Dataset Information

MEK-dependent and -independent signaling events downstream of Tpl-2

ABSTRACT: Comparison of Tpl-2 small molecule inhibitor (SMI) versus MEK SMI activities in LPS-treated human monocytes will reveal a subset of genes that require Tpl-2 but are independent of MEK. Tpl-2 is a highly conserved (94% human versus mouse) serine-threonine kinase expressed in cells important to the inflammatory response, including monocytes, macrophages, dendritic cells, and B/T cells. The role of Tpl-2 in monocytes and macrophages has been especially well-studied. It has been shown in these cells that Tpl-2 is required for the expression of cytokines in response to Toll-like receptor ligands, including LPS. In resting cells, Tpl-2 forms a complex with p105 and ABIN-2. Upon stimulation, this complex dissociates. Dissociated p105 is processed to p50, which impacts transcription. Dissociated Tpl-2 phosphorylates MEK, which, in turn, phosphorylates ERK. ERK activates the transcription factor AP-1 and its downstream gene targets. An open question in the field is whether Tpl-2 acts solely through MEK to drive gene expression, or does Tpl-2 have any MEK-independent targets. Answering this question is important both for understanding basic Tpl-2 biology as well as its role in disease. Based on published data, Tpl-2 is important for inflammatory cytokine production, and in animal models where these cytokines contribute to disease (septic shock, IBD), blocking Tpl-2 ameliorates disease symptoms. We have a highly selective SMI of Tpl-2 that effectively blocks cytokine production in purified human monocytes. This SMI can block production of the same cytokines that a MEK inhibitor blocks, which is expected given that Tpl-2 lies upstream of MEK. However, the MEK SMI only partially inhibits certain cytokines, while the Tpl-2 SMI fully blocks them, suggesting there are additional factors downstream of Tpl-2 that are not MEK-dependent.

ORGANISM(S): Homo sapiens

PROVIDER: GSE84161 | GEO | 2019/07/01

REPOSITORIES: GEO

ACCESS DATA

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

Project description:Analysis of Mtb infected murine macrophages derived from C57Bl/6 WT, TPL2KO, IFNARKO & TPL2IFNAR DKO mice [Set 1] Tuberculosis, caused by Mycobacterium tuberculosis (Mtb), remains a leading cause of mortality and morbidity worldwide, causing approximately 1.4 million deaths per year. Key immune components for host protection during tuberculosis include the cytokines IL?12, IL?1 and TNF??, as well as IFN?? and CD4+ Th1 cells. However, immune factors determining whether individuals control infection or progress to active tuberculosis are incompletely understood. Excess amounts of type I interferon have been linked to exacerbated disease during tuberculosis in mouse models and to active disease in patients, suggesting tight regulation of this family of cytokines is critical to host resistance. In addition, the immunosuppressive cytokine IL?10 is known to inhibit the immune response to Mtb in murine models through the negative regulation of key pro-inflammatory cytokines and the subsequent Th1 response. We show here, using a combination of transcriptomic analysis, genetics and pharmacological inhibitors that the TPL-2-ERK1/2 signaling pathway is important in mediating host resistance to tuberculosis through negative regulation of type I interferon production. The TPL-2-ERK1/2 signalling pathway regulated production by macrophages of several cytokines important in the immune response to Mtb as well as regulating induction of a large number of additional genes, many in a type I IFN dependent manner. In the absence of TPL-2 in vivo, excess type I interferon promoted IL-10 production and exacerbated disease. These findings describe an important regulatory mechanism for controlling tuberculosis and reveal mechanisms by which type I interferon may promote susceptibility to this important disease. Macrophages were derived from C57Bl/6 bone marrow, plated and infected with Mtb H37Rv (or not) in duplicate wells. Samples were then harvested for RNA at time 0 (uninfected only), 15m, 30m, 1hr, 3hr, 6hr and 24hr.

Project description:Analysis of Mtb infected murine macrophages derived from C57Bl/6 WT, TPL2KO, IFNARKO & TPL2IFNAR DKO mice [Set 2] Tuberculosis, caused by Mycobacterium tuberculosis (Mtb), remains a leading cause of mortality and morbidity worldwide, causing approximately 1.4 million deaths per year. Key immune components for host protection during tuberculosis include the cytokines IL‐12, IL‐1 and TNF‐α, as well as IFN‐γ and CD4+ Th1 cells. However, immune factors determining whether individuals control infection or progress to active tuberculosis are incompletely understood. Excess amounts of type I interferon have been linked to exacerbated disease during tuberculosis in mouse models and to active disease in patients, suggesting tight regulation of this family of cytokines is critical to host resistance. In addition, the immunosuppressive cytokine IL‐10 is known to inhibit the immune response to Mtb in murine models through the negative regulation of key pro-inflammatory cytokines and the subsequent Th1 response. We show here, using a combination of transcriptomic analysis, genetics and pharmacological inhibitors that the TPL-2-ERK1/2 signaling pathway is important in mediating host resistance to tuberculosis through negative regulation of type I interferon production. The TPL-2-ERK1/2 signalling pathway regulated production by macrophages of several cytokines important in the immune response to Mtb as well as regulating induction of a large number of additional genes, many in a type I IFN dependent manner. In the absence of TPL-2 in vivo, excess type I interferon promoted IL-10 production and exacerbated disease. These findings describe an important regulatory mechanism for controlling tuberculosis and reveal mechanisms by which type I interferon may promote susceptibility to this important disease. Macrophages were derived from C57Bl/6 WT, TPL2KO, IFNARKO & TPL2IFNARKO bone marrow, plated and infected with Mtb H37Rv (or not) in triplicate wells. The indicated samples were also treated with 5ng/ml IFNgamma at the time of infection. Samples were then harvested for RNA at time 0, 1hr and 6hr. Please note that *Sample and *Medium control samples (e.g. '0hr TPL2-/-IFNabR-/- Sample' vs '0hr TPL2-/-IFNabR-/- Medium Control Sample') are the same sample group (i.e. uninfected) with one group being a repeat re-run of the other (indicated in the correponding SAMPLE description field).

Dataset Information

MEK-dependent and -independent signaling events downstream of Tpl-2

Dataset's files

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets