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1.
Mol Cell ; 81(8): 1666-1681.e6, 2021 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-33823140

RESUMO

Nuclear speckles are prominent nuclear bodies that contain proteins and RNA involved in gene expression. Although links between nuclear speckles and gene activation are emerging, the mechanisms regulating association of genes with speckles are unclear. We find that speckle association of p53 target genes is driven by the p53 transcription factor. Focusing on p21, a key p53 target, we demonstrate that speckle association boosts expression by elevating nascent RNA amounts. p53-regulated speckle association did not depend on p53 transactivation functions but required an intact proline-rich domain and direct DNA binding, providing mechanisms within p53 for regulating gene-speckle association. Beyond p21, a substantial subset of p53 targets have p53-regulated speckle association. Strikingly, speckle-associating p53 targets are more robustly activated and occupy a distinct niche of p53 biology compared with non-speckle-associating p53 targets. Together, our findings illuminate regulated speckle association as a mechanism used by a transcription factor to boost gene expression.

2.
Cell ; 184(8): 2033-2052.e21, 2021 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-33765443

RESUMO

Metastasis is the leading cause of cancer-related deaths, and greater knowledge of the metastatic microenvironment is necessary to effectively target this process. Microenvironmental changes occur at distant sites prior to clinically detectable metastatic disease; however, the key niche regulatory signals during metastatic progression remain poorly characterized. Here, we identify a core immune suppression gene signature in pre-metastatic niche formation that is expressed predominantly by myeloid cells. We target this immune suppression program by utilizing genetically engineered myeloid cells (GEMys) to deliver IL-12 to modulate the metastatic microenvironment. Our data demonstrate that IL12-GEMy treatment reverses immune suppression in the pre-metastatic niche by activating antigen presentation and T cell activation, resulting in reduced metastatic and primary tumor burden and improved survival of tumor-bearing mice. We demonstrate that IL12-GEMys can functionally modulate the core program of immune suppression in the pre-metastatic niche to successfully rebalance the dysregulated metastatic microenvironment in cancer.

3.
Cancer Cell ; 37(3): 289-307.e9, 2020 03 16.
Artigo em Inglês | MEDLINE | ID: mdl-32183949

RESUMO

Here, we utilized spontaneous models of pancreatic and lung cancer to examine how neoantigenicity shapes tumor immunity and progression. As expected, neoantigen expression during lung adenocarcinoma development leads to T cell-mediated immunity and disease restraint. By contrast, neoantigen expression in pancreatic ductal adenocarcinoma (PDAC) results in exacerbation of a fibro-inflammatory microenvironment that drives disease progression and metastasis. Pathogenic TH17 responses are responsible for this neoantigen-induced tumor progression in PDAC. Underlying these divergent T cell responses in pancreas and lung cancer are differences in infiltrating conventional dendritic cells (cDCs). Overcoming cDC deficiency in early-stage PDAC leads to disease restraint, while restoration of cDC function in advanced PDAC restores tumor-restraining immunity and enhances responsiveness to radiation therapy.


Assuntos
Carcinoma Ductal Pancreático/imunologia , Células Dendríticas/imunologia , Imunoterapia/métodos , Neoplasias Pancreáticas/imunologia , Adenocarcinoma de Pulmão/imunologia , Adenocarcinoma de Pulmão/patologia , Animais , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/patologia , Linfócitos T CD8-Positivos/imunologia , Carcinoma Ductal Pancreático/patologia , Carcinoma Ductal Pancreático/terapia , Linhagem Celular Tumoral , Células Dendríticas/patologia , Humanos , Neoplasias Pulmonares/imunologia , Neoplasias Pulmonares/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Mutantes , Camundongos Transgênicos , Neoplasias Pancreáticas/patologia , Neoplasias Pancreáticas/terapia
4.
Nature ; 571(7764): 211-218, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31207603

RESUMO

Exhausted CD8+ T (Tex) cells in chronic infections and cancer have limited effector function, high co-expression of inhibitory receptors and extensive transcriptional changes compared with effector (Teff) or memory (Tmem) CD8+ T cells. Tex cells are important clinical targets of checkpoint blockade and other immunotherapies. Epigenetically, Tex cells are a distinct immune subset, with a unique chromatin landscape compared with Teff and Tmem cells. However, the mechanisms that govern the transcriptional and epigenetic development of Tex cells remain unknown. Here we identify the HMG-box transcription factor TOX as a central regulator of Tex cells in mice. TOX is largely dispensable for the formation of Teff and Tmem cells, but it is critical for exhaustion: in the absence of TOX, Tex cells do not form. TOX is induced by calcineurin and NFAT2, and operates in a feed-forward loop in which it becomes calcineurin-independent and sustained in Tex cells. Robust expression of TOX therefore results in commitment to Tex cells by translating persistent stimulation into a distinct Tex cell transcriptional and epigenetic developmental program.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/patologia , Epistasia Genética , Proteínas de Homeodomínio/metabolismo , Transcrição Genética , Animais , Calcineurina/metabolismo , Sinalização do Cálcio , Retroalimentação Fisiológica , Feminino , Regulação da Expressão Gênica/imunologia , Genótipo , Memória Imunológica , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Fatores de Transcrição NFATC/metabolismo , Evasão Tumoral
5.
Sci Adv ; 5(5): eaaw0946, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-31049400

RESUMO

The transcription factor p63 is a key mediator of epidermal development. Point mutations in p63 in patients lead to developmental defects, including orofacial clefting. To date, knowledge on how pivotal the role of p63 is in human craniofacial development is limited. Using an inducible transdifferentiation model, combined with epigenomic sequencing and multicohort meta-analysis of genome-wide association studies data, we show that p63 establishes enhancers at craniofacial development genes to modulate their transcription. Disease-specific substitution mutation in the DNA binding domain or sterile alpha motif protein interaction domain of p63, respectively, eliminates or reduces establishment of these enhancers. We show that enhancers established by p63 are highly enriched for single-nucleotide polymorphisms associated with nonsyndromic cleft lip ± cleft palate (CL/P). These orthogonal approaches indicate a strong molecular link between p63 enhancer function and CL/P, illuminating molecular mechanisms underlying this developmental defect and revealing vital regulatory elements and new candidate causative genes.


Assuntos
Elementos Facilitadores Genéticos/genética , Células Epiteliais/metabolismo , Ossos Faciais/crescimento & desenvolvimento , Crânio/crescimento & desenvolvimento , Fatores de Transcrição/genética , Proteínas Supressoras de Tumor/genética , Encéfalo/anormalidades , Fenda Labial/genética , Fissura Palatina/genética , Fibroblastos/metabolismo , Prepúcio do Pênis/citologia , Estudo de Associação Genômica Ampla , Células HEK293 , Humanos , Fatores de Transcrição Kruppel-Like/metabolismo , Masculino , Mutação Puntual , Polimorfismo de Nucleotídeo Único , Fatores de Transcrição/metabolismo , Transcrição Genética , Transfecção , Proteínas Supressoras de Tumor/metabolismo , Regulação para Cima/genética
6.
Cell Cycle ; 18(8): 809-823, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30966857

RESUMO

The tumor suppressor protein p53 is activated in response to diverse intrinsic and extrinsic cellular stresses and controls a broad cell-protective gene network. Whether p53:DNA binding and subsequent transcriptional activation differs downstream of these diverse intrinsic and extrinsic activators is controversial. Using primary human fibroblasts, we assessed the genome-wide profile of p53 binding, chromatin structure, and transcriptional dynamics after either genotoxic or nongenotoxic activation of p53. Activation of p53 by treatment with either etoposide or the small-molecule MDM2 inhibitor nutlin 3A yields strikingly similar genome-wide binding of p53 and concomitant changes to local chromatin modifications and structure. DNA damage, but not p53 activation per se, leads to increased expression of genes in an inflammatory cytokine pathway. The NF-κB pathway inhibitor Bay 11-7082 abrogates etoposide-mediated activation of the inflammation gene signature but does not affect expression of canonical p53 target genes. Our data demonstrate that differential activation of p53 within the same cell type leads to highly similar genome-wide binding, chromatin dynamics, and gene expression dynamics and that DNA damage-mediated signaling through NF-κB likely controls the observed pro-inflammatory cytokine gene expression pattern.


Assuntos
Redes Reguladoras de Genes/efeitos dos fármacos , Ativação Transcricional/efeitos dos fármacos , Proteína Supressora de Tumor p53/genética , Apoptose/efeitos dos fármacos , Linhagem Celular , Montagem e Desmontagem da Cromatina/efeitos dos fármacos , Dano ao DNA/efeitos dos fármacos , Etoposídeo/farmacologia , Fibroblastos/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Imidazóis/farmacologia , NF-kappa B/antagonistas & inibidores , NF-kappa B/metabolismo , Nitrilos/farmacologia , Piperazinas/farmacologia , Ligação Proteica/efeitos dos fármacos , Estabilidade Proteica/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-mdm2/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-mdm2/metabolismo , Sulfonas/farmacologia
7.
Artigo em Inglês | MEDLINE | ID: mdl-30785097

RESUMO

In E. coli, a single oligomeric enzyme transcribes the genomic DNA, while multiple auxiliary proteins and regulatory RNA interact with the core RNA polymerase (RP) during different stages of the transcription cycle to influence its function. In this work, using fast protein isolation techniques combined with mass spectrometry (MS) and immuno-analyses, we studied growth phase-specific changes in the composition of E. coli transcription complexes. We show that RP isolated from actively growing cells is represented by prevalent double copy assemblies and single copy RP-RNA and RP-RNA-RapA complexes. We demonstrate that RpoD/σ70 obtained in fast purification protocols carries tightly associated RNA and show evidence pointing to a role of sigma-associated RNA in the formation of native RP-(RNA)-RpoD/σ70 (holoenzyme) complexes. We report that enzymes linked functionally to the metabolism of lipopolysaccharides co-purify with RP-RNA complexes and describe two classes of RP-associated molecules (phospholipids and putative phospholipid-rNT species). We hypothesize that these modifications could enable anchoring of RP-RNA and RNA in cell membranes. We also report that proteins loosely associated with ribosomes and degradosomes (S1, Hfq) co-purify with RP-RNA complexes isolated from actively growing cells - a result consistent with their proposed roles as adaptor-proteins. In contrast, GroEL, SecB, and SecA co-purified with RP obtained from cells harvested in early stationary phase. Our results demonstrate that fast, affinity chromatography-based isolation of large multi-protein assemblies in combination with MS can be used as a tool for analysis of their composition and the profiling of small protein-associated molecules (SPAM).


Assuntos
RNA Polimerases Dirigidas por DNA/metabolismo , Proteínas de Escherichia coli/metabolismo , Escherichia coli , RNA Bacteriano/metabolismo , Cromatografia Líquida de Alta Pressão , RNA Polimerases Dirigidas por DNA/química , RNA Polimerases Dirigidas por DNA/isolamento & purificação , Eletroforese em Gel de Poliacrilamida , Escherichia coli/química , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas de Escherichia coli/química , Proteínas de Escherichia coli/isolamento & purificação , Substâncias Macromoleculares/química , Substâncias Macromoleculares/isolamento & purificação , Substâncias Macromoleculares/metabolismo , RNA Bacteriano/química , RNA Bacteriano/isolamento & purificação , Transcrição Genética
8.
Biomed Res Int ; 2018: 2021890, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30255091

RESUMO

The mucosa is part of the first line of immune defense against pathogen exposure in humans and prevents viral and bacterial infection of the soft palate, lungs, uvula, and nasal cavity that comprise the ear-nose-throat (ENT) region. Bactericidal/permeability-increasing fold containing family A, member 1 (BPIFA1) is a secretory protein found in human upper aerodigestive tract mucosa. This innate material is secreted in mucosal fluid or found in submucosal tissue in the human soft palate, lung, uvula, and nasal cavity. BPIFA1 is a critical component of the innate immune response that prevents upper airway diseases. This review will provide a brief introduction of the roles of BPIFA1 in the upper airway (with a focus on the nasal cavity, sinus, and middle ear), specifically its history, identification, distribution in various human tissues, function, and diagnostic value in various upper airway infectious diseases.


Assuntos
Glicoproteínas/fisiologia , Imunidade Inata , Cavidade Nasal , Fosfoproteínas/fisiologia , Humanos , Pulmão , Cavidade Nasal/imunologia , Cavidade Nasal/microbiologia
9.
Nature ; 558(7709): 307-312, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29849141

RESUMO

Cancer immunotherapy based on genetically redirecting T cells has been used successfully to treat B cell malignancies1-3. In this strategy, the T cell genome is modified by integration of viral vectors or transposons encoding chimaeric antigen receptors (CARs) that direct tumour cell killing. However, this approach is often limited by the extent of expansion and persistence of CAR T cells4,5. Here we report mechanistic insights from studies of a patient with chronic lymphocytic leukaemia treated with CAR T cells targeting the CD19 protein. Following infusion of CAR T cells, anti-tumour activity was evident in the peripheral blood, lymph nodes and bone marrow; this activity was accompanied by complete remission. Unexpectedly, at the peak of the response, 94% of CAR T cells originated from a single clone in which lentiviral vector-mediated insertion of the CAR transgene disrupted the methylcytosine dioxygenase TET2 gene. Further analysis revealed a hypomorphic mutation in this patient's second TET2 allele. TET2-disrupted CAR T cells exhibited an epigenetic profile consistent with altered T cell differentiation and, at the peak of expansion, displayed a central memory phenotype. Experimental knockdown of TET2 recapitulated the potency-enhancing effect of TET2 dysfunction in this patient's CAR T cells. These findings suggest that the progeny of a single CAR T cell induced leukaemia remission and that TET2 modification may be useful for improving immunotherapies.


Assuntos
5-Metilcitosina/metabolismo , Antígenos CD19/imunologia , Dioxigenases/genética , Imunoterapia/métodos , Leucemia Linfocítica Crônica de Células B/imunologia , Leucemia Linfocítica Crônica de Células B/terapia , Linfócitos T/imunologia , Linfócitos T/transplante , Transferência Adotiva , Idoso , Alelos , Diferenciação Celular , Ensaios Clínicos como Assunto , Células Clonais/citologia , Células Clonais/imunologia , Dioxigenases/metabolismo , Epigênese Genética , Células HEK293 , Humanos , Leucemia Linfocítica Crônica de Células B/genética , Leucemia Linfocítica Crônica de Células B/patologia , Masculino , Mutação , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Linfócitos T/citologia , Linfócitos T/metabolismo , Transgenes
10.
PLoS One ; 11(9): e0163555, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27658112

RESUMO

KRAB domain Zinc finger proteins are one of the most abundant families of transcriptional regulators in higher vertebrates. The prevailing view is that KRAB domain proteins function as potent transcriptional repressors by recruiting TRIM28 and promoting heterochromatin spreading. However, the extent to which all KRAB domain proteins are TRIM28-dependent transcriptional repressors is currently unclear. Our studies on mouse ZFP568 revealed that TRIM28 recruitment by KRAB domain proteins is not sufficient to warrant transcriptional repressive activity. By using luciferase reporter assays and yeast two-hybrid experiments, we tested the ability of ZFP568 and other mouse KRAB domain proteins to repress transcription and bind TRIM28. We found that some mouse KRAB domain proteins are poor transcriptional repressors despite their ability to recruit TRIM28, while others showed strong KRAB-dependent transcriptional repression, but no TRIM28 binding. Together, our results show that the transcriptional repressive activity of KRAB-ZNF proteins does not correlate with their ability to recruit TRIM28, and provide evidence that KRAB domains can regulate transcription in a TRIM28-independent fashion. Our findings challenge the current understanding of the molecular mechanisms used by KRAB domain proteins to control gene expression and highlight that a high percentage of KRAB domain proteins in the mouse genome differ from the consensus KRAB sequence at amino acid residues that are critical for TRIM28 binding and/or repressive activity.

11.
Cell Rep ; 13(6): 1194-1205, 2015 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-26527006

RESUMO

Genomic imprinting depends on the establishment and maintenance of DNA methylation at imprinting control regions. However, the mechanisms by which these heritable marks influence allele-specific expression are not fully understood. By analyzing maternal, zygotic, maternal-zygotic, and conditional Trim28 mutants, we found that the transcription factor TRIM28 controls genomic imprinting through distinct mechanisms at different developmental stages. During early genome-wide reprogramming, both maternal and zygotic TRIM28 are required for the maintenance of methylation at germline imprints. However, in conditional Trim28 mutants, Gtl2-imprinted gene expression was lost despite normal methylation levels at the germline IG-DMR. These results provide evidence that TRIM28 controls imprinting after early embryonic reprogramming through a mechanism other than the maintenance of germline imprints. Additionally, our finding that secondary imprints were hypomethylated in TRIM28 mutants uncovers a requirement of TRIM28 after genome-wide reprogramming for interpreting germline imprints and regulating DNA methylation at imprinted gene promoters.


Assuntos
Reprogramação Celular , Genoma , Impressão Genômica , Proteínas Nucleares/genética , Proteínas Repressoras/genética , Animais , Metilação de DNA , Camundongos , Camundongos Endogâmicos C57BL , Proteína 28 com Motivo Tripartido
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