Measurement of natural (CD4+CD25high) and inducible (CD4+IL-10+) regulatory T cells in patients with systemic lupus erythematosus

Expression patterns of T cells-specific long noncoding RNAs in systemic lupus erythematosus patients carrying HLA risk/nonrisk alleles

BACKGROUND

Long noncoding RNAs (LncRNAs) play key roles in the regulation of gene expression and subsequently in the pathogenesis of several autoimmune diseases. This study aimed to explore the peripheral expression levels of T-cells-specific LncRNAs and transcription factors in systemic lupus erythematosus (SLE) patients carrying either human leukocyte antigens (HLA) risk or non-risk alleles.

METHODS

Genotypes of HLA-DRB1 and HLA-DQB1 loci for 106 SLE patients were determined by PCR-SSP. In the next step, patients were stratified based on the presence of HLA-DRB1*03 and/or DRB1*16 allele groups (HLA risk alleles positive or HLA-RPos) or carrying other DRB1 allele groups (HLA-RNeg). Then, transcript levels of LncRNAs (IFNG-AS1, RMRP, Th2LCR, and DQ786243) and mRNAs for transcription factors (Foxp3, Gata3, and Tbx21) were measured using qRT-PCR and compared between two subgroups of patients.

RESULTS

Totally, 47 cases were classified as HLA-RPos and 59 cases as HLA-RNeg patients. The HLA-RPos patients showed decreased transcript levels of DQ786243 (p = .001) and elevated expression of IFNG-AS1 (p = .06) and T-bet mRNA (p = .03) compared to the HLA-RNeg group. We observed significantly lower expression of Th2LCR (p < .0001) and DQ786243 (p = .001) and higher expression of Tbx21 (p = .009) and Foxp3 (p = .02) in DR3-positive versus DR3-negative patients. Likewise, decreased transcript levels of DQ786243 (p = .02) and RMRP (p = .003) were observed in DR16-positive versus DR16-negative patients. ROC curve analysis revealed the potential of DQ786243 and RMRP as biomarkers in SLE disease based on the carriage of HLA risk alleles.

CONCLUSIONS

Our results indicate that the contribution of multiple T cell subsets in SLE disease progression as judged by expression analysis of LncRNAs and transcription factors can be inspired by the inheritance of HLA risk/nonrisk alleles is SLE patients.

The star target in SLE: IL-17

PURPOSE

The purpose of this review is to discuss the significance of IL-17 in SLE and the potential of IL-17-targeted therapy.

BACKGROUND

Systemic lupus erythematosus (SLE) is an autoimmune disease that can affect many organs and tissues throughout the body. It is characterized by overactive B and T cells and loss of immune tolerance to autoantigens. Interleukin-17 (IL-17) is a cytokine that promotes inflammation and has been implicated in the pathogenesis of several autoimmune diseases as well as inflammatory diseases. In in vitro cellular experiments in lupus susceptible mice or SLE patients, there is substantial evidence that IL-17 is a highly promising therapeutic target.

METHODS

We searched papers from PubMed database using the search terms, such as interleukin-17, systemic lupus erythematosus, treatment targets, T cells, lupus nephritis, and other relevant terms.

RESULTS

We discuss in this paper the molecular mechanisms of IL-17 expression, Th17 cell proliferation, and the relationship between IL-17 and Th17. The significance of IL-17 in SLE and the potential of IL-17-targeted therapy are further discussed in detail.

CONCLUSION

IL-17 has a very high potential for the development as a star target in SLE.

Immunomodulatory Activity of Mesenchymal Stem Cells in Lupus Nephritis: Advances and Applications

Lupus nephritis (LN) is a significant cause of various acute and chronic renal diseases, which can eventually lead to end-stage renal disease. The pathogenic mechanisms of LN are characterized by abnormal activation of the immune responses, increased cytokine production, and dysregulation of inflammatory signaling pathways. LN treatment is an important issue in the prevention and treatment of systemic lupus erythematosus. Mesenchymal stem cells (MSCs) have the advantages of immunomodulation, anti-inflammation, and anti-proliferation. These unique properties make MSCs a strong candidate for cell therapy of autoimmune diseases. MSCs can suppress the proliferation of innate and adaptive immune cells, such as natural killer cells (NKs), dendritic cells (DCs), T cells, and B cells. Furthermore, MSCs suppress the functions of various immune cells, such as the cytotoxicity of T cells and NKs, maturation and antibody secretion of B cells, maturation and antigen presentation of DCs, and inhibition of cytokine secretion, such as interleukins (ILs), tumor necrosis factor (TNF), and interferons (IFNs) by a variety of immune cells. MSCs can exert immunomodulatory effects in LN through these immune functions to suppress autoimmunity, improve renal pathology, and restore kidney function in lupus mice and LN patients. Herein, we review the role of immune cells and cytokines in the pathogenesis of LN and the mechanisms involved, as well as the progress of research on the immunomodulatory role of MSCs in LN.

Treg cells in health and autoimmune diseases: New insights from single cell analysis

Autoimmune diseases, such as Systemic Lupus Erythematosus (SLE) or Rheumatoid Arthritis (RA) are characterized by the breakdown of immunological tolerance. Defects of regulatory T cells have been described among the various mechanisms, that are important for the development of autoimmune diseases, due to their critical role as regulators of peripheral immune tolerance and homeostasis. Initially T suppressor cells have been described as one population of peripheral T cells. Based on new technological advances a new understanding of the heterogeneity of different Treg cell populations in the lymphoid and non-lymphoid tissue has evolved over the last years. While initially Foxp3 has been defined as the main master regulator of Treg cells, we have learned that Treg cells from various tissue can be identified by a specific transcriptomic and epigenetic signature. Epigenetic mechanisms allow Treg cell stability, but we have also learned that certain Treg subsets are plastic and can under specific circumstances even enhance autoimmunity and inflammatory processes. Quantitative and functional defects of Treg cells have been observed in a variety of autoimmune diseases. Due to our understanding of the nature of this cell population, Treg cells have been a target of new Treg based therapies, such as low-dose IL-2. In addition, ongoing clinical trials aim to test safety and efficacy of transferred, in vitro expanded Treg cells in patients with autoimmune diseases and transplant patients.

Correlation of Blood FoxP3+ Regulatory T Cells and Disease Activity of Atopic Dermatitis

Objectives

To investigate CD4+CD25+FoxP3+ T regulatory cells (Tregs) in the peripheral blood of patients with atopic dermatitis (AD) and its correlation with disease severity.

Methods

Blood samples from 79 AD patients before and after four-week conventional treatment were collected. Cell counts of CD4+CD25+FoxP3+Tregs, CD4+CD25+FoxP3-T effector cells (Teffs), and CD4+IL-10+Tregs were analyzed by flow cytometry. Serum levels of IL-4, IL-10, IL-12, IL-13, IFN-γ, and TGF-β were measured by ELISA.

Results

The pretreatment cell count of CD4+CD25+FoxP3+Tregs positively correlated with disease severity in all patients (P < 0.0001). However, when that correlation was rechecked based on the treatment response, a much stronger correlation of that was found in those patients with remission after treatment, while no correlation of that was found in patients without remission. Both the cell count and proportions of peripheral CD4+CD25+FoxP3+Tregs and CD4+CD25+FoxP3-Teffs reduced significantly after treatment in patients with remission, but remained unchanged in patients without remission. The cell count and proportion of CD4+IL-10+Tregs did not change after treatment in both groups. In patients with remission, serum levels of IL-4 and IL-13 significantly reduced (all P < 0.05); IL-12 and IFN-γ levels increased significantly (all P < 0.05); IL-10 and TGF-β levels remained unchanged after treatment. None of those cytokine levels changed in patients without remission.

Conclusions

CD4+CD25+FoxP3+Tregs is associated with AD development and severity in some patients but not in others. AD maybe divided into CD4+CD25+FoxP3+Treg-associated subtype, which CD4+CD25+FoxP3+Treg is parallel to the activity of AD, and nonassociated subtype, which CD4+CD25+FoxP3+Treg is not related. This subgroup difference may contribute partly to the nonidentical markers that have been found in AD and should be studied further.

Treg cells in autoimmunity: from identification to Treg-based therapies

Regulatory (Treg) cells are key regulators of inflammation and important for immune tolerance and homeostasis. A major progress has been made in the identification and classification of Treg cells. Due to technological advances, we have gained deep insights in the epigenetic regulation of Treg cells. The use of fate reporter mice allowed addressing the functional consequences of loss of Foxp3 expression. Depending on the environment Treg cells gain effector functions upon loss of Foxp3 expression. However, the traditional view that Treg cells become necessarily pathogenic by gaining effector functions was challenged by recent findings and supports the notion of Treg cell lineage plasticity. Treg cell stability is also a major issue for Treg cell therapies. Clinical trials are designed to use polyclonal Treg cells as therapeutic tools. Here, we summarize the role of Treg cells in selected autoimmune diseases and recent advances in the field of Treg targeted therapies.

The role of IL-17 in systemic lupus erythematosus and its potential as a therapeutic target

INTRODUCTION

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by autoantibodies production and immune complex deposition with systemic clinical manifestations. Interleukin (IL)-17-producing cells play a crucial role in disease pathogenesis and represent an attractive therapeutic target. Areas covered: This review provides an update on the possibility of targeting IL-17 in SLE. The rational for this approach as well as currently available and future targets are discussed. Expert opinion: Although human expression studies and animal models indicate that IL-17 blocking may be a promising therapeutic strategy for SLE, direct evidence for IL-17 inhibition in SLE patients is unavailable. Biologic therapies and small-molecule drugs that target IL-17 production are required for the achievement of a favorable clinical effect in SLE patients.

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 CD127^low/∅. 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.

Regulatory T-cell levels in systemic lupus erythematosus patients: a meta-analysis

Background

The contribution of regulatory T-cells (Tregs) to systemic lupus erythematosus (SLE) pathogenesis remains a matter of debate. The objective of this study was to quantify the association between peripheral blood Tregs and disease status in SLE patients.

Method

EMBASE and PubMed databases were searched using ‘systemic lupus erythematosus’ and ‘regulatory T-cells’ as relevant key terms. A meta-analysis of studies that examined the proportion of Tregs among peripheral blood mononuclear cells (PBMCs) and CD4+T-cells was performed using Stata software. Subgroup analysis was performed based on ethnic groups and Treg definition markers.

Results

The Treg/PBMC and Treg/CD4+T-cell ratios were significantly lower in SLE patients than in healthy controls (HCs), whereas patients with active and inactive SLE showed no difference in these indicators. A subgroup analysis indicated that Asian SLE patients had a substantially lower proportion of Tregs/PBMCs than HCs, but this difference was not seen for white and Latin American SLE patients. Patients defined by CD4+CD25+Foxp3+, CD4+CD25+ and CD4+Foxp3+ had a much lower Treg/PBMC ratio compared with HCs. Ethnic groups and choice of Treg definition markers had no influence on the proportion of Tregs/CD4+T-cells.

Conclusion

The proportion of Tregs among both PBMCs and CD4+T-cells was significantly decreased in SLE patients. Ethnic group and Treg definition markers may influence the proportion of Tregs among PBMCs. Further study of the correlation between SLE disease activity and the proportion of Tregs in peripheral blood is needed to determine the physiological role of this association.

Belimumab restores Treg/Th17 balance in patients with refractory systemic lupus erythematosus

Belimumab, a specific inhibitor of the soluble B lymphocyte stimulator (BlyS), is the first biological drug approved by the United States Food and Drug Administration for the treatment of patients with active systemic lupus erythematosus (SLE) refractory to standard therapy. Given that an imbalance between regulatory T cells (Treg) and interleukin (IL)-17A-secreting T cells (Th17) has been reported in various autoimmune disorders, we assessed the frequency of both Treg and Th17 peripheral blood populations before and after belimumab administration in 20 patients with active SLE refractory to standard therapy. After six months of treatment, the mean SELENA-SLEDAI score as well as the mean anti-double-stranded DNA antibody titers were significantly decreased. In addition, we observed a significant increase in Treg percentages and a parallel, significant decrease in Th17 percentages, accompanied by significantly reduced serum levels of IL-21. In vitro studies showed that Treg purified from belimumab-treated patients were fully functional and displayed a suppressor function similar to that of Treg purified from healthy donors. Belimumab can restore Treg/Th17 balance in SLE patients with uncontrolled disease activity, and this results in decreased flare rate and reduced glucocorticoid dosage.

The Proportion of Regulatory T Cells in Patients with Systemic Lupus Erythematosus: A Meta-Analysis

Background

Accumulating evidence indicates that a deficiency in or dysfunction of regulatory T cells (Tregs) is involved in the pathogenesis of systemic lupus erythematosus (SLE). As different markers have been used to identify Tregs, recent studies on the proportions of Tregs in SLE patients have generated controversial results. To clarify the status of Tregs in such patients, we determined the proportions of Tregs present during development of the disease, with special consideration of controversial cellular markers.

Methods

We identified studies reporting the proportions of Tregs in SLE patients by searching relevant databases through March 2018. Using the PRISMA guidelines, we performed a random effects meta-analysis of the frequencies of Tregs defined in different ways. Inconsistency was evaluated using the I-squared index (I²), and publication bias was assessed by examining funnel plot asymmetry using the Begger and Egger tests.

Results

Forty-four studies involving 2779 participants were included in the meta-analysis. No significant difference in the proportions of Tregs was evident between 1772 patients and 1007 controls [−0.191, (−0.552, 0.362), p = 0.613, I² = 95.7%]. We next conducted subanalyses based on individual definitions of Tregs. When the Treg definition included “FOXP3-positive” cells, the proportions did not differ between SLE patients and controls [−0.042, (−0.548, 0.632), p = 0.889, I² = 96.6%]; this was the case when Tregs were defined as either “CD25^low/−FOXP3⁺” or “CD25^high/+FOXP3⁺” cells. SLE patients had lower proportions of Tregs that were “single CD25-positive” [−1.428, (−1.982, −0.873), p < 0.001, I² = 93.4%] and “CD127-negative” [−1.093, (−2.002, −0.183), p = 0.018, I² = 92.6%] compared to controls. Tregs defined as “CD25^bright,” “CD25^bright/highCD127^low/−,” and “CD25^highCD127^low/−FOXP3⁺” did not differ in proportion between SLE patients and controls.

Conclusions

The Treg proportions varied by the cellular identification method used. The proportions of Tregs that were accurately identified and functionally validated fell among patients with SLE. Stricter definitions of Tregs are necessary when evaluating the status of such patients.

From autoinflammation to autoimmunity: old and recent findings

Autoimmune diseases and autoinflammatory diseases have a number of similar etiopathogenetic and clinical characteristics, including genetic predisposition and recurrent systemic inflammatory flares. The first phase of ADs involves innate immunity: by means of TLRs, autoantigen presentation, B and T cell recruitment and autoantibody synthesis. The second phase involves adaptive immunity, a self-sustaining process in which immune complexes containing nucleic acids and autoantibodies activate self-directed inflammation. The link between autoimmunity and autoinflammation is IL-1ß, which is crucial in connecting the innate immune response due to NLR activation and the adaptive immune responses of T and B cells. In conclusion, although ADs are still considered adaptive immunity-mediated disorders, there is increasing evidence that innate immunity and inflammasomes are also involved. The aim of this review is to highlight the link between the innate and adaptive immune mechanisms involved in autoimmune diseases.

Novel genetic marker in TGFB2 gene associated with expression of TGF-β2 in leukocyte and SLE susceptibility

Background: TGF-β2 has a role in immune regulation, and genetic variance within the gene might contribute to systemic lupus erythematosus (SLE) pathogenesis. The TGFB2 gene is one candidate gene within the major SLE genetic susceptibility loci. Objective: Investigate the TGFB2 gene located on chromosome 1q41 as a SLE susceptibility gene. Materials and methods: One hundred fifty three SLE patients and 133 healthy controls participated in this study. Four markers selected in two haplotype blocks that have a minor allele frequency greater than 5% in Thai population were genotyped and analyzed in the association study. Results: There was no significant association between SLE susceptibility and the polymorphism in the promoter area (+67_68insACAA) and +89835 (A/G) at the intron 5 of TGFB2 gene. Instead, minor allele of the two new genetic markers at the intron 1 (+720) (corrected p-value = 0.024, OR = 0.4141, 95%CI = 0.22-0.80) and intron 6 (+94399_94400) (corrected p-value = 0.000143, OR = 0.3367, 95%CI = 0.20-0.58) were independently associated as a protective factor to SLE. Additionally, the real time RT-PCR results showed that patients with the protective allele (minor allele) at the +94399_94400 position have higher TGF-β2 mRNA level in leukocytes than patients with the risk allele (p=0.011). Conclusion: Two new genetic markers at intron1 (+720) and intron 6 (+94399_94400) were independently associated with SLE. The observed results have to be confirmed in other populations with a large sample size.

The Yin and Yang of regulatory T cell and therapy progress in autoimmune disease

Autoimmune diseases (ADs) are primarily mediated by the failure of immunological self-tolerance. Regulatory T cells (Tregs) play a critical role in the maintenance of induced tolerance to peripheral self-antigens, suppressing immoderate immune responses deleterious to the host and preventing the AD development. Tregs and suppressive cytokines are homeostatic with effective cells plus pro-inflammatory cytokines in healthy hosts which is defined as "Yang", and ADs are usually induced in case of disturbed homeostasis, which is defined as "Yin". Indeed, the Yin-Yang balance could explain the pathogenic mechanism of ADs. Tregs not only suppress CD4⁺ and CD8⁺ T cells but also can suppress other immune cells such as B cell, natural killer cell, DC and other antigen-presenting cell through cell-cell contact or secreting suppressive cytokines. In Tregs, Foxp3 as an intracellular protein displays a more specific marker than currently used other cell-surface markers (such as CD25, CD40L, CTLA-4, ICOS and GITR) in defining the naturally occurring CD4⁺ Tregs. Though the precise mechanism for the opposite effects of Tregs has not been fully elucidated, the importance of Tregs in ADs has been proved to be associated with kinds of immunocytes. At present, the surface marker, frequency and function of Tregs existed conflicts and hence the Tregs therapy in ADs faces challenges. Though some success has been achieved with Tregs therapy in few ADs both in murine models and humans, more effort should paid to meet the future challenges. This review summarizes the progress and discusses the phenotypic, numeric and functional abnormalities of Tregs and is the first time to systematically review the progress of Tregs therapy in kinds of ADs.

Y-27632, a Rho-associated protein kinase inhibitor, inhibits systemic lupus erythematosus

The purpose of the present study was to evaluate whether Rho-kinase inhibition (Y-27632) modulated the expressions of nuclear factor kappaB (NF-κB) in systemic lupus erythematosus. 20 wild type mice and 20 MRL/lpr mice were applied for the research. The animals were randomly assigned to wild type, wild type+Y-27632 group, MRL/lpr group and MRL/lpr+Y-27632 group. 5mg/kg Y-27632 was intravenously injected to inhibit the ROCK expressions.Y-27632 significantly decreased the serum levels of interleukin-6 (IL-6), IL-1β, tumor necrosis factor-α (TNF-α) and increased IL-10 level in serum of MRL/lpr mice. Flow cytometry (FCM) studies also showed that Y-27632 remarkably increased Regulatory cells(Treg) cell percentage in spleen cells. Western blot analysis demonstrated Y-27632 downregulated the expressions of ROCK1, ROCK2, upregulated the expression of forkhead/winged helix transcription factor(Foxp3), and inhibited the phosphorylations of NF-κBp65 and IκBα. The findings showed that the inhibition of ROCK was beneficial for the prevention of systemic lupus erythematosus, which possibly by suppressing NF-κB activation.

Regulatory T cells in immune-mediated renal disease

Regulatory T cells (Tregs) are CD4+ T cells that can suppress immune responses by effector T cells, B cells and innate immune cells. This review discusses the role that Tregs play in murine models of immune-mediated renal diseases and acute kidney injury and in human autoimmune kidney disease (such as systemic lupus erythematosus, anti-glomerular basement membrane disease, anti-neutrophil cytoplasmic antibody-associated vasculitis). Current research suggests that Tregs may be reduced in number and/or have impaired regulatory function in these diseases. Tregs possess several mechanisms by which they can limit renal and systemic inflammatory immune responses. Potential therapeutic applications involving Tregs include in vivo induction of Tregs or inducing Tregs from naïve CD4+ T cells or expanding natural Tregs ex vivo, to use as a cellular therapy. At present, the optimal method of generating a phenotypically stable pool of Tregs with long-lasting suppressive effects is not established, but human studies in renal transplantation are underway exploring the therapeutic potential of Tregs as a cellular therapy, and if successful may have a role as a novel therapy in immune-mediated renal diseases.

CD4(+)CD25(+)CD127(-) and CD4(+)CD25(+)Foxp3(+) Regulatory T Cell Subsets in Mediating Autoimmune Reactivity in Systemic Lupus Erythematosus Patients

The available clinical as well as experimental studies implicate participation of T regulatory (Treg) subsets in the pathogenesis and course of systemic lupus erythematosus (SLE). Introduction of the CD4(+)CD25(+)CD127(-) and CD4(+)CD25(+)Foxp3(+) regulatory subpopulations analysis into immunological processes assessment and disease activation prognosis in patients with lupus nephritis (LN) may improve monitoring of disease activity and enable an early, and thus more effective, therapeutic treatment. The main goal of the study was to investigate whether the quantitative changes of Treg subpopulations are related to the clinical status of patients with LN. Fifty-four adult SLE patients divided into two groups according to their SLEDAI and renal SLEDAI scores were enrolled into the study. Subpopulations of CD4(+)CD25(+)CD127(-) and CD4(+)CD25(+)Foxp3(+) phenotypes were determined by flow cytometry. The control group had higher absolute number of CD4(+)CD25(+)Foxp3(+) cells compared with the study group (p < 0.001). Also, significant inverse correlation in the absolute number of CD4(+)CD25(+)Foxp3(+) cells and SLEDAI score was observed. There were significant differences in the percentage and absolute number of CD4(+)CD25(+)Foxp3(+) lymphocytes between active and non-active LN groups. The study group had statistically lower values of CD4(+)CD25(+)CD127(-) cells, both in the percentage (p < 0.001) as well as their absolute number (p = 0.014) compared to the control group. There were also statistically significant positive correlations between the absolute number of CD4(+)CD25(+)CD127(-) and CD4(+)CD25(+)Foxp3(+) Tregs.

IN CONCLUSION

(1) reduction in the number of regulatory CD4(+)CD25(+)Foxp3(+) cells is a promising indicator of the activity of SLE, particularly of renal involvement; (2) determination of the number of regulatory cells using the CD4(+)CD25(+)CD127(-) phenotype is unreliable in patients with SLE.

Cytokine Milieu in Undifferentiated Connective Tissue Disease: a Comprehensive Review

Undifferentiated connective tissue disease (UCTD) is a unique clinical entity, a potential forerunner of well-established systemic autoimmune/rheumatic diseases. UCTD is characterized by the presence of various clinical symptoms, as well as a diverse repertoire of autoantibodies, resembling systemic autoimmune diseases. Since approximately one third of these patients consequently transform into a full-blown systemic autoimmune/rheumatic disease, it is of major importance to assess pathogenic factors leading to this progression. In view of the fact that the serological and clinical picture of UCTD and systemic autoimmune diseases are very similar, it is assumed that analogous pathogenic factors perpetuate both disease entities. In systemic autoimmune conditions, a quantitative and qualitative impairment of regulatory T cells has been shown previously, and in parallel, a relative dominance of pro-inflammatory Th17 cells has been introduced. Moreover, the imbalance between regulatory and Th17 cells plays a pivotal role in the initiation and propagation of UCTD. Additionally, we depict a cytokine imbalance, which give raise to a biased T cell homeostasis from the UCTD phase throughout the fully developed systemic autoimmune disease stage. The levels of interleukin (IL)-6, IL-12, IL-17, IL-23, and interferon (IFN)-γ were pathologically increased with a parallel reduction of IL-10. We believe that the assessment of Th17/Treg cell ratio, as well as the simultaneous quantitation of cytokines may give a useful diagnostic tool at the early UCTD stage to identify patients with a higher chance of consecutive disease progression toward serious systemic autoimmune diseases. Moreover, the early targeted immunomodulating therapy in these patients may decelerate, or even stop this progression, before the development of serious autoimmune conditions with organ damage.

Autoimmune Liver Disease Post-Liver Transplantation: A Summary and Proposed Areas for Future Research

Autoimmune liver diseases (AILD) are rare diseases with a reported prevalence of less than 50 per 100 000 population. As the research landscape and our understanding of AILDs and liver transplantation evolves, there remain areas of unmet needs. One of these areas of unmet needs is prevention of disease recurrence after liver transplantation. Disease recurrence is not an insignificant event because allograft loss with the need for retransplantation can occur. Patients transplanted for AILD are more likely to experience acute rejection compared to those transplanted for non-AILD, and the reason(s) behind this observation is unclear. Tasks for the future include a better understanding of the pathogenesis of AILD, definition of the precise pathogenetic mechanisms of recurrent AILD, and development of strategies that can identify recipients at risk for disease recurrence. Importantly, the role of crosstalk between alloimmune responses and autoimmune responses in AILD is an important area that needs further study.

This article reviews the relevant literature of de novo autoimmune hepatitis, recurrent autoimmune hepatitis, recurrent primary sclerosing cholangitis, and recurrent primary biliary cirrhosis in terms of the clinical entity, the scientific advancements, and future scientific goals to enhance our understanding of these diseases.

A review of the relevant literature of de novo autoimmune hepatitis, recurrent autoimmune hepatitis, recurrent primary sclerosing cholangitis, and recurrent primary biliary cirrhosis in terms of the clinical entity, the scientific advancements and future scientific goals to enhance our understanding of these diseases.

Regulatory T cells in kidney disease and transplantation

Regulatory T cells (Tregs) have been shown to be important in maintaining immune homeostasis and preventing autoimmune disease, including autoimmune kidney disease. It is also likely that they play a role in limiting kidney transplant rejection and potentially in promoting transplant tolerance. Although other subsets of Tregs exist, the most potent and well-defined Tregs are the Foxp3 expressing CD4(+) Tregs derived from the thymus or generated peripherally. These CD4(+)Foxp3(+) Tregs limit autoimmune renal disease in animal models, especially chronic kidney disease, and kidney transplantation. Furthermore, other subsets of Tregs, including CD8 Tregs, may play a role in immunosuppression in kidney disease. The development and protective mechanisms of Tregs in kidney disease and kidney transplantation involve multiple mechanisms of suppression. Here we review the development and function of CD4(+)Foxp3(+) Tregs. We discuss the specific application of Tregs as a therapeutic strategy to prevent kidney disease and to limit kidney transplant rejection and detail clinical trials in this area of transplantation.

T cells and IL-17 in lupus nephritis

Systemic lupus erythematosus (SLE) is a complicated autoimmune disorder characterized by autoantibodies production, immune complex formation, and immune dysregulation, resulting in damage of multiple organs including the kidney. Lupus nephritis (LN) is the most common severe manifestation of SLE involving the majority of patients. Even though there are a number of reports indicating that interleukin-17 (IL-17) and Th17 cells play important roles in the pathogenesis of LN, the precise molecular mechanisms underline the development of LN have not been totally elucidated. In this review, we briefly summarize general characteristics of T and IL-17 cells in SLE. In addition, we discuss in detail T cell signaling pathways which control IL-17 production in patients with LN and in glomerulonephritis in lupus-prone mice. A better understanding of signaling and gene regulation defects in LN will lead to the identification of novel therapeutic targets and predictive biomarkers for diagnosis and prognosis of this disease.

Circulating level of regulatory T cells in rheumatic heart disease: An observational study

BACKGROUND

The regulatory T cell (Treg) is essential for prevention of autoimmunity. In a preliminary study, we showed significant deficiency of Tregs (CD4CD25 T cells) in rheumatic heart disease (RHD) patients (an autoimmune disease), but the markers used could not reliably differentiate Treg from nonregulatory conventional T cells (Tcon). The study aim was to reassess the level of circulatory Tregs by using more specific markers.

METHODS

70 adults of RHD and 35 controls were studied. Patients were subdivided according to the extent of left-sided valvular involvement. 35 patients with significant mitral-valve disease only were enrolled in the univalvular group while 35 patents with significant involvement of both mitral and aortic-valves in the multivalvular group. Circulating Treg cell level was determined by flow-cytometry.

RESULTS

Level of Tregs (CD4+CD25(med-high)CD127(low) Foxp3(high)) in CD4+ T lymphocyte was significantly lower in RHD patients compared to controls (median 0.6% versus 3.2%; p=0.001) with no significant difference in Tcon cells (p=0.94). Within the study group Treg count was significantly lower in patients with multivalvular-disease only (median 0.1% versus 3.2%; p=0.001) with no significant difference in Treg cell count between the univalvular group and control (median 1.9% versus 3.2%, p=0.10).

CONCLUSION

There is significant deficiency of circulating Tregs in patients of chronic RHD and the deficiency is greater in patients with multivalvular than univalvular involvement.

Effects of royal jelly supplementation on regulatory T cells in children with SLE

BACKGROUND AND OBJECTIVE

To our knowledge, no previous studies have focused on the immunomodulatory effects of fresh royal jelly (RJ) administration on systemic lupus erythematosus (SLE) in humans. Our aim was to study the effect of fresh RJ administration on the disease course in children with SLE with some immunological markers (CD4⁺ and CD8⁺ regulatory T cells and T lymphocytes apoptosis).

METHODS

This was an open-label study in which 20 SLE children received 2 g of freshly prepared RJ daily, for 12 weeks.

RESULTS

The percentages of CD4⁺ CD25^+high FOXP3⁺cells (CD4⁺ regulatory T cells) and CD8⁺CD25^+high FOXP3⁺cells (CD8⁺ regulatory T cells) were significantly increased after RJ treatment when compared with baseline values. Apoptotic CD4 T lymphocytes were significantly decreased after RJ therapy when compared with baseline values and the control group.

CONCLUSION

This is the first human study on the effect of RJ supplementation in children with SLE. Our results showed improvements with 3-month RJ treatment with regard to the clinical severity score and laboratory markers for the disease. At this stage, it is a single study with a small number of patients, and a great deal of additional wide-scale randomized controlled studies are needed to critically validate the efficacy of RJ in SLE.

T cells as a therapeutic target in SLE

Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease characterized by a loss of tolerance to multiple endogenous antigens. SLE etiology remains largely unknown, despite recent insight into the immunopathogenesis of the disease. T cells are important in the development of the disease by amplifying the immune response and contributing to organ damage. Aberrant signaling, cytokine secretion, and tissue homing displayed by SLE T cells have been extensively studied and the underlying pathogenic molecular mechanisms are starting to be elucidated. T-cell-targeted treatments are being explored in SLE patients. This review is an update on the T-cell abnormalities and related therapeutic options in SLE.

Selected Aspects in the Pathogenesis of Autoimmune Diseases

Autoimmune processes can be found in physiological circumstances. However, they are quenched with properly functioning regulatory mechanisms and do not evolve into full-blown autoimmune diseases. Once developed, autoimmune diseases are characterized by signature clinical features, accompanied by sustained cellular and/or humoral immunological abnormalities. Genetic, environmental, and hormonal defects, as well as a quantitative and qualitative impairment of immunoregulatory functions, have been shown in parallel to the relative dominance of proinflammatory Th17 cells in many of these diseases. In this review we focus on the derailed balance between regulatory and Th17 cells in the pathogenesis of autoimmune diseases. Additionally, we depict a cytokine imbalance, which gives rise to a biased T-cell homeostasis. The assessment of Th17/Treg-cell ratio and the simultaneous quantitation of cytokines, may give a useful diagnostic tool in autoimmune diseases. We also depict the multifaceted role of dendritic cells, serving as antigen presenting cells, contributing to the development of the pathognomonic cytokine signature and promote cellular and humoral autoimmune responses. Finally we describe the function and role of extracellular vesicles in particular autoimmune diseases. Targeting these key players of disease progression in patients with autoimmune diseases by immunomodulating therapy may be beneficial in future therapeutic strategies.

Increased Tim-3 expression on peripheral T lymphocyte subsets and association with higher disease activity in systemic lupus erythematosus

Background

Both the T cell immunoglobulin domain- and mucin domain-containing molecule-3 (Tim-3) and the death receptor Fas contribute to the pathogenesis of various autoimmune diseases, including systemic lupus erythematosus (SLE). The aim of the present study was to determine whether Tim-3 and Fas are co-expressed on certain peripheral T lymphocyte subsets, and whether this expression is associated with greater disease activity in SLE.

Methods

Peripheral blood mononuclear cells were isolated from 46 patients newly diagnosed with SLE and 28 age- and sex-matched healthy controls (HCs). Expression of Tim-3 and Fas on T subsets was analyzed by flow cytometry, while mRNA levels of the Tim-3 ligand galectin-9 and Fas ligand FasL were assayed using real-time RT-PCR.

Results

The proportions of CD3⁺CD4⁺ and CD3⁺CD4^- T cells expressing Tim-3⁺ and Tim⁺Fas⁺ were significantly higher in patients than in HCs (p < 0.05), while the proportions of these subtypes expressing Fas were similar for the two groups. Patients with active SLE, as defined by their score on the SLE Disease Activity Index, had lower proportions of CD3⁺CD4⁺ T cells and higher proportions of CD3⁺CD4⁺Tim-3⁺ and CD3⁺CD4⁺Tim-3⁺Fas⁺ T cells than did patients with stable SLE. Serum levels of complement C3 and C4 proteins, considered as a marker of SLE activity, correlated negatively with proportions of CD3⁺CD4⁺ and CD3⁺CD4^- T cells expressing Tim-3.

Conclusions

Expression of Tim-3 and co-expression of Tim-3 and Fas on certain peripheral T subsets are associated with disease activity in SLE patients. Future research should examine whether the same is true of other T subsets implicated in SLE, and should explore the potential role(s) of Tim-3 in the disease pathway.

Virtual slides

http://www.diagnosticpathology.diagnomx.eu/vs/1855527845145188

Pathological conditions re-shape physiological Tregs into pathological Tregs

CD4⁺FOXP3⁺ regulatory T cells (Tregs) are a subset of CD4 T cells that play an essential role in maintaining peripheral immune tolerance, controlling acute and chronic inflammation, allergy, autoimmune diseases, and anti-cancer immune responses. Over the past 20 years, significant progress has been made since Tregs were first characterized in 1995. Many concepts and principles regarding Tregs generation, phenotypic features, subsets (tTregs, pTregs, iTregs, and iTreg35), tissue specificity (central Tregs, effector Tregs, and tissue resident Tregs), homeostasis (highly dynamic and apoptotic), regulation of Tregs by receptors for PAMPs and DAMPs, Treg plasticity (re-differentiation to other CD4 T helper cell subsets, Th1, Th2, Tfh and Th17), and epigenetic regulation of Tregs phenotypes and functions have been innovated. In this concise review, we want to briefly analyze these eight new progresses in the study of Tregs. We have also proposed for the first time a novel concept that "physiological Tregs" have been re-shaped into "pathological Tregs" in various pathological environments. Continuing of the improvement in our understanding on this important cellular component about the immune tolerance and immune suppression, would lead to the future development of novel therapeutics approaches for acute and chronic inflammatory diseases, allergy, allogeneic transplantation-related immunity, sepsis, autoimmune diseases, and cancers.

Regulatory T cells: regulators of life

Pregnancy still represents one of the most fascinating paradoxical phenomena in science. Immediately after conception, the maternal immune system is challenged by the presence of foreign paternal antigens in the semen. This triggers mechanisms of recognition and tolerance that all together allow the embryo to implant and later the fetus to develop. Tolerance mechanisms to maintain pregnancy are of special interest as they defy the classical immunology rules. Several cell types, soluble factors, and immune regulatory molecules have been proposed to contribute to fetal tolerance. Within these, regulatory T cells (Treg) are one of the most studied immune cell populations lately. They are reportedly involved in fetal acceptance. Here, we summarize several aspects of Treg biology in normal and pathologic pregnancies focusing on Treg frequencies, subtypes, antigen specificity, and activity as well as on factors influencing Treg generation, recruitment, and function. This review also highlights the contribution of fetal Treg in tolerance induction and addresses the role of Treg in autoimmune diseases and infections during gestation. Finally, the potential of Treg as a predictive marker for the success of assisted reproductive techniques and for therapeutic interventions is discussed.

Regulatory T-cell differentiation and their function in immune regulation

Regulatory T-cells (Treg) represent a subset of CD4+ T-cells characterized by high suppressive capacity, which can be generated in the thymus or induced in the periphery. The deleterious phenotype of the Scurfy mouse, which develops an X-linked lymphoproliferative disease resulting from defective T-cell tolerance, clearly demonstrates the importance of Treg cells for the maintenance of immune homeostasis. Although significant progress has been achieved, much information regarding the development, characteristics and function of Treg cells remain lacking. This chapter highlights the most recent discoveries in the field of Treg biology, focusing on the development and role of this cell subset in the maintenance of immune balance.

Immunotargeting and eradication of orthotopic melanoma using a chemokine-enhanced DNA vaccine

DNA vaccines are attractive candidates for tumor immunotherapy. However, the potential of DNA vaccines in treating established malignant lesions has yet to be demonstrated. Here we demonstrate that transient alteration of either intratumoral or intradermal (ID) chemotactic gradients provide a favorable milieu for DNA vaccine-mediated activation of tumor-specific immune response in both prophylactic and therapeutic settings. Specifically, we show that priming of established B16 ID melanoma lesions via forced intratumoral expression of CCL21 boosted DNA vaccination-dependent systemic cytotoxic immune response leading to the regression of tumor nodules. In this setting, application of CCL20 was not effective likely due to the engagement of the regulatory T cells. However, priming of the skin at DNA vaccine administration sites outside the tumor bed with both CCL20 and CCL21 chemokines along with structural modifications of the DNA vaccine significantly improved vaccine efficacy. This optimized ID vaccination regimen led to the inhibition of distant established melanomas and prolonged tumor-free survival of mice observed in 60% of vaccinated animals with complete tumor remission in 30%. These effects were mediated by extranodal priming and activation of T cells at vaccine administration sites and progressive accumulation of systemic antigen-specific cytotoxic T cells (CTLs) on successive vaccinations. These results underscore the potential of chemokine-enhanced DNA vaccination to mount therapeutic immune response against established tumors.

Regulatory T cells in systemic lupus erythematosus and pregnancy

Systemic lupus erythematosus (SLE) is a chronic multisystem autoimmune disorder that predominantly affects women of reproductive age. As clinical outcomes improve, pregnancy in these women is becoming more common. Although epidemiological data have documented an improvement in the prognosis of pregnancy in these women over recent years, they are still at significantly increased risk of pregnancy complications, such as miscarriage, stillbirth, pre-eclampsia and impaired foetal growth. The pathogenesis of SLE involves marked immune dysfunction, and in particular, the function of immunosuppressive elements of the immune system is impaired, including regulatory T-cell function. Because regulatory T cells are likely to be the key cell-modulating feto-maternal tolerance, this review overviews the possibility that regulatory T-cell impairments contribute to pregnancy pathology in women with SLE and contribute to the clinical challenge of managing these women during pregnancy.

Calcium/calmodulin-dependent protein kinase IV suppresses IL-2 production and regulatory T cell activity in lupus

The activity of calcium/calmodulin-dependent protein kinase IV (CaMK4) is increased in T cells from patients with systemic lupus erythematosus (SLE) and has been shown to reduce IL-2 production by promoting the effect of the transcriptional repressor cAMP responsive element modulator-α on the IL2 promoter. In this article, we demonstrate that T cells from MRL/lpr mice display increased levels of CaMK4 in the nucleus, and that genetic deletion of Camk4 results in improved survival. We demonstrate that absence of CaMK4 restores IL-2 production, curbs increased T cell activation, and augments the number and activity of regulatory T cells. Analogously, silencing of CaMK4 in T cells from patients with SLE increases the expression of FoxP3 on stimulation in the presence of TGF-β. Our results demonstrate the importance of the serine/threonine kinase CaMK4 in the generation and function of regulatory T cells in patients with SLE and lupus-prone mice, and its potential to serve as a therapeutic target.

NK cell count as predictor of clinical response in patients with rheumatoid arthritis treated with rituximab

Purpose

The relationship between antiCD20 therapy with rituximab and the lymphocytes phenotype in patients with rheumatoid arthritis was investigated, with an attempt to establish a relationship between commonly used clinical activity indices and variations in leukocyte count, in particular natural killer (NK) lymphocytes.

Methods

Patients with seropositive (cyclic citrullinated peptides and rheumatoid factor positive) rheumatoid arthritis (according to the American College of Rheumatology 1987 criteria) refractory to conventional and antitumor necrosis factor-alpha agents who were subsequently treated with rituximab, a chimeric monoclonal antibody directed against CD20, were enrolled between January 2009 and September 2009. All subjects were treated with rituximab standard rheumatologic dose of 1.0 g on days 1 and 15 every 6 months for at least 2 years. A clinical evaluation was performed at baseline and subsequently every 3 months thereafter. At each assessment activated NK (CD56+/CD16+/CD54bright) cell count was collected and disease activity was assessed using Disease Activity Score in 28 Joints and the Simplified Disease Activity Index (SDAI).

Results

Thirty-four patients were enrolled (mean age ± standard deviation: 54.8 ± 12.8 years). Basal SDAI was 21.75 ± 5.4 and NK cell count mean value was 157.6 ± 90. After 24 months, SDAI was 14 ± 1.2 and NK cell count mean value was 301.7 ± 21 (P < 0.05). An inverted correlation between SDAI and NK count was observed at 3 months (r = −0.36, P < 0.05), 6 months (r = −0.48, P < 0.45), 9 months (r = −0.47, P < 0.05), 12 months (r = −0.41, P < 0.01), 15 months (r = −0.58, P < 0.05), 18 months (r = −0.53, P < 0.05), 21 months (r = −0.68, P < 0.05), and 24 months (r = −0.61, P < 0.05). A linear regression model between all variables collected and SDAI/Disease Activity Score in 28 Joints at 6 months and 12 months confirmed a significant relationship between SDAI/Disease Activity Score in 28 Joints and NK cell count.

Conclusion

The data confirm the clinical efficacy of rituximab and suggests the use of NK cells as a predictor of clinical response in patients with rheumatoid arthritis.

Increased CD45RA+ FoxP3(low) regulatory T cells with impaired suppressive function in patients with systemic lupus erythematosus

BACKGROUND

The role of naturally occurring regulatory T cells (Treg) in the control of the development of systemic lupus erythematosus (SLE) has not been well defined. Therefore, we dissect the phenotypically heterogeneous CD4(+)FoxP3(+) T cells into subpopulations during the dynamic SLE development. METHODLOGY/PRINCIPAL FINDINGS: To evaluate the proliferative and suppressive capacities of different CD4(+) T cell subgroups between active SLE patients and healthy donors, we employed CD45RA and CD25 as surface markers and carboxyfluorescein diacetatesuccinimidyl ester (CFSE) dilution assay. In addition, multiplex cytokines expression in active SLE patients was assessed using Luminex assay. Here, we showed a significant increase in the frequency of CD45RA(+)FoxP3(low) naive Treg cells (nTreg cells) and CD45RA(-)FoxP3(low) (non-Treg) cells in patients with active SLE. In active SLE patients, the increased proportions of CD45RA(+)FoxP3(low) nTreg cells were positively correlated with the disease based on SLE disease activity index (SLEDAI) and the status of serum anti-dsDNA antibodies. We found that the surface marker combination of CD25(+)CD45RA(+) can be used to defined CD45RA(+)FoxP3(low) nTreg cells for functional assays, wherein nTreg cells from active SLE patients demonstrated defective suppression function. A significant correlation was observed between inflammatory cytokines, such as IL-6, IL-12 and TNFα, and the frequency of nTreg cells. Furthermore, the CD45RA(+)FoxP3(low) nTreg cell subset increased when cultured with SLE serum compared to healthy donor serum, suggesting that the elevated inflammatory cytokines of SLE serum may promote nTreg cell proliferation/expansion.

CONCLUSIONS/SIGNIFICANCE

Our results indicate that impaired numbers of functional CD45RA(+)FoxP3(low) naive Treg cell and CD45RA(-)FoxP3(low) non-suppressive T cell subsets in inflammatory conditions may contribute to SLE development. Therefore, analysis of subsets of FoxP3(+) T cells, using a combination of FoxP3, CD25 and CD45RA, rather than whole FoxP3(+) T cells, will help us to better understand the pathogenesis of SLE and may lead to the development of new therapeutic strategies.

Regulatory T cells in systemic lupus erythematosus (SLE); role of peptide tolerance

Regulatory T cells play an important role in the maintenance and regulation of immune tolerance and in the prevention of autoimmunity. Recent studies have demonstrated a deficiency in number and function of regulatory T cells in lupus and other autoimmune diseases. This may contribute to immune dysregulations and a defect in self-tolerance mechanisms. How to balance and "reset" the immune response from harmful pro-inflammatory to beneficial anti-inflammatory is the current strategy of the research. In this regard, several studies have been performed with various peptides, drugs, steroids and epigenetic agents to induce or modify regulatory cells and some measure of success has been achieved in the animal model of SLE and with lupus patient cells. Challenges ahead include the heterogeneous nature, phenotype and function of regulatory cells and the difficulties in manipulation of regulatory function in healthy versus diseased states. In this review, we will provide some recent findings indicating challenges and potential benefits of targeting of regulatory T cells in lupus.

Regulatory T-cells in systemic lupus erythematosus and rheumatoid arthritis

Regulatory T-cells (Tregs) are the guardians of peripheral tolerance acting to prevent autoimmune diseases such as systemic lupus erythomatosus (SLE) and rheumatoid arthritis (RA). Defects in Tregs have been reported in these two diseases despite significant differences in their clinical phenotype and pathogenesis. In both diseases the potency of Treg fails to keep pace with the activation of effector cells and are unable to resist the ensuing inflammation. This review will discuss the phenotypic, numeric, and functional abnormalities in Tregs and their role in patients and murine models of SLE and RA.

Malignant lymphomas and autoimmunity-a single center experience from Hungary

Autoimmune diseases and malignant lymphomas have numerous similarities in their etiology and pathogenesis. Patients with autoimmune disorders have increased risk to develop non-Hodgkin's lymphomas, yet little is known about the occurrence of autoimmune features within lymphoma patients. Our aim was to examine the prevalence of autoimmune diseases among patients with non-Hodgkin's (NHL) and Hodgkin's lymphoma (HL). We reviewed 352 patients' charts with malignant lymphomas to assess the rate of associated autoimmune diseases. Of 231 NHL patients, 30 (12.9%) had autoimmune disorders, while there were 11 patients who suffered from more than one disease entity. It was Sjögren's syndrome that occurred in the largest number (eight cases), other frequent entities were undifferentiated connective tissue disease (seven), thyroiditis (six), rheumatoid arthritis (four), and systemic vasculitis (four). The female/male ratio was significantly different between patients with or without autoimmune diseases, while no other clinical features differed significantly between the two groups. Ten patients (33.3%) were initially diagnosed with lymphoma, 13 (43.3%) of them had already been diagnosed with autoimmune disease at the time of lymphoma occurrence. Six patients (20%) with previously diagnosed immunological disorder developed new autoimmune condition after the treatment of lymphoma. Lymphoma and autoimmune disease occurred simultaneously in one patient. Among the 121 HL patients, 14 (11.5%) had associated autoimmune disease. Ten patients developed thyroiditis after the lymphoma treatment, two had immune thrombocytopenia, and one had autoimmune hemolytic anemia. One female patient was diagnosed with systemic sclerosis 10 years before the onset of HL. Our results highlight that an increased risk for the development of autoimmune diseases should be considered in patients both with NHL and HL.

Expression and functional role of HLA-G in immune cells from patients with systemic lupus erythematosus

Human leukocyte antigen (HLA)-G is a class I non-classical HLA molecule with an important regulatory role on the immune response. The possible role of this molecule in the pathogenesis of SLE has not been explored. In this work, we evaluated the expression and function of HLA-G in SLE patients. We studied 37 SLE patients as well as 25 healthy donors. Peripheral blood monocytes and in vitro-generated dendritic cells (DCs) were analyzed for HLA-G expression by flow cytometry. We found that monocytes from SLE patients as well as mature CD83+ DCs showed a diminished expression of HLA-G compared with healthy controls. In addition, monocytes from SLE patients showed a diminished induction of HLA-G expression in response to stimulation with IL-10. Furthermore, functional assays showed that these monocytes pre-treated with IFN-γ exhibited a diminished capability to inhibit the proliferation of autologous lymphocytes. Finally, lymphocytes from SLE patients tended to display a lower acquisition of HLA-G (by trogocytosis) from autologous monocytes compared to controls. Our results might have implications for the immune abnormalities observed in patients with SLE.

Human FoxP3+ regulatory T cells in systemic autoimmune diseases

Since the characterization of CD4(+)CD25(+) regulatory T (Treg) cells in mice, significant progress has been made in the definitions of the phenotype and the function of human Treg cells in health and in pathological conditions. Recent advances in the field leading to a better molecular definition of Treg subsets in humans and the description of the dynamics of differentiation of Treg cells should bring new insights in the understanding of human chronic systemic autoimmune diseases. How Treg cells are compromised in these diseases is a challenging issue because the elucidation of the mechanisms leading to such anomaly might lead to promising novel therapeutic approaches.

Alteration of CD4CD25Foxp3 T cell level in Kawasaki disease

PURPOSE

Exaggerated pro-inflammatory reactions during the acute phase of Kawasaki disease (KD) suggest the role of immune dysregulation in the pathogenesis of KD. We investigated the profiles of T regulatory cells and their correlation with the clinical course of KD.

METHODS

Peripheral blood mononuclear cells were collected from 17 KD patients during acute febrile and subacute afebrile phases. T cells expressing CD4, CD25, and Foxp3 were analyzed using flow cytometry, and the results were correlated with the clinical course of KD.

RESULTS

The percentage of circulating CD4(+)CD25(high)Foxp3(+) T cells among CD4(+) T cells was significantly higher during the subacute afebrile phase than during the acute febrile phase (1.10%±1.22% vs. 0.55%±0.53%, P=0.049). Although levels of CD4(+)CD25(low)Foxp3(+) T cells and CD4(+)CD25(-)Foxp3(+) T cells were only slightly altered, the percentage of CD4(+)CD25(+)Foxp3(-) T cells among CD4(+) T cells was significantly lower during the subacute afebrile phase than during the acute febrile phase (2.96%±1.95% vs. 5.64%±5.69%, P=0.036). Consequently, the ratio of CD25(high)Foxp3(+) T cells to CD25(+)Foxp3(-) T cells was higher during the subacute afebrile phase than during the acute febrile phase (0.45%±0.57% vs. 0.13%±0.13%, P=0.038).

CONCLUSION

Decreased CD4(+)CD25(high)Foxp3(+) T cells and/or an imbalanced ratio of CD4(+)CD25(high)Foxp3(+) T cells to CD4(+)CD25(+)Foxp3(-) T cells might play a role in KD development. Considering that all KD patients were treated with intravenous immunoglobulin (IVIG), recovery of CD4(+)CD25(high)Foxp3(+) T cells during the subacute afebrile phase could be a mechanism of IVIG.

Elevated Th17 cells are accompanied by FoxP3+ Treg cells decrease in patients with lupus nephritis

To investigate the variations of T-helper 17 (Th17) and regulatory T (Treg) cells in patients with lupus nephritis (LN), a total of 60 systemic lupus erythematosus patients and 28 healthy controls (HCs) were enrolled. The frequency of Th17 cells and Treg cells in peripheral blood mononuclear cells (PBMCs) was evaluated by flow cytometric analysis. The serum concentrations of interleukin-17 (IL-17) and transforming growth factor-beta 1 (TGF-β1) were measured by enzyme-linked immunosorbent assay (ELISA). The results demonstrated in LN patients a significant decrease in the frequency of CD4+CD25(high) and CD4+CD25+FoxP3+ T cells and a significant increase in the frequency of Th17 cells in peripheral blood, and the ratio of Th17 to Treg cell frequency was significantly increased along with increased SLEDAI scores. LN patients had a lower percentage and expression of FoxP3 in CD4+CD25(high) T cells than SLE patients without nephritis. The concentration of TGF-β1 was found decreased in SLE patients compared with that from healthy controls, though no significant difference was found between LN patients and SLE patients without nephritis. The expression of IL-17 levels in LN patients exhibited a significant increase compared with patients without nephritis and healthy controls. Based on our results, the significantly elevated Th17 cells are accompanied by FoxP3+ Treg cells decrease in lupus nephritis, suggesting that Th17/Treg functional imbalance may be involved in the pathogenesis of renal damage in SLE patients.

Role of regulatory T cells in rheumatoid arthritis: facts and hypothesis

Regulatory T cells (Treg) are a CD4⁺ lymphocyte subset involved in self-tolerance and autoimmunity prevention. There is evidence for a phenotypic and/or functional impairment of this cell subset during the natural history of several chronic autoimmune/inflammatory diseases, including rheumatoid arthritis (RA). Although the intracellular transcription factor FoxP3 is thought to be the master regulator of Treg cell function, a number of other molecules expressed on the cell surface have been proposed for the identification of Treg cells. This is important in order to favour their possible selective isolation and in the development of new therapeutic strategies. In the present paper, available data on phenotypic and functional characterization of Treg cells in both peripheral blood and synovial fluid from RA patients are reviewed and their possible pathogenic role in triggering and perpetuating rheumatoid joint inflammation is discussed.

[Novel therapeutic possibilities in systemic lupus erythematosus]

Systemic lupus erythematosus (SLE) is an autoimmune disorder involving different organs and organ systems with consequent characteristic clinical and serologic symptoms. Despite of the improvement in lupus survival, approximately 10-20% of patients do not respond to traditional immune suppressive therapies. Relapses are more frequent; e.g. after cyclophosphamide therapy diffuse proliferative nephritis flares in 1/3 of patients. Different immune competent cells and inflammatory mediators participate in the pathogenesis of SLE involving both the adaptive and innate immunity. Several pathogenic elements and mechanisms may serve as therapeutic targets, consequently. Authors summarize novel therapeutic possibilities and their mechanisms regarding the pathogenesis of SLE. Immune modulation of B and T cells, co-stimulatory pathways, cytokine network, soluble mediators and autologous hemopoietic stem cell transplantation are discussed.

Quantification of regulatory T cells in peripheral blood of patients with systemic lupus erythematosus

Regulatory T cells (Tregs) are supposed to stop immune responses in the course of immune activation. However, chronic activation of immune system in systemic lupus erythematosus (SLE) and many other autoreactive disorders are evidence of malfunction of this system. Therefore, it is plausible to quantify presence of these cells in different diseases. Forty-one patients with diagnosis of SLE were enrolled in this study. Patients were divided into two groups of patients with active and inactive disease based on the disease activity score. Flow cytometry analysis was used to determine the frequency of regulatory T cells in peripheral blood according to high expression of CD25 and intracellular Forkhead/winged-helix (Foxp3). Further 30 healthy individuals considered as control group. Significantly less CD4+CD25hi regulatory T cells were detected in active patients (P < 0.001) compared to healthy individuals. The percentage of CD4+CD25hi cells were inversely correlated with the SLEDAI disease score in patients with active disease (r = -0.837, P < 0.0001). Patients with active disease had lower frequencies of CD4+Foxp3+ cells. However, increased frequencies of CD4+Foxp3+ T cells were observed in peripheral blood of patients with inactive disease compared with active patients or healthy individuals (P < 0.010). Moreover, a significant difference between the proportion of CD4+CD25-Foxp3+ population in healthy controls and patients with active disease was shown (P < 0.0005). Presence of lower frequencies of Tregs in patients with SLE could be evaluated as an immune turbulence and could be employed as a target for immunotherapeutic manipulation. However, controversies need to be resolved.