Project description:Interleukin 1b and interferon g are two cytokines that are central to the inflammatory response. They both have a broad range of activity, each directing the immune response to be towards either the innate response (IL-1b and IFN-g) or the cellular response (IFN-g), however invivo there is a lot of subtle interactions. Microarray analysis has been used to characterize the transcriptional response to recombinant rainbow trout IL-1b and IFN-g in a rainbow trout macrophage cell line RTS-11. The use of the cell line removes the host response and the interference of other cellular factors that occur when performing whole fish experiments, or even primary cultures. RNA was extracted from stimulated or control cells following 6h incubation, this was used to hybridize to a 16K v1 salmonid cDNA array constructed by GRASP consortium. Keywords: Dual label cDNA microarray
Project description:Complex interplay between T helper (Th) cells and macrophages contributes to the formation and progression of atherosclerotic plaques. While Th1 cytokines promote inflammatory activation of lesion macrophages, Th2 cytokines attenuate macrophage-mediated inflammation and enhance their repair functions. In spite of its biologic importance, the biochemical and molecular basis of how Th2 cytokines promote maturation of anti-inflammatory macrophages is not understood. We show here that in response to interleukin-4 (IL-4), signal transducer and activator of transcription 6 (STAT6) and PPARg-coactivator-1b (PGC-1b) induce macrophage programs for fatty acid oxidation and mitochondrial biogenesis. Transgenic expression of PGC-1b primes macrophages for alternative activation and strongly inhibits proinflammatory cytokine production, whereas inhibition of oxidative metabolism or RNAi-mediated knockdown of PGC-1b attenuates this immune response. These data elucidate a molecular pathway that directly links mitochondrial oxidative metabolism to the anti-inflammatory program of macrophage activation, suggesting a potential role for metabolic therapies in treating atherogenic inflammation. Total RNA was prepared from three independent experimental replicates using Trizol reagent (Invitrogen) and validated by northern blot. Microarray experiments were performed with 20-25 ?g of total RNA, which was labelled with fluorescent nucleotides and hybridized to murine cDNA slides. Hybridized slides were interrogated via an Agilent scanner. Cells were activated with either interleukin-4, interferon-gamma/lipo-polysaccharide, or vehicle in low-glucose media.
Project description:Transcriptomes from macrophages at three stages were examined: a) Non-stimulated, b)Stimulated by Interleukin 4, c)Stimulated by LPS and Interferon gamma. Four biological replicate of each experiment were performed.
Project description:Scrub typhus is a life-threatening disease caused by Orientia tsutsugamushi, a bacterium that mainly infects endothelial cells in vitro and in vivo. Evidence suggests that the interaction of O. tsutsugamushi with myeloid cells may play a pivotal role in O. tsutsugamushi infection. We showed here that O. tsutsugamushi intensively replicated within human monocyte-derived macrophages. Bacterial organisms stimulated the expression of a large panel of genes including type I interferon, interferon-stimulated, inflammatory, apoptosis-related genes and induced an M1-type gene response in macrophages. This transcriptional signature was accompanied by functional consequences such as the release of inflammatory cytokines such as Tumor Necrosis Factor and interleukin-gamma. Live O. tsutsugamushi organisms were necessary for type I interferon response and, to a lesser degree, to inflammatory response. As interferon-gamma is known to elicit M1 polarization, we assessed the effect of interferon-gamma on O. tsutsugamushi fate in macrophages. Exogenous interferon-gamma partly inhibited O. tsutsugamushi replication within macrophages. Our results suggest that the inflammatory response induced by O. tsutsugamushi may account for the local and systemic inflammation observed in scrub typhus and that interferon-gamma may be useful as an adjuvant treatment of patients with scrub typhus. Macrophages (4 M-CM-^W 10.5 cells per assay) were incubated with O. tsutsugamushi at a bacterium-to-cell ratio of 20:1 for 8 hours. RNA samples (four samples per experimental condition) were processed for microarray analysis.
Project description:Scrub typhus is a life-threatening disease caused by Orientia tsutsugamushi, a bacterium that mainly infects endothelial cells in vitro and in vivo. Evidence suggests that the interaction of O. tsutsugamushi with myeloid cells may play a pivotal role in O. tsutsugamushi infection. We showed here that O. tsutsugamushi intensively replicated within human monocyte-derived macrophages. Bacterial organisms stimulated the expression of a large panel of genes including type I interferon, interferon-stimulated, inflammatory, apoptosis-related genes and induced an M1-type gene response in macrophages. This transcriptional signature was accompanied by functional consequences such as the release of inflammatory cytokines such as Tumor Necrosis Factor and interleukin-gamma. Live O. tsutsugamushi organisms were necessary for type I interferon response and, to a lesser degree, to inflammatory response. As interferon-gamma is known to elicit M1 polarization, we assessed the effect of interferon-gamma on O. tsutsugamushi fate in macrophages. Exogenous interferon-gamma partly inhibited O. tsutsugamushi replication within macrophages. Our results suggest that the inflammatory response induced by O. tsutsugamushi may account for the local and systemic inflammation observed in scrub typhus and that interferon-gamma may be useful as an adjuvant treatment of patients with scrub typhus.