Search results for " Dendritic cells"

A newly established murine immature dendritic cell line can be differentiated into a mature state, but exerts tolerogenic function upon maturation in…

2007

AbstractThe phenotype and function of murine dendritic cells (DCs) are primarily studied using bone-marrow–derived DCs (BM-DCs), but may be hampered by the heterogenous phenotype of BM-DCs due to their differential state of maturation. Here we characterize a newly established murine DC line (SP37A3) of myeloid origin. During maintainance in the presence of granulocyte-macrophage colony-stimulating factor (GM-CSF) and M-CSF, SP37A3 cells resemble immature DCs characterized by low expression of major histocompatibility complex (MHC) II and costimulatory molecules and low T-cell stimulatory capacity. Upon stimulation, SP37A3 cells acquire a mature phenotype and activate naive T cells as potent…

Uptake of microparticle-adsorbed protein antigen by bone marrow-derived dendritic cells results in up-regulation of interleukin-1α and interleukin-12…

1995

Dendritic cells synthesize and express major histocompatibility complex (MHC) class II peptide-binding elements constitutively and, therefore, belong to the category of professional antigen-presenting cells. Unlike other cells that show constitutive class II expression, such as B cells and certain T cell clones, dendritic cells possess the unique capacity to activate naive T cells. Using dendritic cells generated in vitro by culture of mouse bone marrow in the presence of low doses of recombinant mouse granulocyte/macrophage colony-stimulating factor, we found that discrete maturation stages of these cells can be distinguished which were correlated with defined functional capabilities. The …

Autoimmune skin inflammation is dependent on plasmacytoid dendritic cell activation by nucleic acids via TLR7 and TLR9

2010

Lupus-prone mice develop a chronic inflammatory response to cutaneous injury that depends on the production of type I interferon, TLR7, and TLR9.

Microbiota-Induced Type I Interferons Instruct a Poised Basal State of Dendritic Cells

2019

Summary Environmental signals shape host physiology and fitness. Microbiota-derived cues are required to program conventional dendritic cells (cDCs) during the steady state so that they can promptly respond and initiate adaptive immune responses when encountering pathogens. However, the molecular underpinnings of microbiota-guided instructive programs are not well understood. Here, we report that the indigenous microbiota controls constitutive production of type I interferons (IFN-I) by plasmacytoid DCs. Using genome-wide analysis of transcriptional and epigenetic regulomes of cDCs from germ-free and IFN-I receptor (IFNAR)-deficient mice, we found that tonic IFNAR signaling instructs a spec…

gd T cells condition dendritic cells in vivo for priming pulmonary CD8 T cell responses against Mycobacterium tuberculosis

2006

gammadelta T cells and dendritic cells are quickly recruited to the lungs shortly after intranasal vaccination with BCG, but the functional in vivo interplay between these two cell populations and its role in the induction of adaptive immune responses is unclear. Using TCR-deficient mice and bone marrow chimeras, we show here that gammadelta T cells provide a non-redundant early source of IFN-gamma in vivo, which enhances IL-12 production by lung dendritic cells. The in vivo-conditioned dendritic cells, in turn, prime a more efficient lung CD8 T cell response against Mycobacterium tuberculosis. Thus, strategies exploiting gammadelta T cell function and IFN-gamma production could be valuable…

Interleukin-7 (IL-7) knockout mice. Implications for lymphopoiesis and organ-specific immunity.

1998

Interleukin-7 (IL-7) is produced by both immune and non-immune cells including stromal cell lines, B-cells, monocytes/macrophages, follicular dendritic cells, keratinocytes, and gut epithelial cells. The development of IL-7 knockout mice aided to elucidate the role of this multifaceted cytokine in lymphopoiesis. Additionally, IL-7 gene-deleted mice may represent an excellent model in order to define the functional role of locally secreted IL-7 in organ-specific immunity and in anti-microbial responses as well. For instance, analysis of IL-7 gene-deleted mice revealed reduced numbers of total T-lymphocytes with preservation of the CD4/CD8 ratio and increased ratio of alpha beta + T-cells com…

2014

The maturation status of dendritic cells determines whether interacting T cells are activated or if they become tolerant. Previously we could induce T cell tolerance by applying a 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase inhibitor (HMGCRI) atorvastatin, which also modulates MHC class II expression and has therapeutic potential in autoimmune disease. Here, we aimed at elucidating the impact of this therapeutic strategy on T cell differentiation as a consequence of alterations in dendritic cell function. We investigated the effect of HMGCRI during differentiation of peripheral human monocytes and murine bone marrow precursors to immature DC in vitro and assessed their phenotype. To …

Friend retrovirus infection of myeloid dendritic cells impairs maturation, prolongs contact to naïve T cells, and favors expansion of regulatory T ce…

2007

AbstractRetroviruses have developed immunmodulatory mechanisms to avoid being attacked by the immune system. The mechanisms of this retrovirus-associated immune suppression are far from clarified. Dendritic cells (DCs) have been attributed a decisive role in these pathogenic processes. We have used the Friend retrovirus (FV) mouse model in order to acquire further knowledge about the role of infection of DCs in virus-induced immunosuppression. About 20% of the myeloid DCs that were generated from the bone marrow of FV-infected mice carried FV proteins. The infection was productive, and infected DCs transmitted the virus in cell culture and in vivo. FV infection of DCs led to a defect in DC …

Neutrophil extracellular traps mediate transfer of cytoplasmic neutrophil antigens to myeloid dendritic cells toward ANCA induction and associated au…

2012

AbstractAntineutrophil cytoplasmic antibodies (ANCAs) target proteins normally retained within neutrophils, indicating that cell death is involved in the autoimmunity process. Still, ANCA pathogenesis remains obscure. ANCAs activate neutrophils inducing their respiratory burst and a peculiar form of cell death, named NETosis, characterized by formation of neutrophil extracellular traps (NETs), decondensed chromatin threads decorated with cytoplasmic proteins endorsed with antimicrobial activity. NETs have been consistently detected in ANCA-associated small-vessel vasculitis, and this association prompted us to test whether the peculiar structure of NET favors neutrophil proteins uploading i…

First results for resetting the antitumor immune response by immune corrective surgery in colon cancer.

1998

BACKGROUND: A critical step for cancer recurrence is the failure of the cellular immune response. It is suspected that chronic humoral immune responses against some tumor-associated antigens (TAA) can contribute to that failure. METHODS: In this study, we tested the ability of an immune corrective surgical procedure to prevent recurrences of colon cancer in stages I, II, and III. Radiolabeled anti-TAG antibodies injected intravenously become concentrated on TAG-72 immune complexes presented by follicular dendritic cells, which are responsible for the persistent humoral response against TAG-72 TAA. Using a hand-held gamma probe, we can intraoperatively detect and remove lymph nodes involved …