High levels of thyroid hormone impair regulatory T cells function via reduced PD-1 expression

Author(s):  
Yi Zhong ◽  
Ting-Ting Lu ◽  
Xiao-Mei Liu ◽  
Bing-Li Liu ◽  
Yun Hu ◽  
...  

Abstract Context Regulatory T cells (Tregs) dysfunction plays an important role in the development and progression of Graves’ disease (GD). Programmed cell death 1 (PD-1) prompts FoxP3 in Tregs expression and enhances the suppressive activity of Tregs. Whether abnormal expression of PD-1 contributes to the breakdown of Tregs and the role of thyroid hormone in the PD-1 expression of Tregs in GD remain substantially undefined. Objective To evaluate the role of PD-1 in Tregs function and triiodothyronine (T3) in PD-1 expression in patients with GD and mice treated with T3. Methods We recruited 30 patients with GD and 30 healthy donors. PD-1 expression in Tregs and Tregs function were determined. To evaluate the effects of thyroid hormone on PD-1 expression in Tregs, we used T3 for the treatment of human peripheral blood mononuclear cells (PBMCs). We then treated mice with T3 to confirm the effect of thyroid hormone on PD-1 expression in Tregs and Tregs function in vivo. Results PD-1 expression in Tregs and the suppressive function of Tregs significantly decreased in patients with GD. T3 reduced PD-1 expression in human Tregs in a concentration- and time-dependent manner in vitro. High levels of circulating T3 reduced PD-1 expression in Tregs, impaired Tregs function, and disrupted T-helper cell (Th1 and Th2) balance in mice treated with T3. Conclusions Tregs dysfunction in GD patients might be due to down-regulation of PD-1 expression in Tregs induced by high levels of serum T3.

2021 ◽  
Author(s):  
Yannick D. Muller ◽  
Leonardo M.R. Ferreira ◽  
Emilie Ronin ◽  
Patrick Ho ◽  
Vinh Nguyen ◽  
...  

Infusion of regulatory T cells (Tregs) engineered with a chimeric antigen receptor (CAR) targeting donor-derived human leukocyte antigen (HLA) is a promising strategy to promote transplant tolerance. Here, we describe an anti-HLA-A2 CAR (A2-CAR) generated by grafting the complementarity-determining regions (CDRs) of a human monoclonal anti-HLA-A2 antibody into the framework regions of the Herceptin 4D5 single-chain variable fragment and fusing it with a CD28-zeta signaling domain. The CDR-grafted A2-CAR maintained the specificity of the original antibody. We then generated HLA-A2 mono-specific human CAR Tregs either by deleting the endogenous T-cell receptor (TCR) via CRISPR/Cas9 and introducing the A2-CAR using lentiviral transduction or by directly integrating the CAR construct into the TCR alpha constant locus using homology-directed repair. These A2-CAR+TCRdeficient human Tregs maintained both Treg phenotype and function in vitro. Moreover, they selectively accumulated in HLA-A2-expressing islets transplanted from either HLA-A2 transgenic mice or deceased human donors. A2-CAR+TCRdeficient Tregs did not impair the function of these HLA-A2+ islets, whereas similarly engineered A2-CAR+TCRdeficientCD4+ conventional T cells rejected the islets in less than 2 weeks. A2-CAR+TCRdeficient Tregs delayed graft-versus-host disease only in the presence of HLA-A2, expressed either by co-transferred peripheral blood mononuclear cells or by the recipient mice. Altogether, we demonstrate that genome-engineered mono-antigen-specific A2-CAR Tregs localize to HLA-A2-expressing grafts and exhibit antigen-dependent in vivo suppression, independent of TCR expression. These approaches may be applied towards developing precision Treg cell therapies for transplant tolerance.


Biology ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 211 ◽  
Author(s):  
Nour Z. Atwany ◽  
Seyedeh-Khadijeh Hashemi ◽  
Manju Nidagodu Jayakumar ◽  
Mitzi Nagarkatti ◽  
Prakash Nagarkatti ◽  
...  

Regulatory T cells (Tregs) are key players in the regulation of inflammatory responses. In this study, two natural molecules, namely, sparteine sulfate (SS) and harpagoside (Harp), were investigated for their ability to induce Tregs in human peripheral blood mononuclear cells (PBMCs). PBMCs were isolated from healthy volunteers and grown in the presence or absence of ConA, with TGF-beta, SS or Harp. Expression of the mRNA of FoxP3, TGF-beta, IL-10 and GAPDH was assessed via q-PCR. The expression of Treg markers including CD4, CD25, CD127 and FoxP3 was measured via flow cytometry. The secretion of IL-10 and TGF-beta by cultured cells was assessed by ELISA. Furthermore, the suppressive role of SS and Harp on PBMCs in vitro was tested via allogeneic mixed lymphocyte reaction (MLR). Data obtained show that both compounds increased the expression of FoxP3, TGF-beta and IL-10 mRNA in resting PBMCs but to a lesser extent in activated cells. Moreover, they significantly increased the percent of CD4+CD25+FoxP3+CD127− Tregs in activated and naïve PBMCs. Functionally, both compounds caused a significant reduction in the stimulation index in allogeneic MLR. Together, our data demonstrate for the first time that SS and Harp can induce human Tregs in vitro and therefore have great potential as anti-inflammatory agents.


Blood ◽  
2008 ◽  
Vol 111 (7) ◽  
pp. 3675-3683 ◽  
Author(s):  
Xingmin Feng ◽  
Sachiko Kajigaya ◽  
Elena E. Solomou ◽  
Keyvan Keyvanfar ◽  
Xiuli Xu ◽  
...  

Abstract Regulatory T cells (Treg) play important roles in suppressing immune responses and maintaining tolerance. Rabbit antithymocyte globulin (rATG) and horse ATG (hATG) are widely used in the treatment of immune-mediated syndromes, but their effects on Treg are unknown. We show here that in vitro culture of normal human peripheral blood mononuclear cells (PBMCs) with a low-dose rATG resulted in marked expansion of functional Treg by converting CD4+CD25− T cells to CD4+CD25+ T cells. hATG did not expand but rather decreased Treg. Immuno-blot showed increased expression of FOXP3 and NFAT1 in CD4+CD25− and CD4+CD25+ T cells exposed to rATG. PBMCs treated with rATG displayed increased interleukin-10 in culture supernatants than those treated with hATG. Furthermore, rATG and hATG showed differences in their potential to stimulate CD4+ T cells as examined using different activation markers. Microarray revealed that rATG induced markedly different gene-expression patterns in PBMCs, compared with hATG-treated or untreated PBMCs. Our findings indicate that rATG expanded Treg, probably through transcriptional regulation by enhanced NFAT1 expression, in turn conferring CD4+CD25− T cell FOXP3 expression and regulatory activity. The therapeutic effects of rATG may occur not only because of lymphocyte depletion but also enhanced Treg cell number and function.


Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 1901-1901 ◽  
Author(s):  
Yongxian Hu ◽  
Yanjun Gu ◽  
Lixia Sheng ◽  
Huarui Fu ◽  
Kangni Wu ◽  
...  

Abstract Abstract 1901 Regulatory γδ T cells (γδ Tregs) is a novel subset of cells with immunosuppressive function while methods for γδ Treg induction is rarely introduced and its role in graft-versus-host disease (GVHD) prevention remains unkown. Decitabine, a kind of hypomethylating agents, can act synergistically with TGF-β1 to convert a variety of αβ T cells to regulatory αβ T cells with suppressive function but its role in induction and function of γδ Tregs has not been reported. We show here the role of decitabine for the induction of γδ Tregs. Moreover, we provide functional analysis and underlying mechanisms of decitabine-induced γδ Tregs relative to γδ Tregs without decitabine induction as well as in vivo evidences of their preventions on GVHD. Human peripheral blood mononuclear cells (PBMCs) were cultured with IL-2, IL-15, TGF-β1 and zoledronic acid (ZOL). On day 2, 0.5μmol/ml decitabine was added to aliquots of PBMCs. On days 4, 7, and 10, half of the supernatant volume was replaced with media containing cytokines. On day 11, frequencies of γδ Tregs were detected by flow cytometry (FACS). We found the frequency of γδ Tregs was 36.2% in TGF-β1/IL-15/ZOL stimulated group (referred to as common γδ Tregs below) and 59.9% in IL-2/TGF-β1/IL-15/ZOL/decitabine stimulated group (referred to as decitabine-induced γδ Tregs) (p<0.05). In order to compare immunosuppressive function of the two populations, γδ T cells containing γδ Tregs were isolated by magnetic cell sorting system (MACS) and tested for their ability to suppress proliferation of alloreactive PBMCs using CFSE-based assay. After 5 days of in vitro culture, CFSE-labeled PBMCs proliferation was significantly reduced in the presence of enriched γδ Tregs even at 8:1(PBMCs: γδ Tregs) ratio. The inhibition rate was significantly different (decitabine-induced γδ Tregs VS common γδ Tregs at ratio 1:1 is 81.3% VS 68.2%, p<0.05). To clarify the underlying mechanisms we performed ELISA to measure levels of inhibitory cytokines IL-10, IL-4 and TGF-β1 in supernatant of CFSE-based assay. We noted an elevated IL-10 secretion in the decitabine-induced γδ Tregs group compared with common γδ Tregs group (92.7±11pg/ml VS 10.3±2pg/ml at ratio 1:1, p<0.01). We confirmed the result by intracellular IL-10 detection using FACS. Previous reports showed high levels of inducible T-cell costimulator (ICOS) were correlated with IL-10 synthesis. So γδ Tregs were monitored for ICOS expression by FACS. The result revealed that ICOS expression was up-regulated in decitabine-induced γδ Tregs in contrast to common γδ Tregs (MFI: 268 VS 54). Stability of Foxp3 is a critical factor in the immunosuppressive ability of Tregs. Thus we evaluated the frequency of γδ Tregs after 5 days in CFSE-based assay. We observed loss of Foxp3 expression in decitabine-induced γδ Tregs was negligible (<3%) while 15.5% common γδ Tregs lost foxp3 expression. To confirm the results in vitro we tested the functional ability to prevent GVHD in vivo. GVHD was induced in NOD/SCID mice following busulfan and anti-CD122 condition and 1×107 PBMCs transfusion. Animals were co-injected with either decitabine-induced γδ Tregs or common γδ Tregs at a ratio of 1:1. Survival time and GVHD manifestations of the transplanted mice were evaluated. As a result, transplantation of human PBMCs alone induced lethal GVHD with average survival time 25± 8 days while the survival time was 43± 5 days and 58±7 days in mice co-injected with common γδ Tregs and decitabine-induced γδ Tregs, respectively (p<0.05). Clinical manifestations such as hunched back, diarrhea, and body weight loss were statistically different among 3 groups. To investigate the infiltration of human lymphocytes into nonlymphoid tissues in GVHD mice, we performed immunohistochemical analysis of the liver and intestines using anti-human CD45. Remarkably abundant invasion of human CD45+ cells was observed around the veins in the liver and intestines transplanted with PBMCs alone while less invasion in mice co-injected with common γδ Tregs and the lest invasion in mice co-injected with decitabine-induced γδ Tregs. Altogether, our findings reveal that decitabine and the cytokines can efficiently syngenerize to induce γδ Tregs with enhanced immunosuppression on GVHD which are via higher levels of IL-10 production due to ICOS up-regulation as well as stability of Foxp3 expression. Thus γδ Tregs may be potentially exploited therapeutically in a variety of transplantation settings. Disclosures: No relevant conflicts of interest to declare.


2021 ◽  
Vol 12 ◽  
Author(s):  
Yannick D. Muller ◽  
Leonardo M. R. Ferreira ◽  
Emilie Ronin ◽  
Patrick Ho ◽  
Vinh Nguyen ◽  
...  

Infusion of regulatory T cells (Tregs) engineered with a chimeric antigen receptor (CAR) targeting donor-derived human leukocyte antigen (HLA) is a promising strategy to promote transplant tolerance. Here, we describe an anti-HLA-A2 CAR (A2-CAR) generated by grafting the complementarity-determining regions (CDRs) of a human monoclonal anti-HLA-A2 antibody into the framework regions of the Herceptin 4D5 single-chain variable fragment and fusing it with a CD28-ζ signaling domain. The CDR-grafted A2-CAR maintained the specificity of the original antibody. We then generated HLA-A2 mono-specific human CAR Tregs either by deleting the endogenous T-cell receptor (TCR) via CRISPR/Cas9 and introducing the A2-CAR using lentiviral transduction or by directly integrating the CAR construct into the TCR alpha constant locus using homology-directed repair. These A2-CAR+TCRdeficient human Tregs maintained both Treg phenotype and function in vitro. Moreover, they selectively accumulated in HLA-A2-expressing islets transplanted from either HLA-A2 transgenic mice or deceased human donors. A2-CAR+TCRdeficient Tregs did not impair the function of these HLA-A2+ islets, whereas similarly engineered A2-CAR+TCRdeficientCD4+ conventional T cells rejected the islets in less than 2 weeks. A2-CAR+TCRdeficient Tregs delayed graft-versus-host disease only in the presence of HLA-A2, expressed either by co-transferred peripheral blood mononuclear cells or by the recipient mice. Altogether, we demonstrate that genome-engineered mono-antigen-specific A2-CAR Tregs localize to HLA-A2-expressing grafts and exhibit antigen-dependent in vivo suppression, independent of TCR expression. These approaches may be applied towards developing precision Treg cell therapies for transplant tolerance.


2020 ◽  
Author(s):  
Dongdong Wang ◽  
Yi Fu ◽  
Junfen Fan ◽  
Chao Li ◽  
Yi Xu ◽  
...  

Abstract Background: Given their low immunogenicity and multiple differentiation capacities, mesenchymal stem cells (MSCs) have the potential to be used for “off-the-shelf” cell therapy. However, MSC allorejection indicates that they are not fully immune privileged. In this study, we investigated the immunogenicity of human adipose-derived MSCs (Ad-MSCs) and identified potential immunogenic molecules.Methods: To evaluate the immunogenicity of human Ad-MSCs in vivo, cells were transplanted into humanized mice (hu-mice), and T cell infiltration and clearance of human Ad-MSCs were observed by immunofluorescence and bioluminescence imaging. One-way mixed lymphocyte reaction (MLR) and flow cytometry were performed to evaluate the immunogenicity of human Ad-MSCs in vitro. High-throughput TCR repertoire sequencing and mass spectrometry were applied to identify potential immunogenic molecules.Results: Allogeneic human Ad-MSCs recruited T cells during transplantation and caused faster clearance in hu-mice than NOD/ShiLtJGpt-Prkdcem26Cd52Il2rgem26Cd22/Gpt (NSG) mice. The proliferation and activation of T cells was significantly enhanced by human Ad-MSCs, and the expression level of HLA-II on human Ad-MSCs was dramatically increased after coculture with human peripheral blood mononuclear cells (PBMCs) in vitro. In addition, upregulated expression of alpha-enolase (ENO1) on the surface of human Ad-MSCs increased their immunogenicity, and ENO1 inhibitor treatment decreased the human Ad-MSC triggered proliferation of T cells in vitro.Conclusions: We further confirmed the immunogenicity of human Ad-MSCs during allogeneic transplantation and provided a potential target, ENO1, for the safe clinical application of allogeneic human Ad-MSC therapy.


Blood ◽  
1994 ◽  
Vol 83 (9) ◽  
pp. 2516-2525 ◽  
Author(s):  
K Meszaros ◽  
S Aberle ◽  
R Dedrick ◽  
R Machovich ◽  
A Horwitz ◽  
...  

Abstract Mononuclear phagocytes, stimulated by bacterial lipopolysaccharide (LPS), have been implicated in the activation of coagulation in sepsis and endotoxemia. In monocytes LPS induces the synthesis of tissue factor (TF) which, assembled with factor VII, initiates the blood coagulation cascades. In this study we investigated the mechanism of LPS recognition by monocytes, and the consequent expression of TF mRNA and TF activity. We also studied the inhibition of these effects of LPS by rBPI23, a 23-kD recombinant fragment of bactericidal/permeability increasing protein, which has been shown to antagonize LPS in vitro and in vivo. Human peripheral blood mononuclear cells, or monocytes isolated by adherence, were stimulated with Escherichia coli O113 LPS at physiologically relevant concentrations (&gt; or = 10 pg/mL). The effect of LPS was dependent on the presence of the serum protein LBP (lipopolysaccharide-binding protein), as shown by the potentiating effect of human recombinant LBP or serum. Furthermore, recognition of low amounts of LPS by monocytes was also dependent on CD14 receptors, because monoclonal antibodies against CD14 greatly reduced the LPS sensitivity of monocytes in the presence of serum or rLBP. Induction of TF activity and mRNA expression by LPS were inhibited by rBPI23. The expression of tumor necrosis factor showed qualitatively similar changes. Considering the involvement of LPS-induced TF in the potentially lethal intravascular coagulation in sepsis, inhibition of TF induction by rBPI23 may be of therapeutic benefit.


Cytokine ◽  
2016 ◽  
Vol 88 ◽  
pp. 184-192 ◽  
Author(s):  
Hélio Galdino ◽  
Rodrigo Saar Gomes ◽  
Jessica Cristina dos Santos ◽  
Lívia Lara Pessoni ◽  
Anetícia Eduarda Maldaner ◽  
...  

2009 ◽  
Vol 77 (9) ◽  
pp. 3826-3837 ◽  
Author(s):  
Anna Martner ◽  
Susann Skovbjerg ◽  
James C. Paton ◽  
Agnes E. Wold

ABSTRACT Streptococcus pneumoniae is a major pathogen in humans. The pathogenicity of this organism is related to its many virulence factors, the most important of which is the thick pneumococcal capsule that minimizes phagocytosis. Another virulence-associated trait is the tendency of this bacterium to undergo autolysis in stationary phase through activation of the cell wall-bound amidase LytA, which breaks down peptidoglycan. The exact function of autolysis in pneumococcal pathogenesis is, however, unclear. Here, we show the selective and specific inefficiency of wild-type S. pneumoniae for inducing production of phagocyte-activating cytokines in human peripheral blood mononuclear cells (PBMC). Indeed, clinical pneumococcal strains induced production of 30-fold less tumor necrosis factor (TNF), 15-fold less gamma interferon (IFN-γ), and only negligible amounts of interleukin-12 (IL-12) compared with other closely related Streptococcus species, whereas the levels of induction of IL-6, IL-8, and IL-10 production were similar. If pneumococcal LytA was inactivated by mutation or by culture in a medium containing excess choline, the pneumococci induced production of significantly more TNF, IFN-γ, and IL-12 in PBMC, whereas the production of IL-6, IL-8, and IL-10 was unaffected. Further, adding autolyzed pneumococci to intact bacteria inhibited production of TNF, IFN-γ, and IL-12 in a dose-dependent manner but did not inhibit production of IL-6, IL-8, and IL-10 in response to the intact bacteria. Fragments from autolyzed bacteria inhibited phagocytosis of intact bacteria and reduced the in vitro elimination of pneumococci from human blood. Our results suggest that fragments generated by autolysis of bacteria with reduced viability interfere with phagocyte-mediated elimination of live pneumococci.


2018 ◽  
Vol 23 (6) ◽  
pp. 509-517 ◽  
Author(s):  
Anna J. Boland ◽  
Nisha Gangadharan ◽  
Pierce Kavanagh ◽  
Linda Hemeryck ◽  
Jennifer Kieran ◽  
...  

Statins are mainstream therapy in the treatment and prevention of cardiovascular disease through inhibitory effects on cholesterol synthesis. However, statins’ beneficial effects in cardiovascular disease may also be attributable to their role as anti-inflammatory mediators. Here, we investigated the effects of simvastatin treatment on expression levels of interleukin (IL) 1β in both patient with hyperlipidemia and healthy human peripheral blood mononuclear cells (PBMCs) using cholesterol crystals (CC), a cardiovascular pathogenic stimulus for activation of the NOD-like receptor pyrin domain–containing protein 3 (NLRP3) inflammasome. Cholesterol crystal-induced NLRP3 inflammasome activation was used to trigger maturation and release of IL-1β in PBMCs. Specifically, isolated PBMCs from patients with hyperlipidemia at baseline and following 8 weeks of in vivo treatment with simvastatin (10-20 mg) daily were stimulated with lipopolysaccharide (LPS; 100 ng/mL) for 3 hours to induce proIL-Iβ expression followed by CC (2 mg/mL) stimulation for further 18 hours to activate the NLRP3 inflammasome complex to induce maturation/activation of IL-1β. Peripheral blood mononuclear cells were also isolated from healthy donors and stimulated in vitro with simvastatin (50, 25, 5, and 2 µmol/L) prior to stimulation with LPS and CC as described above. The effects of simvastatin treatment on levels of IL-1β expression were determined by enzyme-linked immunosorbent assay and western blot. Both in vitro and in vivo treatments with simvastatin led to a significant reduction in the levels of expression of IL-1β in response to stimulation with CC. Simvastatin inhibits the expression and activation of IL-1β induced by CC in PBMCs, which may contribute to its protective role in patients with cardiovascular disease.


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