12373 results for ""statistically+reactive"+taxa+in+microbial+community"

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• Ewings Sarcoma RNA-Seq

  Sarcomas are cancers of the bone and soft tissue often defined by their gene fusions. However, the timing, context, and processes by which these pathogenic fusions arise are unknown. We explored this in Ewing sarcoma, a cancer driven by EWSR1-ETS fusions, with very few cooperating mutations. Combining whole-genome sequencing with enhanced informatics, we found that the EWSR1-ETS fusion arose from striking rearrangement clusters in 42% of cases (52/124). Notably, these were organized in loops that universally contained the fusion at their center, while also weaving up to 18 genes together with it. We found the same pattern of rearrangements in three additional types of sarcoma. From these data, we define a new signature for sarcoma fusions that precedes other somatic changes, in the earliest replicating DNA of the genome. This dramatic, sudden process impinges on many genes – generating multiple coding changes that profoundly affect the transcriptome, with the disease-defining gene fusion at its core. These rearrangement loops emerge in an early ES clone from which both the primary tumor and the lethal relapse emerged, and then evolved in parallel until clinically detected.

  Study EGAS00001003062

• Comparative transcriptome of CD34+ hematopoietic progenitors from myeloproliferative patients and control donors

  BCR-ABL-negative MPNs are related to mutations activating the JAK2/STAT pathway and occurring in hematopoietic stem cells (HSC). The most prevalent mutation is JAK2V617F. Calreticulin (CALR) and activating MPLW515 mutations are also observed in ET and PMF. Additional non-MPN mutations may be found, particularly in PMF, and can change disease phenotype or accelerate progression to myelofibrosis or leukemia. In this study, we wanted to compare the transcriptome of CD34+ progenitors from JAK2V617F postive MPN patients to the CD34+ progenitors from control donors. The patients were selected for their high JAK2V617F variant allele frequency (from 60 to 100% VAF). Peripheral blood from patients was collected in EDTA tubes. Hematopoietic progenitors (CD34+) were isolated from mononuclear cells (MNCs) by immunomagnetic enrichment (Miltenyi, Biotech) and were amplified for 5 days in serum-free medium in the presence of a cocktail of human recombinant cytokines containing EPO (1 U/mL) (Amgen Thousand Oaks, CA), TPO (20 ng/mL) (Kirin, Japan), SCF (25 ng/mL) (Biovitrum AB, Sweden), IL-3 (10 ng/mL), FLT3-L (10 ng/mL), G-CSF (20 ng/mL) and IL-6 (100 U/mL) (MiltenyiBiotec).

  Study EGAS00001005106

• Germline biallelic mutation affecting the transcription factor Helios causes pleiotropic defects of immunity

  We studied a patient with recurrent respiratory infections and hypogammaglobulinemia and identified a germline homozygous missense mutation in IKZF2 encoding Helios (p.Ile325Val). We show that HeliosI325V retains DNA-binding and dimerization properties, but loses interaction with several partners, including epigenetic remodelers HDAC1, HDAC3 and the ATAC complex. Single-cell RNA-sequencing of peripheral blood mononuclear cells revealed gene expression signatures indicative of a shift towards pro-inflammatory, effector-like status in the patient’s T cells. We observed an upregulation of the anti-inflammatory gene, TSC22D3, encoding the glucocorticoid-induced leucine zipper (GILZ), whose expression was reported to increase upon IL-2 deprivation. We validated this finding in primary T cells, where we observed a pronounced reduction in IL-2 production upon their stimulation, together with a defect in their ability to proliferate, rendering them more anergic. Collectively, we identify a novel germline-encoded inborn error of immunity and define a role for Helios in conventional T cells, whereby interactions with specific binding partners is necessary to mediate the transcriptional programs that enable T-cell homeostasis in health and disease.

  Study EGAS00001005675

• Identification of Germline Monoallelic Mutations in IKZF2 in Patients with Immune Dysregulation.

  Helios, encoded by IKZF2, is a member of the Ikaros family of transcription factors with pivotal roles in T-follicular helper, NK- and T-regulatory cell physiology. Somatic IKZF2 mutations are frequently found in lymphoid malignancies. Although germline mutations in IKZF1 and IKZF3, encoding Ikaros and Aiolos, have recently been identified in patients with phenotypically similar immunodeficiency syndromes, the effect of germline mutations in IKZF2 on human hematopoiesis and immunity remains enigmatic. We identified germline IKZF2 mutations (one nonsense (p.R291X)- and 4 distinct missense variants) in six patients with systemic lupus erythematosus, immune thrombocytopenia or EBV-associated hemophagocytic lymphohistiocytosis. Patients exhibited hypogammaglobulinemia, decreased number of T-follicular helper and NKcells. Single-cell RNA sequencing of PBMCs from the patient carrying the R291X variant revealed upregulation of pro-inflammatory genes associated with T-cell receptor activation and T-cell exhaustion. Functional assays revealed the inability of HeliosR291X to homodimerize and bind target DNA as dimers. Moreover, proteomic analysis by proximity-dependent Biotin Identification revealed aberrant interaction of 3/5 Helios mutants with core components of the NuRD complex conveying HELIOS mediated epigenetic and transcriptional dysregulation.

  Study EGAS00001005874

• Patient-tailored design for selective co-inhibition of leukemic cell subpopulations

  The extensive primary and secondary drug resistance in many cancer types requires rational approaches to design personalized and selective combinatorial therapies that do not only show synergistic effect in overall cancer cell killing but also result in minimal toxic side effects on non-malignant cells. To address the combinatorial explosion in the number of relevant combinations, we implemented a machine learning approach that prioritizes patient-customized drug combinations with a desired synergy-efficacy-toxicity balance by combining single-cell RNA-sequencing with ex vivo single-agent testing in scarce patient-derived primary cells. When applied to two diagnostic and two refractory AML patient cases, each with a different genetic background, our integrated approach accurately predicted patient-specific combinations that were shown to result not only in synergistic cancer cell co-inhibition but were also capable of targeting specific AML cell subpopulations that emerge in differing stages of disease pathogenesis or treatment regimens. Our data-driven approach provides an unbiased means for systematic identification of personalized combinatorial regimens that selectively co-inhibit leukemic cells while avoiding inhibition of non-malignant cells, and highlight the relevance of considering cell heterogeneity for personalized cancer therapy.

  Study EGAS00001004614

• DNA methylation landscape of prostate cancer

  Metastases from primary prostate cancers to rare locations, such as the brain, are becoming more common due to longer life expectancy thanks to improved treatments. Epigenetic dysregulation is a feature of primary prostate cancer, and distinct DNA methylation profiles are associated with the mutually exclusive SPOP mutant or TMPRSS2-ERG fusion genetic backgrounds. Using a cohort of 42 patients with prostate cancer brain metastases (PCBM), with matched primary samples available for 17 patients, we carried out DNA methylation analysis using Illumina EPIC array. We examined the epigenetic distinction between primary PCa and PCBM, the association between epigenetic alterations and mutational background, and particular epigenetic alterations that may be associated with PCBM in particular. Multiregion sampling of PCBM revealed epigenetic heterogeneity in metastases. We found aberrant methylation in PCBM is associated with mutational background, PRC2 complex activity and upregulation of EZH2, an effect that is particularly pronounced in SPOP mutant PCBM. While we detected a hypermethylator phenotype in PCBM, we also observed hypomethylation occurring at the promoters of genes involved in neuroactive ligand-receptor interactions or the calcium signalling pathway, such as GABRB3 and GRM5, a change not observed in non-brain prostate cancer metastases.

  Study EGAS00001006670

• Pre-activated anti-viral innate immunity in the upper airways controls early SARS-CoV-2 infection in children

  Children have reduced SARS-CoV-2 infection rates and a substantially lower risk for developing severe COVID-19 than adults. However, the molecular mechanisms underlying protection in younger age groups remain unknown. Here, we characterize the single-cell transcriptional landscape in the upper airways of SARS-CoV-2-negative (n=18) and age-matched SARS-CoV-2–positive children (n=24) and corresponding samples from adults (n=44), covering an age range of four weeks to 77 years. Children displayed higher basal expression of the relevant pattern recognition receptors (PRR) such as MDA5 (IFIH1) and RIG-I (DDX58) in upper airway epithelial cells, macrophages, and dendritic cells, resulting in stronger innate antiviral responses upon SARS-CoV-2 infection than adults. We further detected distinct immune cell subpopulations including KLRC1 (NKG2A)+ cytotoxic T cells and a CD8+ T cell population with a memory phenotype occurring predominantly in children. Our study provides evidence that the airway immune cells of children are primed for virus sensing, resulting in a stronger early innate antiviral responses to SARS-CoV-2 infection than adults.

  Study EGAS00001005461

• SINGLE-CELL RNA SEQUENCING Single-cell RNA sequencing was performed on 13 ‘mild-moderate’ and 10 ‘critical’ COVID19 PBMC samples

  Summary Epidemiological and clinical reports have indicated that SARS-CoV-2 virulence hinges upon the triggering of an aberrant host immune response, more so than on direct virus-induced cellular damage. To elucidate the immunopathology underlying COVID-19 severity, we performed cytokine and multiplex immune profiling in mild-moderate and critically ill COVID-19 patients. Hypercytokinemia in COVID-19 differed from the IFN-γ-driven cytokine storm in macrophage activation syndrome, and was more pronounced in critical versus mild-moderate COVID-19. Systems modelling of cytokine levels paired with deep-immune profiling showed that classical monocytes drive this hyper-inflammatory phenotype and that a reduction in T-lymphocytes correlates with disease severity, with CD8+ cells being disproportionately affected. Expression of antigen presenting machinery was also reduced in critical disease. Furthermore, we found that neutrophils contributed to disease severity and local tissue damage by amplification of hypercytokinemia and the formation of neutrophil extracellular traps. Together these findings suggest a myeloid-driven immunopathology, in which hyperactivated neutrophils and an ineffective adaptive immune system act as mediators of COVID-19 disease severity.

  Study EGAS00001005039

• Ciliopathies Exome Sequencing Initiative

  The study is aimed at identifying new genes involved in pediatric brain disorders from inbred families originating predominantly in the Middle East. Each patient analyzed to date has a specific and highly unique neurodevelopmental disorder that is likely to be recessive in nature. Many patients have one of the diseases along the "ciliopathy" spectrum of diseases, with evidence of kidney failure, retinal blindness and cerebellar ataxia.

  Study phs000288

• Family Genomics of Congenital Heart Defects

  The study identified the causal mutation in a five-generation pedigree harboring a cardiac septal defect. The inheritance pattern is consistent with an autosomal dominant mutation with high penetrance. We performed whole-genome sequencing (Complete Genomics) on 21 individuals in the pedigree, of which 11 individuals are affected. We identified a single gene, GATA4, as primarily responsible for this cardiac phenotype in this pedigree.

  Study phs000758