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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.
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Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/patología , Epistasis Genética , Proteínas de Homeodominio/metabolismo , Transcripción Genética , Animales , Calcineurina/metabolismo , Señalización del Calcio , Retroalimentación Fisiológica , Femenino , Regulación de la Expresión Génica/inmunología , Genotipo , Memoria Inmunológica , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Factores de Transcripción NFATC/metabolismo , Escape del TumorRESUMEN
Bromodomain and extraterminal motif (BET) proteins are pharmacologic targets for the treatment of diverse diseases, yet the roles of individual BET family members remain unclear. We find that BRD2, but not BRD4, co-localizes with the architectural/insulator protein CCCTC-binding factor (CTCF) genome-wide. CTCF recruits BRD2 to co-bound sites whereas BRD2 is dispensable for CTCF occupancy. Disruption of a CTCF/BRD2-occupied element positioned between two unrelated genes enables regulatory influence to spread from one gene to another, suggesting that CTCF and BRD2 form a transcriptional boundary. Accordingly, single-molecule mRNA fluorescence in situ hybridization (FISH) reveals that, upon site-specific CTCF disruption or BRD2 depletion, expression of the two genes becomes increasingly correlated. HiC shows that BRD2 depletion weakens boundaries co-occupied by CTCF and BRD2, but not those that lack BRD2. These findings indicate that BRD2 supports boundary activity, and they raise the possibility that pharmacologic BET inhibitors can influence gene expression in part by perturbing domain boundary function.
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Ensamble y Desensamble de Cromatina , Cromatina/metabolismo , Proteínas Cromosómicas no Histona/metabolismo , Células Madre Embrionarias/metabolismo , Elementos de Facilitación Genéticos , Proteínas Represoras/metabolismo , Transcripción Genética , Animales , Sitios de Unión , Factor de Unión a CCCTC , Sistemas CRISPR-Cas , Línea Celular , Cromatina/genética , Proteínas Cromosómicas no Histona/genética , Factor de Transcripción GATA1/genética , Factor de Transcripción GATA1/metabolismo , Edición Génica/métodos , Hibridación Fluorescente in Situ , Proteínas de Transporte de Membrana/genética , Proteínas de Transporte de Membrana/metabolismo , Ratones , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Unión Proteica , ARN Mensajero/genética , ARN Mensajero/metabolismo , Receptores de Estrógenos/genética , Receptores de Estrógenos/metabolismo , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo , Proteínas Represoras/genética , Imagen Individual de Molécula/métodos , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , TransfecciónRESUMEN
Acute invasive fungal sinusitis (AIFS) is an aggressive disease with significant mortality and morbidity. Surgical debridement is a mainstay of treatment. However, orbital involvement may limit its efficacy and is an independent risk factor for mortality. Traditionally, orbital exenteration has been utilized in cases with orbital invasion and ophthalmoplegia or vision loss. Retrobulbar liposomal amphotericin B injection may improve disease control and has the potential to spare the morbidity associated with exenteration. In this video article, we document the use of serial endonasal debridement with retrobulbar injections to salvage the eye in a patient with significant orbital involvement. A 28-year-old immunocompromised female patient presented with acute onset restricted right extraocular movement, progressive orbital pain, V2 trigeminal numbness, and 20/40 vision. The patient underwent recurrent debridement and retrobulbar injections of liposomal amphotericin B. Her serial exams, including changes in extraocular muscle appearance and gradual improvement in extraocular movement, were documented. The exam six months after initial presentation demonstrated 20/20 vision, minimal extraocular movement restriction, and proper healing of the orbit and ethmoid. The salvage of the patient's orbit suggests that liposomal amphotericin B injections with debridement may be a viable treatment alternative in patients with acute invasive fungal sinusitis and orbital involvement.
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INTRODUCTION: Chronic rhinosinusitis (CRS) can be associated with tumors involving the maxillary sinus, but outcomes after undergoing maxillectomy with free flap reconstruction remain unclear. METHODS: A retrospective analysis of medical records was performed to evaluate evidence of CRS in patients who underwent maxillectomy with free flap reconstruction at a single tertiary care academic institution from 2013 through 2020. RESULTS: Eighty-four patients were assessed. Nineteen (22.6%) patients were diagnosed with CRS after surgery, 23 (27.4%) patients were treated for sinus symptoms, and 49 (58.3%) had radiographic evidence of sinus inflammation for more than 6 months. Risk factors for requiring sinus treatment included adjuvant or neoadjuvant chemotherapy (p = 0.002) and pre-operative use of sinus medication (p < 0.001). Radiographic evidence of sinusitis 6 months after surgery is also closely associated with sinusitis treatment (p = 0.051). CONCLUSIONS: CRS may be underdiagnosed in patients undergoing maxillectomy with microvascular reconstruction. Further evaluation into patient sinus disease and symptoms following neoplastic surgery may lead to a higher quality of life in some long-term survivors.
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The widely expressed bromodomain and extraterminal motif (BET) proteins bromodomain-containing protein 2 (BRD2), BRD3, and BRD4 are multifunctional transcriptional regulators that bind acetylated chromatin via their conserved tandem bromodomains. Small molecules that target BET bromodomains are being tested for various diseases but typically do not discern between BET family members. Genomic distributions and protein partners of BET proteins have been described, but the basis for differences in BET protein function within a given lineage remains unclear. By establishing a gene knockout-rescue system in a Brd2-null erythroblast cell line, here we compared a series of mutant and chimeric BET proteins for their ability to modulate cell growth, differentiation, and gene expression. We found that the BET N-terminal halves bearing the bromodomains convey marked differences in protein stability but do not account for specificity in BET protein function. Instead, when BET proteins were expressed at comparable levels, their specificity was largely determined by the C-terminal half. Remarkably, a chimeric BET protein comprising the N-terminal half of the structurally similar short BRD4 isoform (BRD4S) and the C-terminal half of BRD2 functioned similarly to intact BRD2. We traced part of the BRD2-specific activity to a previously uncharacterized short segment predicted to harbor a coiled-coil (CC) domain. Deleting the CC segment impaired BRD2's ability to restore growth and differentiation, and the CC region functioned in conjunction with the adjacent ET domain to impart BRD2-like activity onto BRD4S. In summary, our results identify distinct BET protein domains that regulate protein turnover and biological activities.
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Proteínas de Ciclo Celular/genética , Relación Estructura-Actividad , Factores de Transcripción/genética , Acetilación , Secuencias de Aminoácidos/genética , Proteínas de Ciclo Celular/ultraestructura , Diferenciación Celular/genética , Línea Celular , Proliferación Celular/genética , Cromatina/genética , Eritroblastos/química , Eritroblastos/metabolismo , Eritroblastos/ultraestructura , Regulación de la Expresión Génica/genética , Humanos , Dominios Proteicos/genética , Isoformas de Proteínas/genética , Bibliotecas de Moléculas Pequeñas/química , Factores de Transcripción/ultraestructuraRESUMEN
Background: Only a fraction of patients with allergic rhinitis receive allergen-specific immunotherapy (AIT). AIT is most commonly delivered subcutaneously in a series of injections over 3-5 years. Common obstacles to completing this therapy include cost and inconvenience. Intralymphatic immunotherapy (ILIT) has been proposed as a faster alternative, which requires as few as three injections spaced 4 weeks apart. Objective: This systematic review and meta-analysis evaluated the current evidence that supports the use of ILIT for allergic rhinitis. Methods: Clinical trials were identified in the published literature by using an electronic search strategy and were evaluated by using a risk of bias tool. Treatment outcome (symptom scores, medication scores, and combined symptom and medication scores) and provocation testing results (nasal provocation and skin-prick testing) were included in a meta-analysis of standardized mean difference with subgrouping by using a random-effects model. Overall adverse event rates were tabulated, and overall risk ratios were calculated by using a random-effects model. Results: We identified 17 clinical trials that met eligibility criteria. The standardized mean difference of ILIT on the symptom and medication score was -0.72 (95% confidence interval [CI], -0.98 to -0.46; p < 0.0001) (n = 10). The standardized mean difference of ILIT on nasal provocation and skin-prick testing was -1.00 (95% CI, -1.38 to -0.61; p < 0.0001) (n = 7) and -0.73 (95% CI, -0.99 to -0.47; p < 0.0001) (n = 7), respectively. No statistically significant heterogeneity was detected. The overall adverse event rate was 39.5% for ILIT and 23.5% for placebo. Also, 98.4% of adverse events were mild. Conclusion: Our meta-analysis demonstrated that ILIT was safe, conferred desensitization to seasonal and nonseasonal allergens, alleviated allergic rhinitis symptoms, and reduced medication use. A larger randomized, double-blind, placebo controlled trial will be necessary for wider adaptation of this form of AIT.
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Desensibilización Inmunológica , Rinitis Alérgica , Alérgenos , Humanos , Ensayos Clínicos Controlados Aleatorios como Asunto , Rinitis , Rinitis Alérgica/diagnóstico , Rinitis Alérgica/terapia , Pruebas Cutáneas , Resultado del TratamientoRESUMEN
Anaplastic lymphoma kinase (ALK) is a receptor tyrosine kinase physiologically expressed by fetal neural cells. However, aberrantly expressed ALK is involved in the pathogenesis of diverse malignancies, including distinct types of lymphoma, lung carcinoma, and neuroblastoma. The aberrant ALK expression in nonneural cells results from chromosomal translocations that create novel fusion proteins. These protein hybrids compose the proximal part of a partner gene, including its promoter region, and the distal part of ALK, including the coding sequence for the entire kinase domain. ALK was first identified in a subset of T-cell lymphomas with anaplastic large cell lymphoma (ALCL) morphology (ALK+ ALCL), the vast majority of which harbor the well-characterized nucleophosmin (NPM)-ALK fusion protein. NPM-ALK co-opts several intracellular signal transduction pathways, foremost being the STAT3 pathway, normally activated by cytokines from the interleukin-2 (IL-2) family to promote cell proliferation and to inhibit apoptosis. Many genes and proteins modulated by NPM-ALK are also involved in evasion of antitumor immune response, protection from hypoxia, angiogenesis, DNA repair, cell migration and invasiveness, and cell metabolism. In addition, NPM-ALK uses epigenetic silencing mechanisms to downregulate tumor suppressor genes to maintain its own expression. Importantly, NPM-ALK is capable of transforming primary human CD4+ T cells into immortalized cell lines indistinguishable from patient-derived ALK+ ALCL. Preliminary clinical studies indicate that inhibition of NPM-ALK induces long-lasting complete remissions in a large subset of heavily pretreated adult patients and the vast majority of children with high-stage ALK+ ALCL. Combining ALK inhibition with other novel therapeutic modalities should prove even more effective.
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Transformación Celular Neoplásica/genética , Linfoma Anaplásico de Células Grandes/genética , Linfoma de Células T/genética , Proteínas de Fusión Oncogénica/genética , Proteínas Tirosina Quinasas/genética , Quinasa de Linfoma Anaplásico , Animales , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Linfocitos T CD4-Positivos/metabolismo , Linfocitos T CD4-Positivos/patología , Transformación Celular Neoplásica/efectos de los fármacos , Transformación Celular Neoplásica/metabolismo , Transformación Celular Neoplásica/patología , Citocinas/metabolismo , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Linfoma Anaplásico de Células Grandes/tratamiento farmacológico , Linfoma Anaplásico de Células Grandes/metabolismo , Linfoma Anaplásico de Células Grandes/patología , Linfoma de Células T/tratamiento farmacológico , Linfoma de Células T/metabolismo , Linfoma de Células T/patología , MicroARNs/genética , MicroARNs/metabolismo , Terapia Molecular Dirigida/métodos , Proteínas Nucleares/antagonistas & inhibidores , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Nucleofosmina , Proteínas de Fusión Oncogénica/antagonistas & inhibidores , Proteínas de Fusión Oncogénica/metabolismo , Inhibidores de Proteínas Quinasas/farmacología , Inhibidores de Proteínas Quinasas/uso terapéutico , Proteínas Tirosina Quinasas/antagonistas & inhibidores , Proteínas Tirosina Quinasas/metabolismo , Proteínas Tirosina Quinasas Receptoras/antagonistas & inhibidores , Proteínas Tirosina Quinasas Receptoras/genética , Proteínas Tirosina Quinasas Receptoras/metabolismo , Transducción de Señal/efectos de los fármacosRESUMEN
Pharmacologic inhibitors of the bromodomain and extra-terminal motif (BET) protein family are in clinical trials for the treatment of hematologic malignancies, yet the functions of individual BET proteins remain largely uncharacterized. We review the molecular roles of BETs in the context of erythropoiesis. Studies in this lineage have provided valuable insights into their mechanisms of action, and helped define the individual and overlapping functions of BET protein family members BRD2, BRD3, and BRD4. These studies have important ramifications for our understanding of the molecular and physiologic roles of BET proteins, and provide a framework for elucidating some of the beneficial and adverse effects of pharmacologic inhibitors.
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Eritropoyesis/fisiología , Proteínas Nucleares/metabolismo , Dominios Proteicos , Factores de Transcripción/metabolismo , Animales , Cromatina/metabolismo , Humanos , Proteínas Nucleares/antagonistas & inhibidores , Proteínas Nucleares/química , Factores de Transcripción/antagonistas & inhibidores , Factores de Transcripción/químicaRESUMEN
BACKGROUND: This scoping review aims to review cases of extranodal marginal zone lymphoma (MZL) of the larynx to establish best management practices for this rare clinical entity. METHODS: In this paper, we report a case of laryngeal MZL, in accordance with CARE guidelines. We then performed a scoping review according to PRISMA-ScR criteria of published cases of MZL involving the larynx. The following data were collected for each case: age, sex, size, location(s) involved, stage, treatment, follow-up, and recurrence duration. RESULTS: Sixty-six patients with laryngeal MZL, first reported in 1990, were identified. Characterized by its low-grade histological appearance and indolent course, laryngeal MZL is generally confined to the larynx and has an excellent prognosis with radiation used as first-line therapy. CONCLUSIONS: It is imperative for clinicians to consider lymphoma in the differential diagnosis of a laryngeal tumor from any subsite, as certain pathologies may carry high risks of metastasis.
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BACKGROUND: Cystic fibrosis transmembrane conductance regulator (CFTR) modulators improve pulmonary outcomes in cystic fibrosis (CF) by stabilizing the CFTR protein on respiratory epithelial surfaces. To determine the efficacy of CFTR modulators on sinonasal outcomes in patients with CF, we performed a meta-analysis of clinical trials to date that include functional and radiographic evidence of sinus disease. METHODS: English full-text articles were searched in PubMed, Embase, and Scopus databases. Two reviewers screened articles and a third reviewer resolved disagreements. Articles were included if they reported functional or radiological sinonasal outcomes in patients with CF before and after CFTR modulator therapies. Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed, and the risk of bias in non-randomized studies of interventions tool was used for quality assessment. The generic inverse variance method with random effects model was used for meta-analysis. Standardized mean difference (SMD) and mean difference (MD) were used as effect measurements. RESULTS: Seven prospective and two retrospective studies representing 248 patients were included in this analysis. There was a significant improvement in sinonasal outcome test-22 scores on elexacaftorâtezacaftorâivacaftor (MD = 12.80, [95% confidence interval, CI: 10.46â15.13], p < 0.001, n = 222), with no heterogeneity detected (I2 = 0%, p = 0.820). There was also a significant improvement in LundâMackay scores (SMD = 1.25, [95% CI: 0.58â1.91], p < 0.001, n = 88), with heterogeneity detected (I2 = 67%, p = 0.030). CONCLUSIONS: CFTR modulators improve functional and radiologic sinonasal outcomes. Given the utility of CFTR modulators, the treatment paradigm for CF-related chronic rhinosinusitis promises to evolve.
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Aminofenoles , Regulador de Conductancia de Transmembrana de Fibrosis Quística , Fibrosis Quística , Quinolonas , Rinosinusitis , Humanos , Aminofenoles/uso terapéutico , Benzodioxoles/uso terapéutico , Fibrosis Quística/complicaciones , Fibrosis Quística/diagnóstico por imagen , Fibrosis Quística/tratamiento farmacológico , Regulador de Conductancia de Transmembrana de Fibrosis Quística/agonistas , Regulador de Conductancia de Transmembrana de Fibrosis Quística/genética , Senos Paranasales/diagnóstico por imagen , Quinolonas/uso terapéutico , Resultado del Tratamiento , Rinosinusitis/diagnóstico por imagen , Rinosinusitis/tratamiento farmacológico , Rinosinusitis/etiologíaRESUMEN
The nasoseptal flap is a workhorse reconstructive option for anterior skull base defects during endonasal surgery. This paper highlights the versatility of the nasoseptal flap. After providing a brief historical perspective, this review will focus on the relevant primary literature published in the last ten years. We will touch upon new applications of the flap, how the flap has been modified to expand its reach and robustness, and some of the current limitations. We will conclude by discussing what the future holds for improving upon the design and use of the nasoseptal flap in anterior skull base reconstruction.
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The impact of the coronavirus disease 2019 (COVID-19) pandemic on the management of head and neck cancer must be addressed. Immediate measures to reduce transmission rates and protect patients and providers take priority and necessitate some delays in care, particularly for patients with mild symptoms or less aggressive cancers. However, strict guidelines have yet to be developed, and many unintentional delays in care are to be expected based on the magnitude of the looming public health crisis. The medical complexity of head and neck cancer management may lead to prolonged delays that worsen treatment outcomes. Therefore, those caring for patients with head and neck cancer must take action to reduce these negative impacts as the country rallies to overcome the challenges posed by this pandemic.
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Control de Enfermedades Transmisibles/organización & administración , Infecciones por Coronavirus/prevención & control , Transmisión de Enfermedad Infecciosa/prevención & control , Neoplasias de Cabeza y Cuello/terapia , Pandemias/prevención & control , Seguridad del Paciente , Neumonía Viral/prevención & control , COVID-19 , Manejo de la Enfermedad , Brotes de Enfermedades/estadística & datos numéricos , Femenino , Neoplasias de Cabeza y Cuello/epidemiología , Neoplasias de Cabeza y Cuello/inmunología , Humanos , Huésped Inmunocomprometido , Masculino , Evaluación de Resultado en la Atención de Salud , Pandemias/estadística & datos numéricos , Medición de Riesgo , Estados Unidos , Poblaciones Vulnerables/estadística & datos numéricosRESUMEN
Global changes in chromatin organization and the cessation of transcription during mitosis are thought to challenge the resumption of appropriate transcription patterns after mitosis. The acetyl-lysine binding protein BRD4 has been previously suggested to function as a transcriptional "bookmark" on mitotic chromatin. Here, genome-wide location analysis of BRD4 in erythroid cells, combined with data normalization and peak characterization approaches, reveals that BRD4 widely occupies mitotic chromatin. However, removal of BRD4 from mitotic chromatin does not impair post-mitotic activation of transcription. Additionally, histone mass spectrometry reveals global preservation of most posttranslational modifications (PTMs) during mitosis. In particular, H3K14ac, H3K27ac, H3K122ac, and H4K16ac widely mark mitotic chromatin, especially at lineage-specific genes, and predict BRD4 mitotic binding genome wide. Therefore, BRD4 is likely not a mitotic bookmark but only a "passenger." Instead, mitotic histone acetylation patterns may constitute the actual bookmarks that restore lineage-specific transcription patterns after mitosis.
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Histonas/metabolismo , Proteínas Nucleares/metabolismo , Factores de Transcripción/metabolismo , Acetilación , Animales , Cromatina/genética , Cromatina/metabolismo , Histonas/genética , Ratones , Mitosis/fisiología , Proteínas Nucleares/genética , Factores de Transcripción/genética , Transcripción GenéticaRESUMEN
Anaplastic large cell lymphoma expressing anaplastic lymphoma kinase (ALK+ ALCL) is a distinct subtype of non-Hodgkin lymphoma. In this review, we discuss the historical findings that led to its classification as a unique disease, despite its varied clinical presentation and histology. We discuss the molecular mechanisms underlying ALK+ ALCL pathology and the questions that remain in the field. Finally, we visit how decades of ALK+ ALCL research has yielded more precise drugs that hold promise for the future.
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Besides functioning as a chemotactic factor, CCL5 has been associated with progression of disease in women with breast cancer, immune modulation and metastasis. Here we asked whether CCL5 produced by tumor cells contributed to growth or metastasis of breast cancer. For this purpose, we used two murine mammary carcinomas, the 4T1 tumor which is metastatic and constitutively expresses CCL5, and the 168 tumor which is not metastatic and does not constitutively express CCL5. RNA interference was used to inhibit CCL5 expression from the 4T1 tumor, and a CCL5 transgene was used to express CCL5 by the 168 tumor. Six different clones of 4T1 that exhibited stable reduction in CCL5 expression, and three different clones of 168 that exhibited stable CCL5 expression were compared to the parental tumors and vector transfected controls. Significantly, in both models, tumor-derived CCL5 expression did not correlate with MHC expression, growth rate, or metastatic ability of the tumors. These results show that tumor-derived CCL5 expression alone does not make a significant contribution to breast cancer progression.