Project description:This SuperSeries is composed of the following subset Series: GSE15718: Gene expression in dendritic cells stimulated with LPS in conditions allowing or inhibiting NFAT activation GSE15720: Apoptosis genes specifically modulated by NFAT in LPS-activated dendritic cells GSE15721: Gene expression in macropages stimulated with LPS in conditions allowing or inhibiting NFAT activation Refer to individual Series
Project description:Dendritic cells (DCs) are a special class of leukocytes able to activate both innate and adaptive immune responses. They interact with microbes through germline-encoded pattern-recognition receptors (PRRs), which recognize molecular patterns expressed by various microorganisms. Upon antigen binding, PRRs instruct DCs for the appropriate priming of natural killer cells, followed by specific T-cell responses. Once completed the effector phase, DCs reach the terminal differentiation stage and eventually die by apoptosis. We have observed that following lipopolysaccharide (LPS)-stimulation the initiation of the apoptotic pathway in DCs is due the activation of NFAT proteins. Indeed, LPS induces Src-family kinase and phospholipase C (PLC)γ2 activation, influx of extracellular Ca2+ and calcineurin-dependent nuclear NFAT translocation. The initiation of this pathway is independent of TLR4 engagement, and dependent exclusively on CD14. According with this observation CD14-deficient DCs do not die following LPS stimulation. Nevertheless, CD14-deficient DC death following LPS activation can be restored by co-stimulating DCs with LPS and thapsigargin. Thapsigargin empties the intracellular calcium stores by blocking calcium pumping into the sarcoplasmic and endoplasmic reticulum and thereby activates plasma membrane calcium channels. This, in turn, allows an influx of calcium into the cytosol and NFAT activation. To identify the NFAT controlled apoptosis genes in LPS activated DCs we have performed a kinetic microarray analysis (0, 48 and 60 h) in conditions allowing or inhibiting NFAT activation. Four genes have been selected: Nur77, Gadd45g, Ddit3/Gadd153/Chop-10 and Tia1. To identify apoptosis genes selectively modulated by NFAT, a comparative kinetic (time points 0, 48 and 60 h) microarray analysis was performed in the following conditions: 1) wild type bone marrow derived DCs (wtBMDCs) stimulated with LPS; 2) CD14-deficient BMDCs stimulated with LPS; 3) wtBMDCs stimulated with LPS in presence of thapsigargin; 4) CD14-deficient BMDCs stimulated with LPS in presence of thapsigargin.
Project description:Dendritic cells (DCs) are a special class of leukocytes able to activate both innate and adaptive immune responses. They interact with microbes through germline-encoded pattern-recognition receptors (PRRs), which recognize molecular patterns expressed by various microorganisms. Upon antigen binding, PRRs instruct DCs for the appropriate priming of natural killer cells, followed by specific T-cell responses. Once completed the effector phase, DCs reach the terminal differentiation stage and eventually die by apoptosis. We have observed that following lipopolysaccharide (LPS)-stimulation the initiation of the apoptotic pathway in DCs is due the activation of NFAT proteins. Indeed, LPS induces Src-family kinase and phospholipase C (PLC)γ2 activation, influx of extracellular Ca2+ and calcineurin-dependent nuclear NFAT translocation. The initiation of this pathway is independent of TLR4 engagement, and dependent exclusively on CD14. According with this observation CD14-deficient DCs do not die following LPS stimulation. Nevertheless, CD14-deficient DC death following LPS activation can be restored by co-stimulating DCs with LPS and thapsigargin. Thapsigargin empties the intracellular calcium stores by blocking calcium pumping into the sarcoplasmic and endoplasmic reticulum and thereby activates plasma membrane calcium channels. This, in turn, allows an influx of calcium into the cytosol and NFAT activation. To identify the NFAT controlled apoptosis genes in LPS activated DCs we have performed a kinetic microarray analysis (0, 48 and 60 h) in conditions allowing or inhibiting NFAT activation. Four genes have been selected: Nur77, Gadd45g, Ddit3/Gadd153/Chop-10 and Tia1.
Project description:Interleukin-2 (IL-2) is one of the molecules produced by mouse dendritic cells (DCs) after stimulation by Toll like receptor (TLR) agonists. By analogy with the events following T-cell receptor (TCR) engagement leading to IL-2 production we have observed that DC stimulation with lipopolysaccharide (LPS) induces Src-family kinase and phospholipase C (PLC)γ2 activation, influx of extracellular Ca2+ and calcineurin-dependent nuclear NFAT translocation. We have also observed that the initiation of this pathway is independent of TLR4 engagement, and dependent exclusively on CD14. To determine the role of NFAT in LPS activated dendritic cells we have performed microarray analysis in conditions allowing or inhibiting NFAT activation. We show here that LPS-induced NFAT activation via CD14 is necessary to cause death of terminally differentiated DCs, an event that is essential for maintaining self-tolerance and preventing autoimmunity. Consequently, blocking this pathway in vivo causes prolonged DC survival and an increase in T cell priming capability. Gene expression analyses were performed using Affymetrix GeneChips in the following groups of murine bone marrow-derived dendritic cells: 1) CD14-deficient BMDCs stimulated with LPS; 2) wtBMDCs stimulated with LPS in presence of EGTA; 3) wtBMDCs stimulated with LPS. This experimental setting allowed us to select for effects due to Ca2+ fluxes and exclude the effects due to other causes, particularly the block of TRIF recruitment in CD14-deficient cells and the EGTA effects unrelated to Ca2+ chelation.
Project description:Interleukin-2 (IL-2) is one of the molecules produced by mouse dendritic cells (DCs) after stimulation by Toll like receptor (TLR) agonists. By analogy with the events following T-cell receptor (TCR) engagement leading to IL-2 production we have observed that DC stimulation with lipopolysaccharide (LPS) induces Src-family kinase and phospholipase C (PLC)γ2 activation, influx of extracellular Ca2+ and calcineurin-dependent nuclear NFAT translocation. We have also observed that the initiation of this pathway is independent of TLR4 engagement, and dependent exclusively on CD14. To determine the role of NFAT in LPS activated dendritic cells we have performed microarray analysis in conditions allowing or inhibiting NFAT activation. We show here that LPS-induced NFAT activation via CD14 is necessary to cause death of terminally differentiated DCs, an event that is essential for maintaining self-tolerance and preventing autoimmunity. Consequently, blocking this pathway in vivo causes prolonged DC survival and an increase in T cell priming capability.
Project description:Introgressed variants from other species can be an important source of genetic variation because they may arise rapidly, can include multiple mutations on a single haplotype, and have often been pretested by selection in the species of origin. Although introgressed alleles are generally deleterious, several studies have reported introgression as the source of adaptive alleles-including the rodenticide-resistant variant of Vkorc1 that introgressed from Mus spretus into European populations of Mus musculus domesticus. Here, we conducted bidirectional genome scans to characterize introgressed regions into one wild population of M. spretus from Spain and three wild populations of M. m. domesticus from France, Germany, and Iran. Despite the fact that these species show considerable intrinsic postzygotic reproductive isolation, introgression was observed in all individuals, including in the M. musculus reference genome (GRCm38). Mus spretus individuals had a greater proportion of introgression compared with M. m. domesticus, and within M. m. domesticus, the proportion of introgression decreased with geographic distance from the area of sympatry. Introgression was observed on all autosomes for both species, but not on the X-chromosome in M. m. domesticus, consistent with known X-linked hybrid sterility and inviability genes that have been mapped to the M. spretus X-chromosome. Tract lengths were generally short with a few outliers of up to 2.7 Mb. Interestingly, the longest introgressed tracts were in olfactory receptor regions, and introgressed tracts were significantly enriched for olfactory receptor genes in both species, suggesting that introgression may be a source of functional novelty even between species with high barriers to gene flow.
Project description:We inflicted TBI to wildetype (wt) mice in order to establish whether the anti-inflammatory agent cyclophosphamide can be used therapeutically. Cyclophosphamide was found to regulate distinct inflammatory cells such as activated microglia separate from invading phagocytes and dendritic cells. Cyclophosphamide postinjury selectively reduces antigen-presenting dendritic cells. Findings show feasibility of drug development to interfere with brain inflammation.
Project description:We created mice, which are deficient for Myc specifically in cardiac myocytes by crossing crossed Myc-floxed mice (Mycfl/fl) and MLC-2VCre/+ mice. Serial analysis of earlier stages of gestation revealed that Myc-deficient mice died prematurely at E13.5-14.5. Morphological analyses of E13.5 Myc-null embryos showed normal ventricular size and structure; however, decreased cardiac myocyte proliferation and increased apoptosis was observed. BrdU incorporation rates were also decreased significantly in Myc-null myocardium. Myc-null mice displayed a 3.67-fold increase in apoptotic cardiomyocytes by TUNEL assay. We examined global gene expression using oligonucleotide microarrays. Numerous genes involved in mitochondrial death pathways were dysregulated including Bnip3L and Birc2. Keywords: wildtype vs Myc-null