scholarly journals Classical dendritic cells are required for dietary antigen–mediated induction of peripheral Treg cells and tolerance

2016 ◽  
Vol 17 (5) ◽  
pp. 545-555 ◽  
Author(s):  
Daria Esterházy ◽  
Jakob Loschko ◽  
Mariya London ◽  
Veronica Jove ◽  
Thiago Y Oliveira ◽  
...  
2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Jie Yang ◽  
Yiming Yang ◽  
Huahua Fan ◽  
Hejian Zou

TGF-β-induced regulatory T cells (iTregs) retain Foxp3 expression and immune-suppressive activity in collagen-induced arthritis (CIA). However, the mechanisms whereby transferred iTregs suppress immune responses, particularly the interplay between iTregs and dendritic cells (DCs)in vivo, remain incompletely understood. In this study, we found that after treatment with iTregs, splenic CD11c+DCs, termed “DCiTreg,” expressed tolerogenic phenotypes, secreted high levels of IL-10, TGF-β, and IDO, and showed potent immunosuppressive activityin vitro. After reinfusion with DCiTreg, marked antiarthritic activity improved clinical scores and histological end-points were observed. The serological levels of inflammatory cytokines and anti-CII antibodies were low and TGF-βproduction was high in the DCiTreg-treated group. DCiTregalso induced new iTregsin vivo. Moreover, the inhibitory activity of DCiTregon CIA was lost following pretreatment with the inhibitor of indoleamine 2,3-dioxygenase (IDO). Collectively, these findings suggest that transferred iTregs could induce tolerogenic characteristics in splenic DCs and these cells could effectively dampen CIA in an IDO-dependent manner. Thus, the potential therapeutic effects of iTregs in CIA are likely maintained through the generation of tolerogenic DCsin vivo.


2010 ◽  
Vol 78 (11) ◽  
pp. 4763-4772 ◽  
Author(s):  
Raquel M. Gonçalves ◽  
Karina C. Salmazi ◽  
Bianca A. N. Santos ◽  
Melissa S. Bastos ◽  
Sandra C. Rocha ◽  
...  

ABSTRACT Clearing blood-stage malaria parasites without inducing major host pathology requires a finely tuned balance between pro- and anti-inflammatory responses. The interplay between regulatory T (Treg) cells and dendritic cells (DCs) is one of the key determinants of this balance. Although experimental models have revealed various patterns of Treg cell expansion, DC maturation, and cytokine production according to the infecting malaria parasite species, no studies have compared all of these parameters in human infections with Plasmodium falciparum and P. vivax in the same setting of endemicity. Here we show that during uncomplicated acute malaria, both species induced a significant expansion of CD4+ CD25+ Foxp3+ Treg cells expressing the key immunomodulatory molecule CTLA-4 and a significant increase in the proportion of DCs that were plasmacytoid (CD123+), with a decrease in the myeloid/plasmacytoid DC ratio. These changes were proportional to parasite loads but correlated neither with the intensity of clinical symptoms nor with circulating cytokine levels. One-third of P. vivax-infected patients, but no P. falciparum-infected subjects, showed impaired maturation of circulating DCs, with low surface expression of CD86. Although vivax malaria patients overall had a less inflammatory cytokine response, with a higher interleukin-10 (IL-10)/tumor necrosis factor alpha (TNF-α) ratio, this finding did not translate to milder clinical manifestations than those of falciparum malaria patients. We discuss the potential implications of these findings for species-specific pathogenesis and long-lasting protective immunity to malaria.


Blood ◽  
2006 ◽  
Vol 107 (9) ◽  
pp. 3632-3638 ◽  
Author(s):  
Elena Gonzalez-Rey ◽  
Alejo Chorny ◽  
Amelia Fernandez-Martin ◽  
Doina Ganea ◽  
Mario Delgado

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.


2020 ◽  
Author(s):  
Yuta Nakazawa ◽  
Kazumasa Kanemaru ◽  
Chigusa Nakahashi-Oda ◽  
Akira Shibuya

AbstractAlthough tumor-infiltrating regulatory T (Treg) cells play a pivotal role in tumor immunity, how Treg cell activation are regulated in tumor microenvironments remains unclear. Here, we found that mice deficient in the inhibitory immunoreceptor CD300a on their dendritic cells (DCs) have increased numbers of Treg cells in tumors and greater tumor growth compared with wild-type mice after transplantation of B16 melanoma. Pharmacological impairment of extracellular vesicle (EV) release decreased Treg cell numbers in CD300a-deficient mice. Coculture of DCs with tumor-derived EV (TEV) induced the internalization of CD300a and the incorporation of EVs into endosomes, in which CD300a inhibited TEV-mediated TLR3-TRIF signaling for activation of the IFN-β-Treg cells axis. We also show that higher expression of CD300A was associated with decreased tumor-infiltrating Treg cells and longer survival time in patients with melanoma. Our findings reveal the role of TEV and CD300a on DCs in Treg cell activation in the tumor microenvironment.


2011 ◽  
Vol 79 (8) ◽  
pp. 3338-3347 ◽  
Author(s):  
Wei Li ◽  
Barry P. Katz ◽  
Stanley M. Spinola

ABSTRACTHaemophilus ducreyicauses chancroid, a genital ulcer disease. In human inoculation experiments, most volunteers fail to clear the bacteria despite the infiltration of innate and adaptive immune cells to the infected sites. The immunosuppressive protein indoleamine 2,3-dioxygenase (IDO) is a rate-limiting enzyme in thel-tryptophan-kynurenine metabolic pathway. Tryptophan depletion and tryptophan metabolites contribute to pathogen persistence by inhibiting T cell proliferation, inducing T cell apoptosis, and promoting the expansion of FOXP3+regulatory T (Treg) cells. We previously found that FOXP3+Treg cells are enriched in experimental lesions and thatH. ducreyiinduced IDO transcription in dendritic cells (DC) derived from blood of infected volunteers who developed pustules. Here, we showed that enzymatically active IDO was induced in DC byH. ducreyi. Neutralizing antibodies against interferon alpha/beta receptor 2 chain (IFNAR2) and tumor necrosis factor alpha (TNF-α) inhibited IDO induction. Inhibitors of the mitogen-activated protein kinase (MAPK) p38 and nuclear factor-κB (NF-κB) also inhibited IDO expression. Neither bacterial contact with nor uptake by DC was required for IDO activation.H. ducreyiculture supernatant andH. ducreyilipooligosaccharides (LOS) induced IDO expression, which required type I interferons, TNF-α, and the three MAPK (p38, c-Jun N-terminal kinase, and extracellular signal regulated kinase) and NF-κB pathways. In addition, LOS-induced IFN-β activated the JAK-STAT pathway. Blocking the LOS/Toll-like receptor 4 (TLR4) signaling pathway greatly reducedH. ducreyi-induced IDO production. These findings indicate thatH. ducreyi-induced IDO expression in DC is largely mediated by LOS via type I interferon- and TNF-α-dependent mechanisms and the MAPK, NF-κB, and JAK-STAT pathways.


2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Vasiliy V. Kurilin ◽  
Julia N. Khantakova ◽  
Valeriy P. Tereschenko ◽  
Julia A. Lopatnikova ◽  
Irina A. Obleukhova ◽  
...  

Introduction. Dendritic cells (DCs) control immune responses by modulating T and B cells towards effector or tolerogenic responses. In this study, we evaluated the effects of different immunosuppressive molecules on the phenotypic and functional characteristics of primary dendritic cells from C57BL/6 and CBA mice. Methods. DCs were derived from bone marrow cells in the presence of rmGM-CSF and rmIL-4. DCs were then treated with different types of immunosuppressive molecules (rmIL-10, rmTGF-β, and BAY 11-7082) and cocultured with syngeneic splenocytes. The amount of CD4+CD25hiFoxP3+ Tregs, IL-10 expression, and proliferation were evaluated. Results. Tolerogenic factors were found to have different effects on DCs C57Bl/6 mice. In C57Bl/6 mice, BAY 11-7082 alone had no effect on the expression of DC maturation molecules (CD80, CD86). Transforming growth factor beta (TGF-β), alone and in combination with BAY 11-7082, reduced the expression of these molecules. Cocultivation of DCs with splenocytes in the presence of TGF-β and BAY 11-7082 favored regulatory T cell (CD4+CD25hiFoxP3+) differentiation and disfavored differentiation of CD4+ T cells producing IL-10. In CBA mice, we found that rmIL-10 and rmTGF-β have a weak effect on maturation of DCs and their functional properties to induce Treg cells and IL-10 production. Conclusion. These results indicate that TGF-β and IL-10 have different effects on the phenotypic and functional characteristics of DCs and that the NF-κB inhibitor, BAY 11-7082, has no synergistic effect on these treatments. In mice with an opposite nature of the immune response, the effects of immunoregulatory cytokines (IL-10 and TGF-b) differ on maturation of dendritic cells.


2017 ◽  
Vol 42 (2) ◽  
pp. 455-468 ◽  
Author(s):  
Zhiwei Dong ◽  
Yajie Chen ◽  
Yuan Peng ◽  
Fan Wang ◽  
Zichen Yang ◽  
...  

Background/Aims: Skin transplantation aims to cover skin defects but often fails due to immune rejection of the transplantated tissue. Immature dendritic cells (imDCs) induce immune tolerance but have a low migration rate. After stimulation, imDCs transform into mature DCs, which activate immune rejection. Thus, inducing imDC to obtain a high migration counteracts development of immune tolerance. Methods & Results: We transfected imDCs with a recombinant adenovirus carrying the CCR7 gene (Ad-CCR7) and a small interfering RNA targeting RelB (RelB-siRNA) to concurrently overexpress CCR7 and downregulate RelB expression. Functionally, such cells showed a significantly enhanced migration rate in the chemotactic assay and decreased T-cell proliferation after lipopolysaccharide stimulation in mixed lymphocyte reactions. Cotransfected cells showed an increased ability to induce immune tolerance by upregulating T regulatory (Treg) cells and shifting the Th1/Th2 ratio. Cotransfection of Ad-CCR7 and RelB-siRNA endowed imDCs with resistance to apoptosis and cell death. CCR7 overexpression and RelB knockdown (KD) in imDCs improve skin-graft survival in a murine skin-transplantation model. Conclusion: Transfection with Ad-CCR7 and RelB KD in imDCs may be an effective approach inducing immune tolerance, thus being potentially valuable for inhibiting allograft rejection.


2016 ◽  
Vol 118 ◽  
pp. 110
Author(s):  
Akemi Ushijima ◽  
Tomoko Shima ◽  
Kumiko Inada ◽  
Akitoshi Nakashima ◽  
Osamu Yoshino ◽  
...  

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