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1.
N Engl J Med ; 380(1): 45-56, 2019 01 03.
Artigo em Inglês | MEDLINE | ID: mdl-30501490

RESUMO

BACKGROUND: Patients with diffuse large B-cell lymphoma that is refractory to primary and second-line therapies or that has relapsed after stem-cell transplantation have a poor prognosis. The chimeric antigen receptor (CAR) T-cell therapy tisagenlecleucel targets and eliminates CD19-expressing B cells and showed efficacy against B-cell lymphomas in a single-center, phase 2a study. METHODS: We conducted an international, phase 2, pivotal study of centrally manufactured tisagenlecleucel involving adult patients with relapsed or refractory diffuse large B-cell lymphoma who were ineligible for or had disease progression after autologous hematopoietic stem-cell transplantation. The primary end point was the best overall response rate (i.e., the percentage of patients who had a complete or partial response), as judged by an independent review committee. RESULTS: A total of 93 patients received an infusion and were included in the evaluation of efficacy. The median time from infusion to data cutoff was 14 months (range, 0.1 to 26). The best overall response rate was 52% (95% confidence interval, 41 to 62); 40% of the patients had complete responses, and 12% had partial responses. Response rates were consistent across prognostic subgroups. At 12 months after the initial response, the rate of relapse-free survival was estimated to be 65% (79% among patients with a complete response). The most common grade 3 or 4 adverse events of special interest included cytokine release syndrome (22%), neurologic events (12%), cytopenias lasting more than 28 days (32%), infections (20%), and febrile neutropenia (14%). Three patients died from disease progression within 30 days after infusion. No deaths were attributed to tisagenlecleucel, cytokine release syndrome, or cerebral edema. No differences between response groups in tumor expression of CD19 or immune checkpoint-related proteins were found. CONCLUSIONS: In this international study of CAR T-cell therapy in relapsed or refractory diffuse large B-cell lymphoma in adults, high rates of durable responses were produced with the use of tisagenlecleucel. (Funded by Novartis; JULIET ClinicalTrials.gov number, NCT02445248 .).


Assuntos
Imunoterapia Adotiva , Linfoma Difuso de Grandes Células B/terapia , Receptores de Antígenos de Linfócitos T/uso terapêutico , Receptores de Antígenos Quiméricos/uso terapêutico , Adulto , Idoso , Feminino , Humanos , Linfoma Difuso de Grandes Células B/mortalidade , Linfoma Difuso de Grandes Células B/patologia , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Intervalo Livre de Progressão , Recidiva , Análise de Sobrevida , Adulto Jovem
2.
Lancet ; 389(10072): 917-929, 2017 03 04.
Artigo em Inglês | MEDLINE | ID: mdl-28126333

RESUMO

BACKGROUND: The efficacy of ceritinib in patients with untreated anaplastic lymphoma kinase (ALK)-rearranged non-small-cell lung cancer (NSCLC) is not known. We assessed the efficacy and safety of ceritinib versus platinum-based chemotherapy in these patients. METHODS: This randomised, open-label, phase 3 study in untreated patients with stage IIIB/IV ALK-rearranged non-squamous NSCLC was done in 134 centres across 28 countries. Eligible patients were assigned via interactive response technology to oral ceritinib 750 mg/day or platinum-based chemotherapy ([cisplatin 75 mg/m2 or carboplatin AUC 5-6 plus pemetrexed 500 mg/m2] every 3 weeks for four cycles followed by maintenance pemetrexed); randomisation was stratified by World Health Organization performance status (0 vs 1-2), previous neoadjuvant or adjuvant chemotherapy, and presence of brain metastases as per investigator's assessment at screening. Investigators and patients were not masked to treatment assignment. The primary endpoint was blinded independent review committee assessed progression-free survival, based on all randomly assigned patients (the full analysis set). Efficacy analyses were done based on the full analysis set. All safety analyses were done based on the safety set, which included all patients who received at least one dose of study drug. This trial is registered with ClinicalTrials.gov, number NCT01828099. FINDINGS: Between Aug 19, 2013, and May 11, 2015, 376 patients were randomly assigned to ceritinib (n=189) or chemotherapy (n=187). Median progression-free survival (as assessed by blinded independent review committee) was 16·6 months (95% CI 12·6-27·2) in the ceritinib group and 8·1 months (5·8-11·1) in the chemotherapy group (hazard ratio 0·55 [95% CI 0·42-0·73]; p<0·00001). The most common adverse events were diarrhoea (in 160 [85%] of 189 patients), nausea (130 [69%]), vomiting (125 [66%]), and an increase in alanine aminotransferase (114 [60%]) in the ceritinib group and nausea (in 97 [55%] of 175 patients), vomiting (63 [36%]), and anaemia (62 [35%]) in the chemotherapy group. INTERPRETATION: First-line ceritinib showed a statistically significant and clinically meaningful improvement in progression-free survival versus chemotherapy in patients with advanced ALK-rearranged NSCLC. FUNDING: Novartis Pharmaceuticals Corporation.


Assuntos
Antineoplásicos/administração & dosagem , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Neoplasias Pulmonares/tratamento farmacológico , Pirimidinas/administração & dosagem , Sulfonas/administração & dosagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Antineoplásicos/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carboplatina/administração & dosagem , Carboplatina/efeitos adversos , Carcinoma Pulmonar de Células não Pequenas/mortalidade , Cisplatino/administração & dosagem , Cisplatino/efeitos adversos , Intervalo Livre de Doença , Feminino , Humanos , Estimativa de Kaplan-Meier , Neoplasias Pulmonares/mortalidade , Masculino , Pessoa de Meia-Idade , Pemetrexede/administração & dosagem , Pemetrexede/efeitos adversos , Pirimidinas/efeitos adversos , Sulfonas/efeitos adversos , Resultado do Tratamento , Adulto Jovem
3.
Lancet Oncol ; 18(7): 874-886, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28602779

RESUMO

BACKGROUND: Ceritinib is a next-generation anaplastic lymphoma kinase (ALK) inhibitor, which has shown robust anti-tumour efficacy, along with intracranial activity, in patients with ALK-rearranged non-small-cell lung cancer. In phase 1 and 2 studies, ceritinib has been shown to be highly active in both ALK inhibitor-naive and ALK inhibitor-pretreated patients who had progressed after chemotherapy (mostly multiple lines). In this study, we compared the efficacy and safety of ceritinib versus single-agent chemotherapy in patients with advanced ALK-rearranged non-small-cell lung cancer who had previously progressed following crizotinib and platinum-based doublet chemotherapy. METHODS: In this randomised, controlled, open-label, phase 3 trial, we recruited patients aged at least 18 years with ALK-rearranged stage IIIB or IV non-small-cell lung cancer (with at least one measurable lesion) who had received previous chemotherapy (one or two lines, including a platinum doublet) and crizotinib and had subsequent disease progression, from 99 centres across 20 countries. Other inclusion criteria were a WHO performance status of 0-2, adequate organ function and laboratory test results, a life expectancy of at least 12 weeks, and having recovered from previous anticancer treatment-related toxicities. We randomly allocated patients (1:1; with blocking [block size of four]; stratified by WHO performance status [0 vs 1-2] and presence or absence of brain metastases) to oral ceritinib 750 mg per day fasted (in 21 day treatment cycles) or chemotherapy (intravenous pemetrexed 500 mg/m2 or docetaxel 75 mg/m2 [investigator choice], every 21 days). Patients who discontinued chemotherapy because of progressive disease could cross over to the ceritinib group. The primary endpoint was progression-free survival, assessed by a masked independent review committee using Response Evaluation Criteria in Solid Tumors 1.1 in the intention-to-treat population, assessed every 6 weeks until month 18 and every 9 weeks thereafter. This trial is registered with ClinicalTrials.gov, number NCT01828112, and is ongoing but no longer recruiting patients. FINDINGS: Between June 28, 2013, and Nov 2, 2015, we randomly allocated 231 patients; 115 (50%) to ceritinib and 116 (50%) to chemotherapy (40 [34%] to pemetrexed, 73 [63%] to docetaxel, and three [3%] discontinued before receiving treatment). Median follow-up was 16·5 months (IQR 11·5-21·4). Ceritinib showed a significant improvement in median progression-free survival compared with chemotherapy (5·4 months [95% CI 4·1-6·9] for ceritinib vs 1·6 months [1·4-2·8] for chemotherapy; hazard ratio 0·49 [0·36-0·67]; p<0·0001). Serious adverse events were reported in 49 (43%) of 115 patients in the ceritinib group and 36 (32%) of 113 in the chemotherapy group. Treatment-related serious adverse events were similar between groups (13 [11%] in the ceritinib group vs 12 [11%] in the chemotherapy group). The most frequent grade 3-4 adverse events in the ceritinib group were increased alanine aminotransferase concentration (24 [21%] of 115 vs two [2%] of 113 in the chemotherapy group), increased γ glutamyltransferase concentration (24 [21%] vs one [1%]), and increased aspartate aminotransferase concentration (16 [14%] vs one [1%] in the chemotherapy group). Six (5%) of 115 patients in the ceritinib group discontinued because of adverse events compared with eight (7%) of 116 in the chemotherapy group. 15 (13%) of 115 patients in the ceritinib group and five (4%) of 113 in the chemotherapy group died during the treatment period (from the day of the first dose of study treatment to 30 days after the final dose). 13 (87%) of the 15 patients who died in the ceritinib group died because of disease progression and two (13%) died because of an adverse event (one [7%] cerebrovascular accident and one [7%] respiratory failure); neither of these deaths were considered by the investigator to be treatment related. The five (4%) deaths in the chemotherapy group were all due to disease progression. INTERPRETATION: These findings show that patients derive significant clinical benefit from a more potent ALK inhibitor after failure of crizotinib, and establish ceritinib as a more efficacious treatment option compared with chemotherapy in this patient population. FUNDING: Novartis Pharmaceuticals Corporation.


Assuntos
Antineoplásicos/uso terapêutico , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Neoplasias Pulmonares/tratamento farmacológico , Pemetrexede/uso terapêutico , Pirimidinas/uso terapêutico , Receptores Proteína Tirosina Quinases/genética , Sulfonas/uso terapêutico , Taxoides/uso terapêutico , Adulto , Alanina Transaminase/sangue , Quinase do Linfoma Anaplásico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Aspartato Aminotransferases/sangue , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/secundário , Crizotinibe , Progressão da Doença , Intervalo Livre de Doença , Docetaxel , Feminino , Rearranjo Gênico , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Compostos de Platina/administração & dosagem , Pirazóis/uso terapêutico , Piridinas/uso terapêutico , Pirimidinas/efeitos adversos , Critérios de Avaliação de Resposta em Tumores Sólidos , Retratamento , Sulfonas/efeitos adversos , gama-Glutamiltransferase/sangue
4.
Toxicol Pathol ; 42(4): 684-95, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24448599

RESUMO

The purpose of this article is to characterize skin lesions in cynomolgus monkeys following vildagliptin (dipeptidyl peptidase-4 inhibitor) treatment. Oral vildagliptin administration caused dose-dependent and reversible blister formation, peeling and flaking skin, erosions, ulcerations, scabs, and sores involving the extremities at ≥5 mg/kg/day and necrosis of the tail and the pinnae at ≥80 mg/kg/day after 3 weeks of treatment. At the affected sites, the media and the endothelium of dermal arterioles showed hypertrophy/hyperplasia. Skin lesion formation was prevented by elevating ambient temperature. Vildagliptin treatment also produced an increase in blood pressure and heart rate likely via increased sympathetic tone. Following treatment with vildagliptin at 80 mg/kg/day, the recovery time after lowering the temperature in the feet of monkeys and inducing cold stress was prolonged. Ex vivo investigations showed that small digital arteries from skin biopsies of vildagliptin-treated monkeys exhibited an increase in neuropeptide Y-induced vasoconstriction. This finding correlated with a specific increase in NPY and in NPY1 receptors observed in the skin of vildagliptin-treated monkeys. Present data provide evidence that skin effects in monkeys are of vascular origin and that the effects on the NPY system in combination with increased peripheral sympathetic tone play an important pathomechanistic role in the pathogenesis of cutaneous toxicity.


Assuntos
Adamantano/análogos & derivados , Neuropeptídeo Y/efeitos adversos , Nitrilas/efeitos adversos , Pirrolidinas/efeitos adversos , Dermatopatias/patologia , Pele/efeitos dos fármacos , Lesões do Sistema Vascular/patologia , Adamantano/administração & dosagem , Adamantano/efeitos adversos , Administração Oral , Animais , Pressão Sanguínea/efeitos dos fármacos , Temperatura Baixa , Dipeptidases/sangue , Dipeptidil Peptidase 4/metabolismo , Inibidores da Dipeptidil Peptidase IV , Dipeptidil Peptidases e Tripeptidil Peptidases/sangue , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos , Macaca fascicularis , Neuropeptídeo Y/administração & dosagem , Nitrilas/administração & dosagem , Norepinefrina/urina , Pirrolidinas/administração & dosagem , Pele/patologia , Dermatopatias/induzido quimicamente , Estresse Fisiológico , Lesões do Sistema Vascular/induzido quimicamente , Vasoconstrição/efeitos dos fármacos , Vildagliptina
5.
EJHaem ; 5(1): 76-83, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38406517

RESUMO

CD19-targeting treatments have shown promise in relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL). Loncastuximab tesirine (loncastuximab tesirine-lpyl [Lonca]) is a CD19-targeting antibody-drug conjugate indicated for R/R DLBCL after at least two systemic treatments. CD19 expression was evaluated in patients receiving Lonca in the LOTIS-2 clinical trial with available tissue samples obtained after last systemic therapy/before Lonca treatment. Lonca cytotoxicity was evaluated in a panel of six lymphoma cell lines with various CD19 expression levels. Quantitative systems pharmacology (QSP) modelling was used to predict Lonca responses. Lonca responses were seen in patients across all CD19 expression levels, including patients with low/no detectable CD19 expression and H-scores at baseline. Similarly, Lonca induced cytotoxicity in cell lines with different levels of CD19 expression, including one with very low expression. QSP modelling predicted that CD19 expression by immunohistochemistry alone does not predict Lonca response, whereas inclusion of CD19 surface density improved response prediction. Virtual patients responded to Lonca with estimated CD19 as low as 1000 molecules/cell of CD19, normally below the immunohistochemistry detection level. We found Lonca is an effective treatment for R/R DLBCL regardless of CD19 expression by immunohistochemistry. These results provide the basis for future studies addressing CD19-targeted agent sequencing.

6.
Nat Med ; 24(10): 1504-1506, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30275569

RESUMO

We identified genetic mutations in CD19 and loss of heterozygosity at the time of CD19- relapse to chimeric antigen receptor (CAR) therapy. The mutations are present in the vast majority of resistant tumor cells and are predicted to lead to a truncated protein with a nonfunctional or absent transmembrane domain and consequently to a loss of surface antigen. This irreversible loss of CD19 advocates for an alternative targeting or combination CAR approach.


Assuntos
Resistencia a Medicamentos Antineoplásicos/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Receptores de Antígenos de Linfócitos T/genética , Receptores de Antígenos Quiméricos/genética , Antígenos CD19/genética , Antígenos CD19/imunologia , Humanos , Imunoterapia Adotiva , Perda de Heterozigosidade/genética , Mutação , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/imunologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Receptores de Antígenos Quiméricos/imunologia , Receptores de Antígenos Quiméricos/uso terapêutico , Linfócitos T/imunologia
7.
PLoS Biol ; 1(3): E74, 2003 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-14691545

RESUMO

Understanding and harnessing cellular potency are fundamental in biology and are also critical to the future therapeutic use of stem cells. Transcriptome analysis of these pluripotent cells is a first step towards such goals. Starting with sources that include oocytes, blastocysts, and embryonic and adult stem cells, we obtained 249,200 high-quality EST sequences and clustered them with public sequences to produce an index of approximately 30,000 total mouse genes that includes 977 previously unidentified genes. Analysis of gene expression levels by EST frequency identifies genes that characterize preimplantation embryos, embryonic stem cells, and adult stem cells, thus providing potential markers as well as clues to the functional features of these cells. Principal component analysis identified a set of 88 genes whose average expression levels decrease from oocytes to blastocysts, stem cells, postimplantation embryos, and finally to newborn tissues. This can be a first step towards a possible definition of a molecular scale of cellular potency. The sequences and cDNA clones recovered in this work provide a comprehensive resource for genes functioning in early mouse embryos and stem cells. The nonrestricted community access to the resource can accelerate a wide range of research, particularly in reproductive and regenerative medicine.


Assuntos
Embrião de Mamíferos/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Células-Tronco/citologia , Transcrição Gênica , Animais , Animais Recém-Nascidos , Blastocisto/citologia , Blastocisto/metabolismo , Biologia Computacional , DNA Complementar/metabolismo , Bases de Dados Genéticas , Etiquetas de Sequências Expressas , Biblioteca Gênica , Camundongos , Modelos Genéticos , Dados de Sequência Molecular , Oócitos/citologia , Oócitos/metabolismo , Análise de Componente Principal , RNA Mensageiro/metabolismo , Análise de Sequência de DNA
8.
J Mol Histol ; 44(6): 733-47, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23880984

RESUMO

Dipeptidyl peptidase IV (DPP4) is a peptidase whose inhibition is beneficial in Type II diabetes treatment. Several evidences suggest potential implication of DPP4 in skin disorders such as psoriasis, keloids and fibrotic skin diseases where its inhibition could also be beneficial. DPP4 expression in human skin was described mainly in dermal fibroblasts and a subset of keratinocytes in the basal layer. Of importance in the perspective of preclinical experimentation, DPP4 distribution in skin of non-human primate species has not been documented. This report evidences unexpected differences between a set of human and cynomolgus monkey skin samples revealing a major expression of DPP4 in eccrine sweat glands of cynomolgus monkeys but not in humans. This represents a unique distinctive feature compared to the conserved expression of dipeptidyl peptidases 8 and 9 and potential relevant DPP4 substrates such as neuropeptide Y (NPY) and receptors (NPY-receptor 1 and Neurokinin receptor). Finally the observation that cathepsin D, an unrelated protease, shows the opposite expression compared to DPP4 (present in human but not in cynomolgus monkey eccrine sweat glands) could indicate that human eccrine sweat glands evolved a divergent protease repertoire compared to non-human primates. These unexpected differences in the eccrine sweat glands protease repertoire will need to be confirmed extending the analysis to a major number of donors but could imply possible biochemical divergences, reflecting the functional evolution of the glands and the control of their activity. Our findings also demonstrate that non-human primates studies aiming at understanding DPP4 function in skin biology are not readily translatable to human.


Assuntos
Dipeptidil Peptidase 4/metabolismo , Glândulas Écrinas/metabolismo , Adulto , Animais , Catepsina D/metabolismo , Dipeptidases/genética , Dipeptidases/metabolismo , Dipeptidil Peptidase 4/genética , Dipeptidil Peptidases e Tripeptidil Peptidases/genética , Dipeptidil Peptidases e Tripeptidil Peptidases/metabolismo , Feminino , Regulação da Expressão Gênica , Humanos , Imuno-Histoquímica , Macaca fascicularis , Masculino , Pessoa de Meia-Idade , Neuropeptídeo Y/metabolismo , Receptores de Neuropeptídeo Y/metabolismo
9.
PLoS One ; 5(4): e10369, 2010 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-20442780

RESUMO

In specific cell types like keratinocytes, Notch signaling plays an important pro-differentiation and tumor suppressing function, with down-modulation of the Notch1 gene being associated with cancer development. Besides being controlled by p53, little else is known on regulation of Notch1 gene expression in this context. We report here that transcription of this gene is driven by a TATA-less "sharp peak" promoter and that the minimal functional region of this promoter, which extends from the -342 bp position to the initiation codon, is differentially active in normal versus cancer cells. This GC rich region lacks p53 binding sites, but binds Klf4 and Sp3. This finding is likely to be of biological significance, as Klf4 and, to a lesser extent, Sp3 are up-regulated in a number of cancer cells where Notch1 expression is down-modulated, and Klf4 over-expression in normal cells is sufficient to down-modulate Notch1 gene transcription. The combined knock-down of Klf4 and Sp3 was necessary for the reverse effect of increasing Notch1 transcription, consistent with the two factors exerting an overlapping repressor function through their binding to the Notch1 promoter.


Assuntos
Regulação da Expressão Gênica/genética , Queratinócitos/metabolismo , Fatores de Transcrição Kruppel-Like/fisiologia , Receptor Notch1/genética , Fator de Transcrição Sp3/fisiologia , Linhagem Celular Tumoral , Células Cultivadas , Regulação Neoplásica da Expressão Gênica , Redes Reguladoras de Genes , Humanos , Queratinócitos/citologia , Queratinócitos/patologia , Fator 4 Semelhante a Kruppel , Fatores de Transcrição Kruppel-Like/genética , Fatores de Transcrição Kruppel-Like/metabolismo , Neoplasias , Regiões Promotoras Genéticas , Ligação Proteica , Fator de Transcrição Sp3/genética , Fator de Transcrição Sp3/metabolismo , Transcrição Gênica
10.
Nat Biotechnol ; 28(5): 463-9, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20458316

RESUMO

Earlier and more reliable detection of drug-induced kidney injury would improve clinical care and help to streamline drug-development. As the current standards to monitor renal function, such as blood urea nitrogen (BUN) or serum creatinine (SCr), are late indicators of kidney injury, we conducted ten nonclinical studies to rigorously assess the potential of four previously described nephrotoxicity markers to detect drug-induced kidney and liver injury. Whereas urinary clusterin outperformed BUN and SCr for detecting proximal tubular injury, urinary total protein, cystatin C and beta2-microglobulin showed a better diagnostic performance than BUN and SCr for detecting glomerular injury. Gene and protein expression analysis, in-situ hybridization and immunohistochemistry provide mechanistic evidence to support the use of these four markers for detecting kidney injury to guide regulatory decision making in drug development. The recognition of the qualification of these biomarkers by the EMEA and FDA will significantly enhance renal safety monitoring.


Assuntos
Biomarcadores Farmacológicos/urina , Clusterina/urina , Cistatina C/urina , Testes de Função Renal/métodos , Microglobulina beta-2/urina , Animais , Biomarcadores Farmacológicos/metabolismo , Distribuição de Qui-Quadrado , Clusterina/genética , Clusterina/metabolismo , Creatinina/sangue , Creatinina/metabolismo , Cistatina C/genética , Cistatina C/metabolismo , Perfilação da Expressão Gênica , Histocitoquímica , Rim/química , Rim/efeitos dos fármacos , Rim/lesões , Rim/patologia , Nefropatias/diagnóstico , Nefropatias/patologia , Glomérulos Renais/patologia , Túbulos Renais Proximais/patologia , Masculino , Prognóstico , Proteinúria/urina , Curva ROC , Ratos , Ratos Wistar , Reprodutibilidade dos Testes , Microglobulina beta-2/genética , Microglobulina beta-2/metabolismo
11.
Exp Cell Res ; 312(8): 1312-22, 2006 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-16455075

RESUMO

Dendritic cell (DC) maturation links peripheral events initiated by the encounter with pathogens to the activation and expansion of antigen-specific T lymphocytes in secondary lymphoid organs. Here, we describe an as yet unrecognized modulator of human DC maturation, the transcriptional repressor BCL6. We found that both myeloid and plasmacytoid DCs constitutively express BCL6, which is rapidly downregulated following maturation triggered by selected stimuli. Both in unstimulated and maturing DCs, control of BCL6 protein levels reflects the convergence of several mechanisms regulating BCL6 stability, mRNA transcription and nuclear export. By regulating the induction of several genes implicated in the immune response, including inflammatory cytokines, chemokines and survival genes, BCL6 may represent a pivotal modulator of the afferent branch of the immune response.


Assuntos
Diferenciação Celular/fisiologia , Proteínas de Ligação a DNA/metabolismo , Células Dendríticas/metabolismo , Regulação para Baixo/fisiologia , Células-Tronco Hematopoéticas/metabolismo , Proteínas Repressoras/metabolismo , Transporte Ativo do Núcleo Celular/genética , Apresentação de Antígeno/genética , Células Cultivadas , Proteínas de Ligação a DNA/genética , Células Dendríticas/citologia , Regulação da Expressão Gênica/imunologia , Células-Tronco Hematopoéticas/citologia , Humanos , Fatores Imunológicos/genética , Fatores Imunológicos/metabolismo , Células Progenitoras Mieloides/citologia , Células Progenitoras Mieloides/metabolismo , Plasmócitos/citologia , Plasmócitos/metabolismo , Proteínas Proto-Oncogênicas c-bcl-6 , RNA Mensageiro/metabolismo , Proteínas Repressoras/genética , Fatores de Tempo , Ativação Transcricional/genética
12.
Mol Cell ; 11(6): 1563-74, 2003 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12820969

RESUMO

Transcription factors within a family usually share the ability to recognize similar or identical consensus sites. For example, the five mammalian NF-kappaB/Rel proteins generate more than 12 dimers recognizing 9-11 nucleotide kappaB sites. Each dimer selectively regulates a few target promoters; however, several genes are redundantly induced by more than one dimer. Whether this property simply generates redundancy in target gene activation or underlies more complex regulatory mechanisms is an open issue. We show here that during dendritic cell maturation, rapidly activated dimers (e.g., p50/RelA) bound to a subset of target promoters are gradually replaced by slowly activated dimers (e.g., p52/RelB). Since the dimers have different transcriptional activity at each promoter, the dimer exchange allows fine tuning of the response over time. Further, due to the insensitivity of p52/RelB to the NF-kappaB inhibitors, the IkappaBs, dimer exchange contributes to sustained activation of selected NF-kappaB targets in spite of the resynthesis of IkappaBalpha.


Assuntos
Células Dendríticas/metabolismo , NF-kappa B/química , NF-kappa B/metabolismo , Fatores de Transcrição/metabolismo , Adenoviridae/genética , Células Dendríticas/citologia , Dimerização , Humanos , Proteínas I-kappa B/metabolismo , Interleucina-12/genética , Interleucina-8/genética , Cinética , Lipopolissacarídeos , NF-kappa B/genética , Regiões Promotoras Genéticas , Ligação Proteica , Fatores de Transcrição/genética , Transcrição Gênica , Ativação Transcricional , Fator de Necrose Tumoral alfa/metabolismo
13.
Nat Immunol ; 3(1): 69-75, 2002 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11743587

RESUMO

We found that inflammatory stimuli induce p38 mitogen-activated protein kinase-dependent phosphorylation and phosphoacetylation of histone H3; this selectively occurred on the promoters of a subset of stimulus-induced cytokine and chemokine genes. p38 activity was required to enhance the accessibility of the cryptic NF-kappa B binding sites contained in H3 phosphorylated promoters, which indicated that p38-dependent H3 phosphorylation may mark promoters for increased NF-kappa B recruitment. These results show that p38 plays an additional role in the induction of the inflammatory and immune response: the regulation of NF-kappa B recruitment to selected chromatin targets.


Assuntos
Quimiocina CCL2/genética , Cromatina/metabolismo , Células Dendríticas/metabolismo , Regulação da Expressão Gênica/fisiologia , Histonas/metabolismo , Inflamação/genética , Interleucina-8/genética , Proteínas Quinases Ativadas por Mitógeno/fisiologia , NF-kappa B/metabolismo , Regiões Promotoras Genéticas , Protamina Quinase/metabolismo , Processamento de Proteína Pós-Traducional , Acetilação , Animais , Sítios de Ligação , Cromatina/genética , Cromatina/ultraestrutura , DNA/metabolismo , Dimerização , Histonas/química , Humanos , Interleucina-12/genética , Interleucina-6/genética , Lipopolissacarídeos/farmacologia , Sistema de Sinalização das MAP Quinases/fisiologia , Proteínas Quinases Ativadas por Mitógeno/antagonistas & inibidores , Modelos Genéticos , Fosforilação , Fosfosserina/química , Ligação Proteica , Relação Estrutura-Atividade , Transcrição Gênica , Proteínas Quinases p38 Ativadas por Mitógeno
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