Dirk Baumjohann

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Interleukin 17-producing T helper cells (T(H)-17 cells) are important in experimental autoimmune encephalomyelitis, but their route of entry into the central nervous system (CNS) and their contribution relative to that of other effector T cells remain to be determined. Here we found that mice lacking CCR6, a chemokine receptor characteristic of T(H)-17(More)
Dendritic cell (DC) development is efficiently supported by Flt3-ligand or GM-CSF in vitro, and lymphoid-organ DC maintenance in vivo is critically dependent on Flt3-ligand. However, the relevance of GM-CSF for lymphoid-tissue DC maintenance and the importance of both cytokines for nonlymphoid organ DC homeostasis are not defined. Here, we show that,(More)
T follicular helper (T(FH)) cells are central to the development and regulation of T cell-dependent humoral immune responses. The transcriptional repressor BCL6 is required for T(FH) responses, but the kinetics of BCL6 protein expression in activated CD4(+) T cells have not been established. We measured BCL6 expression during T(FH) cell development at the(More)
Dendritic cells (DCs) play important roles in the initiation of adaptive immune responses. The transport of antigen from the infection site to the draining lymph node by DCs is a crucial component in this process. Accordingly, immunotherapeutic applications of in vitro-generated DCs require reliable methods experimentally in mice and clinically in patients(More)
T follicular helper (Tfh) cells provide help to B cells and are crucial for establishment of germinal center (GC) reactions, including production of high-affinity antibodies and generation of memory B cells and long-lived plasma cells. Here we report that the magnitude of the Tfh cell response was dictated by the amount of antigen and directly correlated(More)
Dendritic cell (DC) migration into the draining lymph nodes is critical for T cell priming. Here, we show that magnetic resonance imaging (MRI) can be used to visualize DC migration in vivo. We combined clinically approved small particles of iron oxide (SPIO) with protamine sulfate to achieve efficient uptake by murine bone marrow-derived DC. SPIO-DC were(More)
CD4(+) T helper (TH) cells regulate appropriate cellular and humoral immune responses to a wide range of pathogens and are central to the success of vaccines. However, their dysregulation can cause allergies and autoimmune diseases. The CD4(+) T cell population is characterized not only by a range of distinct cell subsets, such as TH1, TH2 and TH17 cells,(More)
There is growing evidence that the maturation state of dendritic cells (DCs) is a critical parameter determining the balance between tolerance and immunity. We report that mouse CD4(+) effector memory T (T(EM)) cells, but not naive or central memory T cells, constitutively expressed CD40L at levels sufficient to induce DC maturation in vitro and in vivo in(More)
The generation of germinal centers (GCs) is a hallmark feature of the adaptive immune response, resulting in the production of high-affinity antibodies that neutralize pathogens and confer protection upon reinfection. The GC response requires interactions between different immune cell types, and the coordination of complex and dynamic gene expression(More)
CD4(+) Th17 are heterogeneous in terms of cytokine production and capacity to initiate autoimmune diseases, such as experimental autoimmune encephalomyelitis (EAE). Here we demonstrate that experimental priming of encephalitogenic Th cells expressing RORγt and T-bet and producing IL-17A, IFN-γ and GM-CSF but not IL-10 (Th1/Th17), is dependent on the(More)