Mesenchymal Stromal Cells Promote a Sustained Increase of the CD69 Marker on Activated CD3+ Lymphocytes: Potential Immunomodulatory Role

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 2417-2417
Author(s):  
Felipe Saldanha Araujo ◽  
Rodrigo Alexandre Panepucci ◽  
Kelen Cristina Farias ◽  
Amelia G Araujo ◽  
Maristela Delgado Orellana ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Mesenchymal Stromal Cells ◽  
Stromal Cells ◽  
Immune Modulation ◽  
Regulatory Function ◽  
Sustained Increase

Abstract Mesenchymal stromal cells (MSCs) exert an immune regulatory function and suppress T-cell proliferation in vitro and in vivo. One of the ways by which MSCs may modulate immune responses is by the induction of CD4+CD25+FOXP3+ regulatory T cells (Treg), which suppress alloreactivity in vitro and prevent or attenuate GVHD in animal models. TGF-b (TGFB1 gene), one of the factors secreted by MSC, is known to induce the expression of FOXP3 and to drive the generation of Tregs from CD4+CD25− T cells. T cell activation is characterized by the expression of many surface molecules, and CD69 is one of the earliest markers, transiently expressed following activation. CD69 is selectively expressed at sites of chronic inflammation and recent in vivo and in vitro results indicate that this receptor may modulate the inflammatory response, by inducing TGF-b production. Despite the importance of secreted factors, cell to cell contacts promote increased lymphocyte immune modulation. Interestingly, TGF-b is known to induce the expression of b-IG-H3 (TGFBI gene), a secreted extracellular matrix adaptor protein, whose expression is higher on hematopoietic stem cells adherent to MSC. Given the potential role of CD69 as a regulatory molecule, we explored the effects of MSC on the expression of CD69, TGFB1, FOXP3 and TGFBI on co-cultured T-cells. Peripheral blood mononuclear cells (PBMC) from 6 individuals were co-activated by anti-CD3/CD28 beads and cultured either in the presence or in the absence of MSC (5:1) adhered to the bottom of culture wells. IL2 (20U/ml) was added in the 3rd day for full activation. Cultured PBMC were collected 1, 3 and 5 days after activation. Percentage of CD69+ cells and proliferation of activated lymphocytes (cell division tracking by CFSE) were evaluated by flow cytometry on gated CD3+ lymphocytes. Transcripts levels of TGFB1, TGFBI, FOXP3 and IL10 were determined by real time PCR and normalized using ACTB as an endogenous control. Relative expression levels were calculated in comparison with activated PBMC cultivated alone at the 5th day. Proliferation of lymphocytes co-cultured with MSC was significantly inhibited. As expected, activation of lymphocytes cultured alone was evidenced by the expression of CD69 in 5% of cells in the first day (mean percentage), followed by a decrease in the subsequent days (4% and 3%, respectively). Interestingly, lymphocytes co-cultured with MSC displayed a completely different pattern, with a similar initial activation (7%) which was followed by significant increase in the 3rd day (16%), maintained in the 5th day (14%). Furthermore, TGFBI and IL10 were both expressed at significantly higher levels on PBMC co-cultured with MSC, compared to PBMC alone, in all days evaluated. In addition, their transcript levels decreased faster on PBMC cultured alone. In the other hand, TGFB1 and FOXP3 levels in PBMC cultured alone or in the presence of MSC were similarly higher in the 1st day, but decreased till the 5th day, when their levels were slightly, but significantly higher on PBMC co-cultured with MSC, compared to PBMC cultured alone. We demonstrate for the first time that co-culture with MSC causes a sustained increase of the CD69 marker on CD3+ lymphocytes, which is accompanied by increased levels of TGFB1, TGFBI, FOXP3 and IL10 on total PBMC. Our results are in line with the proposed immunoregulatory role of CD69. In addition, higher TGFBI levels on PBMC may increase lymphocyte adherence to MSC, thus favoring immune modulation. This work was supported by FINEP, CNPq and FAPESP.

scholarly journals IL-27 promotes T cell–dependent colitis through multiple mechanisms

2010 ◽  
Vol 208 (1) ◽  
pp. 115-123 ◽  
Author(s):  
Jennifer H. Cox ◽  
Noelyn M. Kljavin ◽  
Nandhini Ramamoorthi ◽  
Lauri Diehl ◽  
Marcel Batten ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Intestinal Inflammation ◽  
Interferon Γ ◽  
Transfer Model ◽  
Proinflammatory Role ◽  
Immune Pathology

Interleukin-27 (IL-27) is a cytokine known to have both proinflammatory and immunoregulatory functions. The latter appear to dominate in vivo, where IL-27 suppresses TH17 responses and promotes the differentiation of Tr1 cells expressing interferon-γ and IL-10 and lacking forkhead box P3 (Foxp3). Accordingly, IL-27 receptor α (Il27ra)–deficient mice suffer from exacerbated immune pathology when infected with various parasites or challenged with autoantigens. Because the role of IL-27 in human and experimental mouse colitis is controversial, we studied the consequences of Il27ra deletion in the mouse T cell transfer model of colitis and unexpectedly discovered a proinflammatory role of IL-27. Absence of Il27ra on transferred T cells resulted in diminished weight loss and reduced colonic inflammation. A greater fraction of transferred T cells assumed a Foxp3+ phenotype in the absence of Il27ra, suggesting that IL-27 functions to restrain regulatory T cell (Treg) development. Indeed, IL-27 suppressed Foxp3 induction in vitro and in an ovalbumin-dependent tolerization model in vivo. Furthermore, effector cell proliferation and IFN-γ production were reduced in the absence of Il27ra. Collectively, we describe a proinflammatory role of IL-27 in T cell–dependent intestinal inflammation and provide a rationale for targeting this cytokine in pathological situations that result from a breakdown in peripheral immune tolerance.

scholarly journals Leptin: A Critical Regulator of CD4+ T-cell Polarization in Vitro and in Vivo

Endocrinology ◽  
2010 ◽  
Vol 151 (1) ◽  
pp. 56-62 ◽  
Author(s):  
Arvind Batra ◽  
Besir Okur ◽  
Rainer Glauben ◽  
Ulrike Erben ◽  
Jakob Ihbe ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Polarization ◽  
Th2 Cells ◽  
Regulatory Function ◽  
Wild Type ◽  
T Helper ◽  
T Cell Polarization

Abstract Besides being mandatory in the metabolic system, adipokines like leptin directly affect immunity. Leptin was found to be necessary in T helper 1 (Th1)-dependent inflammatory processes, whereas effects on Th2 cells are rarely understood. Here, we focused on leptin in T-helper cell polarization and in Th2-mediated intestinal inflammation in vivo. The induction of cytokine-producing Th1 or Th2 cells from naive CD4+ T cells under polarizing conditions in vitro was generally decreased in cells from leptin-deficient ob/ob mice compared with wild-type mice. To explore the in vivo relevance of leptin in Th2-mediated inflammation, the model of oxazolone-induced colitis was employed in wild-type, ob/ob, and leptin-reconstituted ob/ob mice. Ob/ob mice were protected, whereas wild-type and leptin-reconstituted ob/ob mice developed colitis. The disease severity went in parallel with local production of the Th2 cytokine IL-13. A possible explanation for the protection of ob/ob mice in Th1- as well as in Th2-dependent inflammation is provided by a decreased expression of the key transcription factors for Th1 and Th2 polarization, T-bet and GATA-3, in naive ob/ob T cells. In conclusion, these results support the regulatory function of the adipokine leptin within T-cell polarization and thus in the acquired immune system and support the concept that there is a close interaction with the endocrine system.

scholarly journals Allogeneic Adipose-Derived Mesenchymal Stromal Cells Ameliorate Experimental Autoimmune Encephalomyelitis by Regulating Self-Reactive T Cell Responses and Dendritic Cell Function

2017 ◽  
Vol 2017 ◽  
pp. 1-15 ◽  
Author(s):  
Per Anderson ◽  
Elena Gonzalez-Rey ◽  
Francisco O’Valle ◽  
Francisco Martin ◽  
F. Javier Oliver ◽  
...  
Keyword(s):  
T Cell ◽  
Mesenchymal Stromal Cells ◽  
Stromal Cells ◽  
Cell Function ◽  
Multipotent Mesenchymal Stromal Cells ◽  
Brain Inflammation ◽  
Inos Inhibitor ◽  
Cox 1

Multipotent mesenchymal stromal cells (MSCs) have emerged as a promising therapy for autoimmune diseases, including multiple sclerosis (MS). Administration of MSCs to MS patients has proven safe with signs of immunomodulation but their therapeutic efficacy remains low. The aim of the current study has been to further characterize the immunomodulatory mechanisms of adipose tissue-derived MSCs (ASCs) in vitro and in vivo using the EAE model of chronic brain inflammation in mice. We found that murine ASCs (mASCs) suppress T cell proliferation in vitro via inducible nitric oxide synthase (iNOS) and cyclooxygenase- (COX-) 1/2 activities. mASCs also prevented the lipopolysaccharide- (LPS-) induced maturation of dendritic cells (DCs) in vitro. The addition of the COX-1/2 inhibitor indomethacin, but not the iNOS inhibitor L-NAME, reversed the block in DC maturation implicating prostaglandin (PG) E2 in this process. In vivo, early administration of murine and human ASCs (hASCs) ameliorated myelin oligodendrocyte protein- (MOG35-55-) induced EAE in C57Bl/6 mice. Mechanistic studies showed that mASCs suppressed the function of autoantigen-specific T cells and also decreased the frequency of activated (CD11c+CD40high and CD11c+TNF-α+) DCs in draining lymph nodes (DLNs). In summary, these data suggest that mASCs reduce EAE severity, in part, through the impairment of DC and T cell function.

scholarly journals Bacterial Pathogens Induce Abscess Formation by CD4+ T-Cell Activation via the CD28–B7-2 Costimulatory Pathway

2000 ◽  
Vol 68 (12) ◽  
pp. 6650-6655 ◽  
Author(s):  
Arthur O. Tzianabos ◽  
Anil Chandraker ◽  
Wiltrud Kalka-Moll ◽  
Francesca Stingele ◽  
Victor M. Dong ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Pathogenic Bacteria ◽  
Cell Activation ◽  
Bacterial Pathogens ◽  
Abscess Formation

ABSTRACT Abscesses are a classic host response to infection by many pathogenic bacteria. The immunopathogenesis of this tissue response to infection has not been fully elucidated. Previous studies have suggested that T cells are involved in the pathologic process, but the role of these cells remains unclear. To delineate the mechanism by which T cells mediate abscess formation associated with intra-abdominal sepsis, the role of T-cell activation and the contribution of antigen-presenting cells via CD28-B7 costimulation were investigated. T cells activated in vitro by zwitterionic bacterial polysaccharides (Zps) known to induce abscess formation required CD28-B7 costimulation and, when adoptively transferred to the peritoneal cavity of naı̈ve rats, promoted abscess formation. Blockade of T-cell activation via the CD28-B7 pathway in animals with CTLA4Ig prevented abscess formation following challenge with different bacterial pathogens, including Staphylococcus aureus,Bacteroides fragilis, and a combination ofEnterococcus faecium and Bacteroides distasonis. In contrast, these animals had an increased abscess rate following in vivo T-cell activation via CD28 signaling. Abscess formation in vivo and T-cell activation in vitro required costimulation by B7-2 but not B7-1. These results demonstrate that abscess formation by pathogenic bacteria is under the control of a common effector mechanism that requires T-cell activation via the CD28–B7-2 pathway.

Blocking the regulatory T cell molecule LAG-3 augments in vivo anti-tumor immunity in an autochthonous model of prostate cancer

2006 ◽  
Vol 24 (18_suppl) ◽  
pp. 2573-2573
Author(s):  
C. G. Drake ◽  
C. Kelleher ◽  
T. Bruno ◽  
T. Harris ◽  
D. Flies ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
T Cells ◽  
T Cell ◽  
Regulatory T Cell ◽  
Specific Antigen ◽  
Cell Activity ◽  
Cd8 T Cell ◽  
Regulatory Function

2573 Background: LAG-3 is a CD4 homolog expressed on activated T cells, NK cells, tumor infiltrating lymphocytes (TIL), and plasmacytoid dendritic cells. Recently, we showed that LAG-3 was relatively overexpressed in specific T cells rendered unresponsive in vivo by the presence of cognate self-antigen. These anergic T cells display regulatory function both in vitro and in vivo, and blockade of LAG-3 with a non-depleting monoclonal antibody significantly mitigates their regulatory T cell activity. Methods: Using a novel model of prostate cancer in which a tumor-specific antigen is expressed in autochthonous tumors, we tested whether treatment with a non-depleting anti-LAG-3 antibody affected trafficking and function of tumor-specific T cells. Results: LAG-3 blockade significantly augments specific CD8 T cell trafficking to antigen-expressing tumors, but not to normal tissue. Most significantly, LAG-3 blockade functionally reversed CD8 T cell tolerance as assayed by an in vivo cytotoxic T lymphocyte (CTL) assay. Combining LAG-3 blockade with specific anti-tumor vaccination results in a dramatic increase in activated CD8 T cells in the tumor parenchyma. Conclusions: Taken together, these data support the concept that treatment with a LAG-3 blocking antibody may significantly delay disease progression in patients with cancer. We have recently generated a panel of monoclonal antibodies directed against human LAG-3; several of these antibodies significantly augment human T cell responses in vitro. No significant financial relationships to disclose.

The Inhibitory Receptor LAG-3 Is Not Essential for Regulatory T Cells Function but Influences Donor T Cell Potency in Acute Graft-Versus-Host-Disease

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 1900-1900
Author(s):  
Emanuela I Sega ◽  
Dennis B Leveson-Gower ◽  
Mareike Florek ◽  
Robert S Negrin
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Treg Function ◽  
Donor T Cells ◽  
Alloreactive T Cell

Abstract Abstract 1900 GVHD is a major complication of bone marrow transplantation (BMT) and results from donor T cells becoming activated and reacting to host antigens. Recently, lymphocyte activation gene-3 (LAG-3) has emerged as an important molecule, negatively regulating T cell activation and has been proposed to play an important role in CD4+CD25+Foxp3+ regulatory T cell (Treg) function. We investigated the functional in vivo role of LAG-3 in Treg and conventional T cells in murine GVHD with the hypothesis that LAG-3 engagement diminishes alloreactive T cell responses after BMT. Using murine models of acute GVHD in which allogeneic bone marrow cells are transplanted into lethally irradiated hosts, we and others have shown previously that donor Treg are able to suppress GVHD induced by donor allogeneic conventional T cells (Tcon). The role of LAG-3 in Treg function was evaluated both in vitro and in vivo by directly comparing Treg isolated from LAG-3−/− donor mice to Treg isolated from wild type donors (WT Treg). In vitro, in a mixed lymphocyte reaction assay, LAG-3−/− Treg efficiently suppressed the proliferation of alloreactive T cells in a manner similar to WT Treg. In vivo, a bioluminescent imaging assay (BLI) was utilized that allows for quantitative assessment of Tcon proliferation in addition to traditional metrics of GVHD severity including weight loss, survival and GVHD score. Both LAG-3−/− Treg and WT Treg were equally potent at suppressing Tcon proliferation as illustrated by BLI of luc+ T cells and demonstrated a significant increase in median survival time (MST) as compared to mice receiving Tcon only (35 days for Tcon vs. 58 and 68 days for WT and LAG-3−/− Treg, respectively, P=0.03), but there was no significant difference in MST between the groups receiving WT and LAG-3−/− Treg. Interestingly, when LAG-3−/− Tcon were used to induce GVHD in the absence of Treg, GVHD lethality was accelerated. Thus, all mice receiving LAG-3−/− Tcon showed decreased survival and significantly lower body weights than mice receiving WT Tcon (P=0.017). GVHD scores of LAG-3−/− Tcon recipients were also significantly higher than WT Tcon recipients at Day 20 post BMT (6.0 vs. 2.2, P=<0.0001). The addition of WT Treg induced only a modest yet statistically significant increase in median survival in mice receiving both LAG-3−/− Tcon and WT Treg as compared to mice receiving LAG-3−/− Tcon alone (45 days vs. 14.5 days, P=0.0075). In contrast, WT Treg more efficiently suppressed the proliferation of WT Tcon, increasing the MST to 70 days versus a MST of 26 days for mice receiving WT Tcon (P=0.0002). Re-isolation experiments using CFSE-labeled Tcon did not show differences in proliferation between WT and LAG-3−/− Tcon at five days following BMT. Since LAG-3 is upregulated as early as 2 days after T cell activation and gradually decreases over the next few days, is it possible that a difference in proliferation could be detected at an earlier timepoint thus explaining the difference in potency between the WT and LAG-3−/− Tcon. Together our results indicate, contrary to previous published results, that the absence of the LAG-3 molecule on Treg does not impair Treg function in our mouse model of acute GVHD. However, the absence of LAG-3 on Tcon induces a more severe GVHD suggesting that LAG-3 engagement on donor T cells diminishes alloreactive T cell response after BMT. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Deltex Regulates T-Cell Activation by Targeted Degradation of Active MEKK1

2005 ◽  
Vol 25 (4) ◽  
pp. 1367-1378 ◽  
Author(s):  
Wen-Hsien Liu ◽  
Ming-Zong Lai
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Cell Receptor ◽  
Mitogen Activated Protein Kinase ◽  
Dominant Form

ABSTRACT Deltex is known as a Notch signal mediator, but its physiological action mechanism is poorly understood. Here we identified a new regulatory role of Deltex in T-cell activation. Deltex expression was constitutive in resting T cells and was reduced upon T-cell receptor (TCR)-stimulated activation. The biological role of Deltex is supported by the enhanced T-cell activation when Deltex1 was down-regulated by small interfering RNA. Overexpression of Deltex1 suppressed T-cell activation but not the proximal TCR activation events. The impaired activation of mitogen-activated protein kinase by Deltex could be partly attributed to a selective down-regulation of MEKK1 protein in T cells. We further found that Deltex promoted degradation of the C-terminal catalytic fragment of MEKK1 [MEKK1(C)]. Deltex1 interacted directly with MEKK1(C) and stimulated the ubiquitination of MEKK1(C) as shown by in vivo and in vitro ubiquitination analysis. Therefore, MEKK1(C), the dominant form of MEKK1 in T cells, is a target of Deltex E3 ubiquitin ligase. Our results reveal a novel mechanism as to how Deltex selectively suppresses T-cell activation through degradation of a key signaling molecule, MEKK1.

scholarly journals NKG2D signaling within the pancreatic islets reduces NOD diabetes and increases protective central memory CD8+ T cell numbers

2020 ◽  
Author(s):  
Ada Admin ◽  
Andrew P. Trembath ◽  
Kelsey L. Krausz ◽  
Neekun Sharma ◽  
Ivan C. Gerling ◽  
...  
Keyword(s):  
T Cells ◽  
Type 1 Diabetes ◽  
T Cell ◽  
Autoimmune Diabetes ◽  
Central Memory ◽  
Anatomical Location

NKG2D is implicated in autoimmune diabetes. However, the role of this receptor in diabetes pathogenesis is unclear owing to conflicting results with studies involving global inhibition of NKG2D signaling. We found that NKG2D and its ligands are present in human pancreata, with expression of NKG2D and its ligands increased in the islets of patients with type 1 diabetes. To directly assess the role of NKG2D in the pancreas, we generated NOD mice that express an NKG2D ligand in b-islet cells. Diabetes was reduced in these mice. The reduction corresponded with a decrease in the effector to central memory CD8<sup>+</sup> T cell ratio. Further, NKG2D signaling during in vitro activation of both mouse and human CD8+ T cells resulted in an increased number of central memory CD8<sup>+</sup> T cells and diabetes protection by central memory CD8<sup>+</sup> T cells in vivo. Taken together, these studies demonstrate that there is a protective role for central memory CD8<sup>+</sup> T cells in autoimmune diabetes and that this protection is enhanced with NKG2D signaling. These findings stress the importance of anatomical location when determining the role NKG2D signaling plays, as well as when developing therapeutic strategies targeting this pathway, in type 1 diabetes development.

Regulatory dendritic cells program generation of interleukin-4–producing alternative memory CD4 T cells with suppressive activity

Blood ◽  
2011 ◽  
Vol 117 (4) ◽  
pp. 1218-1227 ◽  
Author(s):  
Xiongfei Xu ◽  
Zhenhong Guo ◽  
Xueyu Jiang ◽  
Yushi Yao ◽  
Qiangguo Gao ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
Cd4 T Cells ◽  
Cd4 T Cell ◽  
Interleukin 4 ◽  
Delayed Type Hypersensitivity ◽  
Regulatory Function

Abstract The heterogeneity and mechanisms for the generation of CD4 memory T (CD4 Tm) cells remain elusive. Distinct subsets of dendritic cells (DCs) have been found to regulate a distinct T-helper (Th)–cell subset differentiation by influencing cytokine cues around CD4 T cells; however, whether and how the regulatory DC subset can regulate Tm-cell differentiation remains unknown. Further, there is no ideal in vitro experimental system with which to mimic the 3 phases of the CD4 T-cell immune response (expansion, contraction, memory generation) and/or to culture CD4 Tm cells for more than a month. By analyzing CD4 T cells programmed by long-term coculture with regulatory DCs, we identified a population of long-lived CD4 T cells with a CD44hiCD62L−CCR7− effector memory phenotype and rapid, preferential secretion of the Th2 cytokines interleukin-4 (IL-4), IL-5, IL-10, and IL-13 after antigenic stimulation. These regulatory DC-programmed Tm cells suppress CD4 T-cell activation and proliferation in vitro via IL-10 and inhibit the delayed-type hypersensitivity response once infused in vivo. We also identify their natural counterpart, which is up-regulated by regulatory DC transfusion and negatively regulates the recall response in vivo. Different from interferon-γ–producing conventional Tm cells, these IL-4–producing CD4 Tm cells act as alternative Tm cells with a regulatory function, suggesting a new way of negative immune regulation by memory T cells.

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