Search results for "antigen-presenting cells"
showing 10 items of 91 documents
Expression of the actin-bundling protein fascin in cultured human dendritic cells correlates with dendritic morphology and cell differentiation.
2000
Dendritic cells are key players of the immune system as they efficiently induce primary immune responses by activating naive T cells. We generated human dendritic cells from CD14+ blood precursors and investigated expression of the actin-bundling protein fascin during maturation by western blotting, immunofluorescence, and cytofluorometry. Cells obtained by culture of CD14+ blood precursors in the presence of granulocyte-macrophage colony-stimulating factor and interleukin-4, which were only weakly positive for the maturation marker CD83, expressed low amounts of fascin. Addition of a cytokine cocktail including tumor necrosis factor alpha, interleukin-1beta, interleukin-6, and prostaglandi…
Dendritic cell aggresome-like-induced structure formation and delayed antigen presentation coincide in influenza virus-infected dendritic cells.
2005
Abstract Influenza virus infection induces maturation of murine dendritic cells (DCs), which is most important for the initiation of an immune response. However, in contrast to EL-4 and MC57 cells, DCs present viral CTL epitopes with a delay of up to 10 h. This delay in Ag presentation coincides with the up-regulation of MHC class I molecules as well as costimulatory molecules on the cell surface and the accumulation of newly synthesized ubiquitinated proteins in large cytosolic structures, called DC aggresome-like-induced structures (DALIS). These structures were observed previously after LPS-induced maturation of DCs, and it was speculated that they play a role in the regulation of MHC cl…
Characterization of lymphokine-mediated activation of macrophages for antigen presentation: studies with long-term cultured bone marrow-derived macro…
1984
In cultures of bone marrow (BM) supplemented with L cell-derived colony-stimulating factor a pure population of macrophages (M phi) differentiates, which can be further propagated with a doubling time of 3.8 days. "Young" BMM phi obtained on day 8 of culture were shown to act as antigen-presenting cells inducing the antigen-specific proliferation of the cloned T cell line ST2/K.9, whereas "old" M phi had lost this ability. However, at any time tested (up to 132 days) the presentation function of old BMM phi could be completely restored by pulsing the cells with lymphokines (LK). A duration of 11 hr for the LK-pulse was sufficient to trigger the M phi to exert an optimal presentation functio…
Immune Evasion Proteins Enhance Cytomegalovirus Latency in the Lungs
2009
ABSTRACT CD8 T cells control cytomegalovirus (CMV) infection in bone marrow transplantation recipients and persist in latently infected lungs as effector memory cells for continuous sensing of reactivated viral gene expression. Here we have addressed the question of whether viral immunoevasins, glycoproteins that specifically interfere with antigen presentation to CD8 T cells, have an impact on viral latency in the murine model. The data show that deletion of immunoevasin genes in murine CMV accelerates the clearance of productive infection during hematopoietic reconstitution and leads to a reduced latent viral genome load, reduced latency-associated viral transcription, and a lower inciden…
Plasmacytoid dendritic cells are inefficient in activation of human regulatory T cells
2011
BACKGROUND: Dendritic cells (DC) play a key role in initiation and regulation of immune responses. Plasmacytoid DC (pDC), a small subset of DC, characterized as type-I interferon producing cells, are critically involved in anti-viral immune responses, but also mediate tolerance by induction of regulatory T cells (Treg). In this study, we compared the capacity of human pDC and conventional DC (cDC) to modulate T cell activity in presence of Foxp3(+) Treg. PRINCIPAL FINDINGS: In coculture of T effector cells (Teff) and Treg, activated cDC overcome Treg anergy, abrogate their suppressive function and induce Teff proliferation. In contrast, pDC do not break Treg anergy but induce Teff prolifera…
Cetuximab +/- chemotherapy enhances dendritic cell-mediated phagocytosis of colon cancer cells and ignites a highly efficient colon cancer antigen-sp…
2012
Cetuximab is a human/mouse chimeric IgG1 monoclonal antibody (mAb) to epidermal growth factor receptor, approved for colorectal carcinoma treatment in combination with chemotherapy. The immune-mediated effects elicited by its human fraction of crystallization moiety might critically contribute to the overall anti-tumor effectiveness of the antibody. We therefore investigated cetuximab ability to promote colon cancer cell opsonization and phagocytosis by human dendritic cells (DCs) that are subsequently engaged in antigen-cross presentation to cytotoxic T-lymphocyte (CTL) precursors. Human colon cancer cell lines were evaluated for susceptibility to DC-mediated phagocytosis before and after …
Current Progress in Particle-Based Systems for Transdermal Vaccine Delivery
2020
Transcutaneous immunization (TCI) via needle-free and non-invasive drug delivery systems is a promising approach for overcoming the current limitations of conventional parenteral vaccination methods. The targeted access to professional antigen-presenting cell (APC) populations within the skin, such as Langerhans cells (LCs), various dermal dendritic cells (dDCs), macrophages, and others makes the skin an ideal vaccination site to specifically shape immune responses as required. The stratum corneum (SC) of the skin is the main penetration barrier that needs to be overcome by the vaccine components in a coordinated way to achieve optimal access to dermal APC populations that induce priming of…
General considerations in the interpretation of I-J genetic restrictions: evidence that the antigen-binding chain of antigen-specific T-suppressor fa…
1987
SUMMARY (CBA × B10)F1 [(H-2k x H-2b)] mice produce two types of antigen-specific T-suppressor factor (TsF), which can be separated by affinity chromatography on anti-I-J monoclonal antibody. After reduction and alkylation, both chains of F1 TsF are required for biological activity. However, the antigen-binding chain (AgBC) of F1 TsFk (AgBCk) is only complemented by I-Jk and likewise for F1 TsFb. In other words, interchain complementation shows the same genetic restriction in interchain complementation in parental and F1 mice. F1 TsF bearing, for example, I-Jk (TsFk), interacts with haptenized ‘antigen-presenting cells’ (‘APC’) of both parental haplotypes, and may be described as showing dua…
Granulocyte-macrophage colony-stimulating factor-cultured bone marrow-derived macrophages reveal accessory cell function and synthesis of MHC class I…
1988
The antigen-mediated activation of a number of T cell clones by bone marrow (BM) cells cultivated in the presence of various colony-stimulating factor (CSF) preparations was investigated. BM macrophages (BMM phi) grown in L929 cell supernatant as a crude source of macrophage colony-stimulating factor (M-CSF) as well as BM cells propagated in the presence of recombinant M-CSF exhibited transient antigen presentation potential to some T cell clones, being maximal on day 7 and having declined to a low level by day 19 of in vitro culture. Treatment of these long-term-cultivated BMM phi populations with recombinant interferon-gamma (IFN-gamma) resulted in predominant antigen presentation capacit…
Dendritic Cell-Specific Deletion of β-Catenin Results in Fewer Regulatory T-Cells without Exacerbating Autoimmune Collagen-Induced Arthritis.
2015
Dendritic cells (DCs) are professional antigen presenting cells that have the dual ability to stimulate immunity and maintain tolerance. However, the signalling pathways mediating tolerogenic DC function in vivo remain largely unknown. The beta-catenin pathway has been suggested to promote a regulatory DC phenotype. The aim of this study was to unravel the role of beta-catenin signalling to control DC function in the autoimmune collagen-induced arthritis model (CIA). Deletion of beta-catenin specifically in DCs was achieved by crossing conditional knockout mice with a CD11c-Cre transgenic mouse line. Bone marrow-derived DCs (BMDCs) were generated and used to study the maturation profile of …