Identification of LPS-responsive genes in bone marrow-derived dendritic cells
ABSTRACT: Transcriptional profiling of in vitro generated murine dendritic cells after stimulation with LPS for various timepoints. 4 condition experiment - LPS stimulation at 0, 1, 6, and 24 hours. 3 independent biological replicates for each condition.
Project description:Hematopoietic progenitors from mouse bone marrow were differentiated into dendritic cells for 5 days with GM-CSF and IL-4. On day 6, MHCIIhi and MHCIIlo BMDC subpopulations were sorted to purify by flow cytometry. RNA was extracted and processed for microarray analysis. Two condition experiment; Biological replicates: 5 replicates per condition.
Project description:Hematopoietic progenitors from mouse bone marrow were differentiated into dendritic cells for 5 days with GM-CSF and IL-4. On day 6, MHCIIhi and MHCIIlo BMDC subpopulations were sorted to purify by flow cytometry. RNA was extracted and processed for microarray analysis. Two condition experiment; Biological replicates: 4 replicates per condition.
Project description:genes regualted by LPS or LPS+cAMP stimulation in BMDCs; We used microarrays to identify genes that up-regulated by LPS+cAMP compared with just LPS. Experiment Overall Design: BMDCs were stimilated with LPS (10 ng/ml) in the presence or absence of cAMP (100 microM) for 3h. Specifically up-regualted gene by cMP was identified.
Project description:Dendritic cells isolated from murine bone marrow were cultured for 7 days and then stimulated with 100 ng/mL LPS for 24h. Cells were derived from either wildtype or microRNA-146a knock-out mice. Total RNA was isolated from the cells following stimulation.
Project description:Differentially expressed genes of CD11b+Gr-1+ immature myeloid cells (IMCs) in the bone marrow and colonic tumor setting of histidine decarboxylase (HDC)-KO mice were examined by microarray (Affymetrix Mouse 430.2 array). Myeloid differentiation-related candidate genes were sought to be isolated and functionally studied. Total RNA of HDC-expressing CD11b+Gr-1+ IMCs of bone marrow were extracted from HDC-EGFP and HDC-EGFP/HDC-KO mice (3 mice in each group). CD11b+Gr-1+ myeloid-derived suppressor cells (MDSCs) of colon tumor were sorted from 10-12 colon tumors of WT and HDC-KO mice (5 mice in each group), and pooled to extract total RNA for microarray studies. Two technical replicates for each of the four groups. Four sets of comparisons were performed to screen for upregulated or downregulated genes in the HDC-KO CD11b+Gr-1+ IMCs or MDSCs (experiment group) compared to the WT group: (1) HDC-expressing CD11b+Gr-1+ IMCs of bone marrow of HDC KO mice compared to bone marrow IMCs of WT mice; (2) CD11b+Gr-1+ MDSCs in tumors of HDC-KO mice compared to WT mice; (3) CD11b+Gr-1+ MDSCs of WT colon tumors compared to IMCs in the WT bone marrow; and (4) CD11b+Gr-1+ MDSCs of colon tumors of HDC-KO mice compared to IMCs in the bone marrow of HDC-KO mice.
Project description:Lipid A (a hexaacylated 1,4 bis-phosphate) is a potent immune stimulant for TLR4/MD-2. Upon lipid A ligation, the TLR4/MD-2 complex dimerizes and initiates signal transduction. Historically, studies also suggested the existence of TLR4/MD-2-independent LPS signaling. Here we define the role of TLR4 and MD-2 in LPS signaling by using genome wide expression profiling in TLR4- and MD-2-deficient macrophages after stimulations with peptidoglycan-free LPS and synthetic E.coli lipid A. Of the 1,396 genes found significantly induced or repressed by any one of the treatments in the wildtype macrophages, none was present in the TLR4- or MD-2-deficient macrophages, confirming that the TLR4/MD-2 complex is the only receptor for endotoxin, and are both absolutely required for responses to LPS. Using a molecular genetics approach, we investigated the mechanism of TLR4/MD-2 activation by combining the known crystal structure of TLR4/MD-2 with computer modeling. We used lipid IVa, a defined lipid A mimetic to model the activation of mouse TLR4/MD2. The two phosphates on lipid A were predicted to interact extensively with the two positively charged patches mouse TLR4 according to our dimeric murine TLR4/MD-2/lipid IVa model. These two patches are composed of K263, R337, and K360 (Positive Patch 1), and K367 and R434 (Positive Patch 2). When either Positive Patch was abolished by mutagenesis into Ala, the responses to LPS and lipid A were almost abrogated. Thus, ionic interactions between the two phosphates on lipid A and the two positively charged patches on murine TLR4 appear to be essential for LPS receptor activation. The gene expression profile of macrophages from C57BL/6 and MD-2-deficient mice following either 10 ng LPS /mL, 100 ng lipid A/mL or 10 nM Pam2 stimulation for 2 hours were compared to PBS-stimulated control cells . In vitro differentiated macrophages from two individual WT and MD-2-deficient mice were cultured and stimulated with agonists separately, comparing the gene expression to PBS-stimulated control cells from the same mouse. Comparisons of PBS-stimulated WT cells to PBS-stimulated MD-2-deficient cells were performed to directly compare basal gene expression in the two genotypes.
Project description:The experiment investigates bovine gene expression in response to LPS in uninfected and Theileria annulata-infected cell cultures A subset of genes are identified which are activated in response to LPS stimulation with further modulation due to parasite infection. Six experimental conditions with three replicates per condition. Total RNA prepared from cell cultures. BL20 (uninfected bovine lymphosarcoma cell line), BL20 4 hours post-LPS stimulation, BL20 18 hours post-LPS, TBL (T. annulata infected bovine cell line), TBL 4 hours post-LPS, TBL 18 hours post-LPS. Each hydridisation represents bovine and parasite gene expression on a single channel and 2 technical replicates of each probeset are represented on the chip.
Project description:This SuperSeries is composed of the following subset Series: GSE31066: Lipopolysaccharide (LPS) response in macrophages from TLR4-deficient mice GSE31067: Lipopolysaccharide (LPS) response in macrophages from MD-2-deficient mice Refer to individual Series
Project description:We measured TNFα activity on the transcriptional level by identifying TNFα-inducible genes in human blood monocyte-derived macrophages (MDM). On the basis that TNFα does not act in isolation, we used bacterial lipopolysaccharide (LPS) as a prototypic model of a stimulus to invoke secretion of a wide range of immunologically active factors, including TNFα. In order to identify gene expression attributable to LPS-induced TNFα, we compared the transcriptome of MDM 24 hours after stimulation with 100 ng/ml ultra-pure LPS in the presence and absence of the soluble TNF receptor fusion protein Etanercept (10 µg/ml).