Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 7.840
Filtrar
Mais filtros

Intervalo de ano de publicação
1.
Cell ; 187(18): 4964-4980.e21, 2024 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-39059380

RESUMO

The highly conserved and essential Plasmodium falciparum reticulocyte-binding protein homolog 5 (PfRH5) has emerged as the leading target for vaccines against the disease-causing blood stage of malaria. However, the features of the human vaccine-induced antibody response that confer highly potent inhibition of malaria parasite invasion into red blood cells are not well defined. Here, we characterize 236 human IgG monoclonal antibodies, derived from 15 donors, induced by the most advanced PfRH5 vaccine. We define the antigenic landscape of this molecule and establish that epitope specificity, antibody association rate, and intra-PfRH5 antibody interactions are key determinants of functional anti-parasitic potency. In addition, we identify a germline IgG gene combination that results in an exceptionally potent class of antibody and demonstrate its prophylactic potential to protect against P. falciparum parasite challenge in vivo. This comprehensive dataset provides a framework to guide rational design of next-generation vaccines and prophylactic antibodies to protect against blood-stage malaria.


Assuntos
Anticorpos Monoclonais , Anticorpos Antiprotozoários , Antígenos de Protozoários , Imunoglobulina G , Vacinas Antimaláricas , Malária Falciparum , Plasmodium falciparum , Proteínas de Protozoários , Animais , Humanos , Camundongos , Anticorpos Monoclonais/imunologia , Anticorpos Antiprotozoários/imunologia , Antígenos de Protozoários/imunologia , Proteínas de Transporte/imunologia , Epitopos/imunologia , Eritrócitos/parasitologia , Eritrócitos/imunologia , Imunoglobulina G/imunologia , Vacinas Antimaláricas/imunologia , Malária Falciparum/imunologia , Malária Falciparum/prevenção & controle , Malária Falciparum/parasitologia , Plasmodium falciparum/imunologia , Proteínas de Protozoários/imunologia
2.
Cell ; 185(2): 235-249, 2022 01 20.
Artigo em Inglês | MEDLINE | ID: mdl-34995481

RESUMO

How cells become specialized, or "mature," is important for cell and developmental biology. While maturity is usually deemed a terminal fate, it may be more helpful to consider maturation not as a switch but as a dynamic continuum of adaptive phenotypic states set by genetic and environment programing. The hallmarks of maturity comprise changes in anatomy (form, gene circuitry, and interconnectivity) and physiology (function, rhythms, and proliferation) that confer adaptive behavior. We discuss efforts to harness their chemical (nutrients, oxygen, and growth factors) and physical (mechanical, spatial, and electrical) triggers in vitro and in vivo and how maturation strategies may support disease research and regenerative medicine.


Assuntos
Diferenciação Celular , Animais , Pesquisa Biomédica , Proliferação de Células , Humanos , Modelos Biológicos
3.
Cell ; 185(26): 4873-4886.e10, 2022 12 22.
Artigo em Inglês | MEDLINE | ID: mdl-36513064

RESUMO

Respiratory syncytial virus (RSV) infection is a major cause of severe lower respiratory tract infection and death in young infants and the elderly. With no effective prophylactic treatment available, current vaccine candidates aim to elicit neutralizing antibodies. However, binding and neutralization have poorly predicted protection in the past, and accumulating data across epidemiologic cohorts and animal models collectively point to a role for additional antibody Fc-effector functions. To begin to define the humoral correlates of immunity against RSV, here we profiled an adenovirus 26 RSV-preF vaccine-induced humoral immune response in a group of healthy adults that were ultimately challenged with RSV. Protection from infection was linked to opsonophagocytic functions, driven by IgA and differentially glycosylated RSV-specific IgG profiles, marking a functional humoral immune signature of protection against RSV. Furthermore, Fc-modified monoclonal antibodies able to selectively recruit effector functions demonstrated significant antiviral control in a murine model of RSV.


Assuntos
Infecções por Vírus Respiratório Sincicial , Vírus Sincicial Respiratório Humano , Camundongos , Animais , Infecções por Vírus Respiratório Sincicial/prevenção & controle , Anticorpos Neutralizantes , Anticorpos Antivirais , Imunoglobulina G , Fragmentos Fc das Imunoglobulinas , Proteínas Virais de Fusão
4.
Cell ; 184(25): 6119-6137.e26, 2021 12 09.
Artigo em Inglês | MEDLINE | ID: mdl-34890551

RESUMO

Prognostically relevant RNA expression states exist in pancreatic ductal adenocarcinoma (PDAC), but our understanding of their drivers, stability, and relationship to therapeutic response is limited. To examine these attributes systematically, we profiled metastatic biopsies and matched organoid models at single-cell resolution. In vivo, we identify a new intermediate PDAC transcriptional cell state and uncover distinct site- and state-specific tumor microenvironments (TMEs). Benchmarking models against this reference map, we reveal strong culture-specific biases in cancer cell transcriptional state representation driven by altered TME signals. We restore expression state heterogeneity by adding back in vivo-relevant factors and show plasticity in culture models. Further, we prove that non-genetic modulation of cell state can strongly influence drug responses, uncovering state-specific vulnerabilities. This work provides a broadly applicable framework for aligning cell states across in vivo and ex vivo settings, identifying drivers of transcriptional plasticity and manipulating cell state to target associated vulnerabilities.


Assuntos
Biomarcadores Tumorais/metabolismo , Carcinoma Ductal Pancreático/metabolismo , Neoplasias Pancreáticas/metabolismo , Microambiente Tumoral , Adulto , Idoso , Linhagem Celular Tumoral , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Pessoa de Meia-Idade , Análise de Célula Única
5.
Nat Immunol ; 24(7): 1161-1172, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37322179

RESUMO

Despite the success of COVID-19 vaccines, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants of concern have emerged that can cause breakthrough infections. Although protection against severe disease has been largely preserved, the immunological mediators of protection in humans remain undefined. We performed a substudy on the ChAdOx1 nCoV-19 (AZD1222) vaccinees enrolled in a South African clinical trial. At peak immunogenicity, before infection, no differences were observed in immunoglobulin (Ig)G1-binding antibody titers; however, the vaccine induced different Fc-receptor-binding antibodies across groups. Vaccinees who resisted COVID-19 exclusively mounted FcγR3B-binding antibodies. In contrast, enhanced IgA and IgG3, linked to enriched FcγR2B binding, was observed in individuals who experienced breakthrough. Antibodies unable to bind to FcγR3B led to immune complex clearance and resulted in inflammatory cascades. Differential antibody binding to FcγR3B was linked to Fc-glycosylation differences in SARS-CoV-2-specific antibodies. These data potentially point to specific FcγR3B-mediated antibody functional profiles as critical markers of immunity against COVID-19.


Assuntos
COVID-19 , Vacinas , Humanos , ChAdOx1 nCoV-19 , Vacinas contra COVID-19/efeitos adversos , COVID-19/prevenção & controle , SARS-CoV-2 , Anticorpos Antivirais , Imunoglobulina G , Receptores Fc/genética , Anticorpos Neutralizantes , Vacinação
6.
Cell ; 183(6): 1508-1519.e12, 2020 12 10.
Artigo em Inglês | MEDLINE | ID: mdl-33207184

RESUMO

The urgent need for an effective SARS-CoV-2 vaccine has forced development to progress in the absence of well-defined correlates of immunity. While neutralization has been linked to protection against other pathogens, whether neutralization alone will be sufficient to drive protection against SARS-CoV-2 in the broader population remains unclear. Therefore, to fully define protective humoral immunity, we dissected the early evolution of the humoral response in 193 hospitalized individuals ranging from moderate to severe. Although robust IgM and IgA responses evolved in both survivors and non-survivors with severe disease, non-survivors showed attenuated IgG responses, accompanied by compromised Fcɣ receptor binding and Fc effector activity, pointing to deficient humoral development rather than disease-enhancing humoral immunity. In contrast, individuals with moderate disease exhibited delayed responses that ultimately matured. These data highlight distinct humoral trajectories associated with resolution of SARS-CoV-2 infection and the need for early functional humoral immunity.


Assuntos
COVID-19 , Imunidade Humoral , Imunoglobulina A/imunologia , Imunoglobulina M/imunologia , Receptores de IgG/imunologia , SARS-CoV-2/imunologia , COVID-19/imunologia , COVID-19/mortalidade , Feminino , Células HL-60 , Humanos , Masculino
7.
Cell ; 183(6): 1496-1507.e16, 2020 12 10.
Artigo em Inglês | MEDLINE | ID: mdl-33171099

RESUMO

Antibodies are key immune effectors that confer protection against pathogenic threats. The nature and longevity of the antibody response to SARS-CoV-2 infection are not well defined. We charted longitudinal antibody responses to SARS-CoV-2 in 92 subjects after symptomatic COVID-19. Antibody responses to SARS-CoV-2 are unimodally distributed over a broad range, with symptom severity correlating directly with virus-specific antibody magnitude. Seventy-six subjects followed longitudinally to ∼100 days demonstrated marked heterogeneity in antibody duration dynamics. Virus-specific IgG decayed substantially in most individuals, whereas a distinct subset had stable or increasing antibody levels in the same time frame despite similar initial antibody magnitudes. These individuals with increasing responses recovered rapidly from symptomatic COVID-19 disease, harbored increased somatic mutations in virus-specific memory B cell antibody genes, and had persistent higher frequencies of previously activated CD4+ T cells. These findings illuminate an efficient immune phenotype that connects symptom clearance speed to differential antibody durability dynamics.


Assuntos
Anticorpos Antivirais/imunologia , Formação de Anticorpos , Linfócitos T CD4-Positivos/imunologia , COVID-19 , Imunoglobulina G/imunologia , Ativação Linfocitária , Mutação , COVID-19/genética , COVID-19/imunologia , Humanos , SARS-CoV-2/genética , SARS-CoV-2/imunologia
8.
Cell ; 183(1): 185-196.e14, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-33007262

RESUMO

Several HIV-1 and SIV vaccine candidates have shown partial protection against viral challenges in rhesus macaques. However, the protective efficacy of vaccine-elicited polyclonal antibodies has not previously been demonstrated in adoptive transfer studies in nonhuman primates. In this study, we show that passive transfer of purified antibodies from vaccinated macaques can protect naive animals against SIVmac251 challenges. We vaccinated 30 rhesus macaques with Ad26-SIV Env/Gag/Pol and SIV Env gp140 protein vaccines and assessed the induction of antibody responses and a putative protective signature. This signature included multiple antibody functions and correlated with upregulation of interferon pathways in vaccinated animals. Adoptive transfer of purified immunoglobulin G (IgG) from the vaccinated animals with the most robust protective signatures provided partial protection against SIVmac251 challenges in naive recipient rhesus macaques. These data demonstrate the protective efficacy of purified vaccine-elicited antiviral antibodies in this model, even in the absence of virus neutralization.


Assuntos
Imunização Passiva/métodos , Vacinas contra a SAIDS/imunologia , Vírus da Imunodeficiência Símia/imunologia , Vacinas contra a AIDS/imunologia , Animais , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Formação de Anticorpos/imunologia , Produtos do Gene env/imunologia , Produtos do Gene gag/imunologia , Produtos do Gene pol/imunologia , HIV-1/imunologia , Imunoglobulina G/imunologia , Macaca mulatta/imunologia , Síndrome de Imunodeficiência Adquirida dos Símios/imunologia
9.
Cell ; 173(2): 400-416.e11, 2018 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-29625055

RESUMO

For a decade, The Cancer Genome Atlas (TCGA) program collected clinicopathologic annotation data along with multi-platform molecular profiles of more than 11,000 human tumors across 33 different cancer types. TCGA clinical data contain key features representing the democratized nature of the data collection process. To ensure proper use of this large clinical dataset associated with genomic features, we developed a standardized dataset named the TCGA Pan-Cancer Clinical Data Resource (TCGA-CDR), which includes four major clinical outcome endpoints. In addition to detailing major challenges and statistical limitations encountered during the effort of integrating the acquired clinical data, we present a summary that includes endpoint usage recommendations for each cancer type. These TCGA-CDR findings appear to be consistent with cancer genomics studies independent of the TCGA effort and provide opportunities for investigating cancer biology using clinical correlates at an unprecedented scale.


Assuntos
Neoplasias/patologia , Bases de Dados Genéticas , Genômica , Humanos , Estimativa de Kaplan-Meier , Neoplasias/genética , Neoplasias/mortalidade , Modelos de Riscos Proporcionais
10.
Cell ; 165(1): 234-246, 2016 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-26924578

RESUMO

The prevailing approach to addressing secondary drug resistance in cancer focuses on treating the resistance mechanisms at relapse. However, the dynamic nature of clonal evolution, along with potential fitness costs and cost compensations, may present exploitable vulnerabilities-a notion that we term "temporal collateral sensitivity." Using a combined pharmacological screen and drug resistance selection approach in a murine model of Ph(+) acute lymphoblastic leukemia, we indeed find that temporal and/or persistent collateral sensitivity to non-classical BCR-ABL1 drugs arises in emergent tumor subpopulations during the evolution of resistance toward initial treatment with BCR-ABL1-targeted inhibitors. We determined the sensitization mechanism via genotypic, phenotypic, signaling, and binding measurements in combination with computational models and demonstrated significant overall survival extension in mice. Additional stochastic mathematical models and small-molecule screens extended our insights, indicating the value of focusing on evolutionary trajectories and pharmacological profiles to identify new strategies to treat dynamic tumor vulnerabilities.


Assuntos
Resistencia a Medicamentos Antineoplásicos , Modelos Biológicos , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Animais , Ensaios de Seleção de Medicamentos Antitumorais , Camundongos , Cromossomo Filadélfia , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Proteínas Proto-Oncogênicas c-bcr/análise , Proteínas Proto-Oncogênicas c-bcr/genética
11.
Cell ; 165(4): 910-20, 2016 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-27087446

RESUMO

Oncogenic mutations regulate signaling within both tumor cells and adjacent stromal cells. Here, we show that oncogenic KRAS (KRAS(G12D)) also regulates tumor cell signaling via stromal cells. By combining cell-specific proteome labeling with multivariate phosphoproteomics, we analyzed heterocellular KRAS(G12D) signaling in pancreatic ductal adenocarcinoma (PDA) cells. Tumor cell KRAS(G12D) engages heterotypic fibroblasts, which subsequently instigate reciprocal signaling in the tumor cells. Reciprocal signaling employs additional kinases and doubles the number of regulated signaling nodes from cell-autonomous KRAS(G12D). Consequently, reciprocal KRAS(G12D) produces a tumor cell phosphoproteome and total proteome that is distinct from cell-autonomous KRAS(G12D) alone. Reciprocal signaling regulates tumor cell proliferation and apoptosis and increases mitochondrial capacity via an IGF1R/AXL-AKT axis. These results demonstrate that oncogene signaling should be viewed as a heterocellular process and that our existing cell-autonomous perspective underrepresents the extent of oncogene signaling in cancer. VIDEO ABSTRACT.


Assuntos
Carcinoma Ductal Pancreático/metabolismo , Carcinoma Ductal Pancreático/patologia , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patologia , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Transdução de Sinais , Animais , Comunicação Celular , Humanos , Camundongos , Fosfoproteínas/análise , Fosfoproteínas/metabolismo , Proteoma/análise , Proteoma/metabolismo , Células Estromais/metabolismo
12.
Cell ; 166(3): 766-778, 2016 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-27453469

RESUMO

The ability to reliably and reproducibly measure any protein of the human proteome in any tissue or cell type would be transformative for understanding systems-level properties as well as specific pathways in physiology and disease. Here, we describe the generation and verification of a compendium of highly specific assays that enable quantification of 99.7% of the 20,277 annotated human proteins by the widely accessible, sensitive, and robust targeted mass spectrometric method selected reaction monitoring, SRM. This human SRMAtlas provides definitive coordinates that conclusively identify the respective peptide in biological samples. We report data on 166,174 proteotypic peptides providing multiple, independent assays to quantify any human protein and numerous spliced variants, non-synonymous mutations, and post-translational modifications. The data are freely accessible as a resource at http://www.srmatlas.org/, and we demonstrate its utility by examining the network response to inhibition of cholesterol synthesis in liver cells and to docetaxel in prostate cancer lines.


Assuntos
Bases de Dados de Proteínas , Proteoma , Acesso à Informação , Antineoplásicos/uso terapêutico , Linhagem Celular Tumoral , Colesterol/biossíntese , Docetaxel , Feminino , Humanos , Internet , Fígado/efeitos dos fármacos , Masculino , Mutação , Neoplasias da Próstata/tratamento farmacológico , Splicing de RNA , Taxoides/uso terapêutico
13.
Cell ; 167(2): 433-443.e14, 2016 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-27667685

RESUMO

While a third of the world carries the burden of tuberculosis, disease control has been hindered by a lack of tools, including a rapid, point-of-care diagnostic and a protective vaccine. In many infectious diseases, antibodies (Abs) are powerful biomarkers and important immune mediators. However, in Mycobacterium tuberculosis (Mtb) infection, a discriminatory or protective role for humoral immunity remains unclear. Using an unbiased antibody profiling approach, we show that individuals with latent tuberculosis infection (Ltb) and active tuberculosis disease (Atb) have distinct Mtb-specific humoral responses, such that Ltb infection is associated with unique Ab Fc functional profiles, selective binding to FcγRIII, and distinct Ab glycosylation patterns. Moreover, compared to Abs from Atb, Abs from Ltb drove enhanced phagolysosomal maturation, inflammasome activation, and, most importantly, macrophage killing of intracellular Mtb. Combined, these data point to a potential role for Fc-mediated Ab effector functions, tuned via differential glycosylation, in Mtb control.


Assuntos
Anticorpos Antibacterianos/imunologia , Interações Hospedeiro-Patógeno/imunologia , Imunidade Humoral , Tuberculose Latente/imunologia , Mycobacterium tuberculosis/imunologia , Adulto , Feminino , Glicosilação , Humanos , Fragmentos Fc das Imunoglobulinas/imunologia , Ativação de Macrófagos , Masculino , Pessoa de Meia-Idade , Polissacarídeos/imunologia , Análise Serial de Proteínas , Receptores de IgG/imunologia , Adulto Jovem
14.
Cell ; 166(3): 755-765, 2016 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-27372738

RESUMO

To provide a detailed analysis of the molecular components and underlying mechanisms associated with ovarian cancer, we performed a comprehensive mass-spectrometry-based proteomic characterization of 174 ovarian tumors previously analyzed by The Cancer Genome Atlas (TCGA), of which 169 were high-grade serous carcinomas (HGSCs). Integrating our proteomic measurements with the genomic data yielded a number of insights into disease, such as how different copy-number alternations influence the proteome, the proteins associated with chromosomal instability, the sets of signaling pathways that diverse genome rearrangements converge on, and the ones most associated with short overall survival. Specific protein acetylations associated with homologous recombination deficiency suggest a potential means for stratifying patients for therapy. In addition to providing a valuable resource, these findings provide a view of how the somatic genome drives the cancer proteome and associations between protein and post-translational modification levels and clinical outcomes in HGSC. VIDEO ABSTRACT.


Assuntos
Proteínas de Neoplasias/genética , Neoplasias Císticas, Mucinosas e Serosas/genética , Neoplasias Ovarianas/genética , Proteoma , Acetilação , Instabilidade Cromossômica , Reparo do DNA , DNA de Neoplasias , Feminino , Dosagem de Genes , Humanos , Espectrometria de Massas , Fosfoproteínas/genética , Processamento de Proteína Pós-Traducional , Análise de Sobrevida
15.
Immunity ; 54(8): 1715-1727.e7, 2021 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-34283971

RESUMO

Allergic airway inflammation is driven by type-2 CD4+ T cell inflammatory responses. We uncover an immunoregulatory role for the nucleotide release channel, Panx1, in T cell crosstalk during airway disease. Inverse correlations between Panx1 and asthmatics and our mouse models revealed the necessity, specificity, and sufficiency of Panx1 in T cells to restrict inflammation. Global Panx1-/- mice experienced exacerbated airway inflammation, and T-cell-specific deletion phenocopied Panx1-/- mice. A transgenic designed to re-express Panx1 in T cells reversed disease severity in global Panx1-/- mice. Panx1 activation occurred in pro-inflammatory T effector (Teff) and inhibitory T regulatory (Treg) cells and mediated the extracellular-nucleotide-based Treg-Teff crosstalk required for suppression of Teff cell proliferation. Mechanistic studies identified a Salt-inducible kinase-dependent phosphorylation of Panx1 serine 205 important for channel activation. A genetically targeted mouse expressing non-phosphorylatable Panx1S205A phenocopied the exacerbated inflammation in Panx1-/- mice. These data identify Panx1-dependent Treg:Teff cell communication in restricting airway disease.


Assuntos
Asma/imunologia , Comunicação Celular/imunologia , Conexinas/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Linfócitos T Reguladores/imunologia , Animais , Linhagem Celular , Proliferação de Células/fisiologia , Conexinas/genética , Modelos Animais de Doenças , Células HEK293 , Humanos , Células Jurkat , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas do Tecido Nervoso/genética , Sistema Respiratório/imunologia
16.
Cell ; 161(1): 12-17, 2015 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-25815980

RESUMO

Nutrition presents unanswered scientific questions of high public health importance. We envision model systems composed of interacting gastrointestinal and metabolic tissues derived from human embryonic stem cells, populated by gut microbiota. The culture will be embedded in 3D scaffolds, creating a controlled experimental system that enables tissue sampling and imaging.


Assuntos
Células-Tronco Embrionárias/citologia , Trato Gastrointestinal/fisiologia , Modelos Biológicos , Animais , Dieta , Trato Gastrointestinal/microbiologia , Humanos , Modelos Animais , Fenômenos Fisiológicos da Nutrição
17.
Cell ; 163(4): 988-98, 2015 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-26544943

RESUMO

While antibody titers and neutralization are considered the gold standard for the selection of successful vaccines, these parameters are often inadequate predictors of protective immunity. As antibodies mediate an array of extra-neutralizing Fc functions, when neutralization fails to predict protection, investigating Fc-mediated activity may help identify immunological correlates and mechanism(s) of humoral protection. Here, we used an integrative approach termed Systems Serology to analyze relationships among humoral responses elicited in four HIV vaccine trials. Each vaccine regimen induced a unique humoral "Fc fingerprint." Moreover, analysis of case:control data from the first moderately protective HIV vaccine trial, RV144, pointed to mechanistic insights into immune complex composition that may underlie protective immunity to HIV. Thus, multi-dimensional relational comparisons of vaccine humoral fingerprints offer a unique approach for the evaluation and design of novel vaccines against pathogens for which correlates of protection remain elusive.


Assuntos
Vacinas contra a AIDS/imunologia , Anticorpos Antivirais/imunologia , Imunoglobulina G/imunologia , Animais , Anticorpos Antivirais/sangue , Citotoxicidade Celular Dependente de Anticorpos , Complexo Antígeno-Anticorpo/imunologia , Ensaios Clínicos como Assunto , Desenho de Fármacos , Infecções por HIV/imunologia , Humanos , Imunoglobulina G/sangue , Receptores Fc/imunologia
18.
Nature ; 627(8005): 821-829, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38448584

RESUMO

Animals in the natural world constantly encounter geometrically complex landscapes. Successful navigation requires that they understand geometric features of these landscapes, including boundaries, landmarks, corners and curved areas, all of which collectively define the geometry of the environment1-12. Crucial to the reconstruction of the geometric layout of natural environments are concave and convex features, such as corners and protrusions. However, the neural substrates that could underlie the perception of concavity and convexity in the environment remain elusive. Here we show that the dorsal subiculum contains neurons that encode corners across environmental geometries in an allocentric reference frame. Using longitudinal calcium imaging in freely behaving mice, we find that corner cells tune their activity to reflect the geometric properties of corners, including corner angles, wall height and the degree of wall intersection. A separate population of subicular neurons encode convex corners of both larger environments and discrete objects. Both corner cells are non-overlapping with the population of subicular neurons that encode environmental boundaries. Furthermore, corner cells that encode concave or convex corners generalize their activity such that they respond, respectively, to concave or convex curvatures within an environment. Together, our findings suggest that the subiculum contains the geometric information needed to reconstruct the shape and layout of naturalistic spatial environments.


Assuntos
Meio Ambiente , Percepção de Forma , Hipocampo , Neurônios , Animais , Feminino , Masculino , Camundongos , Cálcio/análise , Cálcio/metabolismo , Percepção de Forma/fisiologia , Hipocampo/citologia , Hipocampo/fisiologia , Neurônios/metabolismo , Neurônios/fisiologia , Propriedades de Superfície
19.
Nature ; 2024 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-39294382

RESUMO

Avulsing rivers create new pathways on the floodplain and the associated flooding can profoundly affect society1-4. River avulsions are thought to occur when the water column becomes perched above the floodplain5 or when the slope down the flanks of the channel provides a steeper descent than the existing river channel6,7. We test these classical ideas by quantifying the topography around avulsing rivers and show that these mechanisms, historically invoked separately, work together. Near coasts, rivers avulse when the slope away from the channel is steeper, not because they are perched. The opposite is true near mountain fronts; on fans, the alternative paths are similarly steep to the downstream path, so rivers avulse when they are perched above the surrounding landscape. We reconcile these findings and present a new theoretical framework that identifies which rivers are vulnerable to avulsion and predicts the path of an avulsing river. These first-order rules of avulsion suggest that avulsion risks are underestimated in many coastal environments8 and that probabilistic predictions of avulsion pathfinding can efficiently map hazards with minimal information. Applying these principles for risk assessment could particularly benefit the Global South, which is disproportionately affected by avulsions.

20.
Nature ; 631(8022): 876-883, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38987605

RESUMO

Advancements in precision oncology over the past decades have led to new therapeutic interventions, but the efficacy of such treatments is generally limited by an adaptive process that fosters drug resistance1. In addition to genetic mutations2, recent research has identified a role for non-genetic plasticity in transient drug tolerance3 and the acquisition of stable resistance4,5. However, the dynamics of cell-state transitions that occur in the adaptation to cancer therapies remain unknown and require a systems-level longitudinal framework. Here we demonstrate that resistance develops through trajectories of cell-state transitions accompanied by a progressive increase in cell fitness, which we denote as the 'resistance continuum'. This cellular adaptation involves a stepwise assembly of gene expression programmes and epigenetically reinforced cell states underpinned by phenotypic plasticity, adaptation to stress and metabolic reprogramming. Our results support the notion that epithelial-to-mesenchymal transition or stemness programmes-often considered a proxy for phenotypic plasticity-enable adaptation, rather than a full resistance mechanism. Through systematic genetic perturbations, we identify the acquisition of metabolic dependencies, exposing vulnerabilities that can potentially be exploited therapeutically. The concept of the resistance continuum highlights the dynamic nature of cellular adaptation and calls for complementary therapies directed at the mechanisms underlying adaptive cell-state transitions.


Assuntos
Adaptação Fisiológica , Plasticidade Celular , Resistencia a Medicamentos Antineoplásicos , Neoplasias , Feminino , Humanos , Camundongos , Adaptação Fisiológica/efeitos dos fármacos , Adaptação Fisiológica/genética , Linhagem Celular Tumoral , Plasticidade Celular/efeitos dos fármacos , Plasticidade Celular/genética , Reprogramação Celular/efeitos dos fármacos , Reprogramação Celular/genética , Resistencia a Medicamentos Antineoplásicos/genética , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Epigênese Genética , Transição Epitelial-Mesenquimal/genética , Regulação Neoplásica da Expressão Gênica/genética , Neoplasias/tratamento farmacológico , Neoplasias/genética , Neoplasias/patologia , Fenótipo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA