Dendritic cells (DCs) process and present self and foreign antigens to induce tolerance or immunity. In vitro models suggest that induction of immunity is controlled by regulating the presentation of antigen, but little is known about how DCs control antigen presentation in vivo. To examine antigen processing and presentation in vivo we specifically targeted antigens to the two major subsets of DCs using chimeric monoclonal antibodies. Unlike CD8+ DCs that express the cell surface protein CD205, CD8- DCs, which are positive for the 33D1 antigen, are specialized for presentation on MHC class II. This difference in antigen processing is intrinsic to the DC subsets and associated with increased expression of proteins associated with MHC processing.
Differential antigen processing by dendritic cell subsets in vivo.
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View SamplesAdjuvants are critical for the success of vaccines, and agonists for microbial pattern recognition receptors are promising new candidates. A mechanism for the immune enhancing role of adjuvants is to stimulate innate immunity. We studied the innate immune response in humans to synthetic double stranded RNA (poly ICLC), a ligand for TLR3 and MDA-5 cytosolic RNA helicase. Transcriptional analysis of blood samples from eight volunteers, after subcutaneous administration of poly ICLC showed upregulation of genes involved in multiple innate immune pathways in all subjects, including interferon and inflammasome signaling. Blocking of type I interferon receptor ex vivo significantly dampened the response to poly IC. Comparative transcriptional analysis showed that several innate pathways were similarly induced in volunteers immunized with the highly efficacious Yellow Fever Vaccine. Therefore a chemically defined microbial agonist like poly ICLC can be a reliable and authentic microbial mimic for inducing innate immunity, here for a live attenuated viral vaccine in humans.
Synthetic double-stranded RNA induces innate immune responses similar to a live viral vaccine in humans.
Time
View SamplesPatients with systemic lupus erythematosus (SLE) have a markedly increased risk to develop cardiovascular disease, and traditional cardiovascular risk factors fail to account for this increased risk. We used microarray to probe the platelet transcriptome in individuals with SLE and healthy controls, and the gene and protein expression of a subset of differentially expressed genes was further investigated and correlated to platelet activation status. Real-time PCR was used to confirm a type I interferon (IFN) gene signature in patients with SLE, and the IFN-regulated proteins PRKRA, IFITM1 and CD69 (p<0.0001) were found to be up-regulated in platelets from SLE patients as compared to healthy volunteers. Notably, patients with a history of vascular disease had increased expression of type I IFN-regulated proteins as well as more activated platelets as compared with patients without vascular disease. We suggest that interferogenic immune complexes stimulate production of IFN which up-regulates the megakaryocytic type I IFN-regulated genes and proteins. This could affect platelet activation and contribute to development of vascular disease in SLE. In addition, platelets with type I IFN signature could be a novel marker for vascular disease in SLE.
Platelet transcriptional profile and protein expression in patients with systemic lupus erythematosus: up-regulation of the type I interferon system is strongly associated with vascular disease.
Sex, Age, Specimen part, Disease
View SamplesNormal development requires tight regulation of cell proliferation and cell death. Here, we investigated these control mechanisms in the hyaloid vessels, a temporary vascular network in the mammalian eye that requires a Wnt/ß-catenin response for scheduled regression. Transcriptome analysis of the postnatal day 5 mouse hyaloid showed expression of several Wnt pathway proteins. We investigated whether the hyaloid Wnt response was linked to the oncogene Myc, and the cyclin-dependent kinase inhibitor P21 (CDKN1A), both established regulators of cell cycle progression and cell death. Our analysis showed that the Wnt pathway coreceptors LRP5 and LRP6 have overlapping activities mediating the Wnt/ß-catenin signaling in hyaloid vascular endothelial cells (VECs). We also showed that both Myc and Cdkn1a are downstream of the Wnt response and are required for hyaloid regression but for different reasons. Conditional deletion of Myc in VECs suppressed both proliferation and cell death. By contrast, conditional deletion of Cdkn1a resulted in VEC over-proliferation that countered the effects of cell death on regression. When combined with analysis of MYC, and P21 protein levels, this analysis suggests that a Wnt/ß-catenin, MYC-P21 pathway regulates scheduled hyaloid vessel regression. Overall design: Hyaloid vascular preparations from postnatal day 5 mice were harvested in cold PBS and RNA extracted in Tri Reagent. RNA amplifcation was performed on total RNA before cDNA library was made. Samples were then sequenced using Illimina HiSeq2500 to obtain 25-30 million paired-end reads.
Developmental vascular regression is regulated by a Wnt/β-catenin, MYC and CDKN1A pathway that controls cell proliferation and cell death.
Specimen part, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Hematopoietic stem cell function and survival depend on c-Myc and N-Myc activity.
Age, Specimen part
View SamplesAnalysis of HSCs from control and c-myc N-myc deficient long-term hematopoietic stem cells. HSCs lacking both c-myc and N-myc display increased apoptosis rates. Data provide insight into the molecular changes occuring upon complete loss of Myc activity, clarifying the resulting apoptotic mechanism and the role of Myc family proteins in HSCs.
Hematopoietic stem cell function and survival depend on c-Myc and N-Myc activity.
Age, Specimen part
View SamplesAnalysis of HSCs from control and c-myc N-myc deficient long-term hematopoietic stem cells. HSCs lacking both c-myc and N-myc display increased apoptosis rates. Data provide insight into the molecular changes occuring upon complete loss of Myc activity, clarifying the resulting apoptotic mechanism and the role of Myc family proteins in HSCs and commited progenitors.
Hematopoietic stem cell function and survival depend on c-Myc and N-Myc activity.
Age, Specimen part
View SamplesGene expression array analysis component. Ligand-dependent transcription by the nuclear receptor glucocorticoid receptor (GR) is mediated by interactions with co-regulators. The role of these interactions in determining selective binding of GR to regulatory elements remains unclear. Recent findings indicate a large fraction of genomic GR binding coincides with chromatin that is accessible prior to hormone treatment, suggesting that receptor binding is dictated by proteins that maintain chromatin in an open state. Combining nucleolytic cleavage and chromatin immunoprecipitation with high-throughput sequencing, we identify the activator protein 1 (AP1) as a major partner for productive GR-chromatin interactions. AP1 is critical for GR-regulated transcription and recruitment to co-occupied regulatory elements, illustrating an extensive AP1-GR interaction network. Importantly, the maintenance of baseline chromatin accessibility facilitates GR recruitment and is dependent on AP1 binding. We propose a model where the basal occupancy of transcription factors act to prime chromatin and direct inducible transcription factors to select regions in the genome.
Transcription factor AP1 potentiates chromatin accessibility and glucocorticoid receptor binding.
Sex, Cell line, Treatment, Time
View SamplesAnalysis of five Notch signaling-dependent human T-ALL cell lines (ALLSIL, DND41, HPBALL, KOPTK1, TALL-1) treated with gamma-secretase inhibitor (GSI) to block Notch signaling. Samples include parental cells, cells rescued by retroviral transduction with ICN (a GSI-independent form of activated Notch1), and cells retrovirally transduced with c-Myc (an important downstream target of Notch1). Results allow segregation of bona fide Notch targets from other genes affected by gamma-secretase inhibition as well as from targets downstream of c-Myc.
High-level IGF1R expression is required for leukemia-initiating cell activity in T-ALL and is supported by Notch signaling.
Cell line
View SamplesArabidopsis MPK4 is involved in the control of antagonism between salicylic acid (SA) and ethylene (ET)/jasmonic acid (JA) pathways in the plant innate immune system as a repressor of the SA pathway, but an activator of the ET/JA pathway. Here we and use comparative microarray analysis of ctr1, ctr1/mpk4, mpk4 and wild type to show that MPK4 is required for only a narrow subset of ET regulated genes.
Arabidopsis systemic immunity uses conserved defense signaling pathways and is mediated by jasmonates.
Age, Specimen part
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