Development of a unique epigenetic signature during in vivo Th17 differentiation.

Activated naive CD4(+) T cells are highly plastic cells that can differentiate into various T helper (Th) cell fates characterized by the expression of effector cytokines like IFN-γ (Th1), IL-4 (Th2) or IL-17A (Th17). Although previous studies have demonstrated that epigenetic mechanisms including DNA demethylation can stabilize effector cytokine expression, a comprehensive analysis of the changes in the DNA methylation pattern during differentiation of naive T cells into Th cell subsets is lacking. Hence, we here performed a genome-wide methylome analysis of ex vivo isolated naive CD4(+) T cells, Th1 and Th17 cells.

Streamlining homogeneous glycoprotein production for biophysical and structural applications by targeted cell line development.

Studying the biophysical characteristics of glycosylated proteins and solving their three-dimensional structures requires homogeneous recombinant protein of high quality.We introduce here a new approach to produce glycoproteins in homogenous form with the well-established, glycosylation mutant CHO Lec3.2.

Peritoneal cavity is dominated by IFNγ-secreting CXCR3+ Th1 cells.

The chemokine receptor CXCR3, which was shown to take part in many inflammatory processes, is considered as a Th1 specific marker. Here, we show in a mouse model that CXCR3 expressing CD4(+) cells preferentially migrate to the peritoneal cavity under steady-state conditions. The peritoneal cavity milieu leads to an up-regulated expression of CXCR3.

Deletion of the Candida albicans histidine kinase gene CHK1 improves recognition by phagocytes through an increased exposure of cell wall beta-1,3-glucans.

The pathogenic fungus Candida albicans is able to cover its most potent proinflammatory cell wall molecules, the β-glucans, underneath a dense mannan layer, so that the pathogen becomes partly invisible for immune cells such as phagocytes. As the C. albicans histidine kinases Chk1p, Cos1p and CaSln1p had been reported to be involved in virulence and cell wall biosynthesis, we investigated whether deletion of the respective genes influences the activity of phagocytes against C.

Glycoprotein production for structure analysis with stable, glycosylation mutant CHO cell lines established by fluorescence-activated cell sorting.

Stable mammalian cell lines are excellent tools for the expression of secreted and membrane glycoproteins. However, structural analysis of these molecules is generally hampered by the complexity of N-linked carbohydrate side chains. Cell lines with mutations are available that result in shorter and more homogenous carbohydrate chains.

Molecular analysis of the bacterial drinking water community with respect to live/dead status.

The assessment of the physiological state of the bacteria in drinking water is a critical issue, especially with respect to the presence of pathogenic bacteria. Though molecular methods can provide insight into the taxonomic composition of the drinking water microflora, the question if a bacterial species is alive or dead still needs to be addressed. To distinguish live and dead bacteria at the taxonomic level, we combined three methods: i) a staining procedure indicating membrane-injured cells (using SYTO9 and Propidium Iodide) that is considered to distinguish between live and dead cells, ii) Fluorescence Activated Cell Sorting (FACS) of the membrane injured and intact bacteria, and iii) molecular analyses of the RNA extracted from the bacteria before and after sorting to analyse the bacterial community at the species level.

Monocytes/macrophages and/or neutrophils are the target of IL-10 in the LPS endotoxemia model.

IL-10 is a potent regulator of the innate and adaptive immune responses. Several cell types produce IL-10 and its receptor chains and these may regulate different immune responses. Here we report that inactivation of the IL-10 receptor (IL-10R1) gene in mice leads to an increased susceptibility to chemically induced colitis as in the classical IL-10-deficient mutant.

Intranasal immunization promotes th17 immune responses.

Th17 cells are a lineage of CD4+ T cells characterized by IL-17 secretion, which plays a crucial role in immune responses against important respiratory pathogens, such as Mycobacterium tuberculosis. In this study, we demonstrated that intranasal (i.n.

CD4+Foxp3+ regulatory T cell expansion induced by antigen-driven interaction with intestinal epithelial cells independent of local dendritic cells.

Background: Regulatory T cells (T(regs)) have potential anti-inflammatory effects and are likely to be important in the pathogenesis of chronic inflammatory bowel disease (IBD). However, the induction and expansion of T(regs) at sites of mucosal inflammation are not yet fully understood and may involve antigen presentation by local dendritic cells (DCs) and/or intestinal epithelial cells (IECs).

Methods: To determine the unique ways in which the gut induces or expands T(regs), a transgenic mouse model that is based on the specific expression of a model autoantigen (influenza haemagglutinin (HA)) in the intestinal epithelium (VILLIN-HA) was used.

Listeria monocytogenes desensitizes immune cells to subsequent Ca2+ signaling via listeriolysin O-induced depletion of intracellular Ca2+ stores.

Listeriolysin O (LLO), the pore-forming toxin of Listeria monocytogenes, is a prototype of the cholesterol-dependent cytolysins (CDCs) secreted by several pathogenic and nonpathogenic gram-positive bacteria. In addition to mediating the escape of the bacterium into the cytosol, this toxin is generally believed to be a central player in host-pathogen interactions during L. monocytogenes infection.

Chronic antigen stimulation in vivo induces a distinct population of antigen-specific Foxp3 CD25 regulatory T cells.

The concept of immune regulation/suppression has been well-established and, besides thymus-derived CD4+CD25+ regulatory T (TR) cells, it became clear that a variety of additional peripherally induced TR cells play vital roles in protection from many harmful immune responses including intestinal inflammation. In the present study, we have analyzed in vivo-induced Ag-specific CD4+ TR cells with respect to their molecular and functional phenotype. By comparative genomics we could show that these Ag-specific TR cells induced by chronic Ag stimulation in vivo clearly differ in their genetic program from naturally occurring thymus-derived CD4+CD25+ TR cells.

The multiple mechanisms of Ca2+ signalling by listeriolysin O, the cholesterol-dependent cytolysin of Listeria monocytogenes.

Cholesterol-dependent cytolysins (CDCs) represent a large family of conserved pore-forming toxins produced by several Gram-positive bacteria such as Listeria monocytogenes, Streptococcus pyrogenes and Bacillus anthracis. These toxins trigger a broad range of cellular responses that greatly influence pathogenesis. Using mast cells, we demonstrate that listeriolysin O (LLO), a prototype of CDCs produced by L.

UBD, a downstream element of FOXP3, allows the identification of LGALS3, a new marker of human regulatory T cells.

Here, we report the identification of the ubiquitin-like gene UBD as a downstream element of FOXP3 in human activated regulatory CD4(+)CD25(hi) T cells (T(reg)). Retroviral transduction of UBD in human allo-reactive effector CD4(+) T helper (T(h)) cells upregulates CD25 and mediates downregulation of IL4 and IL5 expression similar to overexpression of FOXP3. Moreover, UBD impairs T(h) cell proliferation without upregulation of FOXP3 and impairs calcium mobilization.