Tregs In Systemic Lupus Erythematosus Research Articles

TIGIT reverses IFN-α-promoted Th1-like Tregs via in-sequence effects dependent on STAT4

ObjectivesThe induction direction of interferon (IFN)-α in T-cell phenotype and function varies depending on the activation state of the cell and the time of stimulation. To assess the effects of elevated IFN-α on regulatory T cells (Tregs) in systemic lupus erythematosus (SLE) patients, we investigated the differentiation of Th1-like Tregs under in-sequence and out-of-sequence conditions and the reversal effect of activating TIGIT on immune suppression.MethodsPhenotypes and activation levels of Tregs from SLE patients and healthy controls were analyzed using flow cytometry. In vitro culture conditions based on the sequence of TCR activation and IFN-α stimulation simulated in-sequence or out-of-sequence effects. CD4+T cells and Tregs were cultured under the above conditions with or without TIGIT agonist. Expression of related characteristic markers and phosphorylation levels of AKT, mTOR, and STATs were detected using flow cytometry and ELISA.ResultsThe frequency of Th1-like Tregs and activation levels of Tregs increased, but TIGIT expression in Tregs decreased in SLE patients. IFN-α promoted the conversation of Tregs to Th1-like Tregs while reducing immunosuppressive function under in-sequence conditions. The STAT4 pathway, but not the STAT1 pathway, was crucial for the IFN-α-mediated in-sequence effects. Reactivation of TIGIT reversed Th1 polarization of Tregs by suppressing AKT/mTOR and STAT4 signaling.ConclusionsOur findings suggest that IFN-α mediated in-sequence effects on Tregs may be responsible for the expansion of Th1-like Tregs in SLE. TIGIT can restore immune suppression damage in Tregs and represents a potential therapeutic target for SLE.

IL-6 alters migration capacity of CD4+Foxp3+ regulatory T cells in systemic lupus erythematosus.

Regulatory T cells (Tregs) are impaired in human systemic lupus erythematosus (SLE) and involved in disease pathogenesis. However, the mechanisms responsible for the Treg dysfunction in SLE remain unclear. In this study, we aimed to investigate the chemotaxis of Treg response to inflammatory stimulation. Sixty two patients were enrolled, and chemokine receptors, including CCR4, CCR5, CCR6, CCR8 and CXCR3 on CD4+Foxp3+Tregs and non-Treg CD4 T cells, were analysed using FACS. The expression of CCR4 and CCR6 on Tregs of SLE patients decreased, while the expression of CCR4 on non-Treg CD4 T cells increased, as compared with those of age- and sex-matched healthy donors. In parallel, in SLE, the chemotactic capacity of non-Treg CD4 T cells response to CCR4 and CCR6 ligands dramatically increased, while that of Tregs significantly decreased. Moreover, we found that cytokines IL-6 and IL-10 positively and negatively modulate the expression of those receptors respectively. IL-6, the significantly increased cytokine in active SLE, dramatically elevated CCR4 and CCR6 expression on non-Treg CD4 T cells. However, as for Tregs, these cells produced more IL-10 than non-Treg CD4 T cells upon IL-6 stimulation, and these IL-10 led to the inhibition of CCR4 and CCR6. In sum, our data provided new evidence suggesting a functional deficiency of Tregs in SLE. It may suggest that those dysfunctional Tregs have less access to the inflammation locus to exert inhibitory capacity.

CD8+ T regulatory cells in lupus.

T regulatory cells (Tregs) have a key role in the maintenance of immune homeostasis and the regulation of immune tolerance by preventing the inflammation and suppressing the autoimmune responses. Numerical and functional deficits of these cells have been reported in systemic lupus erythematosus (SLE) patients and mouse models of SLE, where their imbalance and dysregulated activities have been reported to significantly influence the disease pathogenesis, progression and outcomes. Most studies in SLE have focused on CD4+ Tregs and it has become clear that a critical role in the control of immune tolerance after the breakdown of self-tolerance is provided by CD8+ Tregs. Here we review the role, cellular and molecular phenotypes, and mechanisms of action of CD8+ Tregs in SLE, including ways to induce these cells for immunotherapeutic modulation in SLE.

Low expressions of PD-L1 and CTLA-4 by induced CD4+CD25+ Foxp3+ Tregs in patients with SLE and their correlation with the disease activity

BackgroundThe induction of CD4+CD25+Foxp3+ Treg from CD4+CD25− T cells is deficient in the patients with systemic lupus erythematosus (SLE). Whether the induced CD4+CD25+Foxp3+ Tregs possess defective function remains unclear. The purpose of the present research was to study the expression differences of functional membrane molecule between SLE patients and healthy controls by the induced CD4+CD25+Foxp3+ Treg, in order to achieve a better understanding for the function deficiency of Treg in SLE. MethodsPeripheral blood mononuclear cells (PBMCs) isolated from healthy donors and SLE patients were used to separated CD4+CD25− T cells. These CD4+CD25− T cells were induced to differentiate into CD4+CD25+Foxp3+ Tregs through incubating with CD3 and CD28 antibodies, TGF-β, IL-2 and rapamycin in vitro. Flow cytometry was applied to analyze the expressions of PD-1, PD-L1, CTLA-4, mTGF-β, LAP, CD39, mIL-10 and cIL-10, by the induced CD4+CD25+ T cells and the induced CD4+CD25+Foxp3+ Tregs. Results(1) The induced CD4+CD25+ T cells and the induced CD4+CD25+Foxp3+ Tregs of both healthy controls and SLE patients both highly expressed PD-1. Nevertheless, the expressions of PD-L1 by the induced CD4+CD25+ T cells and the induced CD4+CD25+Foxp3+ Tregs in SLE patients were significantly lower than those in healthy controls, which were negatively correlated with SLEDAI; (2) The expressions of CTLA-4 by the induced CD4+CD25+ T cells and the induced CD4+CD25+Foxp3+ Tregs in SLE patients were also significantly reduced as compared with those in healthy controls, which were negatively correlated with SLEDAI; (3) As compared with healthy controls, the expressions of mTGF-β by the induced CD4+CD25+ T cells and the induced CD4+CD25+Foxp3+ Tregs were also reduced in SLE patients, but there was no significant difference between active and inactive patients. While the expressions of LAP between SLE patients and healthy controls did not show significant difference; (4) The expressions of CD39 and mIL-10 displayed scarce significant differences between healthy controls and SLE patients, while the expressions of cIL-10 by the induced CD4+CD25+ T cells and the induced CD4+CD25+Foxp3+ Tregs in SLE patients were significantly increased, which were not correlated with SLEDAI. ConclusionThere were deficiencies in the expressions of PD-L1 and CTLA-4 in the induced CD4+CD25+Foxp3+ Treg of SLE patients, which might be associated with the defective development and function of Treg involved in the pathological process of SLE.

Abstract 128: Leptin Accelerates Autoimmune Disease Progression and the Development of Hypertension in an Experimental Model of Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a chronic autoimmune disorder that predominately affects women and is associated with high rates of hypertension and cardiovascular disease. SLE is characterized by B and T lymphocyte dysfunction and altered cytokine production, including elevated levels of the adipocytokine leptin. Leptin promotes the expansion of proinflammatory T helper (T H ) 1 and T H 17 cells and inhibits the differentiation of regulatory T cells (T REG ). Because T cells are mechanistically linked to the development of hypertension in SLE, we hypothesized that administration of leptin would alter T H subsets and accelerate the development of hypertension in a female mouse model of SLE. To test this hypothesis, 30 week old female SLE (NZBWF1, n=21) and control (NZW, n=25) mice were implanted with minipumps to continuously deliver recombinant mouse leptin (0.5 mg/kg/day) or vehicle for four weeks. At the conclusion of the study, splenic CD4 + T H subsets were analyzed by flow cytometric analyses and no significant alterations in T H 1, T H 2, T H 17, or T REG cells were detected; however, circulating T REG in SLE mice were lower after leptin administration (1.1±0.2% SLE-vehicle vs. 0.52±0.1% SLE-leptin, p<0.05). Circulating IgG isotypes were also analyzed to correlate with T H subset activities and circulating levels of IgG2a were higher in SLE mice administered leptin (0.79±0.2 mg/mL SLE-vehicle vs. 1.2±0.05 mg/mL SLE-leptin, p<0.05), indicating increased T H 1 activity. In further support of inflammatory T cell activity, circulating levels of TNF-α and IL-17 were elevated in SLE mice administered leptin (TNF-α: 18.6±8.4 pg/mL SLE-vehicle vs. 80.5±15.9 pg/mL SLE-leptin, p<0.01) (IL-17: 0.46±0.1 pg/mL SLE-vehicle vs. 1.68±0.5 pg/mL, p<0.01). Mean arterial pressure (MAP; mmHg), measured in conscious mice by carotid catheter, was higher in SLE mice than in control mice (113±3 Control-vehicle vs. 128±3, p=0.06), and leptin further increased blood pressure in SLE mice (SLE-leptin: 134±3; p<0.01 vs. Control-vehicle and Control-leptin). In conclusion, these data suggest that leptin plays a pathogenic role in the development of hypertension in autoimmunity, in part by altering the balance of T H 1, T H 17, and T REG activity.

Significant association of CD4+CD25+Foxp3+ regulatory T cells with clinical findings in patients with systemic lupus erythematosus.

Regulatory T (Treg) cells are one of the important mechanisms in maintaining self-tolerance and immune homeostasis. CD4+CD25+Foxp3+Treg is considered to have a role in the pathogenesis of systemic lupus erythematosus (SLE). However, the data reported is controversial, and a conclusive result has not been given thus far. The aim of the present study is to evaluate the role of CD4+Treg in SLE further. The peripheral blood T cells (PBMCs) from patients with SLE and healthy controls were isolated, and followed by the isolation of CD3+T cells. The PBMCs were tested for the expressions of CD25 and Foxp3 molecules on the surface of CD4+T cells, and CD3+T cells were tested for their cytokine expressions including IFN-γ, TGF-β, and IL-10, with the method of flow cytometry. The correlations of test results with clinical features of the disease were evaluated by linear correlation analysis. CD4+CD25+ Foxp3+Treg decreased in SLE patients and was correlated with the SLE Disease Activity Index (SLEDAI), and a few immunological abnormalities, including anti-dsDNA antibody positive, IgG increase and C3 decrease, and types of tissue damage, including leukocytopenia and kidney damage. IFN-γ+ cells in the CD4+CD25+T subset fresh-isolated from SLE patients increased slightly, but IFN-γ-producing response to stimulation in CD4+CD25+T subset of SLE decreased. The number of TGF-β-producing cells in the CD4+CD25+T subset from SLE patients also decreased. While the percentages of CD4+CD25+IL-10+T subset in the CD3+T cells increased in SLE, however, these changes of cytokine expressions did not show any significant correlations with SLEDAI. There is clear and definite evidence from the present study indicating the important role of CD4+CD25+Foxp3+Treg in the pathogenesis of SLE, for the abnormalities in functional cytokine productions of the CD4+CD25+ T subset, and for the feasibility of a CD4+CD25+Foxp3+Treg- based immunotherapy in SLE.

The Regulatory T Cell in Active Systemic Lupus Erythematosus Patients: A Systemic Review and Meta-Analysis.

Background: Regulatory T cells (Tregs) researches in systemic lupus erythematosus (SLE) have floundered over the years, reports on the numbers and function of Tregs in SLE present quite contradictory results. We therefore conducted a meta-analysis to verify the changes of Tregs in active SLE.Methods: We systematically searched PubMed, Embase, and ISI web of knowledge databases for eligible articles. In total, 628 active SLE patients and 601 controls from 18 studies were included. Due to a high degree of heterogeneity, a random effects model was used to assess the mean differences in Treg percentages, absolute numbers, and suppression capacities of Tregs between active SLE and controls. Further, subgroup analysis was performed to identify potential sources of heterogeneity.Results: The pooled percentages of Tregs in active SLE patients were found to be lower than those in controls (−0.864 ± 0.308, p = 0.005), with great heterogeneity (I2 = 95.01). The discrepancy of published results might result from the following differences among studies: gating strategies for Tregs, diagnostic criteria for SLE, and thresholds of SLEDAI chosen to differentiate between active and inactive SLE. In active SLE, Tregs gated based on CD25 alone showed lower pooled frequency than those gated by Foxp3+ or CD127low/∅. The percentages of Tregs in active SLE was significantly lower than that in controls when the enrolled SLE patients were diagnosed according to the 1997 modified criteria, whereas they were comparable to controls when diagnosed by the 1982 criteria; the higher threshold of SLEDAI score used to define active SLE tended to achieve a lower percentage of Tregs. The pooled absolute numbers of Tregs in active SLE were significantly decreased compared to those in controls (−1.328 ± 0.374, p < 0.001), but seemed to be unaffected by gating strategies. Suppression capacities of Tregs from active SLE patients showed no abnormalities based on the limited pooled data. Longitudinal monitoring of active SLE showed a significant decrease in Treg percentage at remission.Conclusions: This study implies that loss of Tregs may play a role in the pathogenesis of active SLE and help clarify contradictory Treg results in SLE.

Tregs in SLE: an Update.

There has been great interest in understanding why T regulatory cells (Tregs) are reduced in number and/or in function in several autoimmune diseases including systemic lupus erythematosus (SLE). Although research has provided some answers, there is still much to learn. Recent investigations on the mechanisms responsible for the impairment of the Tregs in SLE have identified relevant abnormalities in cellular and molecular pathways that have been instrumental in the design of studies in animal models and in the development of pilot immunotherapeutic studies in lupus patients. We review the progress made in the field in the last 5years, discussing the mechanistic studies, together with the preclinical and clinical works that are moving forward the understanding of the physiopathology of Tregs in SLE.

Blockade of Treg Cell Differentiation and Function by the Interleukin-21-Mechanistic Target of Rapamycin Axis Via Suppression of Autophagy in Patients With Systemic Lupus Erythematosus.

The mechanistic target of rapamycin (mTOR) has become a therapeutic target in systemic lupus erythematosus (SLE). In T cells, mTOR plays a central role in lineage specification, including development of regulatory cells (Treg cells). This study sought to investigate whether mTOR is activated within Treg cells and whether this contributes to the depletion and dysfunction of Treg cells in patients with SLE. Activities of mTOR complexes 1 (mTORC1) and 2 (mTORC2) were examined by quantifying phosphorylation of translation initiation factor 4E-binding protein 1, S6 kinase, and Akt in SLE patients relative to age- and sex-matched female healthy control subjects. Polarization of Treg cells from naive CD4+ T cells was assessed in the presence of interleukin-6 (IL-6), IL-17, and IL-21. The suppressor function of sorted CD4+CD25+ Treg cells was measured by determining their impact on the proliferation of autologous CD4+CD25- responder T cells. Treg cell expression of FoxP3, GATA-3, and CTLA-4 was monitored by flow cytometry. Autophagy was assessed using immunoblotting of light chain 3 lipidation. The effect of mTOR blockade was evaluated by testing the impact of rapamycin treatment on Treg cell function. SLE Treg cells exhibited increased activities of mTORC1 and mTORC2, whereas autophagy, the expression of GATA-3 and CTLA-4, and the suppressor function of Treg cells were diminished. IL-21, but not IL-6 or IL-17, blocked the development of Treg cells. IL-21 stimulated mTORC1 and mTORC2, and it abrogated the autophagy, differentiation, and function of Treg cells. Moreover, IL-21 constrained the expression of GATA-3 and CTLA-4 selectively in Treg cells. In turn, blockade of mTORC1 by 3-day rapamycin treatment enhanced transforming growth factor β production, while dual blockade of mTORC1 and mTORC2 by 4-week rapamycin treatment induced autophagy, restored the expression of GATA-3 and CTLA-4, and corrected Treg cell function. IL-21-driven mTOR activation is a pharmacologically targetable checkpoint of the deficient autophagy that underlies Treg cell dysfunction in SLE.

Two separate effects contribute to regulatory T cell defect in systemic lupus erythematosus patients and their unaffected relatives.

SummaryForkhead box P3 (FoxP3)+ regulatory T cells (Tregs) are functionally deficient in systemic lupus erythematosus (SLE), characterized by reduced surface CD25 [the interleukin (IL)‐2 receptor alpha chain]. Low‐dose IL‐2 therapy is a promising current approach to correct this defect. To elucidate the origins of the SLE Treg phenotype, we studied its role through developmentally defined regulatory T cell (Treg) subsets in 45 SLE patients, 103 SLE‐unaffected first‐degree relatives and 61 unrelated healthy control subjects, and genetic association with the CD25‐encoding IL2RA locus. We identified two separate, uncorrelated effects contributing to Treg CD25. (1) SLE patients and unaffected relatives remarkably shared CD25 reduction versus controls, particularly in the developmentally earliest CD4+FoxP3+CD45RO–CD31+ recent thymic emigrant Tregs. This first component effect influenced the proportions of circulating CD4+FoxP3highCD45RO+ activated Tregs. (2) In contrast, patients and unaffected relatives differed sharply in their activated Treg CD25 state: while relatives as control subjects up‐regulated CD25 strongly in these cells during differentiation from naive Tregs, SLE patients specifically failed to do so. This CD25 up‐regulation depended upon IL2RA genetic variation and was related functionally to the proliferation of activated Tregs, but not to their circulating numbers. Both effects were found related to T cell IL‐2 production. Our results point to (1) a heritable, intrathymic mechanism responsible for reduced CD25 on early Tregs and decreased activation capacity in an extended risk population, which can be compensated by (2) functionally independent CD25 up‐regulation upon peripheral Treg activation that is selectively deficient in patients. We expect that Treg‐directed therapies can be monitored more effectively when taking this distinction into account.

Leptin levels in patients with systemic lupus erythematosus inversely correlate with regulatory T cell frequency.

Leptin levels are increased in patients with systemic lupus erythematosus (SLE) but little is known on how this correlates with several disease characteristics including the frequency of regulatory T cells (Tregs). Here we compared serum leptin levels with frequency of circulating Tregs in 47 lupus patients vs. 25 healthy matched controls. Correlations with lupus disease activity were also analyzed, as well as Treg proliferation potential. It was found that leptin was remarkably increased in SLE patients as compared to controls, particularly in SLE patients with moderate and severe active SLE, and the increase correlated with disease activity. Importantly, increased leptin in lupus patients inversely correlated with the frequency of Tregs but not in controls, and leptin neutralization resulted in the expansion of Tregs ex vivo. Thus, hyperleptinemia in lupus patients correlates directly with disease activity and inversely with Treg frequency. The finding that leptin inhibition expands Tregs in SLE suggests possible inhibition of this molecule for an enhanced Treg function in the disease.

Low-dose interleukin-2 selectively corrects regulatory T cell defects in patients with systemic lupus erythematosus

ObjectivesDefects in regulatory T cell (Treg) biology have been associated with human systemic autoimmune diseases, such as systemic lupus erythematosus (SLE). However, the origin of such Treg defects and their...

Regulatory T cells in systemic lupus erythematosus

Autoantibodies are associated with various autoimmune diseases. Systemic lupus erythematosus (SLE) is an autoantibody-associated autoimmune disease which affects multiple organs. Although both genetic and environmental factors are implicated in lupus pathogenesis, the etiology of the disease remains elusive. The discovery of CD4(+)CD25(+) regulatory T cells (Tregs) that characteristically express forkhead box p3 (Foxp3) gene have greatly advanced our understanding of immune systems in autoimmune diseases. CD4(+) Tregs can be classified into two main populations: thymus-derived naturally occurring Tregs (nTregs) and induced Tregs (iTregs) generated from CD4(+)CD25(-) precursors in the periphery. Recently, accumulating evidence suggests that these Tregs play important roles in the regulation of humoral immune responses. In this review, we discuss recent findings on the role of Tregs in SLE.

AB0029 Imbalance between Immunoregulatory and Effector TH17 Pathway in Active Sle

BackgroundDefective function of regulatory T cells (Treg) leads to the impairment of immune tolerance implicated in the pathogenesis of autoimmune inflammation in systemic lupus erythematosus (SLE).MethodsTo investigate the role of...

Mechanistic target of rapamycin complex 1 expands Th17 and IL-4+ CD4-CD8- double-negative T cells and contracts regulatory T cells in systemic lupus erythematosus.

The mechanistic target of rapamycin (mTOR) is activated in CD4(-)CD8(-) double-negative (DN) T cells and its blockade is therapeutic in systemic lupus erythematosus (SLE) patients. Murine studies showed the involvement of mTOR complex 1 (mTORC1) and 2 (mTORC2) in the differentiation of Th1/Th17 cells and Th2 cells, respectively. In this study, we investigated the roles of mTORC1 and mTORC2 in T cell lineage development in SLE and matched healthy control (HC) subjects. mTORC1 activity was increased, whereas mTORC2 was reduced, as assessed by phosphorylation of their substrates phosphorylated S6 kinase 1 or phosphorylated S6 ribosomal protein and phosphorylated Akt, respectively. Rapamycin inhibited mTORC1 and enhanced mTORC2. IL-4 expression was increased in freshly isolated CD8(+) lupus T cells (SLE: 8.09 ± 1.93%, HC: 3.61 ± 0.49%; p = 0.01). DN T cells had greater IL-4 expression than CD4(+) or CD8(+) T cells of SLE patients after 3-d in vitro stimulation, which was suppressed by rapamycin (control: 9.26 ± 1.48%, rapamycin: 5.03 ± 0.66%; p < 0.001). GATA-3 expression was increased in CD8(+) lupus T cells (p < 0.01) and was insensitive to rapamycin treatment. IFN-γ expression was reduced in all lupus T cell subsets (p = 1.0 × 10(-5)) and also resisted rapamycin. IL-17 expression was increased in CD4(+) lupus T cells (SLE: 3.62 ± 0.66%, HC: 2.29 ± 0.27%; p = 0.019), which was suppressed by rapamycin (control: 3.91 ± 0.79%, rapamycin: 2.22 ± 0.60%; p < 0.001). Frequency of regulatory T cells (Tregs) was reduced in SLE (SLE: 1.83 ± 0.25%, HC: 2.97 ± 0.27%; p = 0.0012). Rapamycin inhibited mTORC1 in Tregs and promoted their expansion. Neutralization of IL-17, but not IL-4, also expanded Tregs in SLE and HC subjects. These results indicate that mTORC1 expands IL-4(+) DN T and Th17 cells, and contracts Tregs in SLE.

THU0172 The role of T regulatory lymphocytes in lupus nephritis

BackgroundRegulatory T cells (Tregs) play a key role in the maintenance of immune tolerance and in the development of autoimmune diseases. Expression of Foxp3, a member of forkheadbox family of...

FRI0266 The mechanism of umbilical cord mesenchymal stem cells in the upregulation of regulatory t cells by tgf-b1 in systemic lupus erythematosus

ObjectivesThe aim of this study is to investigate the mechanism of umbilical cord mesenchymal stem cells (UC-MSC) in the upregulation of peripheral regulatory T cells in patients with systemic lupus...

Highly suppressive CD39+ Tregs decrease during disease activity in patients with Systemic Lupus Erythematosus (P4124)

Abstract Objective: Reports on changes in the number and function of Tregs in Systemic Lupus Erythematosus (SLE) have been contradictory, possibly because most of those studies focused on identifying the whole Treg population, without dissecting the Treg subsets. This study aimed to enumerate the number and to study the role of various Treg subsets such as CD39+ Tregs , Naïve Tregs and activated Tregs in SLE patients. Results: Thirty SLE patients, 8 with active disease and 22 in remission, were recruited. The proportion of Tregs (CD4+CD25+Foxp3+) did not differ between patients with active lupus and those in remission (8.2±2.4% vs 7.5±3.8%, respectively; p=0.83). Similarly, there were no differences in these two groups of SLE patients in respect to the numbers of the naïve (CD4+CD45RA+Foxp3+) and activated Tregs (CD4+CD45RA-Foxp3high). However, the proportion of CD39+ Tregs was found to be significantly lower SLE patients with a flare, compared to those on remission (21.6±8.1% vs 41.9±4.7%, respectively; p=0.01). FACS-sorted CD39+ Tregs were found to be significantly more suppressive than CD39- Tregs. At the cut-off point 15.3%, CD39+ Tregs differentiated patients with active lupus from those in remission with the sensitivity of 95% and specificity of 75%. Conclusions: Fewer CD39+ Tregs in patients with active lupus indicates that CD39+ Tregs may play a crucial role in the pathogenesis of SLE. Furthermore, peripheral blood CD39+ Treg may be a biomarker for flares in SLE patients.

Mechanism of umbilical cord mesenchymal stem cells in the up-regulation of regulatory T cells by transforming growth factor β1 in systemic lupus erythematosus

To explore the mechanism of umbilical cord mesenchymal stem cells (UC-MSC) in the up-regulation of peripheral regulatory T cells in patients with systemic lupus erythematosus (SLE). Peripheral blood mononuclear cells (PBMC) from 20 SLE patients and normal controls were co-cultured with UC-MSC at different ratios respectively for 72 hours. And the proportions of CD4+CD25+Foxp3+regulatory T cells were analyzed by flow cytometry. PBMC and sera from active SLE patients and normal controls were used to stimulate UC-MSC. The expressions of transforming growth factor β1 (TGF-β1) on UC-MSC were detected by real-time fluorescence quantitative polymerase chain reaction (real-time PCR). The supernatant level of TGF-β1 was determined by enzyme-linked immunosorbent assay (ELISA). And the TGF-β1 small interfering RNA (siRNA) was used to interfere with the TGF-β1 expression on UC-MSC and determine its effect on the regulation of SLE Treg cells. TGF-β1 inhibitor was added into the culture system of UC-MSC and PBMC from active SLE patients to observe its role on the up-regulation of Treg cells by UC-MSC. UC-MSC could dose-dependently up-regulate the peripheral CD4+CD25+Foxp3+Treg proportion in SLE patients. And such an effect was not dependent on cell-cell contact. UC-MSC had no regulatory effect on Treg cells in normal controls. Compared with the non-stimulated and normal PBMC stimulated groups, PBMC from SLE patients significantly promoted TGF-β1 mRNA expression on UC-MSC (relative gene expression was 1.00 ± 0.09, 1.95 ± 0.62, 4.20 ± 2.34 respectively, both P < 0.05). The supernatant level of TGF-β1 was significantly elevated in the presence of SLE PBMC. Sera of SLE patients (5%) enhanced TGF-β1 mRNA expression on UC-MSC and it was significantly higher than fetal bovine serum cultured group (12.19 ± 4.49 vs 1.33 ± 0.06, P < 0.01) and normal individual sera cultured group (2.53 ± 0.72, P < 0.01). Additionally, TGF-β1 siRNA interfered UC-MSC failed to up-regulate Treg cells in SLE patients . Furthermore, TGF-β1 specific inhibitor SB431542 significantly inhibited the regulatory role of UC-MSC on Treg cells in SLE patients. Immune microenvironment in SLE patients can significantly stimulate the TGF-β1 expression on UC-MSC and plays an important role in the up-regulation of Treg cells in patients.

Foxp3+ Helios+ regulatory T cells are expanded in active systemic lupus erythematosus

ObjectivesRecent data debate the suitability of Helios, an Ikaros family member, as a marker for thymic-derived regulatory T cells (Treg). Nevertheless, Foxp3+ Helios+ Treg may be of particular relevance in...