Listeria monocytogenes
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REPOSITORIES: ENA
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Project description:Sequencing of Listeria monocytogenes isolated from Irish Seafood products and processing environments
| PRJNA698557 | ENA
Project description:Listeria monocytogenes (Lm) kills up to 60% of infected newborns and adults >60 years of age but is asymptomic is most young adults. Monocytes are central to effective host defense against Lm. We hypothesize that age-dependent, pathway-specific differences in the ability of the monocyte to respond to Lm explain the increased risk of the newborn and older adult to severely suffer or die from Lm infection. To delineate age-dependent differences in innate responses that lead to differential infectious outcome, monocytes were isolated from cord blood (newborn) and peripheral blood (young and older adults) and infected with Lm. RNA was collected to determine age-dependent transcriptomic changes upon infection.
2015-09-01 | GSE67983 | GEO
Project description:The foodborne pathogen Listeria monocytogenes (Lm) can cause invasive infection in susceptible animals and humans. To survive and proliferate within hosts, this facultative intracellular pathogen needs to tightly coordinate the expression of a complex regulatory network, including virulence factors. Here, we identify and characterize MouR a novel virulence regulator of Lm. Through RNA-seq transcriptomic analysis, we characterized the MouR regulatory network and demonstrated how MouR positively controls the expression of the Agr system (agrBDCA) of Lm. Resolving MouR 3D structure revealed a dimeric DNA-binding transcription factor belonging to the VanR class of the GntR superfamily of regulatory proteins. We showed that by direct binding to the agr promoter region, MouR ultimately modulates chitinase activity and biofilm formation. Importantly, we demonstrated by in vitro cell invasion assays and in vivo mice infections the crucial role of MouR for Lm full virulence.
2018-10-22 | GSE106833 | GEO
Project description:IFN-Is have a detrimental effect in the case of Listeria monocyteogenes (Lm) infection. Previously it has been shown that Ifnar-/- mice are protected from the infection induced death. However, we have found that IRF9, a downstream component of the IFNAR signalling, has a role in addition to the IFNAR signalling in protecting the mice from Lm infection. This is due to Irf9-/- mice being more protected than Ifnar-/- mice. Among other hypotheses, we think that the recently shown role of Irf9 in glucose metabolism can be effective in this additional protection. Furthermore, our metabolic screens point to similar direction. Therefore, we would like to measure the differential gene expression pattern in livers from uninfected and 1 day infected Wt, Irf9-/- and Ifnar-/- mice.
2021-06-09 | GSE162448 | GEO
Project description:Whole genome seqeuncing of EURL Lm reference strains
| PRJNA808240 | ENA
Project description:Cerebral listeriosis is characterized by neuronal apoptosis and microglial cell activation, but little is known about the bacterial virulence factors involved in this process and how bacterial dissemination is controlled. Here, we show that the cellular target of Listeria monocytogenes (LM) in murine hippocampal cultures is microglia rather than neurons or other glial cells, which are rarely infected. This in vitro model served to demonstrate that infected microglial cells release a soluble factor to the medium responsible for neuronal apoptosis. We investigated the production of this factor in a well-established murine microglia cell model BV2 cells, and compared with J-774 macrophage cells after infection with different LM bacterial mutants. Our purpose was to study in both cell types parameters such as the listericidal capacities, pro-inflammatory cytokines released, and bacterial factors involved in the intracellular cycle. Our data reveal that microglia shows unique features to handle a LM infection. Microglia is three times more permissive for LM intracellular growth than murine macrophages; while producing five times higher levels of pro-inflammatory cytokines IL-6, MCP-1 and TNF-α than macrophages. Using different LM mutants (i.e., LMWT, LM∆LLO, LM∆ActA or LM∆plcB) we conclude that LLO and ActA are not involved in LM proliferation within microglia cells, while they are required for survival within macrophages. Moreover, ActA controls TNF-α production, a cytokine involved in neural apoptosis. Transcriptional differential response of microglia infected with different LM mutants reflected ActA controls the TNF-a signaling pathway through out molecules and chemokines involved in this pathway such as NFkβ, MAPK-1, Ccl2, Ccl3, Ccl4 and CxCl10.
2011-10-03 | GSE32505 | GEO
Project description:Listeria monocytogenes (Lm) kills up to 60% of infected newborns and adults >60 years of age but is asymptomic is most young adults. Monocytes are central to effective host defense against Lm. We hypothesize that age-dependent, pathway-specific differences in the ability of the monocyte to respond to Lm explain the increased risk of the newborn and older adult to severely suffer or die from Lm infection. To delineate age-dependent differences in innate responses that lead to differential infectious outcome, monocytes were isolated from cord blood (newborn) and peripheral blood (young and older adults) and infected with Lm. RNA was collected to determine age-dependent transcriptomic changes upon infection. Total RNA was isolated from purified human monocytes from 6 adult, 6 cord , 6 older adult blood donors that were infected with wild-type Listeria monocytogenes at a multiplicity of infected (MOI)=5 for 2 and 6 hr.
2015-09-01 | E-GEOD-67983 | biostudies-arrayexpress
Project description:Cerebral listeriosis is characterized by neuronal apoptosis and microglial cell activation, but little is known about the bacterial virulence factors involved in this process and how bacterial dissemination is controlled. Here, we show that the cellular target of Listeria monocytogenes (LM) in murine hippocampal cultures is microglia rather than neurons or other glial cells, which are rarely infected. This in vitro model served to demonstrate that infected microglial cells release a soluble factor to the medium responsible for neuronal apoptosis. We investigated the production of this factor in a well-established murine microglia cell model BV2 cells, and compared with J-774 macrophage cells after infection with different LM bacterial mutants. Our purpose was to study in both cell types parameters such as the listericidal capacities, pro-inflammatory cytokines released, and bacterial factors involved in the intracellular cycle. Our data reveal that microglia shows unique features to handle a LM infection. Microglia is three times more permissive for LM intracellular growth than murine macrophages; while producing five times higher levels of pro-inflammatory cytokines IL-6, MCP-1 and TNF-α than macrophages. Using different LM mutants (i.e., LMWT, LM∆LLO, LM∆ActA or LM∆plcB) we conclude that LLO and ActA are not involved in LM proliferation within microglia cells, while they are required for survival within macrophages. Moreover, ActA controls TNF-α production, a cytokine involved in neural apoptosis. Transcriptional differential response of microglia infected with different LM mutants reflected ActA controls the TNF-a signaling pathway through out molecules and chemokines involved in this pathway such as NFkβ, MAPK-1, Ccl2, Ccl3, Ccl4 and CxCl10. The project implies the analysis of two replicates from three different conditions, in total 6 samples: microglia cells non-infected, microglia cells infected with Listeria monocytogenes (LM) wild type (LLO+), microglia cells infected with LM deficient in listeriolysin O (LLO-) and microglia cells infected with LM deficient in ActA (1942). References samples were microglia cells non-infected (NT). Infection with LM was performed for 1 hour, followed by 24 hours in medium with antibiotics to avoid bacterial extracellular growth. Gene expression analysis was performed using Partek Genomics Suite software (version 6.11.0801; Partek). GeneChip data were filtered to remove those probe sets with an intensity raw value close to background levels. Probe sets for each array are pre-processed using RMA. Also, probe sets whose expression change under all experimental conditions was below a threshold, based on the standard desviation of the normalised intensity values, were filtered.
2011-10-02 | E-GEOD-32505 | biostudies-arrayexpress
Project description:Purpose: ATAC-seq analysis of naive and three effector OT-I cell subsets (from a Klrg1-Cre fate reporter mouse model) isolated from the spleen of C57BL/6 mice 0 and 8 days post infection with OVA-expressing Listeria monocytogenes. The hypothesis tested in the present study was that chromatin remodeling in KLRG1+ effector CD8 T lymphocytes promotes the differentiation into KLRG1- memory CD8 T lymphocytes that provide long-lasting immunity against infectious diseases and malignancies. Methods: DNA was obtained from 50,000 FACS-purified OT-I cell subsets isolated from spleen 0 and 8 days post infection with ovalbumin-expressing Listeria monocytogenes (LM-OVA) (experiment 3). Results: Using ATAC-seq technology, we analyzed the chromatin accessibility landscape of naive and three effector OT-I cells (KLRG1+ Reporter+, KLRG1- Reporter+ (exKLRG1) and KLRG1- Reporter-). Conclusions: Our study represents the first fate mapping analysis of KLRG1+ effector OT-I cells, demonstrates that KLRG1+ effector OT-I cells differentiate into all memory T cell lineages thereby promoting protective immunity. RNA-seq identified CX3CR1 as a marker of circulating exKLRG1 early memory OT-I cells, and ATAC-seq analysis revealed that chromatin remodeling enabled exKLRG1 memory cells to exhibit both a high cytotoxic and proliferative capacity.
2018-03-01 | GSE110876 | GEO
Project description:Type 1 CD8α+ conventional dendritic cells (cDC1s) harbor and transport Listeria monocytogenes (LM) within the spleen and thereby promote infection; cDC1s are also required for CD8+ T cell priming. To test the role of the second lineage of splenic cDC in regulating infection or adaptive immunity to LM we used Dock8-deficient mice, which have impaired 33D1+ type 2 cDC (cDC2) function. We found reduced CD8+ T cell activation in Dock8-deficient mice, but this was not due to impaired cDC2 function but rather resistance to LM infection. Bacterial resistance was due to loss of marginal zone B (MZB) cells. We showed that IL-10 production by MZB cells did not alter antigen handling pathways in dendritic cells (DCs), including ones relevant for cross-priming or Listeria survival. Instead, IL-10 increased intracellular LM in macrophages in the marginal zone, which transfer bacteria to cDC1s. Bacteria-harboring cDC1s then traffic into the splenic white pulp where protection from sterilizing phagocytes promotes LM expansion. This work uncovers a unique crosstalk between the innate immune cells in the marginal zone, facilitated by IL-10, that promotes both infection but also CD8+ T cell activation.
2019-06-20 | GSE124771 | GEO