TY - JOUR A1 - Lutz, Manfred B. A1 - Strobl, Herbert A1 - Schuler, Gerold A1 - Romani, Nikolaus T1 - GM-CSF monocyte-derived cells and Langerhans cells as part of the dendritic cell family JF - Frontiers in Immunology N2 - Dendritic cells (DCs) and macrophages (Mph) share many characteristics as components of the innate immune system. The criteria to classify the multitude of subsets within the mononuclear phagocyte system are currently phenotype, ontogeny, transcription patterns, epigenetic adaptations, and function. More recently, ontogenetic, transcriptional, and proteomic research approaches uncovered major developmental differences between Flt3L-dependent conventional DCs as compared with Mphs and monocyte-derived DCs (MoDCs), the latter mainly generated in vitro from murine bone marrow-derived DCs (BM-DCs) or human CD14\(^{+}\) peripheral blood monocytes. Conversely, in vitro GM-CSF-dependent monocyte-derived Mphs largely resemble MoDCs whereas tissue-resident Mphs show a common embryonic origin from yolk sac and fetal liver with Langerhans cells (LCs). The novel ontogenetic findings opened discussions on the terminology of DCs versus Mphs. Here, we bring forward arguments to facilitate definitions of BM-DCs, MoDCs, and LCs. We propose a group model of terminology for all DC subsets that attempts to encompass both ontogeny and function. KW - macrophages KW - dendritic cells KW - GM-CSF KW - monocytes KW - Langerhans cells Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-158730 VL - 8 IS - 1388 ER - TY - JOUR A1 - Schierer, Stefan A1 - Ostalecki, Christian A1 - Zinser, Elisabeth A1 - Lamprecht, Ricarda A1 - Plosnita, Bianca A1 - Stich, Lena A1 - Doerrie, Jan A1 - Lutz, Manfred B A1 - Schuler, Gerold A1 - Baur, Andreas S T1 - Extracellular vesicles from mature dendritic cells (DC) differentiate monocytes into immature DC JF - Life Science Alliance N2 - During inflammation, murine and human monocytes can develop into dendritic cells (DC), but this process is not entirely understood. Here, we demonstrate that extracellular vesicles (EV) secreted by mature human DC (maDC) differentiate peripheral monocytes into immature DC, expressing a unique marker pattern, including 6-sulfo LacNAc (slan), Zbtb46, CD64, and CD14. While EV from both maDC and immature DC differentiated monocytes similar to GM-CSF/IL-4 stimulation, only maDC-EV produced precursors, which upon maturation stimulus developed into T-cell-activating and IL-12p70-secreting maDC. Mechanistically, maDC-EV induced cell signaling through GM-CSF, which was abundant in EV as were IL-4 and other cytokines and chemokines. When injected into the mouse skin, murine maDC-EV attracted immune cells including monocytes that developed activation markers typical for inflammatory cells. Skin-injected EV also reached lymph nodes, causing a similar immune cell infiltration. We conclude that DC-derived EV likely serve to perpetuate an immune reaction and may contribute to chronic inflammation. KW - medical research KW - immunology Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-228587 VL - 1 IS - 6 ER - TY - JOUR A1 - John, Vini A1 - Kotze, Leigh A. A1 - Ribechini, Eliana A1 - Walzl, Gerhard A1 - Du Plessis, Nelita A1 - Lutz, Manfred B. T1 - Caveolin-1 controls vesicular TLR2 expression, p38 signaling and T cell suppression in BCG infected murine monocytic myeloid-derived suppressor cells JF - Frontiers in Immunology N2 - Monocytic myeloid-derived suppressor cells (M-MDSCs) and granulocytic MDSCs (G-MDSCs) have been found to be massively induced in TB patients as well in murine Mtb infection models. However, the interaction of mycobacteria with MDSCs and its role in TB infection is not well studied. Here, we investigated the role of Cav-1 for MDSCs infected with Mycobacterium bovis Bacille-Calmette-Guerín (BCG). MDSCs that were generated from murine bone marrow (MDSCs) of wild-type (WT) or Cav1\(^{−/−}\) mice upregulated Cav-1, TLR4 and TLR2 expression after BCG infection on the cell surface. However, Cav-1 deficiency resulted in a selective defect of intracellular TLR2 levels predominantly in the M-MDSC subset. Further analysis indicated no difference in the phagocytosis of BCG by M-MDSCs from WT and Cav1\(^{−/−}\) mice or caveosome formation, but a reduced capacity to up-regulate surface markers, to secrete various cytokines, to induce iNOS and NO production required for suppression of T cell proliferation, whereas Arg-1 was not affected. Among the signaling pathways affected by Cav-1 deficiency, we found lower phosphorylation of the p38 mitogen-activated protein kinase (MAPK). Together, our findings implicate that (i) Cav-1 is dispensable for the internalization of BCG, (ii) vesicular TLR2 signaling in M-MDSCs is a major signaling pathway induced by BCG, (iii) vesicular TLR2 signals are controlled by Cav-1, (iv) vesicular TLR2/Cav-1 signaling is required for T cell suppressor functions. KW - myeloid-derived suppressor cell (MDSC) KW - caveolin-1 (Cav-1) KW - TLR2 KW - TLR4 KW - BCG KW - T cell suppression Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-195528 SN - 1664-3224 VL - 10 IS - 2826 ER - TY - JOUR A1 - Thomann, Anna Sophie A1 - Schneider, Theresa A1 - Cyran, Laura A1 - Eckert, Ina Nathalie A1 - Kerstan, Andreas A1 - Lutz, Manfred B. T1 - Conversion of Anergic T Cells Into Foxp3\(^-\) IL-10\(^+\) Regulatory T Cells by a Second Antigen Stimulus In Vivo JF - Frontiers in Immunology N2 - T cell anergy is a common mechanism of T cell tolerance. However, although anergic T cells are retained for longer time periods in their hosts, they remain functionally passive. Here, we describe the induction of anergic CD4\(^+\) T cells in vivo by intravenous application of high doses of antigen and their subsequent conversion into suppressive Foxp3\(^-\) IL-10\(^+\) Tr1 cells but not Foxp3\(^+\) Tregs. We describe the kinetics of up-regulation of several memory-, anergy- and suppression-related markers such as CD44, CD73, FR4, CD25, CD28, PD-1, Egr-2, Foxp3 and CTLA-4 in this process. The conversion into suppressive Tr1 cells correlates with the transient intracellular CTLA-4 expression and required the restimulation of anergic cells in a short-term time window. Restimulation after longer time periods, when CTLA-4 is down-regulated again retains the anergic state but does not lead to the induction of suppressor function. Our data require further functional investigations but at this stage may suggest a role for anergic T cells as a circulating pool of passive cells that may be re-activated into Tr1 cells upon short-term restimulation with high and systemic doses of antigen. It is tentative to speculate that such a scenario may represent cases of allergen responses in non-allergic individuals. KW - T cells KW - anergy KW - Tr1 KW - conversion KW - in vivo Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-241429 SN - 1664-3224 VL - 12 ER - TY - JOUR A1 - Döhler, Anja A1 - Schneider, Theresa A1 - Eckert, Ina A1 - Ribechini, Eliana A1 - Andreas, Nico A1 - Riemann, Marc A1 - Reizis, Boris A1 - Weih, Falk A1 - Lutz, Manfred B. T1 - RelB\(^{+}\) Steady-State Migratory Dendritic Cells Control the Peripheral Pool of the Natural Foxp3\(^{+}\) Regulatory T Cells JF - Frontiers in Immunology N2 - Thymus-derived natural Foxp3\(^{+}\) CD4\(^{+}\) regulatory T cells (nTregs) play a key role in maintaining immune tolerance and preventing autoimmune disease. Several studies indicate that dendritic cells (DCs) are critically involved in the maintenance and proliferation of nTregs. However, the mechanisms how DCs manage to keep the peripheral pool at constant levels remain poorly understood. Here, we describe that the NF-κB/Rel family transcription factor RelB controls the frequencies of steady-state migratory DCs (ssmDCs) in peripheral lymph nodes and their numbers control peripheral nTreg homeostasis. DC-specific RelB depletion was investigated in CD11c-Cre × RelB\(^{fl/fl}\) mice (RelB\(^{DCko}\)), which showed normal frequencies of resident DCs in lymph nodes and spleen while the subsets of CD103\(^{-}\) Langerin\(^{-}\) dermal DCs (dDCs) and Langerhans cells but not CD103\(^{+}\) Langerin\(^{+}\) dDC of the ssmDCs in skin-draining lymph nodes were increased. Enhanced frequencies and proliferation rates were also observed for nTregs and a small population of CD4\(^{+}\) CD44\(^{high}\) CD25\(^{low}\) memory-like T cells (Tml). Interestingly, only the Tml but not DCs showed an increase in IL-2-producing capacity in lymph nodes of RelB\(^{DCko}\) mice. Blocking of IL-2 in vivo reduced the frequency of nTregs but increased the Tml frequencies, followed by a recovery of nTregs. Taken together, by employing RelB\(^{DCko}\) mice with increased frequencies of ssmDCs our data indicate a critical role for specific ssmDC subsets for the peripheral nTreg and IL-2\(^{+}\) Tml frequencies during homeostasis. KW - lymph nodes KW - dendritic cells KW - RelB KW - regulatory T cells KW - IL-2 Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-158121 VL - 8 IS - 726 ER - TY - JOUR A1 - Silva-Vilches, Cinthia A1 - Pletinckx, Katrien A1 - Lohnert, Miriam A1 - Pavlovic, Vladimir A1 - Ashour, Diyaaeldin A1 - John, Vini A1 - Vendelova, Emilia A1 - Kneitz, Susanne A1 - Zhou, Jie A1 - Chen, Rena A1 - Reinheckel, Thomas A1 - Mueller, Thomas D. A1 - Bodem, Jochen A1 - Lutz, Manfred B. T1 - Low doses of cholera toxin and its mediator cAMP induce CTLA-2 secretion by dendritic cells to enhance regulatory T cell conversion JF - PLoS ONE N2 - Immature or semi-mature dendritic cells (DCs) represent tolerogenic maturation stages that can convert naive T cells into Foxp3\(^{+}\) induced regulatory T cells (iTreg). Here we found that murine bone marrow-derived DCs (BM-DCs) treated with cholera toxin (CT) matured by up-regulating MHC-II and costimulatory molecules using either high or low doses of CT (CT\(^{hi}\), CT\(^{lo}\)) or with cAMP, a known mediator CT signals. However, all three conditions also induced mRNA of both isoforms of the tolerogenic molecule cytotoxic T lymphocyte antigen 2 (CTLA-2α and CTLA-2β). Only DCs matured under CT\(^{hi}\) conditions secreted IL-1β, IL-6 and IL-23 leading to the instruction of Th17 cell polarization. In contrast, CT\(^{lo}\)- or cAMP-DCs resembled semi-mature DCs and enhanced TGF-β-dependent Foxp3\(^{+}\) iTreg conversion. iTreg conversion could be reduced using siRNA blocking of CTLA-2 and reversely, addition of recombinant CTLA-2α increased iTreg conversion in vitro. Injection of CT\(^{lo}\)- or cAMP-DCs exerted MOG peptide-specific protective effects in experimental autoimmune encephalomyelitis (EAE) by inducing Foxp3\(^{+}\) Tregs and reducing Th17 responses. Together, we identified CTLA-2 production by DCs as a novel tolerogenic mediator of TGF-β-mediated iTreg induction in vitro and in vivo. The CT-induced and cAMP-mediated up-regulation of CTLA-2 also may point to a novel immune evasion mechanism of Vibrio cholerae. KW - small interfering RNAs KW - toxins KW - regulatory T cells KW - T cells KW - cytokines KW - cholera KW - cell differentiation KW - immune evasion Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-158244 VL - 12 IS - 7 ER - TY - JOUR A1 - Aintablian, Arpa A1 - Strozniak, Sandra A1 - Heuer, Marion A1 - Lutz, Manfred B. T1 - M-MDSC in vitro generation from mouse bone marrow with IL-3 reveals high expression and functional activity of arginase 1 JF - Frontiers in Immunology N2 - Myeloid-derived suppressor cells (MDSC) represent major regulators of immune responses, which can control T cells via their inducible nitric oxide synthase (iNOS)- and arginase 1 (Arg1)-mediated effector functions. While GM-CSF is well documented to promote MDSC development, little is known about this potential of IL-3, an established growth factor for mast cells. Here, we show that IL-3, similar to GM-CSF, generates monocytic MDSC (M-MDSC) from murine bone marrow (BM) cells after 3 days of in vitro culture. At this time point, predominantly CD11b+ CD49a+ monocytic and CD11b+ CD49a- FcεR I- neutrophilic cells were detectable, while CD11blow/neg FcεR I+ mast cells accumulated only after extended culture periods. Both growth factors were equivalent in generating M-MDSC with respect to phenotype, cell yield and typical surface markers. However, IL-3 generated M-MDSC produced less TNF, IL-1β and IL-10 after activation with LPS + IFN-γ but showed higher Arg1 expression compared to GM-CSF generated M-MDSC. Arg1 was further induced together with iNOS after MDSC activation. Accordingly, an increased Arg1-dependent suppressor activity by the IL-3 generated M-MDSC was observed using respective iNOS and Arg1 inhibitors. Together, these data indicate that M-MDSC can be generated in vitro by IL-3, similar to GM-CSF, but with increased Arg1 expression and Arg1-mediated suppression capacity. This protocol now allows further in vitro studies on the role of IL-3 for MDSC biology. KW - myeloid-derived suppressor cells (MDSC) KW - bone marrow KW - IL-3 KW - GM-CSF KW - in vitro culture KW - protocol Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-317769 VL - 14 ER -