Staphylococcus aureus has emerged as a significant pathogen causing severe, invasive disease in otherwise healthy people. Despite considerable advances in understanding the epidemiology, resistance mechanisms, and virulence factors produced by the bacteria, there is limited knowledge of the in vivo host immune response to acute, invasive S. aureus infections. Herein, we report that peripheral blood mononuclear cells from patients with severe S. aureus infections demonstrate a distinctive and robust gene expression profile which is validated in a distinct group of patients and on a different microarray platform. Application of a systems-wide modular analysis framework reveals significant over-expression of innate immunity genes and under-expression of genes related to adaptive immunity. Simultaneous flow cytometry analyses demonstrated marked alterations in immune cell numbers, with decreased central memory CD4 and CD8 T cells and increased number of monocytes. CD14+ monocyte numbers significantly correlated with the gene expression levels of genes related to the innate immune response. These results demonstrate the value of applying a systems biology approach that reveals the significant alterations in the components of circulating blood lymphocytes and monocytes in invasive S. aureus infections.
Enhanced monocyte response and decreased central memory T cells in children with invasive Staphylococcus aureus infections.
Sex, Treatment, Race
View SamplesEach infectious agent represents a unique combination of pathogen-associated molecular patterns that interact with specific pattern-recognition receptors expressed on immune cells. Therefore, we surmised that the blood immune cells of individuals with different infections might bear discriminative transcriptional signatures. Gene expression profiles were obtained for 131 peripheral blood samples from pediatric patients with acute infections caused by influenza A virus, Gram-negative (Escherichia coli) or Gram-positive (Staphylococcus aureus and Streptococcus pneumoniae) bacteria. Thirty-five genes were identified that best discriminate patients with influenza A virus infection from patients with either E coli or S pneumoniae infection. These genes classified with 95% accuracy (35 of 37 samples) an independent set of patients with either influenza A, E coli, or S pneumoniae infection. A different signature discriminated patients with E coli versus S aureus infections with 85% accuracy (34 of 40). Furthermore, distinctive gene expression patterns were observed in patients presenting with respiratory infections of different etiologies. Thus, microarray analyses of patient peripheral blood leukocytes might assist in the differential diagnosis of infectious diseases.
Gene expression patterns in blood leukocytes discriminate patients with acute infections.
Sex, Age, Treatment, Race
View SamplesSystemic onset Juvenile Idiopathic Arthritis (SoJIA) represents up to 20% of Juvenile Idiopathic Arthritis (JIA). We have previously reported that this disease is Interleukin 1 (IL1)-mediated, and that IL-1 blockade results in clinical remission in the majority of patients. The diagnosis of SoJIA, however, still relies on clinical findings as no specific diagnostic tests are available, which leads to delays in the initiation of specific therapy. To identify specific diagnostic markers, we analyzed gene expression profiles in 19 pediatric patients with SoJIA during the systemic phase of the disease (fever and/or arthritis), 25 SoJIA patients with no systemic symptoms (arthritis only or no symptoms), 39 healthy controls, 94 pediatric patients with acute viral and bacterial infections (available under GSE6269), 38 pediatric patients with Systemic Lupus Erythematosus (SLE), and 6 patients with a second IL-1 mediated disease known as PAPA syndrome. Statistical group comparison and class prediction identified genes differentially expressed in SoJIA patients compared to healthy children. These genes, however, were also changed in patients with acute infections and SLE. By performing an analysis of significance across all diagnostic groups, we generated a list of 88 SoJIA-specific genes (p<0.01 in SoJIA and >0.5 in all other groups). A subset of 12/88 genes permitted us to accurately classify an independent test set of SoJIA patients with systemic disease. We were also able to identify a group of transcripts that changed significantly in patients undergoing IL-1 blockade. Thus, analysis of transcriptional signatures from SoJIA blood leukocytes can help distinguishing this disease from other febrile illnesses and assessing response to therapy. Availability of accurate diagnostic markers for SoJIA patients may allow prompt initiation of effective therapy and prevention of long-term disabilities.
Blood leukocyte microarrays to diagnose systemic onset juvenile idiopathic arthritis and follow the response to IL-1 blockade.
Sex, Age, Treatment, Race
View SamplesMicroglia are yolk sac-derived macrophages residing in the parenchyma of brain and spinal cord, where they interact with neurons and other glial cells by constantly probing their surroundings with dynamic extensions. After different conditioning paradigms and bone marrow (BM) or hematopoietic stem cell (HSC) transplantation, graft-derived cells seed the brain and persistently contribute to the parenchymal brain macrophage compartment. Here we establish that graft-derived macrophages acquire, over time, microglia characteristics, including ramified morphology, longevity, radio-resistance and clonal expansion. However, even after prolonged CNS residence, transcriptomes and chromatin accessibility landscapes of engrafted, BM-derived macrophages remain distinct from yolk sac-derived host microglia. Furthermore, engrafted BM-derived cells display discrete responses to peripheral endotoxin challenge, as compared to host microglia. In human HSC transplant recipients, engrafted cells also remain distinct from host microglia, extending our finding to clinical settings. Collectively, our data emphasize the molecular and functional heterogeneity of parenchymal brain macrophages and highlight potential clinical implications for HSC gene therapies aimed to ameliorate lysosomal storage disorders, microgliopathies or general monogenic immuno-deficiencies. Overall design: overall there are 28 samples, from total of 2 experiments. in each experiment there were at least 3 biological repeats (3 individual mice). Sorting of the CD45.1 and CD45.2 populations were performed from the same animal. Animals were either injected with LPS (2.5 mg/kg) or untreated.
Engrafted parenchymal brain macrophages differ from microglia in transcriptome, chromatin landscape and response to challenge.
Specimen part, Cell line, Subject
View SamplesThe role of Striatin Interacting Protein 2 (Strip2) in differentiation of embryonic stem cells (ESCs) is still under debate. Strip2 silenced (KD) ESCs were differentiated for 4, 8, 12, and 16 days. We show that Strip2 is distributed in the perinucleus or nuclei of wild type (WT) undifferentiated ESCs, but is localized in high-density nuclear bodies in differentiated cells. CellNet analysis of microarray gene expression data for KD and scrambled control (SCR) embryoid bodies (EBs), as well as immunostainings of key pluripotent factors, demonstrated that KD ESCs remain undifferentiated. This occurs even in 16-day old EBs, which possessed a high tumorigenic potential. Correlated with very high expression levels of epigenetic regulator genes, Hat1 and Dnmt3, enzymatic activities of the histone acetyltransferase type B (HAT1) and DNA (cytosine-5)-methyltransferase 3 beta (DNMT3b) were higher in differentiated 16-day old KD EBs than in SCR or WT EBs. The expression levels of let-7, 290 and 302 microRNA families were opposed in KD ESCs, while KD EBs had levels comparable to WT and SCR ESCs during differentiation. This demonstrates that Strip2 is critical to the onset of differentiation, regulating expression of epigenetic regulators, HAT1 and DNMT3b, as well as microRNAs involved in pluripotency.
STRIP2 Is Indispensable for the Onset of Embryonic Stem Cell Differentiation.
Sex, Specimen part
View SamplesPolycomb repressive complex 2 (PRC2-EZH2) methylates histone H3 at lysine 27 (H3K27) and is required to maintain gene repression during development. Misregulation of PRC2 is linked to a range of neoplastic malignancies, which is believed to involve methylation of H3K27. However, the full spectrum of non-histone substrates of PRC2 that might also contribute to PRC2 function is not known. We characterized the target recognition specificity of PRC2 and used the resultant data to screen for novel potential targets. The RNA polymerase II (Pol II) transcription factor, Elongin A (EloA), is methylated by PRC2 in vivo. Mutation of the methylated EloA residue decreased repression of many, but not all, PRC2 target genes as measured by both steady state and nascent RNA levels. We propose that PRC2 regulates transcription of a subset of target genes in part via methylation of EloA. Overall design: We examined the transcripitonal profile of EEDnull, EloAnull, EloA mutant, and parental mouse embryonic stem cells by RNAseq. Please note that the .bw processed data file was generated from the *mESC replicate samples together and linked to the corresponding *rep1 sample records.
Polycomb Repressive Complex 2 Methylates Elongin A to Regulate Transcription.
Specimen part, Subject
View SamplesPolycomb repressive complex 2 (PRC2-EZH2) methylates histone H3 at lysine 27 (H3K27) and is required to maintain gene repression during development. Misregulation of PRC2 is linked to a range of neoplastic malignancies, which is believed to involve methylation of H3K27. However, the full spectrum of non-histone substrates of PRC2 that might also contribute to PRC2 function is not known. We characterized the target recognition specificity of PRC2 and used the resultant data to screen for novel potential targets. The RNA polymerase II (Pol II) transcription factor, Elongin A (EloA), is methylated by PRC2 in vivo. Mutation of the methylated EloA residue decreased repression of many, but not all, PRC2 target genes as measured by both steady state and nascent RNA levels. We propose that PRC2 regulates transcription of a subset of target genes in part via methylation of EloA. Overall design: We examined the nascent transcripiton profile of mES cells by adding 5-Bromouridine (BrU) to the media for 10 min. Following RNA isolation, BrU-labelled nascent RNA species were affinity purified using BrdU antibody and sequenced after library preparation. Please note that each .bw file was generated from two replicate samples together and linked to the corresponding *rep1 sample records.
Polycomb Repressive Complex 2 Methylates Elongin A to Regulate Transcription.
Specimen part, Subject
View SamplesThe analysis of patient blood transcriptional profiles offers a means to investigate the immunological mechanisms relevant to human diseases on a genome-wide scale. In addition, such studies provide a basis for the discovery of clinically relevant biomarker signatures. We designed a strategy for microarray analysis that is based on the identification of transcriptional modules formed by genes coordinately expressed in multiple disease data sets. Mapping changes in gene expression at the module level generated disease-specific transcriptional fingerprints that provide a stable framework for the visualization and functional interpretation of microarray data. These transcriptional modules were used as a basis for the selection of biomarkers and the development of a multivariate transcriptional indicator of disease progression in patients with systemic lupus erythematosus. Thus, this work describes the implementation and application of a methodology designed to support systems-scale analysis of the human immune system in translational research settings.
A modular analysis framework for blood genomics studies: application to systemic lupus erythematosus.
Sex, Age, Race
View SamplesWe designed a strategy for microarray analysis that is based on the identification of transcriptional modules formed by genes coordinately expressed in multiple disease data sets. Mapping changes in gene expression at the module level generated disease-specific transcriptional fingerprints that provide a stable framework for the visualization and functional interpretation of microarray data.
A modular analysis framework for blood genomics studies: application to systemic lupus erythematosus.
Sex, Age, Race
View SamplesTranscriptional modules were used as a basis for the selection of biomarkers and the development of a multivariate transcriptional indicator of disease progression in patients with systemic lupus erythematosus.
A modular analysis framework for blood genomics studies: application to systemic lupus erythematosus.
Sex, Age, Race
View Samples