scholarly journals The thymic microenvironment gradually modulates the phenotype of thymus-homing peripheral conventional dendritic cells

2021 ◽  
Author(s):  
Susanne Herppich ◽  
Michael Beckstette ◽  
Jochen Huehn
Keyword(s):  
Dendritic Cells ◽  
Ex Vivo ◽  
Indirect Evidence ◽  
Treg Cells ◽  
Clonal Deletion ◽  
Central Tolerance ◽  
Cytokines And Chemokines ◽  
Efficient Induction ◽  
High Degree ◽  
Capacity Characteristic

AbstractThymic conventional dendritic cells (t-DCs) are crucial for the development of T cells. A substantial fraction of t-DCs originates extrathymically and migrates to the thymus. Here, these cells contribute to key processes of central tolerance like the clonal deletion of self-reactive thymocytes and the generation of regulatory T (Treg) cells. So far, it is only incompletely understood which impact the thymic microenvironment has on thymus-homing conventional DCs (cDCs), which phenotypic changes occur after the entry of peripheral cDCs into the thymus and which functional properties these modulated cells acquire. In the present study, we mimicked the thymus-homing of peripheral cDCs by introducing ex vivo isolated splenic cDCs (sp-DCs) into re-aggregated thymic organ cultures (RTOCs). Already after two days of culture, the transcriptomic profile of sp-DCs was modulated and had acquired certain key signatures of t-DCs. The regulated genes included immunomodulatory cytokines and chemokines as well as co-stimulatory molecules. After four days of culture, sp-DCs appeared to have at least partially acquired the peculiar Treg cell-inducing capacity characteristic of t-DCs. Taken together, our findings indicate that peripheral cDCs possess a high degree of plasticity enabling them to quickly adapt to the thymus-specific microenvironment. We further provide indirect evidence that thymus-specific properties such as the efficient induction of Treg cells under homeostatic conditions can be partially transferred to thymus-homing peripheral cDC subsets.

scholarly journals Vasoactive intestinal peptide generates human tolerogenic dendritic cells that induce CD4 and CD8 regulatory T cells

Blood ◽  
2006 ◽  
Vol 107 (9) ◽  
pp. 3632-3638 ◽  
Author(s):  
Elena Gonzalez-Rey ◽  
Alejo Chorny ◽  
Amelia Fernandez-Martin ◽  
Doina Ganea ◽  
Mario Delgado
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
Vasoactive Intestinal Peptide ◽  
Ex Vivo ◽  
Inflammatory Diseases ◽  
Treg Cells ◽  
Peripheral Tolerance ◽  
Blood Monocytes ◽  
Endogenous Factors ◽  
Tolerogenic Dcs

Induction of antigen-specific tolerance is critical for autoimmunity prevention and immune tolerance maintenance. In addition to their classical role as sentinels of the immune response, dendritic cells (DCs) play important roles in maintaining peripheral tolerance through the induction/activation of regulatory T (Treg) cells. The possibility of generating tolerogenic DCs opens new therapeutic perspectives in autoimmune/inflammatory diseases. Characterizing endogenous factors that contribute to the development of tolerogenic DCs is highly relevant. We here report that the immunosuppressive neuropeptide vasoactive intestinal peptide (VIP) induces the generation of human tolerogenic DCs with the capacity to generate CD4 and CD8 Treg cells from their respective naive subsets. The presence of VIP during the early stages of DC differentiation from blood monocytes generates a population of IL-10-producing DCs unable to fully mature after the effects of inflammatory stimuli. CD4 Treg cells generated with VIP-differentiated DCs resemble the previously described Tr1 cells in terms of phenotype and cytokine profile. CD8 Treg cells generated with tolerogenic VIP DCs have increased numbers of IL-10-producing CD8+CD28--CTLA4+ T cells. CD4 and CD8 Treg cells primarily suppress antigen-specific TH1-mediated responses. Therefore, the possibility of generating or expanding ex vivo tolerogenic DCVIPs opens new therapeutic perspectives for treating autoimmune diseases and graft-versus-host disease after allogeneic transplantation in humans.

scholarly journals Epithelial and dendritic cells in the thymic medulla promote CD4+Foxp3+ regulatory T cell development via the CD27–CD70 pathway

2013 ◽  
Vol 210 (4) ◽  
pp. 715-728 ◽  
Author(s):  
Jonathan M. Coquet ◽  
Julie C. Ribot ◽  
Nikolina Bąbała ◽  
Sabine Middendorp ◽  
Gerda van der Horst ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
T Cell ◽  
Treg Cell ◽  
Treg Cells ◽  
Cell Development ◽  
Cell Generation ◽  
Thymic Epithelial Cells ◽  
Clonal Deletion ◽  
Cell Numbers ◽  
Thymic Medulla

CD4+Foxp3+ regulatory T cells (Treg cells) are largely autoreactive yet escape clonal deletion in the thymus. We demonstrate here that CD27–CD70 co-stimulation in the thymus rescues developing Treg cells from apoptosis and thereby promotes Treg cell generation. Genetic ablation of CD27 or its ligand CD70 reduced Treg cell numbers in the thymus and peripheral lymphoid organs, whereas it did not alter conventional CD4+Foxp3− T cell numbers. The CD27–CD70 pathway was not required for pre-Treg cell generation, Foxp3 induction, or mature Treg cell function. Rather, CD27 signaling enhanced positive selection of Treg cells within the thymus in a cell-intrinsic manner. CD27 signals promoted the survival of thymic Treg cells by inhibiting the mitochondrial apoptosis pathway. CD70 was expressed on Aire− and Aire+ medullary thymic epithelial cells (mTECs) and on dendritic cells (DCs) in the thymic medulla. CD70 on both mTECs and DCs contributed to Treg cell development as shown in BM chimera experiments with CD70-deficient mice. In vitro experiments indicated that CD70 on the CD8α+ subset of thymic DCs promoted Treg cell development. Our data suggest that mTECs and DCs form dedicated niches in the thymic medulla, in which CD27–CD70 co-stimulation rescues developing Treg cells from apoptosis, subsequent to Foxp3 induction by TCR and CD28 signals.

scholarly journals Targeting human plasmacytoid dendritic cells through BDCA2 prevents skin inflammation and fibrosis in a novel xenotransplant mouse model of scleroderma

2021 ◽  
pp. annrheumdis-2020-218439
Author(s):  
Rebecca L Ross ◽  
Clarissa Corinaldesi ◽  
Gemma Migneco ◽  
Ian M Carr ◽  
Agne Antanaviciute ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Ex Vivo ◽  
Severe Combined Immunodeficiency ◽  
Indirect Evidence ◽  
Plasmacytoid Dendritic Cells ◽  
Induced Response ◽  
Type I ◽  
Therapeutic Application ◽  
Gene And Protein Expression

ObjectivesPlasmacytoid dendritic cells (pDC) have been implicated in the pathogenesis of autoimmune diseases, such as scleroderma (SSc). However, this has been derived from indirect evidence using ex vivo human samples or mouse pDC in vivo. We have developed human-specific pDC models to directly identify their role in inflammation and fibrosis, as well as attenuation of pDC function with BDCA2-targeting to determine its therapeutic application.MethodsRNAseq of human pDC with TLR9 agonist ODN2216 and humanised monoclonal BDCA2 antibody, CBS004. Organotypic skin rafts consisting of fibroblasts and keratinocytes were stimulated with supernatant from TLR9-stimulated pDC and with CBS004. Human pDC were xenotransplanted into Nonobese diabetic/severe combined immunodeficiency (NOD SCID) mice treated with Aldara (inflammatory model), or bleomycin (fibrotic model) with CBS004 or human IgG control. Skin punch biopsies were used to assess gene and protein expression.ResultsRNAseq shows TLR9-induced activation of human pDC goes beyond type I interferon (IFN) secretion, which is functionally inactivated by BDCA2-targeting. Consistent with these findings, we show that BDCA2-targeting of pDC can completely suppress in vitro skin IFN-induced response. Most importantly, xenotransplantation of human pDC significantly increased in vivo skin IFN-induced response to TLR agonist and strongly enhanced fibrotic and immune response to bleomycin compared with controls. In these contexts, BDCA2-targeting suppressed human pDC-specific pathological responses.ConclusionsOur data indicate that human pDC play a key role in inflammation and immune-driven skin fibrosis, which can be effectively blocked by BDCA2-targeting, providing direct evidence supporting the development of attenuation of pDC function as a therapeutic application for SSc.

scholarly journals Dormant pathogenic CD4+ T cells are prevalent in the peripheral repertoire of healthy mice

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Anna Cebula ◽  
Michal Kuczma ◽  
Edyta Szurek ◽  
Maciej Pietrzak ◽  
Natasha Savage ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell Receptors ◽  
Negative Selection ◽  
Regulatory Cells ◽  
Central Tolerance ◽  
Therapeutic Advantage ◽  
Autoreactive T Cell ◽  
Peptide Complexes ◽  
Self Peptides

Abstract Thymic central tolerance eliminates most immature T cells with autoreactive T cell receptors (TCR) that recognize self MHC/peptide complexes. Regardless, an unknown number of autoreactive CD4+Foxp3− T cells escape negative selection and in the periphery require continuous suppression by CD4+Foxp3+ regulatory cells (Tregs). Here, we compare immune repertoires of Treg-deficient and Treg-sufficient mice to find Tregs continuously constraining one-third of mature CD4+Foxp3− cells from converting to pathogenic effectors in healthy mice. These dormant pathogenic clones frequently express TCRs activatable by ubiquitous autoantigens presented by class II MHCs on conventional dendritic cells, including self-peptides that select them in the thymus. Our data thus suggest that identification of most potentially autoreactive CD4+ T cells in the peripheral repertoire is critical to harness or redirect these cells for therapeutic advantage.

scholarly journals Toll-like receptor 4-mediated cytokine synthesis and post-stroke depressive symptoms

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Michal Korostynski ◽  
Dzesika Hoinkis ◽  
Marcin Piechota ◽  
Slawomir Golda ◽  
Joanna Pera ◽  
...  
Keyword(s):  
Gene Expression ◽  
Depressive Symptoms ◽  
Ex Vivo ◽  
Toll Like Receptor ◽  
Toll Like Receptor 4 ◽  
Post Stroke ◽  
Cytokines And Chemokines ◽  
Patient Health ◽  
Post Stroke Depression ◽  
Cytokine Synthesis

AbstractAltered cytokine synthesis thought to contribute to the pathophysiology of post-stroke depression (PSD). Toll-like receptor 4 (TLR4) is a master regulator of innate immunity. The aim of this study was to explore the putative association between TLR4-mediated cytokine synthesis and subsequent symptoms of PSD. In total, 262 patients with ischemic stroke and without a history of PSD were included. Depressive symptoms were assessed using the Patient Health Questionnaire-9 in 170 patients on Day 8 and in 146 at 3 months after stroke. Blood samples taken on Day 3 after stroke were stimulated ex vivo with lipopolysaccharide (LPS). Ex vivo synthesized cytokines (TNFα, IP-10, IL-1β, IL-6, IL-8, IL-10, and IL-12p70) and circulating cytokines (TNFα, IL-6, sIL-6R, and IL-1ra) were measured using the enzyme-linked immunoassay or cytometric method. RNA sequencing was used to determine the gene expression profile of LPS-induced cytokines and chemokines. LPS-induced cytokine synthesis and the gene expression of TLR4-dependent cytokines and chemokines did not differ between patients with and without greater depressive symptoms. The plasma level of IL-6, but not TNFα, sIL-6R, and IL-1ra, was higher in patients who developed depressive symptoms at 3 months after stroke (median: 4.7 vs 3.4 pg/mL, P = 0.06). Plasma IL-6 predicted the severity of depressive symptoms at 3 months after stroke (β = 0.42, P = 0.03). In conclusion, TLR4-dependent cytokine synthesis was not associated with greater post-stroke depressive symptoms in this study. Circulating IL-6 might be associated with depressive symptoms occurring at 3 months after stroke.

scholarly journals Thapsigargin-Stimulated LAD2 Human Mast Cell Line Is a Potent Cellular Adjuvant for the Maturation of Monocyte-Derived Dendritic Cells for Adoptive Cellular Immunotherapy

2021 ◽  
Vol 22 (8) ◽  
pp. 3978
Author(s):  
Pavla Taborska ◽  
Dmitry Stakheev ◽  
Jirina Bartunkova ◽  
Daniel Smrz
Keyword(s):  
Dendritic Cells ◽  
Mast Cell ◽  
Ex Vivo ◽  
Human Leukocyte ◽  
Poly I:C ◽  
Human Mast Cell ◽  
Cellular Immunotherapy ◽  
Adoptive Cellular Immunotherapy ◽  
Serum Free ◽  
Dc Maturation

The preparation of dendritic cells (DCs) for adoptive cellular immunotherapy (ACI) requires the maturation of ex vivo-produced immature(i) DCs. This maturation ensures that the antigen presentation triggers an immune response towards the antigen-expressing cells. Although there is a large number of maturation agents capable of inducing strong DC maturation, there is still only a very limited number of these agents approved for use in the production of DCs for ACI. In seeking novel DC maturation agents, we used differentially activated human mast cell (MC) line LAD2 as a cellular adjuvant to elicit or modulate the maturation of ex vivo-produced monocyte-derived iDCs. We found that co-culture of iDCs with differentially activated LAD2 MCs in serum-containing media significantly modulated polyinosinic:polycytidylic acid (poly I:C)-elicited DC maturation as determined through the surface expression of the maturation markers CD80, CD83, CD86, and human leukocyte antigen(HLA)-DR. Once iDCs were generated in serum-free conditions, they became refractory to the maturation with poly I:C, and the LAD2 MC modulatory potential was minimized. However, the maturation-refractory phenotype of the serum-free generated iDCs was largely overcome by co-culture with thapsigargin-stimulated LAD2 MCs. Our data suggest that differentially stimulated mast cells could be novel and highly potent cellular adjuvants for the maturation of DCs for ACI.

scholarly journals CD14 Expressing Precursors Give Rise to Highly Functional Conventional Dendritic Cells for Use as Dendritic Cell Vaccine

Cancers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 3818
Author(s):  
Maud Plantinga ◽  
Denise A. M. H. van den Beemt ◽  
Ester Dünnebach ◽  
Stefan Nierkens
Keyword(s):  
Dendritic Cells ◽  
T Cell ◽  
Cord Blood ◽  
T Cell Activation ◽  
Cell Activation ◽  
Ex Vivo ◽  
Dendritic Cell Vaccine ◽  
Cell Vaccine ◽  
Activated T Cells

Induction of long-lasting immunity by dendritic cells (DCs) makes them attractive candidates for anti-tumor vaccination. Although DC vaccinations are generally considered safe, clinical responses remain inconsistent in clinical trials. This initiated studies to identify subsets of DCs with superior capabilities to induce effective and memory anti-tumor responses. The use of primary DCs has been suggested to overcome the functional limitations of ex vivo monocyte-derived DCs (moDC). The ontogeny of primary DCs has recently been revised by the introduction of DC3, which phenotypically resembles conventional (c)DC2 as well as moDC. Previously, we developed a protocol to generate cDC2s from cord blood (CB)-derived stem cells via a CD115-expressing precursor. Here, we performed index sorting and single-cell RNA-sequencing to define the heterogeneity of in vitro developed DC precursors and identified CD14+CD115+ expressing cells that develop into CD1c++DCs and the remainder cells brought about CD123+DCs, as well as assessed their potency. The maturation status and T-cell activation potential were assessed using flow cytometry. CD123+DCs were specifically prone to take up antigens but only modestly activated T-cells. In contrast, CD1c++ are highly mature and specialized in both naïve as well as antigen-experienced T-cell activation. These findings show in vitro functional diversity between cord blood stem cell-derived CD123+DC and CD1c++DCs and may advance the efficiency of DC-based vaccines.

scholarly journals Rapamycin Alternatively Modifies Mitochondrial Dynamics in Dendritic Cells to Reduce Kidney Ischemic Reperfusion Injury

2021 ◽  
Vol 22 (10) ◽  
pp. 5386
Author(s):  
Maria Namwanje ◽  
Bijay Bisunke ◽  
Thomas V. Rousselle ◽  
Gene G. Lamanilao ◽  
Venkatadri S. Sunder ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Immune Responses ◽  
Therapeutic Potential ◽  
Ex Vivo ◽  
Mitochondrial Dynamics ◽  
Graft Loss ◽  
Kidney Injury ◽  
Adaptive Immune ◽  
Consumption Rates ◽  
Regulatory Phenotype

Dendritic cells (DCs) are unique immune cells that can link innate and adaptive immune responses and Immunometabolism greatly impacts their phenotype. Rapamycin is a macrolide compound that has immunosuppressant functions and is used to prevent graft loss in kidney transplantation. The current study evaluated the therapeutic potential of ex-vivo rapamycin treated DCs to protect kidneys in a mouse model of acute kidney injury (AKI). For the rapamycin single (S) treatment (Rapa-S-DC), Veh-DCs were treated with rapamycin (10 ng/mL) for 1 h before LPS. In contrast, rapamycin multiple (M) treatment (Rapa-M-DC) were exposed to 3 treatments over 7 days. Only multiple ex-vivo rapamycin treatments of DCs induced a persistent reprogramming of mitochondrial metabolism. These DCs had 18-fold more mitochondria, had almost 4-fold higher oxygen consumption rates, and produced more ATP compared to Veh-DCs (Veh treated control DCs). Pathway analysis showed IL10 signaling as a major contributing pathway to the altered immunophenotype after Rapamycin treatment compared to vehicle with significantly lower cytokines Tnfa, Il1b, and Il6, while regulators of mitochondrial content Pgc1a, Tfam, and Ho1 remained elevated. Critically, adoptive transfer of rapamycin-treated DCs to WT recipients 24 h before bilateral kidney ischemia significantly protected the kidneys from injury with a significant 3-fold improvement in kidney function. Last, the infusion of DCs containing higher mitochondria numbers (treated ex-vivo with healthy isolated mitochondria (10 µg/mL) one day before) also partially protected the kidneys from IRI. These studies demonstrate that pre-emptive infusion of ex-vivo reprogrammed DCs that have higher mitochondria content has therapeutic capacity to induce an anti-inflammatory regulatory phenotype to protect kidneys from injury.

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