RESUMO
Discoveries of the roles of RAS oncogenes in cancer development four decades ago opened the door to proving that tumor development is driven by somatic mutations' altering the genomes of cancer cells. These discoveries led to illusions about the simplicity of cancer pathogenesis and how cancer could be cured.
Assuntos
Genes ras , Neoplasias , Humanos , Neoplasias/genética , Neoplasias/terapia , Oncogenes , MutaçãoRESUMO
Plasmodium falciparum reticulocyte-binding protein homolog 5 (RH5) is the most advanced blood-stage malaria vaccine candidate and is being evaluated for efficacy in endemic regions, emphasizing the need to study the underlying antibody response to RH5 during natural infection, which could augment or counteract responses to vaccination. Here, we found that RH5-reactive B cells were rare, and circulating immunoglobulin G (IgG) responses to RH5 were short-lived in malaria-exposed Malian individuals, despite repeated infections over multiple years. RH5-specific monoclonal antibodies isolated from eight malaria-exposed individuals mostly targeted non-neutralizing epitopes, in contrast to antibodies isolated from five RH5-vaccinated, malaria-naive UK individuals. However, MAD8-151 and MAD8-502, isolated from two malaria-exposed Malian individuals, were among the most potent neutralizers out of 186 antibodies from both cohorts and targeted the same epitopes as the most potent vaccine-induced antibodies. These results suggest that natural malaria infection may boost RH5-vaccine-induced responses and provide a clear strategy for the development of next-generation RH5 vaccines.
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Nucleosomes block access to DNA methyltransferase, unless they are remodeled by DECREASE in DNA METHYLATION 1 (DDM1LSH/HELLS), a Snf2-like master regulator of epigenetic inheritance. We show that DDM1 promotes replacement of histone variant H3.3 by H3.1. In ddm1 mutants, DNA methylation is partly restored by loss of the H3.3 chaperone HIRA, while the H3.1 chaperone CAF-1 becomes essential. The single-particle cryo-EM structure at 3.2 Å of DDM1 with a variant nucleosome reveals engagement with histone H3.3 near residues required for assembly and with the unmodified H4 tail. An N-terminal autoinhibitory domain inhibits activity, while a disulfide bond in the helicase domain supports activity. DDM1 co-localizes with H3.1 and H3.3 during the cell cycle, and with the DNA methyltransferase MET1Dnmt1, but is blocked by H4K16 acetylation. The male germline H3.3 variant MGH3/HTR10 is resistant to remodeling by DDM1 and acts as a placeholder nucleosome in sperm cells for epigenetic inheritance.
Assuntos
Proteínas de Arabidopsis , Arabidopsis , Metilação de DNA , Histonas , Nucleossomos , Montagem e Desmontagem da Cromatina , DNA , Metilases de Modificação do DNA , Epigênese Genética , Histonas/genética , Nucleossomos/genética , Sêmen , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismoRESUMO
Therapeutic cancer vaccines are designed to increase tumor-specific T cell immunity. However, suppressive mechanisms within the tumor microenvironment (TME) may limit T cell function. Here, we assessed how the route of vaccination alters intratumoral myeloid cells. Using a self-assembling nanoparticle vaccine that links tumor antigen peptides to a Toll-like receptor 7/8 agonist (SNP-7/8a), we treated tumor-bearing mice subcutaneously (SNP-SC) or intravenously (SNP-IV). Both routes generated antigen-specific CD8+ T cells that infiltrated tumors. However, only SNP-IV mediated tumor regression, dependent on systemic type I interferon at the time of boost. Single-cell RNA-sequencing revealed that intratumoral monocytes expressing an immunoregulatory gene signature (Chil3, Anxa2, Wfdc17) were reduced after SNP-IV boost. In humans, the Chil3+ monocyte gene signature is enriched in CD16- monocytes and associated with worse outcomes. Our results show that the generation of tumor-specific CD8+ T cells combined with remodeling of the TME is a promising approach for tumor immunotherapy.
Assuntos
Vacinas Anticâncer , Microambiente Tumoral , Humanos , Camundongos , Animais , Linfócitos T CD8-Positivos , Linhagem Celular Tumoral , Imunoterapia/métodos , Antígenos de Neoplasias , Vacinação/métodos , Adjuvantes ImunológicosRESUMO
mRNA-1273 vaccine efficacy against SARS-CoV-2 Delta wanes over time; however, there are limited data on the impact of durability of immune responses on protection. Here, we immunized rhesus macaques and assessed immune responses over 1 year in blood and upper and lower airways. Serum neutralizing titers to Delta were 280 and 34 reciprocal ID50 at weeks 6 (peak) and 48 (challenge), respectively. Antibody-binding titers also decreased in bronchoalveolar lavage (BAL). Four days after Delta challenge, the virus was unculturable in BAL, and subgenomic RNA declined by â¼3-log10 compared with control animals. In nasal swabs, sgRNA was reduced by 1-log10, and the virus remained culturable. Anamnestic antibodies (590-fold increased titer) but not T cell responses were detected in BAL by day 4 post-challenge. mRNA-1273-mediated protection in the lungs is durable but delayed and potentially dependent on anamnestic antibody responses. Rapid and sustained protection in upper and lower airways may eventually require a boost.
RESUMO
Natural antibodies (Abs) can target host glycans on the surface of pathogens. We studied the evolution of glycan-reactive B cells of rhesus macaques and humans using glycosylated HIV-1 envelope (Env) as a model antigen. 2G12 is a broadly neutralizing Ab (bnAb) that targets a conserved glycan patch on Env of geographically diverse HIV-1 strains using a unique heavy-chain (VH) domain-swapped architecture that results in fragment antigen-binding (Fab) dimerization. Here, we describe HIV-1 Env Fab-dimerized glycan (FDG)-reactive bnAbs without VH-swapped domains from simian-human immunodeficiency virus (SHIV)-infected macaques. FDG Abs also recognized cell-surface glycans on diverse pathogens, including yeast and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike. FDG precursors were expanded by glycan-bearing immunogens in macaques and were abundant in HIV-1-naive humans. Moreover, FDG precursors were predominately mutated IgM+IgD+CD27+, thus suggesting that they originated from a pool of antigen-experienced IgM+ or marginal zone B cells.
Assuntos
Anticorpos Neutralizantes/imunologia , HIV-1/imunologia , Fragmentos Fab das Imunoglobulinas/imunologia , Polissacarídeos/imunologia , SARS-CoV-2/imunologia , Vírus da Imunodeficiência Símia/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Produtos do Gene env do Vírus da Imunodeficiência Humana/imunologia , Animais , Linfócitos B/imunologia , Anticorpos Amplamente Neutralizantes/imunologia , COVID-19/imunologia , Dimerização , Epitopos/imunologia , Glicosilação , Anticorpos Anti-HIV/imunologia , Infecções por HIV/imunologia , Humanos , Fragmentos Fab das Imunoglobulinas/química , Macaca mulatta , Polissacarídeos/química , Receptores de Antígenos de Linfócitos B/química , Vírus da Imunodeficiência Símia/genética , Vacinas/imunologia , Produtos do Gene env do Vírus da Imunodeficiência Humana/química , Produtos do Gene env do Vírus da Imunodeficiência Humana/genéticaRESUMO
The heterogeneity of endothelial cells (ECs) across tissues remains incompletely inventoried. We constructed an atlas of >32,000 single-EC transcriptomes from 11 mouse tissues and identified 78 EC subclusters, including Aqp7+ intestinal capillaries and angiogenic ECs in healthy tissues. ECs from brain/testis, liver/spleen, small intestine/colon, and skeletal muscle/heart pairwise expressed partially overlapping marker genes. Arterial, venous, and lymphatic ECs shared more markers in more tissues than did heterogeneous capillary ECs. ECs from different vascular beds (arteries, capillaries, veins, lymphatics) exhibited transcriptome similarity across tissues, but the tissue (rather than the vessel) type contributed to the EC heterogeneity. Metabolic transcriptome analysis revealed a similar tissue-grouping phenomenon of ECs and heterogeneous metabolic gene signatures in ECs between tissues and between vascular beds within a single tissue in a tissue-type-dependent pattern. The EC atlas taxonomy enabled identification of EC subclusters in public scRNA-seq datasets and provides a powerful discovery tool and resource value.
Assuntos
Células Endoteliais/metabolismo , Análise de Célula Única , Transcriptoma , Animais , Encéfalo/citologia , Sistema Cardiovascular/citologia , Células Endoteliais/classificação , Células Endoteliais/citologia , Trato Gastrointestinal/citologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Músculos/citologia , Especificidade de Órgãos , RNA-Seq , Testículo/citologiaRESUMO
NP105-113-B*07:02-specific CD8+ T cell responses are considered among the most dominant in SARS-CoV-2-infected individuals. We found strong association of this response with mild disease. Analysis of NP105-113-B*07:02-specific T cell clones and single-cell sequencing were performed concurrently, with functional avidity and antiviral efficacy assessed using an in vitro SARS-CoV-2 infection system, and were correlated with T cell receptor usage, transcriptome signature and disease severity (acute n = 77, convalescent n = 52). We demonstrated a beneficial association of NP105-113-B*07:02-specific T cells in COVID-19 disease progression, linked with expansion of T cell precursors, high functional avidity and antiviral effector function. Broad immune memory pools were narrowed postinfection but NP105-113-B*07:02-specific T cells were maintained 6 months after infection with preserved antiviral efficacy to the SARS-CoV-2 Victoria strain, as well as Alpha, Beta, Gamma and Delta variants. Our data show that NP105-113-B*07:02-specific T cell responses associate with mild disease and high antiviral efficacy, pointing to inclusion for future vaccine design.
Assuntos
Antígeno HLA-B7/imunologia , Epitopos Imunodominantes/imunologia , Proteínas do Nucleocapsídeo/imunologia , SARS-CoV-2/imunologia , Linfócitos T Citotóxicos/imunologia , Idoso , Sequência de Aminoácidos , Anticorpos Antivirais/imunologia , Afinidade de Anticorpos/imunologia , COVID-19/imunologia , COVID-19/patologia , Linhagem Celular Transformada , Feminino , Perfilação da Expressão Gênica , Humanos , Memória Imunológica/imunologia , Masculino , Pessoa de Meia-Idade , Receptores de Antígenos de Linfócitos T/imunologia , Índice de Gravidade de Doença , Vaccinia virus/genética , Vaccinia virus/imunologia , Vaccinia virus/metabolismoRESUMO
Varying pH of luminal fluid along the female reproductive tract is a physiological cue that modulates sperm motility. CatSper is a sperm-specific, pH-sensitive calcium channel essential for hyperactivated motility and male fertility. Multi-subunit CatSper channel complexes organize linear Ca2+ signaling nanodomains along the sperm tail. Here, we identify EF-hand calcium-binding domain-containing protein 9 (EFCAB9) as a bifunctional, cytoplasmic machine modulating the channel activity and the domain organization of CatSper. Knockout mice studies demonstrate that EFCAB9, in complex with the CatSper subunit, CATSPERζ, is essential for pH-dependent and Ca2+-sensitive activation of the CatSper channel. In the absence of EFCAB9, sperm motility and fertility is compromised, and the linear arrangement of the Ca2+ signaling domains is disrupted. EFCAB9 interacts directly with CATSPERζ in a Ca2+-dependent manner and dissociates at elevated pH. These observations suggest that EFCAB9 is a long-sought, intracellular, pH-dependent Ca2+ sensor that triggers changes in sperm motility.
Assuntos
Proteínas de Ligação ao Cálcio/metabolismo , Motilidade dos Espermatozoides/fisiologia , Animais , Cálcio/metabolismo , Canais de Cálcio/metabolismo , Sinalização do Cálcio/fisiologia , Proteínas de Ligação ao Cálcio/fisiologia , Linhagem Celular , Membrana Celular/metabolismo , Fertilidade , Células HEK293 , Humanos , Concentração de Íons de Hidrogênio , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Espermatozoides/metabolismoRESUMO
Estrogen receptor-positive (ER+) breast cancers frequently remain dependent on ER signaling even after acquiring resistance to endocrine agents, prompting the development of optimized ER antagonists. Fulvestrant is unique among approved ER therapeutics due to its capacity for full ER antagonism, thought to be achieved through ER degradation. The clinical potential of fulvestrant is limited by poor physicochemical features, spurring attempts to generate ER degraders with improved drug-like properties. We show that optimization of ER degradation does not guarantee full ER antagonism in breast cancer cells; ER "degraders" exhibit a spectrum of transcriptional activities and anti-proliferative potential. Mechanistically, we find that fulvestrant-like antagonists suppress ER transcriptional activity not by ER elimination, but by markedly slowing the intra-nuclear mobility of ER. Increased ER turnover occurs as a consequence of ER immobilization. These findings provide proof-of-concept that small molecule perturbation of transcription factor mobility may enable therapeutic targeting of this challenging target class.
Assuntos
Neoplasias da Mama/metabolismo , Antagonistas do Receptor de Estrogênio/farmacologia , Fulvestranto/farmacologia , Receptores de Estrogênio/antagonistas & inibidores , Receptores de Estrogênio/metabolismo , Animais , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Proliferação de Células/efeitos dos fármacos , Cinamatos/farmacologia , Resistencia a Medicamentos Antineoplásicos , Antagonistas do Receptor de Estrogênio/uso terapêutico , Feminino , Fulvestranto/uso terapêutico , Células HEK293 , Xenoenxertos , Humanos , Indazóis/farmacologia , Ligantes , Células MCF-7 , Camundongos , Camundongos Endogâmicos NOD , Camundongos Nus , Camundongos SCID , Polimorfismo de Nucleotídeo Único , Proteólise/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Transcrição Gênica/efeitos dos fármacosRESUMO
Severe asthma patients with low type 2 inflammation derive less clinical benefit from therapies targeting type 2 cytokines and represent an unmet need. We show that mast cell tryptase is elevated in severe asthma patients independent of type 2 biomarker status. Active ß-tryptase allele count correlates with blood tryptase levels, and asthma patients carrying more active alleles benefit less from anti-IgE treatment. We generated a noncompetitive inhibitory antibody against human ß-tryptase, which dissociates active tetramers into inactive monomers. A 2.15 Å crystal structure of a ß-tryptase/antibody complex coupled with biochemical studies reveal the molecular basis for allosteric destabilization of small and large interfaces required for tetramerization. This anti-tryptase antibody potently blocks tryptase enzymatic activity in a humanized mouse model, reducing IgE-mediated systemic anaphylaxis, and inhibits airway tryptase in Ascaris-sensitized cynomolgus monkeys with favorable pharmacokinetics. These data provide a foundation for developing anti-tryptase as a clinical therapy for severe asthma.
Assuntos
Anticorpos Monoclonais Humanizados/uso terapêutico , Asma/terapia , Mastócitos/enzimologia , Mastócitos/imunologia , Triptases/antagonistas & inibidores , Triptases/imunologia , Adolescente , Regulação Alostérica/imunologia , Animais , Linhagem Celular , Feminino , Humanos , Macaca fascicularis , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos NOD , Camundongos SCID , CoelhosRESUMO
Development of an effective tuberculosis (TB) vaccine has suffered from an incomplete understanding of the correlates of protection against Mycobacterium tuberculosis (Mtb). Intravenous (i.v.) vaccination with Bacille Calmette-Guérin (BCG) provides nearly complete protection against TB in rhesus macaques, but the antibody response it elicits remains incompletely defined. Here we show that i.v. BCG drives superior antibody responses in the plasma and the lungs of rhesus macaques compared to traditional intradermal BCG administration. While i.v. BCG broadly expands antibody titers and functions, IgM titers in the plasma and lungs of immunized macaques are among the strongest markers of reduced bacterial burden. IgM was also enriched in macaques that received protective vaccination with an attenuated strain of Mtb. Finally, an Mtb-specific IgM monoclonal antibody reduced Mtb survival in vitro. Collectively, these data highlight the potential importance of IgM responses as a marker and mediator of protection against TB.
Assuntos
Anticorpos Antibacterianos/sangue , Vacina BCG/administração & dosagem , Imunogenicidade da Vacina , Imunoglobulina M/sangue , Mycobacterium tuberculosis/imunologia , Tuberculose/prevenção & controle , Vacinação , Administração Intravenosa , Animais , Biomarcadores/sangue , Modelos Animais de Doenças , Interações Hospedeiro-Patógeno , Macaca mulatta , Mycobacterium tuberculosis/patogenicidade , Fatores de Tempo , Tuberculose/imunologia , Tuberculose/microbiologiaRESUMO
Personalized cancer vaccines are a promising approach for inducing T cell immunity to tumor neoantigens. Using a self-assembling nanoparticle vaccine that links neoantigen peptides to a Toll-like receptor 7/8 agonist (SNP-7/8a), we show how the route and dose alter the magnitude and quality of neoantigen-specific CD8+ T cells. Intravenous vaccination (SNP-IV) induced a higher proportion of TCF1+PD-1+CD8+ T cells as compared to subcutaneous immunization (SNP-SC). Single-cell RNA sequencing showed that SNP-IV induced stem-like genes (Tcf7, Slamf6, Xcl1) whereas SNP-SC enriched for effector genes (Gzmb, Klrg1, Cx3cr1). Stem-like cells generated by SNP-IV proliferated and differentiated into effector cells upon checkpoint blockade, leading to superior antitumor response as compared to SNP-SC in a therapeutic model. The duration of antigen presentation by dendritic cells controlled the magnitude and quality of CD8+ T cells. These data demonstrate how to optimize antitumor immunity by modulating vaccine parameters for specific generation of effector or stem-like CD8+ T cells.
Assuntos
Antígenos de Neoplasias/imunologia , Linfócitos T CD8-Positivos/imunologia , Vacinas Anticâncer/administração & dosagem , Fator 1-alfa Nuclear de Hepatócito/análise , Nanopartículas , Animais , Apresentação de Antígeno , Vacinas Anticâncer/imunologia , Células Dendríticas/imunologia , Feminino , Imunidade Inata , Camundongos , Camundongos Endogâmicos C57BL , VacinaçãoRESUMO
Long-lived plasma cells (PCs) secrete antibodies that can provide sustained immunity against infection. High-affinity cells are proposed to preferentially select into this compartment, potentiating the immune response. We used single-cell RNA-seq to track the germinal center (GC) development of Ighg2A10 B cells, specific for the Plasmodium falciparum circumsporozoite protein (PfCSP). Following immunization with Plasmodium sporozoites, we identified 3 populations of cells in the GC light zone (LZ). One LZ population expressed a gene signature associated with the initiation of PC differentiation and readily formed PCs in vitro. The estimated affinity of these pre-PC B cells was indistinguishable from that of LZ cells that remained in the GC. This remained true when high- or low-avidity recombinant PfCSP proteins were used as immunogens. These findings suggest that the initiation of PC development occurs via an affinity-independent process.
Assuntos
Linfócitos B , Centro Germinativo , Plasmócitos , Diferenciação Celular , Células Precursoras de Linfócitos BRESUMO
Ebola virus (EBOV) infection often results in fatal illness in humans, yet little is known about how EBOV usurps host pathways during infection. To address this, we used affinity tag-purification mass spectrometry (AP-MS) to generate an EBOV-host protein-protein interaction (PPI) map. We uncovered 194 high-confidence EBOV-human PPIs, including one between the viral transcription regulator VP30 and the host ubiquitin ligase RBBP6. Domain mapping identified a 23 amino acid region within RBBP6 that binds to VP30. A crystal structure of the VP30-RBBP6 peptide complex revealed that RBBP6 mimics the viral nucleoprotein (NP) binding to the same interface of VP30. Knockdown of endogenous RBBP6 stimulated viral transcription and increased EBOV replication, whereas overexpression of either RBBP6 or the peptide strongly inhibited both. These results demonstrate the therapeutic potential of biologics that target this interface and identify additional PPIs that may be leveraged for novel therapeutic strategies.
Assuntos
Proteínas de Transporte , Proteínas de Ligação a DNA , Ebolavirus/fisiologia , Doença pelo Vírus Ebola/metabolismo , Fatores de Transcrição , Proteínas Virais , Replicação Viral/fisiologia , Proteínas de Transporte/química , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Cristalografia por Raios X , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Células HEK293 , Células HeLa , Doença pelo Vírus Ebola/genética , Doença pelo Vírus Ebola/patologia , Humanos , Mapeamento de Interação de Proteínas , Fatores de Transcrição/química , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Ubiquitina-Proteína Ligases , Proteínas Virais/química , Proteínas Virais/genética , Proteínas Virais/metabolismoRESUMO
High-grade serous ovarian cancer (HGSC) exhibits extensive malignant clonal diversity with widespread but non-random patterns of disease dissemination. We investigated whether local immune microenvironment factors shape tumor progression properties at the interface of tumor-infiltrating lymphocytes (TILs) and cancer cells. Through multi-region study of 212 samples from 38 patients with whole-genome sequencing, immunohistochemistry, histologic image analysis, gene expression profiling, and T and B cell receptor sequencing, we identified three immunologic subtypes across samples and extensive within-patient diversity. Epithelial CD8+ TILs negatively associated with malignant diversity, reflecting immunological pruning of tumor clones inferred by neoantigen depletion, HLA I loss of heterozygosity, and spatial tracking between T cell and tumor clones. In addition, combinatorial prognostic effects of mutational processes and immune properties were observed, illuminating how specific genomic aberration types associate with immune response and impact survival. We conclude that within-patient spatial immune microenvironment variation shapes intraperitoneal malignant spread, provoking new evolutionary perspectives on HGSC clonal dispersion.
Assuntos
Linfócitos do Interstício Tumoral/imunologia , Neoplasias Ovarianas/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Antígenos de Neoplasias/genética , Antígenos de Neoplasias/metabolismo , Proteína BRCA1/genética , Proteína BRCA1/metabolismo , Proteína BRCA2/genética , Proteína BRCA2/metabolismo , Antígenos CD8/metabolismo , Análise por Conglomerados , Feminino , Antígenos HLA/genética , Antígenos HLA/metabolismo , Humanos , Perda de Heterozigosidade , Linfócitos do Interstício Tumoral/citologia , Linfócitos do Interstício Tumoral/metabolismo , Pessoa de Meia-Idade , Gradação de Tumores , Neoplasias Ovarianas/classificação , Neoplasias Ovarianas/imunologia , Polimorfismo de Nucleotídeo Único , Receptores de Antígenos de Linfócitos T/genética , Receptores de Antígenos de Linfócitos T/metabolismo , Sequenciamento Completo do Genoma , Adulto JovemRESUMO
Epithelial-mesenchymal transition (EMT) encompasses dynamic changes in cellular organization from epithelial to mesenchymal phenotypes, which leads to functional changes in cell migration and invasion. EMT occurs in a diverse range of physiological and pathological conditions and is driven by a conserved set of inducing signals, transcriptional regulators and downstream effectors. With over 5,700 publications indexed by Web of Science in 2019 alone, research on EMT is expanding rapidly. This growing interest warrants the need for a consensus among researchers when referring to and undertaking research on EMT. This Consensus Statement, mediated by 'the EMT International Association' (TEMTIA), is the outcome of a 2-year-long discussion among EMT researchers and aims to both clarify the nomenclature and provide definitions and guidelines for EMT research in future publications. We trust that these guidelines will help to reduce misunderstanding and misinterpretation of research data generated in various experimental models and to promote cross-disciplinary collaboration to identify and address key open questions in this research field. While recognizing the importance of maintaining diversity in experimental approaches and conceptual frameworks, we emphasize that lasting contributions of EMT research to increasing our understanding of developmental processes and combatting cancer and other diseases depend on the adoption of a unified terminology to describe EMT.
Assuntos
Pesquisa Biomédica/normas , Transição Epitelial-Mesenquimal , Animais , Movimento Celular , Plasticidade Celular , Consenso , Biologia do Desenvolvimento/normas , Humanos , Neoplasias/patologia , Terminologia como AssuntoRESUMO
The mechanistic target of rapamycin (mTOR) coordinates eukaryotic cell growth and metabolism with environmental inputs, including nutrients and growth factors. Extensive research over the past two decades has established a central role for mTOR in regulating many fundamental cell processes, from protein synthesis to autophagy, and deregulated mTOR signaling is implicated in the progression of cancer and diabetes, as well as the aging process. Here, we review recent advances in our understanding of mTOR function, regulation, and importance in mammalian physiology. We also highlight how the mTOR signaling network contributes to human disease and discuss the current and future prospects for therapeutically targeting mTOR in the clinic.
Assuntos
Transdução de Sinais , Serina-Treonina Quinases TOR/metabolismo , Envelhecimento/metabolismo , Animais , Diabetes Mellitus/metabolismo , Glucose/metabolismo , Humanos , Músculos/metabolismo , Neoplasias/metabolismoRESUMO
Metastases account for the great majority of cancer-associated deaths, yet this complex process remains the least understood aspect of cancer biology. As the body of research concerning metastasis continues to grow at a rapid rate, the biological programs that underlie the dissemination and metastatic outgrowth of cancer cells are beginning to come into view. In this review we summarize the cellular and molecular mechanisms involved in metastasis, with a focus on carcinomas where the most is known, and we highlight the general principles of metastasis that have begun to emerge.
Assuntos
Carcinoma/patologia , Metástase Neoplásica/patologia , Animais , Plaquetas/metabolismo , Carcinoma/genética , Carcinoma/metabolismo , Movimento Celular , Transição Epitelial-Mesenquimal , Humanos , Invasividade Neoplásica , Neoplasias/genética , Neoplasias/metabolismo , Neoplasias/patologia , Células Neoplásicas Circulantes/metabolismo , Células Neoplásicas Circulantes/patologia , Neutrófilos/metabolismo , Linfócitos T/imunologia , Microambiente TumoralRESUMO
Cytokines regulate immune responses by binding to cell surface receptors, including the common subunit beta (ßc), which mediates signaling for GM-CSF, IL-3, and IL-5. Despite known roles in inflammation, the structural basis of IL-5 receptor activation remains unclear. We present the cryo-EM structure of the human IL-5 ternary receptor complex, revealing architectural principles for IL-5, GM-CSF, and IL-3. In mammalian cell culture, single-molecule imaging confirms hexameric IL-5 complex formation on cell surfaces. Engineered chimeric receptors show that IL-5 signaling, as well as IL-3 and GM-CSF, can occur through receptor heterodimerization, obviating the need for higher-order assemblies of ßc dimers. These findings provide insights into IL-5 and ßc receptor family signaling mechanisms, aiding in the development of therapies for diseases involving deranged ßc signaling.