Search results for "CD1"
showing 10 items of 333 documents
Interleukin 1α Promotes Th1 Differentiation and Inhibits Disease Progression in Leishmania major–susceptible BALB/c Mice
2003
Protective immunity against pathogens such as Leishmania major is mediated by interleukin (IL)-12–dependent Th1-immunity. We have shown previously that skin-dendritic cells (DCs) from both resistant C57BL/6 and susceptible BALB/c mice release IL-12 when infected with L. major, and infected BALB/c DCs effectively vaccinate against leishmaniasis. To determine if cytokines other than IL-12 might influence disease outcome, we surveyed DCs from both strains for production of a variety of cytokines. Skin-DCs produced significantly less IL-1α in response to lipopolysaccharide/interferon γ or L. major when expanded from BALB/c as compared with C57BL/6 mice. In addition, IL-1α mRNA accumulation in l…
Defective T helper response of hepatocyte-stimulated CD4 T cells impairs antiviral CD8 response and viral clearance.
2007
Background & Aims: In hepatitis, hepatocytes gain the ability to express major histocompatibility complex (MHC) class II molecules and to present antigen to CD4 T cells. Here, we investigated whether MHC class II-expressing hepatocytes influence in vitro the differentiation of CD4 T cells and in vivo the T-cell response to and control of viral infection. Methods: Class II transactivator-transgenic hepatocytes that constitutively express MHC class II molecules were used to stimulate CD4 T cells in vitro, and the effector response type of the stimulated CD4 T cells was determined. The in vivo relevance of the obtained findings was confirmed by infecting nontransgenic or class II transactivato…
Antibodies against tumor necrosis factor (TNF) induce T-cell apoptosis in patients with inflammatory bowel diseases via TNF receptor 2 and intestinal…
2011
Background & Aims The anti–tumor necrosis factor (TNF) antibodies infliximab, adalimumab, and certolizumab pegol have proven clinical efficacy in Crohn's disease. Here, we assessed the effects of anti-TNF antibodies on apoptosis in inflammatory bowel disease (IBD). Methods CD14 + macrophages and CD4 + T cells were isolated from peripheral blood and lamina propria mononuclear cells from patients with IBD and control patients. Cell surface markers and apoptosis were assessed by immunohistology and fluorescence-activated cell sorting techniques. Results Lamina propria CD14 + macrophages showed significantly more frequent and higher membrane-bound TNF (mTNF) expression than CD4 + T cells in IBD…
Preservation of dendritic cell function upon labeling with amino functionalized polymeric nanoparticles.
2010
Dendritic cells (DCs) are key players in eliciting immunity against antigens, therefore making them the focus of many investigations on immune responses in infections, cancer and autoimmune diseases. Nanosized materials have just recently been investigated for their use as carriers of antigens and as labeling agents for DCs. For this later use nanoparticles should be non-toxic and should most importantly not alter the physiological functions of DCs. Here we demonstrate that by the use of polymeric fluorescent nanoparticles as synthesized by the miniemulsion process immature DCs (iDCs) can be efficiently labeled intracellularly. Amino functionalized nanoparticles are more effective than carb…
Dendritic Cells Lose Ability to Present Protein Antigen after Stimulating Antigen-Specific T Cell Responses, despite Upregulation of MHC Class II Exp…
2000
Abstract Immature dendritic cells (DC) take up, process and present protein antigens; mature DC are specialized for stimulating primary T cell responses with increased expression of MHC class II and co-stimulatory molecules, but are incapable of processing and presenting soluble protein. The current study examined whether maturation of DC is triggered by T cell recognition of antigens presented by immature DC. Human DC derived from CD34+ progenitor cells by culture with granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-6 (IL-6) in serum-free medium could prime naive CD4+ T cells to keyhole limpet hemocyanin (KLH) and ovalbumin (OVA). The cultured DC retained the abil…
Microenvironment Regulation of IL23R/IL-23 Axis Drives Chronic Lymphocytic Leukemia (CLL) Progression
2015
Abstract Background : CLL displays a considerable degree of clinical heterogeneity, which is in part ascribable to clone-intrinsic biological features and that are also influenced by clone-extrinsic events related to the microenvironment. Among the dynamics-taking place within the CLL microenvironment, those finalized to the induction of an overly inflammatory milieu may significantly impact on the CLL natural history by hijacking the immunological microenvironment at the same time fostering clone fitness. IL-23 acts as a prototypical pro-inflammatory mediator representing a promising therapeutic target. We analyzed the ability of CLL cells to sense IL-23 through the IL-23R complex (consist…
2 Isolation of T Cells and Establishment of T-cell Lines and Clones
1998
Publisher Summary This chapter elaborates the isolation of T cells and the establishment of T-cell lines and clones. The study of human T cells is best performed using purified cells because the presence of other cell types may have indirect effects on T-cell function. For any kind of functional assay on T-cell specificity, antigen-presenting cells are necessary. T cells appear to play a major role in the development, maintenance, and also resolution of these forms of bacteria-associated arthritides. The E-rosetting technique describes a procedure for separating T cells and non-T cells from a population of MNCs. This method is based on the ability of human T cells to bind to sheep erthrocyt…
Differential expression of alternative H2-M isoforms in B cells, dendritic cells and macrophages by proinflammatory cytokines.
1999
Major histocompatibility (MHC) class II heterodimers bind peptides generated by degradation of endocytosed antigens and display them on the surface of antigen presenting cells (APCs) for recognition by CD4+ T cells. Efficient loading of MHC class II molecules with peptides is catalyzed by the MHC class II-like molecule H2-M. The coordinate regulation of MHC class II and H2-M expression is a prerequisite for efficient MHC class II/peptide assembly in APCs determining both the generation of the T cell repertoire in the thymus and cellular immune responses in the periphery. Here we show that expression of H2-M and MHC class II genes is coordinately and cell type-specific regulated in splenic B…
Multiple levels of MHC class I down-regulation by ras oncogenes.
1996
A number of tumours and oncogene transformed cells displayed reduced MHC class I surface expression which seemed to enable their escape from immune surveillance. To test whether oncogenic activation is directly involved in suppressing MHC class I expression, a model of inducible oncogene expression was chosen. Mouse fibroblasts transfected with different oncogenes expressed under the control of the dexamethasone-inducible MMTV promoter were analysed in the presence and absence of hormone for the mRNA and protein expression of MHC class I molecules as well as the respective oncogenes. Immunofluorescence analyses demonstrated an inverse association of MHC class I and oncogene expression after…
β-Catenin Signaling Drives Differentiation and Proinflammatory Function of IRF8-Dependent Dendritic Cells
2014
Abstract β-Catenin signaling has recently been tied to the emergence of tolerogenic dendritic cells (DCs). In this article, we demonstrate a novel role for β-catenin in directing DC subset development through IFN regulatory factor 8 (IRF8) activation. We found that splenic DC precursors express β-catenin, and DCs from mice with CD11c-specific constitutive β-catenin activation upregulated IRF8 through targeting of the Irf8 promoter, leading to in vivo expansion of IRF8-dependent CD8α+, plasmacytoid, and CD103+CD11b− DCs. β-Catenin–stabilized CD8α+ DCs secreted elevated IL-12 upon in vitro microbial stimulation, and pharmacological β-catenin inhibition blocked this response in wild-type cells…