Monocytes are key players in the immune system. Crossing the blood barrier, they infiltrate tissues and differentiate into (i) macrophages that fight off pathogens and (ii) dendritic cells (DCs) that activate the immune response. A hallmark of monocyte/macrophage activation is the generation of reactive oxygen species (ROS) as a defense against invading microorganisms. How monocytes, macrophage...

Mesenchymal stem cells (MSCs), in addition to their multilineage differentiation, have a direct immunosuppressive effect on T-cell proliferation in vitro. However, it is unclear whether they also modulate the immune system by acting on the very first step. In this investigation, we addressed the effects of human MSCs on the differentiation, maturation, and function of dendritic cells (DCs) deri...

Mucosal-associated invariant T (MAIT) cells are innate T cells that recognize intermediates of the vitamin B2 biosynthetic pathway presented by the monomorphic MR1 molecule. It remains unclear whether, in addition to their cytolytic activity that is important in antimicrobial defense, MAIT cells have immune-modulatory functions that could enhance dendritic cell (DC) maturation. In this study, w...

We have previously shown that human monocyte-derived dendritic cells (DCs) acquired different characteristics in dense or sparse cell cultures. Sparsity promoted the development of IL-12 producing migratory DCs, whereas dense cultures increased IL-10 production. Here we analysed whether the density-dependent endogenous breaks could modulate DC-based vaccines. Using murine bone marrow-derived DC...

Dendritic cells (DCs) have the unique ability to efficiently present T-cell epitopes from exogenous antigens on MHC class I molecules, a process called cross-presentation. In our study we demonstrate that stimulation of monocyte-derived DCs with Toll-like receptor (TLR) ligands differentially affects the uptake and cross-presentation of cellular antigens. Activation of DCs with TLR3 or TLR4 but...

Dendritic cells (DCs) play a critical role in the immune response to viral infection through the facilitation of cell-intrinsic antiviral activity and the activation of adaptive immunity. HIV-1 infection of DCs triggers an IRF3-dependent innate immune response, which requires the activity of cyclic GAMP synthase (cGAS). We report the results of a targeted RNAi screen utilizing primary human mon...

PURPOSE Recent investigations have revealed that populations of macrophages and dendritic cells (DCs) are present in the stroma and epithelium of the cornea, although the precise phenotype and distribution are still controversial. CX(3)CR1, the sole receptor for the chemokine fractalkine, is expressed by these monocyte-derived cells. Transgenic CX(3)CR1(GFP) mice, in which either one (heterozyg...

We investigated whether human monocyte-derived dendritic cells (DCs) differed from tonsillar B cells in the set of cell fate genes they express constitutively and in the way these genes are affected after CD40 ligation. In particular, Bcl-2, TNF receptor-associated factor-2 (TRAF2), and TRAF4 were clearly inducible via CD40 in B cells but not in DCs. DCs, unlike B cells, were induced to increas...

Dendritic cells (DCs) are important for the initiation of immune responses to foreign antigens. Their antigen uptake and presentation capacities enable them to prime and activate T cells. Immature DCs capture antigens; however, they must be activated to mature before serving as efficient antigen-presenting cells. The antigen-presenting capacity of DCs can be diminished during viral infection an...

The phagocyte NADPH oxidase (NOX2) is critical for the bactericidal activity of phagocytic cells and plays a major role in innate immunity. We showed recently that NOX2 activity in mouse dendritic cells (DCs) prevents acidification of phagosomes, promoting antigen cross-presentation. In order to investigate the role of NOX2 in the regulation of the phagosomal pH in human DCs, we analyzed the pr...