Project description:Hexokinase 2 (HK2) is one the most highly upregulated enzymes in glycolysis in activated T cells and cancer cells. We genetically abolished HK2 expression in T cells in vivo and infected mice with LCMV to induce T cell proliferation. CD8+ T cells from were sorted from spleens of WT and HK2 null mice 8 days after infection. Additionally, WT CD8+ T cells were compared to WT primary T cell acute lymphoblastic leukemia (T-ALL). T-ALL cells were sorted from spleens of mice 6 weeks after adoptive transfer of bone marrow that overexpresses mutant Notch1 (Notch1-deltaE).
Project description:The coordinated release of proteins by T cells enables controlled biological responses. While the molecular mechanisms underlying T cell secretion are being increasingly understood, whether the critical ER-to-Golgi trafficking pathway regulates T cell immunity is not known. We utilized mice with a T cell-specific deletion of SEC23B, a core subunit of Coat Protein Complex II (COPII) which drives ER-to-Golgi cargo transport. We found that following activation, SEC23B-deficient T cells display an altered secretome compared to wild-type, which includes reduced secretion of T cell-derived inflammatory mediators, and which is associated with functional ramifications in vitro and in vivo. Together, these data reveal a critical role for the SEC23B-dependent COPII pathway in T cell immunity.
Project description:Host immunity limits iron availability to pathogenic bacteria, but whether immunity limits pathogenic bacteria from accessing host heme, the major source of iron in the body, remains unclear. Using Citrobacter rodentium, a mouse enteric pathogen and Escherichia coli, a major cause of sepsis in humans as models, we find that interleukin-22, a cytokine best known for its ability to promote epithelial barrier function, also suppresses the systemic growth of bacteria by limiting iron availability to the pathogen. Using an unbiased proteomic approach to understand the mechanistic basis of IL-22 dependent iron retention in the host, we have identified that IL-22 induces the production of the plasma hemoglobin scavenger haptoglobin and heme scavenger hemopexin. Moreover, the anti-microbial effect of IL-22 depends on the induction of hemopexin expression, while haptogloblin is dispensable. Impaired pathogen clearance in infected Il22-/- mice was restored by hemopexin administration and hemopexin-deficient mice had increased pathogen loads after infection. These studies reveal a previously unrecognized host defense mechanism regulated by IL-22 that relies on the induction of hemopexin to limit heme availability to bacteria leading to suppression of bacterial growth during systemic infections.
Project description:It has been strongly argued that plant cells should have a means of sensing sugars at the cell surface, so that extracellular and intracellular sugars can be sensed separately and their metabolism coordinated (Lalonde et al., Plant Cell, 11, 707-26, 2000). There is good evidence for an intracellular hexokinase-dependent pathway of hexose sensing in plants, but very little evidence for a hexokinase-independent signalling pathway, such as that provided by SNF3 or RGT2 in yeast. Many papers on sugar sensing in plants cite work from two laboratories as evidence for hexokinase-independent hexose signalling in plants. The first is that in which cell-wall invertase and sucrose synthase genes were induced by treatment of a Chenopodium suspension culture with 30 mM 6-Deoxyglucose (6DOG) for 24 h (Roitsch et al., Plant Physiol 108, 285-294, 1995; Godt et al., J. Plant Physiol 146, 231-238, 1995). The second is that in which a patatin transgene in Arabidopsis was shown to be weakly induced by growth over several days on a mixture of 30 mM glucose plus 30 mM 3-O-methylglucose (3OMG), but strongly induced by growth on 30 mM Glc plus 90 mM 3OMG (Martin et al., Plant J, 11, 53-62, 1997). We are not aware of any examples of Arabidopsis genes which respond to 6DOG or 3OMG yet this is an area of wide significance. Identification of such a gene would help to establish if a hexokinase-independent signalling system operates in plants, and would provide a basis for establishment of a genetic screen for mutants, using the gene promoter linked to a reporter such as luciferase. The aim of this proposal is to discover any genes which are either activated or repressed by glucose AND by 3OMG and/or 6DOG, but not by mannitol (an osmotic control). The use of both 3OMG and 6DOG will help to identify non-specific effects of either. All substrates will first be analysed by HPLC to confirm that they are pure. Arabidopsis Col-0 seedlings will be grown in vitro for 7 days in the absence of sugars, then treated with 30 mM glucose or glucose analogue for 8 h (these conditions are based on concentrations and time courses of Roitsch et al.). RNA will then be isolated from multiple independent plates to minimise biological variation. Experimenter name = Dorthe Villadsen; Experimenter phone = 0131 650 5318; Experimenter fax = 0131 650 5392; Experimenter address = Institute of Cell and Molecular Biology; Experimenter address = University of Edinburgh; Experimenter address = The King_s Buildings; Experimenter address = Mayfield Road; Experimenter address = Edinburgh; Experimenter zip/postal_code = EH9 3JH; Experimenter country = UK Experiment Overall Design: 6 samples were used in this experiment
Project description:It has been strongly argued that plant cells should have a means of sensing sugars at the cell surface, so that extracellular and intracellular sugars can be sensed separately and their metabolism coordinated (Lalonde et al., Plant Cell, 11, 707-26, 2000). There is good evidence for an intracellular hexokinase-dependent pathway of hexose sensing in plants, but very little evidence for a hexokinase-independent signalling pathway, such as that provided by SNF3 or RGT2 in yeast. Many papers on sugar sensing in plants cite work from two laboratories as evidence for hexokinase-independent hexose signalling in plants. The first is that in which cell-wall invertase and sucrose synthase genes were induced by treatment of a Chenopodium suspension culture with 30 mM 6-Deoxyglucose (6DOG) for 24 h (Roitsch et al., Plant Physiol 108, 285-294, 1995; Godt et al., J. Plant Physiol 146, 231-238, 1995). The second is that in which a patatin transgene in Arabidopsis was shown to be weakly induced by growth over several days on a mixture of 30 mM glucose plus 30 mM 3-O-methylglucose (3OMG), but strongly induced by growth on 30 mM Glc plus 90 mM 3OMG (Martin et al., Plant J, 11, 53-62, 1997). We are not aware of any examples of Arabidopsis genes which respond to 6DOG or 3OMG yet this is an area of wide significance. Identification of such a gene would help to establish if a hexokinase-independent signalling system operates in plants, and would provide a basis for establishment of a genetic screen for mutants, using the gene promoter linked to a reporter such as luciferase. The aim of this proposal is to discover any genes which are either activated or repressed by glucose AND by 3OMG and/or 6DOG, but not by mannitol (an osmotic control). The use of both 3OMG and 6DOG will help to identify non-specific effects of either. All substrates will first be analysed by HPLC to confirm that they are pure. Arabidopsis Col-0 seedlings will be grown in vitro for 7 days in the absence of sugars, then treated with 30 mM glucose or glucose analogue for 8 h (these conditions are based on concentrations and time courses of Roitsch et al.). RNA will then be isolated from multiple independent plates to minimise biological variation. Experimenter name = Dorthe Villadsen Experimenter phone = 0131 650 5318 Experimenter fax = 0131 650 5392 Experimenter address = Institute of Cell and Molecular Biology Experimenter address = University of Edinburgh Experimenter address = The King_s Buildings Experimenter address = Mayfield Road Experimenter address = Edinburgh Experimenter zip/postal_code = EH9 3JH Experimenter country = UK Keywords: growth_condition_design
Project description:Circulating tumor cells (CTCs) represent the molecular characteristics of tumor sites and travel in the blood for seeding distant metastases. "EpCAM+/pan-cytokeratin (CK)+/CD45-/DAPI+" has been widely accepted as a CTC definition, especially in breast cancer, prostate cancer and colorectal cancer. However, reports on CTC detection in non-small cell lung cancer are limited due to a lack of efficient CTC marker. We describe hexokinase 2 (HK2) that assays elevated glycolysis of cancer cells, called Warburg effect, as a new marker for CTC detection in lung adenocarcinoma (LUAD), especially the CK negative CTCs. Single-cell sequencing was used to confirm the malignancy of putative CTCs by detecting genome-wide copy number alternations characteristic of malignant cells. We employed this marker in a variety of liquid biopsies from LUAD patients, including peripheral blood, pleural effusion and cerebrospinal fluid.