We used microfluidic devices to characterize the engineered lysis strain and we demonstrate its potential as a drug delivery platform via co-culture with human cancer cells in vitro. Asa proof of principle, we tracked the bacterial population dynamics in ectopic syngeneic colorectal tumours in mice via a luminescent reporter. The lysis strain exhibits pulsatile population dynamics in vivo, with mean bacterial luminescence that remained two orders of magnitude lower than an unmodified strain. Finally, guided by previous findings that certain bacteria can enhance the efficacy of standard therapies, we orally administered the lysis strain alone or in combination with a clinical chemotherapeutic to a syngeneic mouse transplantation model of hepatic colorectal metastases. We found that the combination of both circuit-engineered bacteria and chemotherapy leads to a notable reduction of tumour activity along with a marked survival benefit over either therapy alone.Our approach establishes a methodology for leveraging the tools of synthetic biology to exploit the natural propensity for certain bacteria to colonize disease sites.


Assuntos
Bacteriólise , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/microbiologia , Sistemas de Liberação de Medicamentos/métodos , Salmonella/metabolismo , Administração Oral , Animais , Técnicas de Cocultura , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Simulação por Computador , Feminino , Neoplasias Hepáticas/secundário , Luminescência , Camundongos , Metástase Neoplásica , Transplante de Neoplasias , Percepção de Quorum , Salmonella/genética , Biologia Sintética/métodos , Transplante Isogênico
16.
Nature ; 538(7625): 344-349, 2016 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-27602946

RESUMO

Antimalarial drugs have thus far been chiefly derived from two sources-natural products and synthetic drug-like compounds. Here we investigate whether antimalarial agents with novel mechanisms of action could be discovered using a diverse collection of synthetic compounds that have three-dimensional features reminiscent of natural products and are underrepresented in typical screening collections. We report the identification of such compounds with both previously reported and undescribed mechanisms of action, including a series of bicyclic azetidines that inhibit a new antimalarial target, phenylalanyl-tRNA synthetase. These molecules are curative in mice at a single, low dose and show activity against all parasite life stages in multiple in vivo efficacy models. Our findings identify bicyclic azetidines with the potential to both cure and prevent transmission of the disease as well as protect at-risk populations with a single oral dose, highlighting the strength of diversity-oriented synthesis in revealing promising therapeutic targets.


Assuntos
Antimaláricos/síntese química , Antimaláricos/farmacologia , Azetidinas/uso terapêutico , Descoberta de Drogas , Estágios do Ciclo de Vida/efeitos dos fármacos , Malária Falciparum/tratamento farmacológico , Plasmodium falciparum/efeitos dos fármacos , Plasmodium falciparum/crescimento & desenvolvimento , Animais , Antimaláricos/administração & dosagem , Antimaláricos/uso terapêutico , Compostos Azabicíclicos/administração & dosagem , Compostos Azabicíclicos/síntese química , Compostos Azabicíclicos/farmacologia , Compostos Azabicíclicos/uso terapêutico , Azetidinas/administração & dosagem , Azetidinas/efeitos adversos , Azetidinas/farmacologia , Citosol/enzimologia , Modelos Animais de Doenças , Feminino , Fígado/efeitos dos fármacos , Fígado/parasitologia , Macaca mulatta/parasitologia , Malária Falciparum/prevenção & controle , Malária Falciparum/transmissão , Masculino , Camundongos , Fenilalanina-tRNA Ligase/antagonistas & inibidores , Compostos de Fenilureia/administração & dosagem , Compostos de Fenilureia/síntese química , Compostos de Fenilureia/farmacologia , Compostos de Fenilureia/uso terapêutico , Plasmodium falciparum/citologia , Plasmodium falciparum/enzimologia , Segurança
17.
Proc Natl Acad Sci U S A ; 121(11): e2315789121, 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38437565
18.
BMC Med ; 19(1): 146, 2021 06 18.
Artigo em Inglês | MEDLINE | ID: mdl-34144715

RESUMO

BACKGROUND: As in many countries, quantifying COVID-19 spread in Indonesia remains challenging due to testing limitations. In Java, non-pharmaceutical interventions (NPIs) were implemented throughout 2020. However, as a vaccination campaign launches, cases and deaths are rising across the island. METHODS: We used modelling to explore the extent to which data on burials in Jakarta using strict COVID-19 protocols (C19P) provide additional insight into the transmissibility of the disease, epidemic trajectory, and the impact of NPIs. We assess how implementation of NPIs in early 2021 will shape the epidemic during the period of likely vaccine rollout. RESULTS: C19P burial data in Jakarta suggest a death toll approximately 3.3 times higher than reported. Transmission estimates using these data suggest earlier, larger, and more sustained impact of NPIs. Measures to reduce sub-national spread, particularly during Ramadan, substantially mitigated spread to more vulnerable rural areas. Given current trajectory, daily cases and deaths are likely to increase in most regions as the vaccine is rolled out. Transmission may peak in early 2021 in Jakarta if current levels of control are maintained. However, relaxation of control measures is likely to lead to a subsequent resurgence in the absence of an effective vaccination campaign. CONCLUSIONS: Syndromic measures of mortality provide a more complete picture of COVID-19 severity upon which to base decision-making. The high potential impact of the vaccine in Java is attributable to reductions in transmission to date and dependent on these being maintained. Increases in control in the relatively short-term will likely yield large, synergistic increases in vaccine impact.


Assuntos
Vacinas contra COVID-19/administração & dosagem , COVID-19/mortalidade , COVID-19/epidemiologia , COVID-19/terapia , Humanos , Programas de Imunização/métodos , Indonésia , SARS-CoV-2/imunologia , SARS-CoV-2/isolamento & purificação , Síndrome , Vacinação/métodos , Vacinação/estatística & dados numéricos
19.
Proc Natl Acad Sci U S A ; 115(36): 8954-8959, 2018 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-30126988

RESUMO

Improved biomarkers are needed for prostate cancer, as the current gold standards have poor predictive value. Tests for circulating prostate-specific antigen (PSA) levels are susceptible to various noncancer comorbidities in the prostate and do not provide prognostic information, whereas physical biopsies are invasive, must be performed repeatedly, and only sample a fraction of the prostate. Injectable biosensors may provide a new paradigm for prostate cancer biomarkers by querying the status of the prostate via a noninvasive readout. Proteases are an important class of enzymes that play a role in every hallmark of cancer; their activities could be leveraged as biomarkers. We identified a panel of prostate cancer proteases through transcriptomic and proteomic analysis. Using this panel, we developed a nanosensor library that measures protease activity in vitro using fluorescence and in vivo using urinary readouts. In xenograft mouse models, we applied this nanosensor library to classify aggressive prostate cancer and to select predictive substrates. Last, we coformulated a subset of nanosensors with integrin-targeting ligands to increase sensitivity. These targeted nanosensors robustly classified prostate cancer aggressiveness and outperformed PSA. This activity-based nanosensor library could be useful throughout clinical management of prostate cancer, with both diagnostic and prognostic utility.


Assuntos
Biomarcadores Tumorais , Perfilação da Expressão Gênica , Biblioteca Gênica , Neoplasias Experimentais , Neoplasias da Próstata , Animais , Biomarcadores Tumorais/biossíntese , Biomarcadores Tumorais/genética , Xenoenxertos , Humanos , Masculino , Camundongos , Camundongos Nus , Transplante de Neoplasias , Neoplasias Experimentais/classificação , Neoplasias Experimentais/genética , Neoplasias Experimentais/metabolismo , Neoplasias da Próstata/classificação , Neoplasias da Próstata/genética , Neoplasias da Próstata/metabolismo
20.
Genes Dev ; 27(22): 2397-408, 2013 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-24240230

RESUMO

Historically, biomedical research has been based on two paradigms. First, measurements of biological behaviors have been based on bulk assays that average over large populations. Second, these behaviors have then been crudely perturbed by systemic administration of therapeutic treatments. Nanotechnology has the potential to transform these paradigms by enabling exquisite structures comparable in size with biomolecules as well as unprecedented chemical and physical functionality at small length scales. Here, we review nanotechnology-based approaches for precisely measuring and perturbing living systems. Remarkably, nanotechnology can be used to characterize single molecules or cells at extraordinarily high throughput and deliver therapeutic payloads to specific locations as well as exhibit dynamic biomimetic behavior. These advances enable multimodal interfaces that may yield unexpected insights into systems biology as well as new therapeutic strategies for personalized medicine.


Assuntos
Medicina/tendências , Nanotecnologia , Humanos
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