Project description:Address the effect of mechanical stimulation by confinement on the status of activation of dendritic cells and the role of cPLA2 in orchestrating this response. We performed gene expression analysis using data obtained from RNA-seq of 3 independent experiment of DCs from WT and KO of cPLA2.
Project description:Homeostatic control of dendritic cell (DC) survival is crucial for a productive adaptive immune response, but the molecular mechanism is not well defined. Moreover, how DCs influence homeostasis of the immune system under steady state remains unclear. Combining DC-specific and inducible deletion systems, we report here that the kinase TAK1 is an essential regulator of DC survival and immune system homeostasis and function. Deficiency of TAK1 in CD11c+ cells diminished DC populations, especially the CD8+ and CD103+ DC subsets in the lymphoid and non-lymphoid organs, respectively. This was associated with increased apoptosis of DCs, whereas DC proliferation and differentiation from precursors appeared largely normal. In addition, acute deletion of TAK1 caused DC apoptosis, indicating a direct role of TAK1 in actively maintaining DC survival. TAK1 deficiency impaired activities of the pro-survival NF-kB and AKT pathways but upregulated expression of the pro-apoptotic molecule Bim. Under steady state, loss of TAK1 in DCs resulted in a myeloid proliferative disorder, and altered homeostasis of T cells. In response to antigen stimulation, TAK1-deficient DCs were impaired for T cell priming and regulatory T cell generation. Therefore, TAK1 orchestrates a pro-survival checkpoint in DCs that affects the homeostasis and function of the immune system RNA extracted from three replicate samples of wild-type and Map3k7 (TAK1) knockout dendritic cells was analyzed on Affymetrix gene expression arrays
Project description:Abstract Two major dendritic cell (DC) subsets have been described in the islets of mice: The immunogenic CD8α-CD11b+ DCs and the tolerogenic CD8α+CD103+ DCs. We have recently reported on reduced numbers of the minor population of tolerogenic CD8α+CD103+ DCs in the pancreas of 5 week old pre-diabetic non-obese diabetic (NOD) mice. Aim: To analyze also the larger subset of CD11c+CD8α- DCs isolated from the pancreas of pre-diabetic NOD mice 1) for maturation and tolerance inducing molecules found abnormally expressed on CD8α+CD103+ DCs, and 2) for genome-wide gene expression to further elucidate abnormalities in underlying gene expression networks. Methods: CD11c+CD8α- DCs were isolated from 5 week old C57BL/6 and NOD pancreas. Expression of cell surface markers including CD86, CCR5, CD11b, CD103, Clec9a, CD24 and CD200R3 were measured by FACS. Genome-wide gene expression by microarray was assessed during the steady state and after in vitro LPS stimulation. Results: The steady state pancreatic CD11c+ CD8α- DCs during the pre-diabetic stage showed: 1) A reduced expression of several gene networks important for the prime functions of the cell, such as for cell renewal, immune stimulation and immune tolerance induction, for migration and for the provision of growth factors for beta cell regeneration. This general deficiency state was corroborated by a reduced in vivo proliferation (BrdU incorporation) of the cells and the reduced expression in FACS analysis of CD86, CCR5, CD103, Clec9a, CD24 and CD200R3 on the cells. 2) A hyper reactivity of these cells to LPS correlated with an enhanced pro-inflammatory state characterized by altered expression of a number of classical pro-inflammatory factors and cytokines. Conclusion: The NOD CD11c+CD8α- DCs seem to be Janus-faced depending on the conditions: Deficient in steady state with reduced immune stimulation capabilities also for tolerance induction; over-inflammatory with a molecular profile suggesting a preferential stimulatory capacity for Th1 cells when encountering a Pathogen-Associated Molecular Pattern (PAMP) in the form of LPS. We used microarray gene expression analysis to explain the abnormal expression of several cell surface markers involved in tolerace, migration and maturation in the steady-state and to measure the effect of a PAMP such as LPS We isolated RNA from FACS sorted CD11c+CD8α- DCs in 10 pooled pancreases from pre-diabetic NOD and non-diabetic C57BL/6 mice at 5 weeks. In addition, we treated in another experiment the isolated pancreas DCs with LPS (and PBS), incubated for 18h and measured gene expression. We compared gene expression between strains NOD vs C57BL/6 under steady-state and after in-vitro LPS/PBS stimulation.
Project description:Abstract Two major dendritic cell (DC) subsets have been described in the islets of mice: The immunogenic CD8α-CD11b+ DCs and the tolerogenic CD8α+CD103+ DCs. We have recently reported on reduced numbers of the minor population of tolerogenic CD8α+CD103+ DCs in the pancreas of 5 week old pre-diabetic non-obese diabetic (NOD) mice. Aim: To analyze also the larger subset of CD11c+CD8α- DCs isolated from the pancreas of pre-diabetic NOD mice 1) for maturation and tolerance inducing molecules found abnormally expressed on CD8α+CD103+ DCs, and 2) for genome-wide gene expression to further elucidate abnormalities in underlying gene expression networks. Methods: CD11c+CD8α- DCs were isolated from 5 week old C57BL/6 and NOD pancreas. Expression of cell surface markers including CD86, CCR5, CD11b, CD103, Clec9a, CD24 and CD200R3 were measured by FACS. Genome-wide gene expression by microarray was assessed during the steady state and after in vitro LPS stimulation. Results: The steady state pancreatic CD11c+ CD8α- DCs during the pre-diabetic stage showed: 1) A reduced expression of several gene networks important for the prime functions of the cell, such as for cell renewal, immune stimulation and immune tolerance induction, for migration and for the provision of growth factors for beta cell regeneration. This general deficiency state was corroborated by a reduced in vivo proliferation (BrdU incorporation) of the cells and the reduced expression in FACS analysis of CD86, CCR5, CD103, Clec9a, CD24 and CD200R3 on the cells. 2) A hyper reactivity of these cells to LPS correlated with an enhanced pro-inflammatory state characterized by altered expression of a number of classical pro-inflammatory factors and cytokines. Conclusion: The NOD CD11c+CD8α- DCs seem to be Janus-faced depending on the conditions: Deficient in steady state with reduced immune stimulation capabilities also for tolerance induction; over-inflammatory with a molecular profile suggesting a preferential stimulatory capacity for Th1 cells when encountering a Pathogen-Associated Molecular Pattern (PAMP) in the form of LPS. We used microarray gene expression analysis to explain the abnormal expression of several cell surface markers involved in tolerace, migration and maturation in the steady-state and to measure the effect of a PAMP such as LPS
Project description:Homeostatic control of dendritic cell (DC) survival is crucial for a productive adaptive immune response, but the molecular mechanism is not well defined. Moreover, how DCs influence homeostasis of the immune system under steady state remains unclear. Combining DC-specific and inducible deletion systems, we report here that the kinase TAK1 is an essential regulator of DC survival and immune system homeostasis and function. Deficiency of TAK1 in CD11c+ cells diminished DC populations, especially the CD8+ and CD103+ DC subsets in the lymphoid and non-lymphoid organs, respectively. This was associated with increased apoptosis of DCs, whereas DC proliferation and differentiation from precursors appeared largely normal. In addition, acute deletion of TAK1 caused DC apoptosis, indicating a direct role of TAK1 in actively maintaining DC survival. TAK1 deficiency impaired activities of the pro-survival NF-kB and AKT pathways but upregulated expression of the pro-apoptotic molecule Bim. Under steady state, loss of TAK1 in DCs resulted in a myeloid proliferative disorder, and altered homeostasis of T cells. In response to antigen stimulation, TAK1-deficient DCs were impaired for T cell priming and regulatory T cell generation. Therefore, TAK1 orchestrates a pro-survival checkpoint in DCs that affects the homeostasis and function of the immune system
Project description:Depending on their environment and their exposure to various factors, dendritic cells (DCs) exist in different activation and maturation states. The versatility of DCs allows them to shape the immune system towards an inflammatory or tolerant state depending on the antigens and the environment they encounter. In this study we aimed to provide a proteomic catalogue of differentially expressed and differentially phosphorylated proteins between distinct DC maturation states, brought about by bacteria that differ in their endotoxicity. To achieve this, we have performed unlabeled shotgun proteomics and phosphoproteomics on cell fractions obtained from murine bone marrow DC cultures. The symbiont B. vulgatus stimulation was used to obtain semi-mature DCs, and the pathobiont E. coli stimulation was used to obtain mature DCs. For both shotgun proteome and phosphoproteome analysis two biological replicates consisting of 8 mice were used. Each biological replicate were run as 3 technical replicates.
Project description:We exploited label-free quantitative mass spectrometry to compare primary human blood Dendritic cells (DCs) subsets protein expression to identify new markers. Subsets distinguished are: Plasmacytoid DCs (pDC) and BDCA3+ and CD1c+ myeloid DCs and CD16+ monocytes. The dendritic cells were analyzed by LC-MS/MS and processed by MaxQuant for identification and LFQ quantification.