scholarly journals Elucidating the Role of Ezh2 in Tolerogenic Function of NOD Bone Marrow-Derived Dendritic Cells Expressing Constitutively Active Stat5b

2020 ◽  
Vol 21 (18) ◽  
pp. 6453
Author(s):  
Echarki Zerif ◽  
Farhan Ullah Khan ◽  
Ahmed Aziz Raki ◽  
Véronique Lullier ◽  
Denis Gris ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Dendritic Cells ◽  
Transgenic Mice ◽  
Nod Mice ◽  
Dc Function ◽  
Autoreactive T Cell ◽  
Tolerogenic Function ◽  
Tolerogenic Dc ◽  
Constitutively Active

Tolerogenic dendritic cells (toDCs) are crucial to controlling the development of autoreactive T cell responses and the prevention of autoimmunity. We have reported that NOD.CD11cStat5b-CA transgenic mice expressing a constitutively active (CA) form of Stat5b under the control of a CD11c promoter are protected from diabetes and that Stat5b-CA-expressing DCs are tolerogenic and halt ongoing diabetes in NOD mice. However, the molecular mechanisms by which Stat5b-CA modulates DC tolerogenic function are not fully understood. Here, we used bone marrow-derived DCs (BMDCs) from NOD.CD11cStat5b-CA transgenic mice (Stat5b-CA.BMDCs) and found that Stat5b-CA.BMDCs displayed high levels of MHC class II, CD80, CD86, PD-L1, and PD-L2 and produced elevated amounts of TGFβ but low amounts of TNFα and IL-23. Stat5b-CA.BMDCs upregulated Irf4 and downregulated Irf8 genes and protein expression and promoted CD11c+CD11b+ DC2 subset differentiation. Interestingly, we found that the histone methyltransferase Ezh2 and Stat5b-CA bound gamma-interferon activated site (GAS) sequences in the Irf8 enhancer IRF8 transcription, whereas Stat5b but not Ezh2 bound GAS sequences in the Irf4 promoter to enhance IRF4 transcription. Injection of Stat5b-CA.BMDCs into prediabetic NOD mice halted progression of islet inflammation and protected against diabetes. Importantly, inhibition of Ezh2 in tolerogenic Stat5b-CA.BMDCs reduced their ability to prevent diabetes development in NOD recipient mice. Taken together, our data suggest that the active form of Stat5b induces tolerogenic DC function by modulating IRF4 and IRF8 expression through recruitment of Ezh2 and highlight the fundamental role of Ezh2 in Stat5b-mediated induction of tolerogenic DC function.

scholarly journals Elucidating Role of Ezh2 in Tolerogenic Function of NOD Bone Marrow-Derived Dendritic Cells Expressing Constitutively Active Stat5b.

2019 ◽  
Author(s):  
Echarki Zerif ◽  
Denis Gris ◽  
Gilles Dupuis ◽  
Abdelaziz Amrani
Keyword(s):  
Bone Marrow ◽  
Dendritic Cells ◽  
Transgenic Mice ◽  
Molecular Mechanisms ◽  
Active Form ◽  
Nod Mice ◽  
Autoreactive T Cell ◽  
Tolerogenic Function ◽  
Constitutively Active

Tolerogenic dendritic cells are crucial to control development of autoreactive T cell responses and prevention of autoimmunity. We have reported that NOD.CD11cStat5b-CA transgenic mice expressing a constitutively active form of Stat5b under the control of CD11c promoter are protected from diabetes and that Stat5b-CA-expressing DCs are tolerogenic and halt ongoing diabetes in NOD mice. However, the molecular mechanisms by which Stat5b-CA modulates DC tolerogenic function is not fully understood. Here, we used bone marrow-derived DCs from NOD.CD11cStat5b-CA transgenic mice (Stat5b-CA.BMDC) and found that Stat5b-CA.BMDC displayed high levels of MHC class II, CD80, CD86, PD-L1 and PD-L2 and produced elevated amounts of TGFβ but low amounts of TNF and IL-23. Stat5b-CA.BMDCs upregulated Irf4 and downregulated Irf8 genes and protein expression and promoted CD11c+CD11b+ DC2 subset differentiation. Interestingly, we found that the histone methyltransferase Ezh2 interacted with Stat5b-CA complex that bound GAS sequences in the Irf8 enhancer whereas Ezh2 did not interact with GAS sequences in the case of the Irf4 promoter. Injection of Stat5b-CA.BMDCs to prediabetic NOD mice halted progression of islet inflammation and protected against diabetes. Importantly, inhibition of Ezh2 in tolerogenic Stat5b-CA.BMDCs reduced their ability to prevent diabetes development in NOD recipient mice. Taken together, our data suggest that the active form of Stat5b induces tolerogenic DC function by modulating IRF4 and IRF8 expression through recruitment of Ezh2 and highlight the fundamental role of Ezh2 in Stat5b-mediated induction of tolerogenic DCs function.

Differential role of NF-κB, ERK1/2 and AP-1 in modulating the immunoregulatory functions of bone marrow-derived dendritic cells from NOD mice

2012 ◽  
Vol 272 (2) ◽  
pp. 259-268 ◽  
Author(s):  
Chantal Guindi ◽  
Michaël Ménard ◽  
Alexandre Cloutier ◽  
Simon Gaudreau ◽  
Gilles Besin ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Dendritic Cells ◽  
Nod Mice

Abstract 129: Suppressor of Cytokine Signaling 1 in Dendritic Cells Inhibits Myocardial Inflammation in Experimental Autoimmune Myocarditis

2012 ◽  
Vol 111 (suppl_1) ◽  
Author(s):  
Kazuko Tajiri ◽  
Kyoko Imanaka-Yoshida ◽  
Michiaki Hiroe ◽  
Nobutake Shimojo ◽  
Satoshi Sakai ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
Cd4 T Cells ◽  
Cytokine Signaling ◽  
Autoimmune Myocarditis ◽  
Dc Function ◽  
Autoreactive T Cell ◽  
Experimental Autoimmune Myocarditis ◽  
Experimental Autoimmune

Introduction: Autoimmunity is considered to play an important role in the development of myocarditis and dilated cardiomyopathy. Recent reports have indicated that a subgroup of myocarditis patients may benefit from immune-targeted therapies. Suppressor of cytokine signaling1 (SOCS1) is an intracellular, cytokine-inducible protein that regulates the responses of immune cells to cytokines. We therefore hypothesized that overexpression of SOCS1 may inhibit the inflammation of myocarditis and cardiomyopathy. Methods and Results: Myocarditis was induced by subcutaneous immunization with cardiac specific peptides derived from α-myosin heavy chain in BALB/c mice on days 0 and 7. Plasmid DNA encoding SOCS1 (pSOCS1) was injected intraperitoneally into mice on days 0, 5 and 10. pSOCS1 treatment significantly decreased heart-to-body weight ratios and the number of infiltrating cells in the heart. Echocardiography showed preserved contractile function in pSOCS1-treated mice. Although autoimmune myocarditis is a CD4+ T cell-mediated disease, pSOCS1 treatment does not have a direct suppressive effect on autoreactive T-cell activation. The introduced pSOCS1 suppressed proinflammatory cytokine production and STAT1 phosphorylation in dendritic cells (DCs). In addition, the proliferative responses of autoreactive CD4+ T cells co-cultured with DCs from pSOCS1-treated mice were much weaker than those of cells cultured with DCs from control plasmid-injected mice. These results suggested that the inoculated pSOCS1 may have been transfected into DCs and impaired DC function in vivo. Conclusion: The administration of pSOCS1 protected mice from the development of experimental autoimmune myocarditis, which was mediated by the inhibition of DC function that in turn reduced the activation of autoreactive CD4+ T cells.

scholarly journals Rho-mDia1 pathway is required for adhesion, migration, and T-cell stimulation in dendritic cells

Blood ◽  
2010 ◽  
Vol 116 (26) ◽  
pp. 5875-5884 ◽  
Author(s):  
Hideaki Tanizaki ◽  
Gyohei Egawa ◽  
Kayo Inaba ◽  
Tetsuya Honda ◽  
Saeko Nakajima ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Dendritic Cells ◽  
T Cell ◽  
Immune Responses ◽  
Lymph Nodes ◽  
Actin Polymerization ◽  
Cell Stimulation ◽  
T Cell Stimulation ◽  
Acquired Immune Responses

Abstract Dendritic cells (DCs) are essential for the initiation of acquired immune responses through antigen acquisition, migration, maturation, and T-cell stimulation. One of the critical mechanisms in this response is the process actin nucleation and polymerization, which is mediated by several groups of proteins, including mammalian Diaphanous-related formins (mDia). However, the role of mDia in DCs remains unknown. Herein, we examined the role of mDia1 (one of the isoforms of mDia) in DCs. Although the proliferation and maturation of bone marrow-derived DCs were comparable between control C57BL/6 and mDia1-deficient (mDia1−/−) mice, adhesion and spreading to cellular matrix were impaired in mDia1−/− bone marrow–derived DCs. In addition, fluorescein isothiocyanate-induced cutaneous DC migration to draining lymph nodes in vivo and invasive migration and directional migration to CCL21 in vitro were suppressed in mDia1−/− DCs. Moreover, sustained T-cell interaction and T-cell stimulation in lymph nodes were impaired by mDia1 deficiency. Consistent with this, the DC-dependent delayed hypersensitivity response was attenuated by mDia1-deficient DCs. These results suggest that actin polymerization, which is mediated by mDia1, is essential for several aspects of DC-initiated acquired immune responses.

scholarly journals Dendritic cells mediate the induction of polyfunctional human IL17-producing cells (Th17-1 cells) enriched in the bone marrow of patients with myeloma

Blood ◽  
2008 ◽  
Vol 112 (7) ◽  
pp. 2878-2885 ◽  
Author(s):  
Kavita M. Dhodapkar ◽  
Scott Barbuto ◽  
Phillip Matthews ◽  
Anjli Kukreja ◽  
Amitabha Mazumder ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Dendritic Cells ◽  
Th17 Cells ◽  
T Helper ◽  
Tumor Bed ◽  
Distinct Lineage ◽  
Human Dendritic Cells ◽  
Antigen Presenting ◽  
Dc Maturation

Abstract IL17-producing (Th17) cells are a distinct lineage of T helper cells that regulate immunity and inflammation. The role of antigen-presenting cells in the induction of Th17 cells in humans remains to be fully defined. Here, we show that human dendritic cells (DCs) are efficient inducers of Th17 cells in culture, including antigen-specific Th17 cells. Although most freshly isolated circulating human Th17 cells secrete IL17 alone or with IL2, those induced by DCs are polyfunctional and coexpress IL17 and IFNγ (Th17-1 cells). The capacity of DCs to expand Th17-1 cells is enhanced upon DC maturation, and mature DCs are superior to monocytes for the expansion of autologous Th17 cells. In myeloma, where tumors are infiltrated by DCs, Th17 cells are enriched in the bone marrow relative to circulation. Bone marrow from patients with myeloma contains a higher proportion of Th17-1 cells compared with the marrow in preneoplastic gammopathy (monoclonal gammopathy of undetermined significance [MGUS]). Uptake of apoptotic but not necrotic myeloma tumor cells by DCs leads to enhanced induction of Th17-1 cells. These data demonstrate the capacity of DCs to induce expansion of polyfunctional IL17-producing T cells in humans, and suggest a role for DCs in the enrichment of Th17-1 cells in the tumor bed.

scholarly journals Role of the p38 MAPK/C/EBPβ Pathway in the Regulation of Phenotype and IL-10 and IL-12 Production by Tolerogenic Bone Marrow-Derived Dendritic Cells

Cells ◽  
2018 ◽  
Vol 7 (12) ◽  
pp. 256 ◽  
Author(s):  
Chantal Guindi ◽  
Alexandre Cloutier ◽  
Simon Gaudreau ◽  
Echarki Zerif ◽  
Patrick P. McDonald ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Dendritic Cells ◽  
Dna Binding ◽  
P38 Mapk ◽  
Costimulatory Molecules ◽  
Binding Activity ◽  
Gm Csf ◽  
Dna Binding Activity ◽  
Factor C

Dendritic cells (DCs) play a major role in innate and adaptive immunity and self-immune tolerance. Immunogenic versus tolerogenic DC functions are dictated by their levels of costimulatory molecules and their cytokine expression profile. The transcription factor C/EBPβ regulates the expression of several inflammatory genes in many cell types including macrophages. However, little is known regarding the role of C/EBPβ in tolerogenic versus immunogenic DCs functions. We have previously reported that bone marrow-derived DCs generated with GM-CSF (GM/DCs) acquire the signature of semi-mature tolerogenic IL-10-producing DCs as opposed to immunogenic DCs generated with GM-CSF and IL-4 (IL-4/DCs). Here, we show that tolerogenic GM/DCs exhibit higher levels of phosphorylation and enhanced DNA binding activity of C/EBPβ and CREB than immunogenic IL-4/DCs. We also show that the p38 MAPK/CREB axis and GSK3 play an important role in regulating C/EBPβ phosphorylation and DNA binding activity. Inhibition of p38 MAPK in GM/DCs resulted in a drastic decrease of C/EBPβ and CREB DNA binding activities, a reduction of their IL-10 production and an increase of their IL-12p70 production, a characteristic of immunogenic IL-4/DCs. We also present evidence that GSK3 inhibition in GM/DCs reduced C/EBPβ DNA binding activity and increased expression of costimulatory molecules in GM/DCs and their production of IL-10. Analysis of GM/DCs of C/EBPβ−/− mice showed that C/EBPβ was essential to maintain the semimature phenotype and the production of IL-10 as well as low CD4+ T cell proliferation. Our results highlight the importance of the p38MAPK-C/EBPβ pathway in regulating phenotype and function of tolerogenic GM/DCs.

scholarly journals Distinct Roles of Lymphotoxin α and the Type I Tumor Necrosis Factor (TNF) Receptor in the Establishment of Follicular Dendritic Cells from Non–Bone Marrow–derived Cells

1997 ◽  
Vol 186 (12) ◽  
pp. 1997-2004 ◽  
Author(s):  
Mitsuru Matsumoto ◽  
Yang-Xin Fu ◽  
Hector Molina ◽  
Guangming Huang ◽  
Jinho Kim ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Dendritic Cells ◽  
Tumor Necrosis ◽  
Type I ◽  
Follicular Dendritic Cells ◽  
Wild Type ◽  
Lymphotoxin Α ◽  
Deficient Mice ◽  
Necrosis Factor

In mice deficient in either lymphotoxin α (LT-α) or type I tumor necrosis factor receptor (TNFR-I), organized clusters of follicular dendritic cells (FDC) and germinal centers (GC) are absent from the spleen. We investigated the role of LT-α and TNFR-I in the establishment of spleen FDC and GC structure by using reciprocal bone marrow (BM) transfer. When LT-α–deficient mice were reconstituted with wild-type BM, FDC organization and the ability to form GC were restored, indicating that the LT-α–expressing cells required to establish organized FDC are derived from BM. The role of LT-α in establishing organized FDC structure was further investigated by the transfer of complement receptor 1 and 2 (CR1/2)–deficient BM cells into LT-α–deficient mice. Organized FDC were identified with both the FDC-M1 and anti-CR1 monoclonal antibodies in these BM-chimeric mice, indicating that these cells were derived from the LT-α–deficient recipient. Thus, expression of LT-α in the BM-derived cells, but not in the non–BM-derived cells, is required for the maturation of FDC from non-BM precursor cells. In contrast, when TNFR-I–deficient mice were reconstituted with wild-type BM, they showed no detectable FDC clusters or GC formation. This indicates that TNFR-I expression on non–BM-derived cellular components is necessary for the establishment of these lymphoid structures. TNFR-I–deficient BM was able to restore FDC organization and GC formation in LT-α–deficient mice, indicating that formation of these structures does not require TNFR-I expression on BM-derived cells. The data in this study demonstrate that FDC organization and GC formation are controlled by both LT-α–expressing BM-derived cells and by TNFR-I-expressing non–BM-derived cells.

Effects of B7.2−/− Mature Dendritic Cells on Tolerance Induction to Alloantigens in Fetal Mice Following In Utero Transplantation with Lineage Depleted Bone Marrow.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 2134-2134
Author(s):  
Swati Bhattacharyya ◽  
Morton J. Cowan
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
Dendritic Cells ◽  
Stem Cell ◽  
In Utero ◽  
Relative Role ◽  
Skin Grafts ◽  
Hematopoietic Stem ◽  
Fetal Mice

Abstract In utero hematopoietic stem cell transplantation (IUT) has the potential to cure a variety of marrow stem cell defects without using marrow ablative therapy. However IUT for diseases other than SCID has been unsuccessful. To better understand the barriers to successful IUT we wanted to define the role of the B7.1/B7.2 co-stimulatory molecules in inducing tolerance to allogeneic donor bone marrow cells in the fetal murine recipient. We studied the relative role of B7.1 and B7.2 expression on dendritic cells (DC) on engraftment and in generating donor specific tolerance in fetal mice. Mature DC (mDC) from B7.1−/− or B7.2−/− donors and wild type (wt) lineage depleted (lin−) C57Bl/6 (B6) bone marrow (BM) were injected into gestational day (GD) 14 Balb/c fetuses. Recipients of lin− wt BM and B7.1−/− mDC had a significantly lower survival (47.4%, p<0.01) associated with mild-moderate GvHD compared to the recipients of B7.2−/− mDC and lin− BM (82.3%) where none developed GvHD. Engraftment results in blood at 6 weeks post IUT showed, B7.1−/− recipients had multilineage engraftment (4.7±0.8% T cells and 5.7± 1.1% granulocytes) in their blood, but by 12 weeks, only donor CD3+ (predominantly CD8+) cells (2.1±1.3%) were present. The percent H2Kb+ (donor) T cells (predominantly CD4+) in the blood of recipients of lin− wt BM and B7.2−/− was 11.8±8.5% at 6 weeks p<0.001 and 6.5±2.5% at 12 weeks, p=0.006. The circulating donor CD4+ cells were Th2 (CD4+CD25−IL4+IL10+) and Treg (CD4+CD25+IL4−IL10−). Both fractions inhibited the T cell proliferative response in the MLR. Long term engraftment in thymic tissues was found in the tolerant recipients of lin− wt BM and B7.2−/− mDC (13.4±8.3% donor CD3+ T cells). We also found prolonged (rejection by day 36) acceptance of donor skin grafts in 7 of 12 recipients of B7.2−/− mDC and 2 of 5 recipients of B7.2−/− mDC and lin−BM. All third party C3H grafts were rejected by day 14 and 80% of the Balb/c (self) skin grafts were permanently accepted. We hypothesized that tolerized animals would behave similarly to recipients of megadoses of syngeneic BM with an increase in multilineage engraftment. We injected a total of 200x106 male wt B6 lin− BM cells over 5 days into adult IUT recipients of B7.1−/− or B7.2−/− mDC ± lin− wt BM and wt age-matched allogeneic and syngeneic (female) controls. Mice that had received B7.2−/− mDC + lin− BM in utero showed multi-lineage engraftment in the blood. In contrast, the in utero recipients of B7.1−/− mDC + lin− BM showed no significant engraftment (p<0.05). In conclusion, donor DC costimulatory molecules significantly affect survival, engraftment and GvHD; and these responses to B7.2−/− mDC and lin− BM appear to be mediated by both Th2 and Treg donor cells.

Reduction of Factor VIII Inhibitor Formation with F.VIII-Pulsed Tolerogenic Dendritic Cells in the Murine Hemophilia A Model.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 213-213 ◽  
Author(s):  
Margaret V. Ragni ◽  
Wenhu Wu ◽  
Xiaoyan Liang ◽  
Lina Lu
Keyword(s):  
Bone Marrow ◽  
Dendritic Cells ◽  
T Cell ◽  
Hemophilia A ◽  
Binding Activity ◽  
Control Group ◽  
High Morbidity ◽  
Gm Csf

Abstract Inhibitor formation is a severe complication of hemophilia, occurring in up to 25% and associated with poor response to factor replacement, uncontrolled bleeding, and high morbidity. Preventing inhibitor formation is, thus, a major goal of hemophilia management. The role of dendritic cells (DC) in regulating immune response has been increasingly recognized: immature DC (imDC) induce T regulatory cells in vitro and promote Ag-specific tolerance in vivo. We, therefore, studied the role of imDC propagated from bone marrow with GM-CSF + TGFβ to prevent inhibitor formation in the hemophilia A murine model. Following tail vein injection of recombinant F.VIII (Advate, Baxter) 2.5 U (0.2 μg) on days 0, 2, and 4 in hemophilia A exon 16 KO C57Bl/6 mice, anti-VIII antibodies were detected by semi-quantitative APTT (scored 1-4), peaking on day 6. On rechallenge with F.VIII 2.5 U on days 12, 14, and 16, anti-VIII was detected, peaking on day 17. Anti-VIII production was associated with high level splenic T cell proliferation in response to F.VIII stimulation in vitro, measured by 3H-thymidine incorporation in mixed lymphocyte reaction (MLR). By contrast, there was no antibody formation in F.VIII-treated Wt C57Bl/6 mice: the latter was associated with low T cell response to F.VIII in vitro. Functionally immature DC (imDC) were propagated from the bone marrow of hemophilia A mice with GM-CSF (4ng/ml) and TGFβ (0.2ng/ml). For comparison, functionally mature dendritic cells (mDC) were propagated with GM-CSF (4ng/ml) and IL-4 (1000U/ml).The former (imDC) demonstrated deficient NF-kB binding activity in nuclear protein as detected by gel shifting assay and expressed low level of costimulatory molecules CD80, CD86; by contrast, the latter (mDC) demonstrated enhanced NF-kB binding activity and high levels of co-stimulatory molecules. Administration of 2x106 F.VIII-pulsed imDC (20U/ml x 24h) 7 days before F.VIII dosing on days 0, 2, and 4, led to reduction in inhibitor formation on day 6 (score 1.6 vs. 2.3 in control group) which was further reduced on day 8 (score 1.0 vs. 2.0 in control group). The inhibitor could not be detected on day 8 in 2 of 4 mice pretreated with F.VIII-pulsed imDC. By contrast, high levels of inhibitor were detected in mice pretreated with F.VIII-pulsed mDC (score 3.3). Rechallenge with F.VIII on day 10 in imDC-treated mice resulted in no increase in the reduced or absent anti-VIII effect on day 12. Splenic T cells (CD3+) from the imDC-pretreated mice showed lower proliferative capacity when restimulated in vitro with F.VIII, suggesting that imDC induced F.VIII unresponsiveness. These studies show that FVIII-pulsed imDC reduce the intensity of inhibitor formation, and suggest the potential role of modified DC in preventing or reducing F.VIII inhibitor formation.

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