ABSTRACT: human blood monocytes were isolated, activated and harvested at several timepoints In this study, we identified genes that were differentially expressed in human monocytes activated with eiter NOD2L and/or TLR2/1L. human blood monocytes were purified from healthy donors by Ficoll, Percoll and adherence. Monocytes were activated using NOD2L (MDP) and the TLR2/1L (19kD, triacylated peptide). Cells were harvested before activation (0h) and 6h and 24h after stimulation with ligands.
Project description:A role for vitamin A in host defense against Mycobacterium tuberculosis has been suggested through epidemiological and in vitro studies; however, the antimicrobial mechanism is unclear. Here, we demonstrate that vitamin A mediates host defense through regulation of cellular cholesterol content. Comparison of monocytes stimulated with all-trans retinoic acid (ATRA) or 1,25-dihydroxyvitamin D3, the biologically active forms of vitamin A and vitamin D respectively, indicates that ATRA and 1,25D3 induce mechanistically distinct antimicrobial activities. Gene expression profiling reveals that ATRA but not 1,25D3 triggers a lipid metabolism and efflux pathway, including expression of lysosomal lipid transport gene NPC2. ATRA-induced decrease in total cellular cholesterol content, subcellular lipid reorganization, lysosomal acidification and antimicrobial activity are all dependent upon expression of NPC2. Finally, the addition of HIV-protease inhibitors known to inhibit cholesterol efflux, Ritonavir and Nelfinavir, blocked both ATRA-induced cholesterol decrease as well as antimicrobial activity. Taken together, these results suggest that the vitamin A-mediated host defense mechanism against M. tuberculosis requires regulation of cellular cholesterol. Monocytes derived from four independent healthy blood donors that were stimulated with control (CTRL), ATRA or 1,25D3 at 10-8M for 18 hours.
Project description:Neutrophil recruitment is pivotal to host defense against microbial infection, but also contributes to the immunopathology of disease. We investigated the mechanism of neutrophil recruitment in human infectious disease by bioinformatic pathways analysis of the gene expression profiles in the skin lesions of leprosy. In erythema nodosum leprosum (ENL), which occurs in patients with lepromatous leprosy (L-lep), and is characterized by neutrophil infiltration in lesions, the most overrepresented biologic functional group was “cell movement” including E-selectin, which was coordinately regulated with IL-1. In vitro activation of TLR2, upregulated in ENL lesions, triggered induction of IL-1, which together with IFN-, induced E-selectin expression on, and neutrophil adhesion to endothelial cells. Thalidomide, an effective treatment for ENL, inhibited this neutrophil recruitment pathway. The gene expression profile of ENL lesions comprised an integrated pathway of TLR2/FcR activation, neutrophil migration and inflammation, providing insight into mechanisms of neutrophil recruitment in human infectious disease. 6 ENL skin lesions and 7 Lepromatous leprosy skin lesions
Project description:The immune mechanisms that control resistance vs. susceptibility to mycobacterial infection in humans were investigated by studying leprosy skin lesions, the site where the battle between the host and the pathogen is joined. Using an integrative genomics approach, we found an inverse correlation between of IFN-beta and IFN-gamma gene expression programs at the site of disease. The Type II IFN, IFN-gamma and its downstream vitamin D-dependent antimicrobial genes were preferentially expressed in the lesions from patients with the self-healing tuberculoid form of the disease and mediated antimicrobial activity against the pathogen, Mycobacterium leprae in vitro. In contrast, the Type I IFN, IFN-beta and its downstream genes, including IL-27 and IL-10, were induced in monocytes by M. leprae in vitro, and were preferentially expressed in the lesions of disseminated and progressive lepromatous form. The IFN-gamma induced macrophage antimicrobial response was inhibited by IFN-beta/IL-10, by a mechanism involving blocking the generation of bioactive 1,25-dihyroxy vitamin D as well as inhibiting induction of antimicrobial peptides cathelicidin and DEFB4. The ability of IFN- to inhibit the IFN-gamma induced vitamin D pathway including antimicrobial activity was reversed by neutralization of IL-10, suggesting a possible target for therapeutic intervention. Finally, a common IFN-beta and IL-10 gene signature was identified in both the skin lesions of leprosy patients and in the peripheral blood of active tuberculosis patients. Together these data suggest that the ability of IFN-beta to downregulate protective IFN-gamma responses provides one general mechanism by which some bacterial pathogens of humans evade protective host responses and contribute to pathogenesis. Peripheral blood monuclear cells derived through Ficoll-Hypaque from the blood of healthy human donors (n=4). Cells adhered to tissue culture treated 6-well plates for 2 hours in 1% Fetal Bovine Serum (FBS) RPMI and then stimulated by IL-10 (R&D Systems) 10ng/ml or media alone in 10% FBS RPMI for 24 hours at 37°C, 5% CO2. After stimulation, cells harvested and monocytes isolated through CD14 positive selection (Miltenyi Biotec). RNA from purified monocytes extracted by Trizol and purified by Qiagen RNeasy Kit. RNA probe and microarray performed by UCLA Clinical Microarray Core using Ambion labeling kit and Affymetrix Human U133 Plus 2.0 array.
Project description:Effective innate immunity against many microbial pathogens requires macrophage programs that upregulate phagocytosis and direct antimicrobial pathways, two functions generally assumed to be coordinately regulated. Here the regulation of these key functions was investigated in human blood-derived macrophages. IL-10 induced the phagocytic pathway, including CD209 and scavenger receptors, resulting in phagocytosis of mycobacteria and oxLDL. IL-15 induced the vitamin D-dependent antimicrobial pathway and CD209, yet the cells were less phagocytic. The differential regulation of macrophage functional programs was confirmed by analysis of the spectrum of leprosy lesions: the macrophage phagocytosis pathway was prominent in the clinically progressive, multibacillary form, whereas the vitamin D-dependent antimicrobial pathway predominated in the self-limited form of the disease and in patients undergoing reversal reactions from the multibacillary to the self-limited form. These data indicate that macrophage programs for phagocytosis and antimicrobial responses are distinct and differentially regulated in innate immunity in bacterial infections. Experiment Overall Design: 7 LL lesions, 10 BT lesions, 7 RR lesions
Project description:In innate immune responses, activation of Toll-like receptors (TLRs) triggers direct antimicrobial activity against intracellular bacteria, which in murine, but not human, monocytes and macrophages is mediated principally by nitric oxide. We report here that TLR activation of human macrophages up-regulated expression of the vitamin D receptor and the vitamin D-1-hydroxylase genes, leading to induction of the antimicrobial peptide cathelicidin and killing of intracellular Mycobacterium tuberculosis. We also observed that sera from African-American individuals, known to have increased susceptibility to tuberculosis, had low 25-hydroxyvitamin D and were inefficient in supporting cathelicidin messenger RNA induction. These data support a link between TLRs and vitamin D-mediated innate immunity and suggest that differences in ability of human populations to produce vitamin D may contribute to susceptibility to microbial infection. Experiment Overall Design: The monocyte microarrays were generated using primary human monocytes stimulated with a TLR2/1L or media at 0, 3, 6, 12, 24 hour timepoints. A total of 10 donors were used with time 0 h samples prepared for each. For time points, we used cells from 4 of the 10 donors to prepare media and TLR2/1-stimulated samples. Experiment Overall Design: Dendritic cells were generated by culturing primary human monocytes with GM-CSF (800 U/ml) and IL-4 (1000 U/ml) for 7 days. The cells were then harvested and recultured for 12 hours with TLR2/1L or media. A total of four donors were used. Experiment Overall Design: See manuscript for specific details on data analysis and experimental design and reagents.
Project description:Gene expression profiling was carried out on splenocyte mRNA samples collected from 6 animals subject to repeated social threat and 6 animals subject to non-threatening control conditions (pooled into 3 groups of 2). The primary research question is whether gene expression differs in CD11b+ splenocytes from animals exposed to social threat vs non-threatening control conditions. Keywords: Risk prediction Gene expression profiling was carried out on splenocyte mRNA samples collected from 6 animals subject to repeated social threat and 6 animals subject to non-threatening control conditions (pooled into 3 groups of 2). The primary research question is whether gene expression differs in CD11b+ splenocytes from animals exposed to social threat vs non-threatening control conditions. This study provides an additional body of data from the same general protocol used in Series GSE16661, and will support more extensive analyses than the original study.
Project description:To identify downstream targets of Jak/Stat3 pathways without being distracted by differentiation signalings from MEK/ERK pathway, we exploited a engineered B6 cells, which stably stably expressing a chimeric receptor (GRgp-Y118F). The chimeric receptor can induce the phosphorylation of Stat3 by GCSF without activating the MEK/ERK pathway. To mimic the effect of GCSF, the chimeric B6 cells were also treated with LIF plus a selective MEK chemical inhibitor, PD0325901, to induce LIF/Jak/Stat3 but MEK/ERK pathways. mESCs starved in serum free growth medium for 6hrs were treated with GCSF or with LIF plus PD0325901 for 1hr, after which total RNA was extracted for analysis.
Project description:The requirements for self-renewal differ between EpiSCs and ES cells and the underlying mechanism is largely unknown. Here we show that mouse EpiSCs can be efficiently derived and robustly propagated even from single cells, using two small-molecule inhibitors: CHIR99021 and XAV939. The whole-genome microarray analyses is performed to confirm the identity of EpiSC maintained in CHIR/XAV by comparing the expression profile in EpiSC-CHIR/XAV to those in ESC maintained in 2i and EpiSC maintained in FGF2/activin. Total RNA from ESC-2i, EpiSC-CHIR/XAV, and EpiSC-FGF2/activin were extracted for microarray analisys
Project description:The expansion, trafficking and functional effectiveness of adoptively transferred CD8+ T-cells play a critical role in mediating effective anti-tumor immunity. However, the mechanisms which program the highly proliferative and functional state of CD8+ T-cells are not completely understood. We hypothesized that IL-12, a cytokine commonly induced by TLR activation, could enhance T-cell priming by altering responsiveness to antigen and cytokines. Priming of tumor specific CD8+ T-cells in the presence of IL-12 induced the acquisition of a 'polyfunctional' effector response and increased the generation of memory cells. Moreover, IL-12 priming also promoted high levels of the IL-2 receptor alpha-chain (CD25) and robust IL-2 mediated activation of STAT5. This sensitivity to IL-2 translated into enhanced in vivo proliferation of adoptively transferred CD8+ T-cells. Furthermore, real-time, in vivo imaging of T-cell trafficking confirmed the ability of IL-12 priming to drive in vivo proliferation. IL-12 priming enhanced the anti-tumor function of adoptively transferred cells by reducing established subcutaneous tumor burden, and significantly increasing survival in an established intracranial tumor model. Finally, IL-12 priming of human PBMCs generates tumor specific T-cells phenotypically and functionally similar to IL-12 primed Pmel-1 T-cells. These results highlight IL-12 as an important mediator of CD8+ T-cell effector function and anti-tumor immunity. We primed Pmel-1 TCR transgenic CD8+ T-cells with cognate antigen and either IL-2 or IL-12 and compared their gene expression profiles. This was used to identify pathways or genes necessary for anti-tumor activity in vivo. RNA was isolated from Pmel-1 T-cells primed with antigen and cytokine for 6 days and hybridized to Affymetrix arrays.
Project description:Gene expression profiling was carried out on splenocyte mRNA samples collected from 10 animals subject to repeated social threat (pooled into 2 groups of 5) and 10 animals subject to non-threatening control conditions (pooled into 2 groups of 5). The primary research question is whether gene expression differs in CD11b+ splenocytes from animals exposed to social threat vs non-threatening control conditions. Keywords: Risk prediction RNA from 5 mice/sample was pooled to generate 4 total samples: 2 from mice subject to repeated social threat, and 2 from control mice.