Regulatory T cell-mediated control of autoantibody-induced inflammation

Regulatory T cells play a crucial role in maintaining sperm tolerance and male fertility

Regulatory T cells (Tregs) modulate tissue homeostatic processes and immune responses. Understanding tissue-Treg biology will contribute to developing precision-targeting treatment strategies. Here, we show that Tregs maintain the tolerogenic state of the testis and epididymis, where sperm are produced and mature. We found that Treg depletion induces severe autoimmune orchitis and epididymitis, manifested by an exacerbated immune cell infiltration [CD4 T cells, monocytes, and mononuclear phagocytes (MPs)] and the development of antisperm antibodies (ASA). In Treg-depleted mice, MPs increased projections toward the epididymal lumen as well as invading the lumen. ASA-bound sperm enhance sperm agglutination and might facilitate sperm phagocytosis. Tolerance breakdown impaired epididymal epithelial function and altered extracellular vesicle cargo, both of which play crucial roles in the acquisition of sperm fertilizing ability and subsequent embryo development. The affected mice had reduced sperm number and motility and severe fertility defects. Deciphering these immunoregulatory mechanisms may help to design new strategies to treat male infertility, as well as to identify potential targets for immunocontraception.

The emerging role of regulatory cell-based therapy in autoimmune disease

Autoimmune disease, caused by unwanted immune responses to self-antigens, affects millions of people each year and poses a great social and economic burden to individuals and communities. In the course of autoimmune disorders, including rheumatoid arthritis, systemic lupus erythematosus, type 1 diabetes mellitus, and multiple sclerosis, disturbances in the balance between the immune response against harmful agents and tolerance towards self-antigens lead to an immune response against self-tissues. In recent years, various regulatory immune cells have been identified. Disruptions in the quality, quantity, and function of these cells have been implicated in autoimmune disease development. Therefore, targeting or engineering these cells is a promising therapeutic for different autoimmune diseases. Regulatory T cells, regulatory B cells, regulatory dendritic cells, myeloid suppressor cells, and some subsets of innate lymphoid cells are arising as important players among this class of cells. Here, we review the roles of each suppressive cell type in the immune system during homeostasis and in the development of autoimmunity. Moreover, we discuss the current and future therapeutic potential of each one of these cell types for autoimmune diseases.

Myeloid-derived suppressor cell: A crucial player in autoimmune diseases

Myeloid-derived suppressor cells (MDSCs) are identified as a highly heterogeneous group of immature cells derived from bone marrow and play critical immunosuppressive functions in autoimmune diseases. Accumulating evidence indicates that the pathophysiology of autoimmune diseases was closely related to genetic mutations and epigenetic modifications, with the latter more common. Epigenetic modifications, which involve DNA methylation, covalent histone modification, and non-coding RNA-mediated regulation, refer to inheritable and potentially reversible changes in DNA and chromatin that regulate gene expression without altering the DNA sequence. Recently, numerous reports have shown that epigenetic modifications in MDSCs play important roles in the differentiation and development of MDSCs and their suppressive functions. The molecular mechanisms of differentiation and development of MDSCs and their regulatory roles in the initiation and progression of autoimmune diseases have been extensively studied, but the exact function of MDSCs remains controversial. Therefore, the biological and epigenetic regulation of MDSCs in autoimmune diseases still needs to be further characterized. This review provides a detailed summary of the current research on the regulatory roles of DNA methylation, histone modifications, and non-coding RNAs in the development and immunosuppressive activity of MDSCs, and further summarizes the distinct role of MDSCs in the pathogenesis of autoimmune diseases, in order to provide help for the diagnosis and treatment of diseases from the perspective of epigenetic regulation of MDSCs.

Immune tolerance against infused FVIII in hemophilia A is mediated by PD-L1+ Tregs

A major complication of hemophilia A therapy is the development of alloantibodies (inhibitors) that neutralize intravenously administered coagulation factor VIII (FVIII). Immune tolerance induction therapy (ITI) by repetitive FVIII injection can eradicate inhibitors, and thereby reduce morbidity and treatment costs. However, ITI success is difficult to predict and the underlying immunological mechanisms are unknown. Here, we demonstrated that immune tolerance against FVIII under nonhemophilic conditions was maintained by programmed death (PD) ligand 1-expressing (PD-L1-expressing) regulatory T cells (Tregs) that ligated PD-1 on FVIII-specific B cells, causing them to undergo apoptosis. FVIII-deficient mice injected with FVIII lacked such Tregs and developed inhibitors. Using an ITI mouse model, we found that repetitive FVIII injection induced FVIII-specific PD-L1+ Tregs and reengaged removal of inhibitor-forming B cells. We also demonstrated the existence of FVIII-specific Tregs in humans and showed that such Tregs upregulated PD-L1 in patients with hemophilia after successful ITI. Simultaneously, FVIII-specific B cells upregulated PD-1 and became killable by Tregs. In summary, we showed that PD-1-mediated B cell tolerance against FVIII operated in healthy individuals and in patients with hemophilia A without inhibitors, and that ITI reengaged this mechanism. These findings may impact monitoring of ITI success and treatment of patients with hemophilia A.

Profiling Serum Antibodies Against Muscle Antigens in Facioscapulohumeral Muscular Dystrophy Finds No Disease-Specific Autoantibodies

BACKGROUND

FSHD is caused by specific genetic mutations resulting in activation of the Double Homeobox 4 gene (DUX4). DUX4 targets hundreds of downstream genes eventually leading to muscle atrophy, oxidative stress, abnormal myogenesis, and muscle inflammation. We hypothesized that DUX4-induced aberrant expression of genes triggers a sustained autoimmune response against skeletal muscle cells.

OBJECTIVE

This study aimed at the identification of autoantibodies directed against muscle antigens in FSHD. Moreover, a possible relationship between serum antibody reactivity and DUX4 expression was also investigated.

METHODS

FSHD sera (N = 138, 48±16 years, 48% male) and healthy control sera (N = 20, 47±14 years, 50% male) were analyzed by immunoblotting for antibodies against several skeletal muscle protein extracts: healthy muscle, FSHD muscle, healthy and FSHD myotubes, and inducible DUX4 expressing myoblasts. In addition, DUX4 expressing myoblasts were analyzed by immunofluorescence with FSHD and healthy control sera.

RESULTS

The results showed that the reactivity of FSHD sera did not significantly differ from that of healthy controls, with all the tested muscle antigen extracts. Besides, the immunofluorescent staining of DUX4-expressing myoblasts was not different when incubated with either FSHD or healthy control sera.

CONCLUSION

Since the methodology used did not lead to the identification of disease-specific autoantibodies in the FSHD cohort, we suggest that autoantibody-mediated pathology may not be an important disease mechanism in FSHD. Nevertheless, it is crucial to further unravel if and which role the immune system plays in FSHD pathogenesis. Other innate as well as adaptive immune players could be involved in the complex DUX4 cascade of events and could become appealing druggable targets.

Novel Therapies for Pemphigus Vulgaris

Pemphigus vulgaris (PV) is a severe chronic autoimmune blistering disease that affects the skin and mucous membranes. It is characterized by suprabasal acantholysis due to disruption of desmosomal connections between keratinocytes. Autoantibodies against desmosomal cadherins, desmoglein 3 and 1, have been shown to induce disease. Certain human leukocyte antigen (HLA) types and non-HLA foci confer genetic susceptibility. Until the discovery of corticosteroids in the 1950s, PV was 75% fatal. Since then, multiple PV treatments, such as systemic corticosteroids and adjunctive therapy with immunosuppressive medications (mycophenolate mofetil, azathioprine, cyclophosphamide, cyclosporine, methotrexate, gold, and others) have been introduced; however, none have led to long-term remissions and many have undesired adverse effects. Our growing understanding of the pathophysiologic mechanisms in PV is leading to development of new targeted therapies, such as intravenous immunoglobulin, anti-CD20 monoclonal antibodies, inhibitors of Bruton tyrosine kinase and neonatal Fc receptors, and adoptive cellular transfer, that may result in lasting control of this life-threatening disease.

Bispecific T-Cell Redirection versus Chimeric Antigen Receptor (CAR)-T Cells as Approaches to Kill Cancer Cells

The concepts for T-cell redirecting bispecific antibodies (TRBAs) and chimeric antigen receptor (CAR)-T cells are both at least 30 years old but both platforms are just now coming into age. Two TRBAs and two CAR-T cell products have been approved by major regulatory agencies within the last ten years for the treatment of hematological cancers and an additional 53 TRBAs and 246 CAR cell constructs are in clinical trials today. Two major groups of TRBAs include small, short-half-life bispecific antibodies that include bispecific T-cell engagers (BiTE®s) which require continuous dosing and larger, mostly IgG-like bispecific antibodies with extended pharmacokinetics that can be dosed infrequently. Most CAR-T cells today are autologous, although significant strides are being made to develop off-the-shelf, allogeneic CAR-based products. CAR-Ts form a cytolytic synapse with target cells that is very different from the classical immune synapse both physically and mechanistically, whereas the TRBA-induced synapse is similar to the classic immune synapse. Both TRBAs and CAR-T cells are highly efficacious in clinical trials but both also present safety concerns, particularly with cytokine release syndrome and neurotoxicity. New formats and dosing paradigms for TRBAs and CAR-T cells are being developed in efforts to maximize efficacy and minimize toxicity, as well as to optimize use with both solid and hematologic tumors, both of which present significant challenges such as target heterogeneity and the immunosuppressive tumor microenvironment.

Follicular regulatory T cells are associated with β-cell autoimmunity and the development of type 1 diabetes

OBJECTIVE

Impaired follicular regulatory T (Tfr) cells enhance T follicular helper (Tfh) cells activity, resulting in the expansion of autoreactive B cells and autoantibody production. However, the role of Tfr cells in the pathogenesis of type 1 diabetes (T1D) is unclear.

METHODS

We evaluated the expression and changes in function of circulating Tfr cells by studying patients with T1D alongside those with type 2 diabetes(T2D), first-degree relatives of T1D patients (T1D-FRs) and healthy controls. We also investigated the effects of Tfr cells on disease development in NOD mice and in an adoptive transfer model.

RESULTS

Tfr cells were significantly decreased in both patient groups. However, they showed different correlations with fasting C-peptide (C-P) and the area under the curve of blood C-peptide (C-PAUC) in patients with T1D and T2D. The frequency of Tfr cells was associated with the number of positive autoantibodies and the titer of GAD autoantibody in T1D patients. Furthermore, Tfr cells decreased significantly after 1 year of follow-up. We also observed Tfr cells in four T1D patients treated with rituximab. After rituximab therapy, the frequency of CXCR5+PD-1+ Tfr cells was decreased and of CXCR5+ICOS+ Tfr cells was increased in three patients. We also found that Tfr cells were associated with the development of diabetes in NOD mice and an adoptive transfer model.

CONCLUSIONS

Tfr cell deficiency could be involved in the pathogenesis of T1D. Therapy with Tfr cells has potential value for T1D. Modulation of these cells may be enhance protective immunity to inhibit autoimmune diabetes.

Regulatory T-cells and their impacts on cytokine profile of end-stage renal disease patients suffering from systemic lupus erythematosus

Autoimmunity is an identified factor for development of end-stage renal disease (ESRD). Regulatory T-cells (Tregs) play a fundamental role in preventing autoimmunity. This study aimed to determine Treg frequency and its effects on cytokine profile of ESRD patients with and without systemic lupus erythematosus (SLE). Moreover, this study also determines how Treg number is affected by blood transfusion and gender. Peripheral blood mononuclear cells were isolated from 26 ESRD and 10 healthy subjects and stained with anti-CD4, anti-CD25, and anti-FoxP3 antibodies. Treg frequencies in ESRD patients with and without blood transfusion were determined by flow cytometry. Antibodies against human leukocyte antigens (HLAs) were investigated by panel-reactive antibodies screening. Tumor growth factor (TGF)-β1, interleukin (IL)-4, IL-10, TNF-α, IL-17A, and interferon (IFN)-γ serum levels in participants were measured by enzyme-linked immunoasorbent assay (ELISA). ESRD patients with SLE, unlike the patients without SLE, showed a significant reduction in Treg percentage compared to healthy subjects (P < 0.01). All women had a reduced number of Tregs compared to men. Treg number was significantly decreased in ESRD patients with HLA antibodies (P < 0.05). Blood transfusion enhanced Treg development in ESRD patients without SLE, unlike the patients with SLE (P < 0.05). ESRD patients with low Treg showed a reduction in TGF-β1 and IL-4 and an increase in TNF-α and IL-17A levels compared to control groups (P < 0.05-0.0001). However, no change was observed in IL-10 and IFN-γ levels. Treg frequency was negatively associated with the age of patients (P < 0.01), while this association was not observed in healthy subjects. Based on these findings, it can be observed that reduction in Treg number may contribute to ESRD development in patients with SLE.

Phenotypic and Functional Diversities of Myeloid-Derived Suppressor Cells in Autoimmune Diseases

Myeloid-derived suppressor cells (MDSCs) are identified as a heterogeneous population of cells with the function to suppress innate as well as adaptive immune responses. The initial studies of MDSCs were primarily focused on the field of animal tumor models or cancer patients. In cancer, MDSCs play the deleterious role to inhibit tumor immunity and to promote tumor development. Over the past few years, an increasing number of studies have investigated the role of MDSCs in autoimmune diseases. The beneficial effects of MDSCs in autoimmunity have been reported by some studies, and thus, immunosuppressive MDSCs may be a novel therapeutic target in autoimmune diseases. There are some controversial findings as well. Many questions such as the activation, differentiation, and suppressive functions of MDSCs and their roles in autoimmune diseases remain unclear. In this review, we have discussed the current understanding of MDSCs in autoimmune diseases.

Immune Dysfunction and Autoimmunity as Pathological Mechanisms in Autism Spectrum Disorders

Autism spectrum disorders (ASD) are a group of heterogeneous neurological disorders that are highly variable and are clinically characterized by deficits in social interactions, communication, and stereotypical behaviors. Prevalence has risen from 1 in 10,000 in 1972 to 1 in 59 children in the United States in 2014. This rise in prevalence could be due in part to better diagnoses and awareness, however, these together cannot solely account for such a significant rise. While causative connections have not been proven in the majority of cases, many current studies focus on the combined effects of genetics and environment. Strikingly, a distinct picture of immune dysfunction has emerged and been supported by many independent studies over the past decade. Many players in the immune-ASD puzzle may be mechanistically contributing to pathogenesis of these disorders, including skewed cytokine responses, differences in total numbers and frequencies of immune cells and their subsets, neuroinflammation, and adaptive and innate immune dysfunction, as well as altered levels of immunoglobulin and the presence of autoantibodies which have been found in a substantial number of individuals with ASD. This review summarizes the latest research linking ASD, autoimmunity and immune dysfunction, and discusses evidence of a potential autoimmune component of ASD.

Regulation of the Germinal Center Response

The germinal center (GC) is a specialized microstructure that forms in secondary lymphoid tissues, producing long-lived antibody secreting plasma cells and memory B cells, which can provide protection against reinfection. Within the GC, B cells undergo somatic mutation of the genes encoding their B cell receptors which, following successful selection, can lead to the emergence of B cell clones that bind antigen with high affinity. However, this mutation process can also be dangerous, as it can create autoreactive clones that can cause autoimmunity. Because of this, regulation of GC reactions is critical to ensure high affinity antibody production and to enforce self-tolerance by avoiding emergence of autoreactive B cell clones. A productive GC response requires the collaboration of multiple cell types. The stromal cell network orchestrates GC cell dynamics by controlling antigen delivery and cell trafficking. T follicular helper (Tfh) cells provide specialized help to GC B cells through cognate T-B cell interactions while Foxp3⁺ T follicular regulatory (Tfr) cells are key mediators of GC regulation. However, regulation of GC responses is not a simple outcome of Tfh/Tfr balance, but also involves the contribution of other cell types to modulate the GC microenvironment and to avoid autoimmunity. Thus, the regulation of the GC is complex, and occurs at multiple levels. In this review we outline recent developments in the biology of cell subsets involved in the regulation of GC reactions, in both secondary lymphoid tissues, and Peyer's patches (PPs). We discuss the mechanisms which enable the generation of potent protective humoral immunity whilst GC-derived autoimmunity is avoided.

Cytokine Networks and Survivin Peptide-Specific Cellular Immune Responses Predict Improved Survival in Patients With Glioblastoma Multiforme

PURPOSE

We investigated serum cytokine and T-cell responses directed against tumour-associated antigens (TAAs) in association with survival of patients with glioblastoma multiforme (GBM).

PATIENTS AND METHODS

Peripheral blood from 205 treatment-naïve patients with glioma (GBM = 145; non-GBM = 60) was obtained on the day of surgery to measure (i) circulating T-cells reacting to viral antigens and TAAs, in the presence or absence of cytokine conditioning with IL-2/IL-15/IL-21 or IL-2/IL-7, and (ii) serum cytokine levels (IL-4, IL-5, IL-6, TNF-α, IFN-γ and IL-17A). Patients were followed-up for at least 1000 days post-surgery. Survivin protein and gene expression in resected GBM tumour tissue were confirmed by immunohistochemistry and real-time polymerase chain reaction, respectively. Antigen-specific T-cell responses were gauged by ICS (intracellular cytokine production). Associations between patient survival and immunological reactivity patterns were analysed using univariate and multivariate statistics.

RESULTS

Approximately 2% of patients with GBM and 18% of patients with non-GBM glioma, were alive beyond 1000 days of surgery. Univariate analysis indicated that the combination of three cytokines (IL-4/IL-5/IL-6, p = .0022; IFN-γ/TNF-α/IL-17A, p = .0083) but not a 'partial' combination of these cytokines, the IFN-γ immune response to EBV-EBNA-1 (p < .0001) as well as T-cell responses to the survivin_97-111 peptide (p = .0152) correlated with longer survival among patients with GBM. Multivariate analysis identified survivin_97-111-directed IFN-γ production with IL-2/IL-15/IL-21 conditioning (p = .024), and the combined presence of serum IFN-γ/TNF-α/IL-17a (p = .003) as independent predictors of survival.

CONCLUSION

Serum cytokine patterns and lymphocyte reactivity to survivin_97-111, particularly with IL-2, IL-15 and IL-21 conditioning may be instrumental in predicting survival among patients with GBM. This has implications for clinical follow-up of patients with GBM and the targeted development of immunotherapy for patients with CNS tumours.

Prevalence of IgG Autoantibodies against GD3 Ganglioside in Acute Zika Virus Infection

Zika virus (ZIKV) disease has become a global health emergency with devastating effects on public health. Recent evidences implicate the virus as an emergent neuropathological agent promoting serious pathologies of the human nervous system, that include destructive and malformation consequences such as development of ocular and fetal brain lesions, microcephaly in neonates, and Guillain–Barré syndrome (GBS) in adults. These neurological disorders of both central and peripheral nervous systems are thought to be associated to the neurotropic properties of the virus that has ability to infect neural stem cells as well as peripheral neurons, a hallmark of its pathogenicity. The presence of autoantibodies against gangliosides plays a pivotal role in the etiogenesis of GBS and a variety of neurological disorders. Gangliosides are a class of galactose-containing cerebrosides mainly expressed in nervous system tissues playing a critical role in the physiology of neural cells and neurogenesis. Herein, our findings indicate that patients at acute phase of ZIKV infection without any neurological signs show increased levels of IgG autoantibody against GD3 gangliosides, a class of glycolipid found to be highly expressed in neural stem cell acting in the maintenance of their self-renewal cellular capacity. It is possible that a pathological threshold of these antibodies is only acquired in secondary or subsequent infections. In the light of these evidences, we propose that the target of GD3 by autoimmune responses may possibly has an effect in the neuropathy and neurogenesis disorder seen during ZIKV infection.

PDGF upregulates CLEC-2 to induce T regulatory cells

The effect of platelet derived growth factor (PDGF) on immune cells is not elucidated. Here, we demonstrate PDGF inhibited the maturation of human DCs and induced IL-10 secretion. Culture of PDGF-DCs with T cells induced the polarization of T cells towards FoxP3 expressing T regulatory cells that secreted IL-10. Gene expression studies revealed that PDGF induced the expression of C-type lectin like receptor member 2, (CLEC-2) receptor on DCs. Furthermore, DCs transfected with CLEC-2 induced T regulatory cells in DC-T cell co-culture. CLEC-2 is naturally expressed on platelets. Therefore, to confirm whether CLEC-2 is responsible for inducing the T regulatory cells, T cells were cultured with either CLEC-2 expressing platelets or soluble CLEC-2. Both conditions resulted in the induction of regulatory T cells. The generation of T regulatory cells was probably due to the binding of CLEC-2 with its ligand podoplanin on T cells, since crosslinking of podoplanin on the T cells also resulted in the induction of T regulatory cells. These data demonstrate that PDGF upregulates the expression of CLEC-2 on cells to induce T regulatory cells.

Modulation of an aqueous extract of Chinese medicine prescription Anzi Heji () on ratio of CD4+CD25+FOXP3+ regulatory T cells in anticardiolipin antibody-positive patients with threatened abortion

OBJECTIVE

To evaluate Chinese medicine prescription, Anzi Heji (, AZHJ), on immune regulation of CD4+CD25+FOXP3+ regulatory T cells (Tregs) in anticardiolipin antibody (ACA)-positive patients with threatened abortion.

METHODS

Twenty-seven ACA-positive female patients with threatened abortion in the study group were treated with an aqueous extract of AZHJ 125 mL, twice daily for 4 consecutive weeks. The results were compared with control group composed by 15 healthy pregnant women. The ratio of CD4+CD25+FOXP3+ Treg in peripheral blood was identified by flow cytometry. The indicators of ACA were detected by enzyme-linked immunosorbent assay, and embryo development was checked by B-ultrasound.

RESULTS

Compared with the control group, the ratio of CD4+CD25+FOXP3+ Treg cells in the study group was significantly lower before AZHJ treatment (P<0.01) and significantly increased after AZHJ treatment (P<0.01). After treatment, 20 of 27 patients (85%) showed that ACA indicators turned into negative, and 7 cases of quantitative indicators of ACA titers were significantly decreased (P<0.01). Total efficiency of treating miscarriage by AZHJ was 92.59%.

CONCLUSION

AZHJ can regulate the immune function of pregnant women by increasing number of CD4+CD25+FOXP3+ Tregs.

Humoral autoimmunity: a failure of regulatory T cells?

Regulatory T cells (Tregs) are essential in maintaining tolerance to self. Several lines of evidence indicate that Tregs are functionally impaired in a variety of autoimmune diseases, leading to inefficient regulation of autoimmune T cells. Recent findings also suggest that Tregs are essential in controlling autoreactive B cells. The recently identified follicular regulatory T cell subset (TFR) is thought to regulate the production of autoantibodies in the germinal center (GC) response. Here we provide an update on the role of Tregs in controlling the GC response, and whether defective control over B cell tolerance contributes to autoimmunity.

Regulatory T cells ameliorate intrauterine growth retardation in a transgenic rat model for preeclampsia

Preeclampsia is a multisystemic syndrome during pregnancy that is often associated with intrauterine growth retardation. Immunologic dysregulation, involving T cells, is implicated in the pathogenesis. The aim of this study was to evaluate the effect of upregulating regulatory T cells in an established transgenic rat model for preeclampsia. Application of superagonistic monoclonal antibody for CD28 has been shown to effectively upregulate regulatory T cells. In the first protocol (treatment protocol), we applied 1 mg of CD28 superagonist or control antibody on days 11 and 15 of pregnancy. In the second protocol (prevention protocol), the superagonist or control antibody was applied on days 1, 5, and 9. Superagonist increased regulatory T cells in circulation and placenta from 8.49±2.09% of CD4-positive T cells to 23.50±3.05% and from 3.85±1.45% to 23.27±7.64%, respectively. Blood pressure and albuminuria (30.6±15.1 versus 14.6±5.5 mg/d) were similar in the superagonist or control antibody-treated preeclamptic group for both protocols. Rats treated with CD28 superagonist showed increased pup weights in the prevention protocol (2.66±0.03 versus 2.37±0.05 g) and in the treatment protocol (3.04±0.04 versus 2.54±0.1 g). Intrauterine growth retardation, calculated by brain:liver weight ratio, was also decreased by the superagonist in both protocols. Further analysis of brain development revealed a 20% increase in brain volume by the superagonist. Induction of regulatory T cells in the circulation and the uteroplacental unit in an established preeclamptic rat model had no influence on maternal hypertension and proteinuria. However, it substantially improved fetal outcome by ameliorating intrauterine growth retardation.

Role of myeloid-derived suppressor cells in autoimmune disease

Myeloid-derived suppressor cells (MDSCs) represent an important class of immunoregulatory cells that can be activated to suppress T cell functions. These MDSCs can inhibit T cell functions through cell surface interactions and the release of soluble mediators. MDSCs accumulate in the inflamed tissues and lymphoid organs of patients with autoimmune diseases. Much of our knowledge of MDSC function has come from studies involving cancer models, however many recent studies have helped to characterize MDSC involvement in autoimmune diseases. MDSCs are a heterogeneous group of immature myeloid cells with a number of different functions for the suppression of T cell responses. However, we have yet to fully understand their contributions to the development and regulation of autoimmune diseases. A number of studies have described beneficial functions of MDSCs during autoimmune diseases, and thus there appears to be a potential role for MDSCs in the treatment of these diseases. Nevertheless, many questions remain as to the activation, differentiation, and inhibitory functions of MDSCs. This review aims to summarize our current knowledge of MDSC subsets and suppressive functions in tissue-specific autoimmune disorders. We also describe the potential of MDSC-based cell therapy for the treatment of autoimmune diseases and note some of hurdles facing the implementation of this therapy.

The number of regulatory T cells correlates with hemodynamic improvement in patients with inflammatory dilated cardiomyopathy after immunoadsorption therapy

Inflammatory DCM (iDCM) may be related to autoimmune processes. An immunoadsorption (IA) has been reported to improve cardiac hemodynamics. The benefit of IA is probably related to the removal of autoantibodies. A recent study suggests additional effects of IA on the T cell-mediated immune reactions, especially on regulatory T cells (Tregs). In this prospective study, the correlation between the level of Tregs and improvement of myocardial contractility in response to IA in patients with iDCM was investigated. Patients (n = 18) with iDCM, reduced left ventricular (LV) ejection fraction (<35%), were enrolled for IA. Before and 6 months after IA, LV systolic function was assessed by echocardiography, and blood levels of Tregs were quantified by FACS analysis. Patients (n = 12) with chronic ischaemic heart failure and comparable reduced LV-EF served as controls. IA improved LV-EF in 12 of 18 patients at 6-month follow-up. These patients were classified as 'IA responder'. In 6 patients, LV-EF remained unchanged. At baseline, IA responder and non-responder subgroups showed similar values for C-reactive protein, white blood cells, lymphocytes and T helper cells, but they differ for the number of circulating Tregs (responder: 2.32 ± 1.38% versus non-responder: 4.86 ± 0.28%; P < 0.01). Tregs increased significantly in the IA responders, but remained unchanged in the IA non-responders. In patients with ischaemic cardiomyopathy, none of these values changed over time. A low level of Tregs in patients with chronic iDCM may characterize a subset of patients who do best respond to IA therapy.

Changes of CD4(+) CD25(+) Regulatory T Cells, FoxP3 in Adjuvant Arthritis Rats with Damage of Pulmonary Function and Effects of Tripterygium Glycosides Tablet

Objective. To observe the effects of tripterygium glycosides tablet (TPT) on swelling degree, arthritis index (AI), pulmonary function, cytokines, the expression of regulatory T cells (Treg), and Foxp3 in rats of adjuvant arthritis. Methods. Rats were averagely divided into normal control (NC) group, model control (MC) group, methotrexate (MTX) group, and tripterygium glycosides tablet (TPT) group. Except for the rats of normal group, the others were intracutaneously injected with 0.1 mL of Freund's complete adjuvant in the right hindlimb. NC group and MC group were treated with physiological saline. MTX group and TPT group were treated with MTX, TPT, respectively. Results. The levels of swelling degree, AI, the alveolar inflammation integral, TNF alpha (TNF-α), and endothelium-1 (ET-1 ) in MC group were significantly increased (P < 0.01), and the levels of forced vital capacity (FVC), 25% vital capacity of the peak expiratory flow (FEF(25)), 50% vital capacity of the peak expiratory flow (FEF(50)), 75% vital capacity of the peak expiratory flow (FEF(75)), maximum midexpiratory flow (MMF), peak expiratory flow (PEF), interleukin-10 (IL-10), CD4(+) CD25(+) Treg, and Foxp3 were decreased (P < 0.01). The scores of alveolitis and ET-1 were decreased with treatment of TPT. The levels of FVC, FEF(25), FEF(50), FEF(75), MMF, PEF, IL-10, and CD4(+) CD25(+) Treg in peripheral blood were increased. The expressions of Foxp3 protein and mRNA in lung tissue were also increased in TPT group. Conclusions. The paw swelling can be inhibited by TPT, and the inflammatory response in lung tissue was also decreased, which is a significant improvement in pulmonary function. The mechanism is probably associated with upregulating the expression of IL-10, Foxp3, and downregulating the level of TNF-α.