CD103+ Kidney Dendritic Cells Protect against Crescentic GN by Maintaining IL-10-Producing Regulatory T Cells.
ABSTRACT: Kidney dendritic cells (DCs) regulate nephritogenic T cell responses. Most kidney DCs belong to the CD11b+ subset and promote crescentic GN (cGN). The function of the CD103+ subset, which represents <5% of kidney DCs, is poorly understood. We studied the role of CD103+ DCs in cGN using several lines of genetically modified mice that allowed us to reduce the number of these cells. In all lines, we detected a reduction of FoxP3+ intrarenal regulatory T cells (Tregs), which protect against cGN. Mice lacking the transcription factor Batf3 had a more profound reduction of CD103+ DCs and Tregs than did the other lines used, and showed the most profound aggravation of cGN. The conditional reduction of CD103+ DC numbers by 50% in Langerin-DTR mice halved Treg numbers, which did not suffice to significantly aggravate cGN. Mice lacking the cytokine Flt3L had fewer CD103+ DCs and Tregs than Langerin-DTR mice but exhibited milder cGN than did Batf3-/- mice presumably because proinflammatory CD11b+ DCs were somewhat depleted as well. Conversely, Flt3L supplementation increased the number of CD103+ DCs and Tregs, but also of proinflammatory CD11b+ DCs. On antibody-mediated removal of CD11b+ DCs, Flt3L supplementation ameliorated cGN. Mechanistically, CD103+ DCs caused cocultured T cells to differentiate into Tregs and produced the chemokine CCL20, which is known to attract Tregs into the kidney. Our findings show that CD103+ DCs foster intrarenal FoxP3+ Treg accumulation, thereby antagonizing proinflammatory CD11b+ DCs. Thus, increasing CD103+ DC numbers or functionality might be advantageous in cGN.
Project description:Dendritic cells (DCs) subsets differ in precursor cell of origin, functional properties, requirements for growth factors, and dependence on transcription factors. Lymphoid-tissue resident CD8?(+) conventional DCs (cDCs) and CD11b(low/-)CD103(+) non-lymphoid DCs are developmentally related, each being dependent on FMS-like tyrosine kinase 3 ligand (Flt3L), and requiring the transcription factors Batf3, Irf8, and Id2 for development. It was recently suggested that granulocyte/macrophage colony stimulating factor (GM-CSF) was required for the development of dermal CD11b(low/-)Langerin(+)CD103(+) DCs, and that this dermal DC subset was required for priming autoreactive T cells in experimental autoimmune encephalitis (EAE). Here, we compared development of peripheral tissue DCs and susceptibility to EAE in GM-CSF receptor deficient (Csf2rb(-/-)) and Batf3(-/-) mice. We find that Batf3-dependent dermal CD11b(low/-)Langerin(+) DCs do develop in Csf2rb(-/-) mice, but that they express reduced, but not absent, levels of CD103. Further, Batf3(-/-) mice lacking all peripheral CD11b(low/-) DCs show robust Th cell priming after subcutaneous immunization and are susceptible to EAE. Our results suggest that defective T effector priming and resistance to EAE exhibited by Csf2rb(-/-) mice does not result from the absence of dermal CD11b(low/-)Langerin(+)CD103(+) DCs.
Project description:Skin-derived dendritic cells (DCs) are potent antigen-presenting cells with critical roles in both adaptive immunity and tolerance to self. Skin DCs carry antigens and constitutively migrate to the skin-draining lymph nodes (LNs). In mice, Langerin-CD11b- dermal DCs are a low-frequency, heterogeneous, migratory DC subset that traffics to LNs (Langerin-CD11b- migDCs). Here, we build on the observation that Langerin-CD11b- migDCs are Fms-like tyrosine kinase 3 ligand (Flt3L) dependent and strongly Flt3L responsive, which may relate them to classical DCs. Examination of DC capture of FITC from painted skin, DC isolation from skin explant culture, and from the skin of CCR7 knockout mice, which accumulate migDCs, demonstrate these cells are cutaneous residents. Langerin-CD11b- Flt3L-responsive DCs are largely CD24(+) and CX3CR1(low) and can be depleted from Zbtb46-DTR mice, suggesting classical DC lineage. Langerin-CD11b- migDCs present antigen with equal efficiency to other DC subsets ex vivo, including classical CD8? cDCs and Langerin+CD103+ dermal DCs. Finally, transcriptome analysis suggests a close relationship with other skin DCs, and a lineage relationship with other classical DCs. This work demonstrates that Langerin- CD11b- dermal DCs, a previously overlooked cell subset, may be an important contributor to the cutaneous immune environment.
Project description:Although CD103-expressing dendritic cells (DCs) are widely present in nonlymphoid tissues, the transcription factors controlling their development and their relationship to other DC subsets remain unclear. Mice lacking the transcription factor Batf3 have a defect in the development of CD8alpha+ conventional DCs (cDCs) within lymphoid tissues. We demonstrate that Batf3(-/-) mice also lack CD103+CD11b- DCs in the lung, intestine, mesenteric lymph nodes (MLNs), dermis, and skin-draining lymph nodes. Notably, Batf3(-/-) mice displayed reduced priming of CD8 T cells after pulmonary Sendai virus infection, with increased pulmonary inflammation. In the MLNs and intestine, Batf3 deficiency resulted in the specific lack of CD103+CD11b- DCs, with the population of CD103+CD11b+ DCs remaining intact. Batf3(-/-) mice showed no evidence of spontaneous gastrointestinal inflammation and had a normal contact hypersensitivity (CHS) response, despite previous suggestions that CD103+ DCs were required for immune homeostasis in the gut and CHS. The relationship between CD8alpha+ cDCs and nonlymphoid CD103+ DCs implied by their shared dependence on Batf3 was further supported by similar patterns of gene expression and their shared developmental dependence on the transcription factor Irf8. These data provide evidence for a developmental relationship between lymphoid organ-resident CD8alpha+ cDCs and nonlymphoid CD103+ DCs.
Project description:Dendritic cells (DCs) can be sub-divided into various subsets that play specialized roles in priming of adaptive immune responses. Atherosclerosis is regarded as a chronic inflammatory disease of the vessel wall and DCs can be found in non-inflamed and diseased arteries. We here performed a systematic analyses of DCs subsets during atherogenesis. Our data indicate that distinct DC subsets can be localized in the vessel wall. In C57BL/6 and low density lipoprotein receptor-deficient (Ldlr (-/-)) mice, CD11c(+) MHCII(+) DCs could be discriminated into CD103(-) CD11b(+)F4/80(+), CD11b(+)F4/80(-) and CD11b(-)F4/80(-) DCs and CD103(+) CD11b(-)F4/80(-) DCs. Except for CD103(-) CD11b(-) F4/80(-) DCs, these subsets expanded in high fat diet-fed Ldlr (-/-) mice. Signal-regulatory protein (Sirp)-? was detected on aortic macrophages, CD11b(+) DCs, and partially on CD103(-) CD11b(-) F4/80(-) but not on CD103(+) DCs. Notably, in FMS-like tyrosine kinase 3-ligand-deficient (Flt3l (-/-)) mice, a specific loss of CD103(+) DCs but also CD103(-) CD11b(+) F4/80(-) DCs was evidenced. Aortic CD103(+) and CD11b(+) F4/80(-) CD103(-) DCs may thus belong to conventional rather than monocyte-derived DCs, given their dependence on Flt3L-signalling. CD64, postulated to distinguish macrophages from DCs, could not be detected on DC subsets under physiological conditions, but appeared in a fraction of CD103(-) CD11b(+) F4/80(-) and CD11b(+) F4/80(+) cells in atherosclerotic Ldlr (-/-) mice. The emergence of CD64 expression in atherosclerosis may indicate that CD11b(+) F4/80(-) DCs similar to CD11b(+) F4/80(+) DCs are at least in part derived from immigrated monocytes during atherosclerotic lesion formation. Our data advance our knowledge about the presence of distinct DC subsets and their accumulation characteristics in atherosclerosis, and may help to assist in future studies aiming at specific DC-based therapeutic strategies for the treatment of chronic vascular inflammation.
Project description:Neutrophils are the most abundant cell type in the immune system and play an important role in the innate immune response. Using a diverse range of mouse models with either defective dendritic cell (DC) development or conditional DC depletion, we provide in vivo evidence indicating that conventional DCs play an important role in the regulation of neutrophil homeostasis. Flk2, Flt3L, and Batf3 knockout mice, which have defects in DC development, have increased numbers of liver neutrophils in the steady state. Conversely, neutrophil frequency is reduced in DC-specific PTEN knockout mice, which have an expansion of CD8(+) and CD103(+) DCs. In chimeric CD11c-DTR mice, conventional DC depletion results in a systemic increase of neutrophils in peripheral organs in the absence of histological inflammation or an increase in proinflammatory cytokines. This effect is also present in splenectomized chimeric CD11c-DTR mice and is absent in chimeric mice with 50% normal bone marrow. In chimeric CD11c-DTR mice, diphtheria toxin treatment results in enhanced neutrophil trafficking from the bone marrow into circulation and increased neutrophil recruitment. Moreover, there is an increased expression of chemokines/cytokines involved in neutrophil homeostasis and reduced neutrophil apoptosis. These data underscore the role of the DC pool in regulating the neutrophil compartment in nonlymphoid organs.
Project description:Rheumatoid arthritis (RA) is chronic autoimmune disease which etiology remains unknown. Several cell types have been described to potentiate/aggravate the arthritic process however the initiating event in synovial inflammation is still elusive. Dendritic cells (DCs) are essential for the initiation of primary immune responses and thus we hypothesized that these cells might be crucial for RA induction. DCs are a heterogeneous population of cells comprising different subsets with distinct phenotype and function. Here we investigated which DC subset(s) is/are crucial for the initiation of the arthritic process. We have previously demonstrated that Flt3?/? mice, with reduced DCs, were protected from collagen induced arthritis (CIA). Here we have shown that GM-CSF derived DCs in Flt3L?/? mice are functional but not sufficient to induce arthritis. Batf3?/? mice lacking both CD103+ and CD8?+ cDC1 were resistant to collagen induced arthritis (CIA), demonstrating that this DC subset is crucial for arthritis development. CEP-701 (a Flt3L inhibitor) treatment prevented CIA induction, and reduced dramatically the numbers CD103+ cDC1s present in the lymph nodes and synovium. Hence this study identified cDC1 as the main subset orchestrating the initiation of cell-mediated immunity in arthritis. Highlights • Flt3L independent DCs present in Flt3L?/? mice are functional but are not sufficient to induce arthritis.• BATF3?/? mice lacking cDC1 are protected from arthritis development indicating that cDC1 are necessary for disease induction.• Treatment with a Flt3L inhibitor, CEP701, reduced cDC1 populations and prevented arthritis induction.
Project description:DCs are necessary and sufficient for induction of allergic airway inflammation. CD11b+ DCs direct the underlying Th2 immunity, but debate surrounds the function of CD103+ DCs in lung immunity and asthma after an allergic challenge. We challenged Batf3-/- mice, which lacked lung CD103+ DCs, with the relevant allergen house dust mite (HDM) as a model to ascertain their role in asthma. We show that acute and chronic HDM exposure leads to defective Th1 immunity in Batf3-deficient mice. In addition, chronic HDM challenge in Batf3-/- mice results in increased Th2 and Th17 immune responses and exacerbated airway inflammation. Mechanistically, Batf3 absence does not affect induction of Treg or IL-10 production by lung CD4+ T cells following acute HDM challenge. Batf3-dependent CD103+ migratory DCs are the main source of IL-12p40 in the mediastinal lymph node DC compartment in the steady state. Moreover, CD103+ DCs selectively increase their IL-12p40 production upon HDM administration. In vivo IL-12 treatment reverts exacerbated allergic airway inflammation upon chronic HDM challenge in Batf3-/- mice, restraining Th2 and Th17 responses without triggering Th1 immunity. These results suggest a protective role for lung CD103+ DCs to HDM allergic airway inflammation through the production of IL-12.
Project description:Tumor necrosis factor (TNF) antagonists are popular therapies for inflammatory diseases. These agents enhance the numbers and function of regulatory T cells (Tregs), which are important in controlling inflammatory diseases. However, elevated Treg levels increase susceptibility to infections, including histoplasmosis. We determined the mechanism by which Tregs expand in TNF-neutralized mice infected with Histoplasma capsulatum Lung CD11c+ CD11b+ dendritic cells (DCs), but not alveolar macrophages, from H. capsulatum-infected mice treated with anti-TNF induced a higher percentage of Tregs than control DCs in vitro CD11b+ CD103+ DCs, understood to be unique to the intestines, were augmented in lungs with anti-TNF treatment. In the absence of this subset, DCs from anti-TNF-treated mice failed to amplify Tregs in vitro CD11b+ CD103+ DCs from TNF-neutralized mice displayed higher retinaldehyde dehydrogenase 2 (RALDH2) gene expression, and CD11b+ CD103+ RALDH+ DCs exhibited greater enzyme activity. To determine if CD11b+ CD103+ DCs migrated from gut to lung, fluorescent beads were delivered to the gut via oral gavage, and the lungs were assessed for bead-containing DCs. Anti-TNF induced migration of CD11b+ CD103+ DCs from the gut to the lung that enhanced the generation of Tregs in H. capsulatum-infected mice. Therefore, TNF neutralization promotes susceptibility to pulmonary H. capsulatum infection by promoting a gut/lung migration of DCs that enhances Tregs.
Project description:A crosstalk between commensals, gut immune cells, and colonic epithelia is required for a proper function of intestinal mucosal barrier. Here we investigated the importance of two distinct intestinal dendritic cell (DC) subsets in controlling intestinal inflammation. We show that Clec9A-diphtheria toxin receptor (DTR) mice after depletion of CD103(+)CD11b(-) DCs developed severe, low-dose dextran sodium sulfate (DSS)-induced colitis, whereas the lack of CD103(+)CD11b(+) DCs in Clec4a4-DTR mice did not exacerbate intestinal inflammation. The CD103(+)CD11b(-) DC subset has gained a functional specialization that able them to repress inflammation via several epithelial interferon-? (IFN-?)-induced proteins. Among others, we identified that epithelial IDO1 and interleukin-18-binding protein (IL-18bp) were strongly modulated by CD103(+)CD11b(-) DCs. Through its preferential property to express IL-12 and IL-15, this particular DC subset can induce lymphocytes in colonic lamina propria and in epithelia to secrete IFN-? that then can trigger a reversible early anti-inflammatory response in intestinal epithelial cells.
Project description:Although dendritic cells (DCs) play an important role in mediating protection against influenza virus, the precise role of lung DC subsets, such as CD11b- and CD11b+ conventional DCs or plasmacytoid DCs (pDCs), in different lung compartments is currently unknown. Early after intranasal infection, tracheal CD11b-CD11chi DCs migrated to the mediastinal lymph nodes (MLNs), acquiring co-stimulatory molecules in the process. This emigration from the lung was followed by an accumulation of CD11b+CD11chi DCs in the trachea and lung interstitium. In the MLNs, the CD11b+ DCs contained abundant viral nucleoprotein (NP), but these cells failed to present antigen to CD4 or CD8 T cells, whereas resident CD11b-CD8+ DCs presented to CD8 cells, and migratory CD11b-CD8- DCs presented to CD4 and CD8 T cells. When lung CD11chi DCs and macrophages or langerin+CD11b-CD11chi DCs were depleted using either CD11c-diphtheria toxin receptor (DTR) or langerin-DTR mice, the development of virus-specific CD8+ T cells was severely delayed, which correlated with increased clinical severity and a delayed viral clearance. 120G8+ CD11cint pDCs also accumulated in the lung and LNs carrying viral NP, but in their absence, there was no effect on viral clearance or clinical severity. Rather, in pDC-depleted mice, there was a reduction in antiviral antibody production after lung clearance of the virus. This suggests that multiple DCs are endowed with different tasks in mediating protection against influenza virus.