CD 127−and FoxP3+Expression on CD25+CD4+T Regulatory Cells upon Specific Diabetogeneic Stimulation in High-risk Relatives of Type 1 Diabetes Mellitus Patients

Regulatory T Cells: A New Target of Chinese Medicine in Treatment of Atherosclerosis

Inflammation and immune disorders are integral to the occurrence and progression of atherosclerosis (AS). With the role of regulatory T cells (Tregs) in immune regulation attracting attention, it has been widely accepted that Treg decrease and dysfunction are involved in AS pathogenesis. Chinese medicine (CM) has the advantages of being dual-directional, multi-targeted, and having minimal side effects in immune regulation. The anti-atherosclerosis effects of CM via Treg modulation have been revealed in clinical and animal studies. Therefore, this article reviews existing research on Tregs, the relationship between Tregs and AS, and the progress of CM for treating and prevention of atherosclerotic cardio-cerebrovascular diseases by regulating Tregs. Although the underlying mechanisms remain to be elucidated, CM treatment targeting Treg cells might provide a promising and novel future approach for prevention and treatment of AS.

Children with type 1 diabetes of early age at onset - immune and metabolic phenotypes

Objectives We aimed to evaluate children with type 1 diabetes (T1D) with early age at onset (EAO) for clinical, immune and metabolic features in order to identify age-related disease phenotypes. Methods Comparative study of two groups of T1D children: EAO (≤5 years) and later age at onset (LAO; >5 years), regarding the presence of other autoimmune (AI) diseases, diabetes ketoacidosis and immunologic profile at onset and metabolic data 1 year after diagnosis. Statistical analysis was performed with significance set for p < 0.05. Results The study included 137 children (EAO = 52, mean age 3.6 ± 1.5 [mean ± standard deviation (SD)] and LAO = 85, mean age 10.4 ± 2.9). EAO was more associated with concomitant AI diseases (p = 0.032). Despite no differences in disease onset, EAO presented with lower C-peptide levels (p = 0.01) and higher absolute lymphocyte number (p < 0.0001), with an inverse correlation between these two variables (p = 0.028). Additionally, the EAO group had a higher frequency of serum detection of three antibodies (Abs) (p = 0.0008), specifically insulin Abs (p = 0.0001). One year after diagnosis, EAO had higher total daily insulin (TDI) dose (p = 0.008), despite similar hemoglobin A1c (HbA1c). Conclusions Our data show an association of EAO T1D with more AI diseases, higher number of Abs, lower initial insulin reservoir and higher insulin requirements 1 year after diagnosis. In this group, immune imbalance seems more evident and disease progression faster, probably reflecting distinct "immune environment" with different ages at disease onset. Further studies in the field of immunogenetics and immune tolerance are required, to improve patient stratification and find novel targets for therapeutic intervention.

IL-33 improves the suppressive potential of regulatory T cells in patients with type 1 diabetes

AIMS

The presented study was aimed to analyze the influence of IL-33 on regulatory T cells (Tregs) suppressive potential in patients with type 1 diabetes.

METHODS

We analyzed the ability of IL-33 treated Tregs to inhibit the production of IFN-γ by effector T lymphocytes in an in vitro co-culture. The study group consisted of 22 patients with type 1 diabetes and 12 age and sex-matched healthy individuals.

RESULTS

Our findings revealed that in vitro IL-33 treatment of Tregs derived from patients with type 1 diabetes resulted in quantitative as well as qualitative changes in this cell population, confirming immunoregulatory features of IL-33.

CONCLUSION

IL-33 could be considered as a potential therapeutic tool in adoptive therapies of type 1 diabetes.

Evaluation of CD4+ CD25+ FoxP3+ Regulatory T cells and FoxP3 and CTLA-4 gene Expression in Patients wwith Newly Diagnosed Tuberculosis in Northeast of Iran

Background:

Tuberculosis (TB) is the world's second most common infectious disease after Human Immunodeficiency Virus Infection/Acquired Immunodeficiency Syndrome (HIV/AID) and the most frequent cause of mortality especially in developing countries. T regulatory (Treg) cells, which have suppressive activity and express forkhead winged-helix family transcriptional repressor p3 (FoxP3), suppress the immune responses against pathogens such as Mycobacterium tuberculosis. There are controversial results regarding the role of FoxP3 expressing cells in the blood of patients with TB.

Objectives:

The aim of this study was to evaluate the frequency CD4+ CD25+ Treg cells, and FoxP3 and Cytotoxic T Lymphocyte Antigen 4 (CTLA-4) gene expressions in peripheral blood of patients with tuberculosis and patients with positive tuberculin skin test before and after Peripheral Blood Mononuclear Cells (PBMCs) activation with Purified Protein Derivative (PPD).

Patients and Methods:

In this cross-sectional study, Peripheral Mononuclear Cells (PBMCs) were isolated from peripheral blood of 29 patients with newly diagnosed pulmonary TB and 19 patients with positive tuberculin skin test. The PBMCs were activated with PPD for 72 hours. Activated cells were harvested, RNA was extracted and cDNA was synthesized. A real-time Taqman method was designed and optimized for evaluation of Foxp3 gene expression and SYBR Green method was used and optimized for evaluation of CTLA-4 gene expression. A flow cytometry analysis was used to evaluate the frequency of CD4+ CD25+ Foxp3+ regulatory T cells in both groups.

Results:

There was no significant difference in the frequency of CD4+ CD25+ FoxP3+ regulatory T cells between the two groups. Expression of FoxP3 and CTLA-4 in peripheral blood of patients with newly diagnosed TB was significantly lower than the control group after and before activation with PPD.

Conclusions:

The expression of FoxP3 and CTLA-4 in PBMCs of patients with newly diagnosed TB was low, which might suggest that Treg cells may be sequestered in the lungs.

Frequency of regulatory T-cells in the peripheral blood of patients with pulmonary tuberculosis from shanxi province, china

BACKGROUND

Tuberculosis (TB) is a disease caused by the chronic and continuous infection of the pathogen Mycobacterium tuberculosis (M. tuberculosis). M. tuberculosis is an intracellular bacterial pathogen and is eliminated mainly through CD4(+) effector Th cells. M. tuberculosis induces regulatory T lymphocytes (Tregs) that mediate immune suppression by cell-to-cell contact or by secreting cytokines such as transforming growth factor-β (TGF-β). To understand the role of regulatory T-cells in the pathogenesis of TB, we have measured the in vivo frequency of regulatory T-cells and associated in vivo cytokine production in pulmonary tuberculosis patients.

METHODOLOGY/PRINCIPAL FINDINGS

In this study, we analyzed blood samples from 3 different populations (Group 1: patients with active TB, Group 2: patients recovered from TB and Group 3: healthy controls). We measured natural regulatory T-cell expression in peripheral blood using flow cytometry, and levels of blood serum IFN-γ and TGF-β1 using ELISA. The in vivo function of inductive regulatory T cells was mainly indicated by the expression of IFN-γ, TGF-β1, etc. Frequencyof natural regulatory T cells and inductive regulatory T cells in the peripheral blood samples from Group 1 patients were all significantly higher (P<0.05) than those from Groups 2 and 3.

CONCLUSION/SIGNIFICANCE

Our results indicate that frequency of natural regulatory T cells and inductive regulatory T cells are significantly higher in the peripheral blood of patients with active pulmonary tuberculosis. These findings have potential application in improving TB diagnostic methods.

Low frequency of regulatory T cells in the peripheral blood of children with type 1 diabetes diagnosed under the age of five

The highest annual increase in the incidence of type 1 diabetes (T1D) in children under the age of 5 years and aggressive process of β-cell destruction in this age group indicate the need to assess the immune system. The aim of this study was to evaluate regulatory T cells (Tregs) frequency in the peripheral blood of children <5 years of age with newly diagnosed T1D in comparison with diabetic children diagnosed at a later age and healthy controls. 40 children with newly diagnosed T1D (20 children <5 years of age and 20 older patients) and 40 age-matched controls were included in this study. Flow cytometric analysis of Tregs was performed using the following markers: CD4, CD25, CD127, FoxP3, IL-10, and TGF-β. Apoptosis was measured using anti-active caspase 3 monoclonal antibody. Fasting C-peptide and HbA1c were monitored as well. We showed that T1D children <5 years had lower C-peptide concentration than diabetic children ≥5 years of age (0.32 vs. 0.80 ng/ml, respectively, p = 0.0005). There was lower frequency of CD4(+)CD25(high)CD127(low)FoxP3(+) Tregs in T1D children <5 years than ≥5 years of age (0.87 vs. 1.56 %, respectively, p = 0.017). Diabetic children <5 years had lower CD4(+)CD25(high)CD127(low)FoxP3(+), CD4(+)CD25(high)IL-10, and CD4(+)CD25(high)TGF-β Tregs compared to age-matched controls. There was no difference in Tregs apoptosis between the examined groups. This study highlights the distinctiveness of diabetes in children <5 years of age. Understanding the differences of immune system activity in the young diabetic children would open the way to identify children at risk for T1D and enables the use of novel forms of intervention.

Case report: type 1 diabetes in monozygotic quadruplets

Type 1 diabetes (T1D) is an autoimmune disease characterized by the lack of insulin due to an autoimmune destruction of pancreatic beta cells. Here, we report a unique case of a family with naturally conceived quadruplets in which T1D was diagnosed in two quadruplets simultaneously. At the same time, the third quadruplet was diagnosed with the pre-diabetic stage. Remarkably, all four quadruplets were positive for anti-islet cell antibodies, GAD65 and IA-A2. Monozygotic status of the quadruplets was confirmed by testing 14 different short tandem repeat polymorphisms. Serological examination confirmed that all quadruplets and their father suffered from a recent enteroviral infection of EV68-71 serotype. To assess the nature of the molecular pathological processes contributing to the development of diabetes, immunocompetent cells isolated from all family members were characterized by gene expression arrays, immune-cell enumerations and cytokine-production assays. The microarray data provided evidence that viral infection, and IL-27 and IL-9 cytokine signalling contributed to the onset of T1D in two of the quadruplets. The propensity of stimulated immunocompetent cells from non-diabetic members of the family to secrete high level of IFN-α further corroborates this conclusion. The number of T regulatory cells as well as plasmacytoid and/or myeloid dendritic cells was found diminished in all family members. Thus, this unique family is a prime example for the support of the so-called 'fertile-field' hypothesis proposing that genetic predisposition to anti-islet autoimmunity is 'fertilized' and precipitated by a viral infection leading to a fully blown T1D.

Type I diabetes-associated tolerogenic properties of interleukin-2

Type 1 Diabetes (T1D) results from insulin-producing beta cells destruction by diabetogenic T lymphocytes in humans and nonobese diabetic (NOD) mice. The breakdown of tolerance has been associated with a defect in the number and the function of naturally occurring regulatory T cells (nTreg) that are the master player in peripheral tolerance. Gene knockout experiments in mouse models have shown a nonredundant activity of IL-2 related to its critical role in inducing nTreg and controlling peripheral T cell tolerance. Whereas strong evidence has suggested that IL-2 is critically required for nTreg-mediated T1D control, several fundamental questions remain to be addressed. In this paper, we highlight the recent findings and controversies regarding the tolerogenic properties of IL-2 mediated through nTreg. We further discuss a potential link between the immunomodulatory role of interleukin-2 and the pathogenesis of type 1 diabetes.

Imbalance in T-cell and cytokine profiles in patients with relapsing-remitting multiple sclerosis

Multiple sclerosis (MS) is characterized by autoimmune attack leading to demyelination of the white matter in the central nervous system with devastating clinical consequences. Several immune-mediated destruction mechanisms were previously proposed including different T-cell subsets but complex view on immune system function in patients with MS is missing. In the present study, T-lymphocyte populations and pro-inflammatory as well as suppressive cytokine profiles were evaluated in detail in previously untreated patients with relapsing-remitting MS (RRMS). CD4(+) and CD8(+) naïve, central memory (Tcm), effector memory (Tem), terminal effector memory (Ttem), CD4(+) regulatory T-cells (Treg) and CD8(+) T-suppressor cells (Ts) were analysed using flow cytometry, and levels of ten plasma cytokines were determined using fluorescent bead-based immunoassay. We evaluated two groups of RRMS with minor (n=33) and major (n=25) clinical impairment and compared them with healthy controls (n=40) in order to detect any correlation between severity of MS clinical symptoms and immune disturbances. Significant differences were noted in CD4(+)CD45RA(+)CCR7(+) naïve T-cells, CD4(+)CD45RO(+)CCR7(-) and CD8(+)CD45RO(+)CCR7(-) Tem cells, while no differences were recognized in Tcm, Ttem, Treg and Ts cells in RRMS patients. Nine out of ten studied cytokines were disturbed in plasma samples of patients with RRMS. In conclusion, we demonstrate complex immune dysbalances in untreated MS patients.

Evaluation of T regulatory cell apoptosis in children with newly recognized type 1 diabetes mellitus

BACKGROUND

Type 1 diabetes is a metabolic disease characterized by an autoimmune, T-cell dependent destruction of insulin producing pancreatic beta cells. T regulatory cells (Tregs) are critical regulators of immune tolerance.

OBJECTIVE

The aim of the study was to investigate CD4 +CD25 highFoxP3 cell apoptosis in the peripheral blood of children with newly diagnosed type 1 diabetes mellitus.

METHODS

34 children (15 girls and 19 boys) with new onset of type 1 diabetes mellitus, of the mean age 6.9 ±5.2 (range 0.9-17.5 yr) and 18 healthy controls (8 girls, 10 boys) of the mean age 7.3 ±4.6 (1.9-17.5 yr) were included into the study. Flow cytometric analysis of Tregs was performed using the following markers: anti-CD4, anti-CD25 and transcription factor FoxP3. Apoptosis was measured using anti-active caspase-3 monoclonal antibody. The percentage of apoptotic cells was measured within CD4 +CD25 highFoxP3+ cells.

RESULTS AND CONCLUSION

There was no statistically significant difference in the percentage of apoptotic CD4 +CD25 highFoxP3 + cells between children with diabetes and healthy subjects; the median value 0 (range 0-26.8) vs. 0 (range 0-2.6), respectively (P = 0.302). Further, clinical studies on a larger cohort of diabetic children are needed to evaluate T regulatory cell apoptosis, especially for future immune-based therapy.

3G11 expression in CD4+ T cell-mediated autoimmunity and immune tolerance

3G11 is a sialylated carbohydrate epitope of the disialoganglioside molecule expressed on mouse CD4(+) T cells. Recent research showed that 3G11 expression is related to the modulation of T cell function, i.e., 3G11(-) T cells exhibit anergic/Treg characteristics and efficiently inhibit autoimmunity in the central nervous system. The relationship between 3G11 expression and immune tolerance is summarized in this literature review.

Prediction and pathogenesis in type 1 diabetes

A combination of genetic and immunological features is useful for prediction of autoimmune diabetes. Patterns of immune response correspond to the progression from a preclinical phase of disease to end-stage islet damage, with biomarkers indicating transition from susceptibility to active autoimmunity, and to a final loss of immune regulation. Here, we review the markers that provide evidence for immunological checkpoint failure and that also provide tools for assessment of individualized disease risk. When viewed in the context of genetic variation that influences immune response thresholds, progression from susceptibility to overt disease displays predictable modalities of clinical presentation resulting from a sequential series of failed homeostatic checkpoints for selection and activation of immunity.

Numerical defects in CD8+CD28- T-suppressor lymphocyte population in patients with type 1 diabetes mellitus and multiple sclerosis

Type 1 diabetes mellitus (T1D) and multiple sclerosis (MS) are organ-specific autoimmune diseases leading to an attack of auto-aggressive lymphocytes against the pancreatic beta-cells and central nervous system, respectively. Using four-colour flow cytometry, T-lymphocyte populations having an important function in autoimmune processes were analyzed. T-regulatory cells (Treg) CD4(+)CD25(+)CD127(low), T-suppressor cells (Ts) CD8(+)CD28(-), activated helper CD4(+)CD25(+)CD127(+) and cytotoxic CD8(+)CD25(+) T-cells and also naive CD4(+)CD45RA(+) and memory T-cells CD4(+)CD45RO(+) were compared in the group of patients with T1D (n=30), MS (n=31) and in the group of healthy controls (n=29). Significant differences in Ts cells, activated helper and cytotoxic cells and also memory T-cells were recognized in the group of T1D patients compared to healthy controls. Ts population was significantly lowered in MS patients as well. However, no significant differences were noticed in Treg population. The observed data demonstrate significant differences among patients with T1D and MS in comparison to healthy individuals.

microRNA-342, microRNA-191 and microRNA-510 are differentially expressed in T regulatory cells of type 1 diabetic patients

Regulatory T cells (Tregs) are critical regulators of autoimmune diseases, including type 1 diabetes mellitus. It is hypothesised that Tregs' function can be influenced by changes in the expression of specific microRNAs (miRNAs). Thus, we performed miRNAs profiling in a population of Tregs separated from peripheral blood of five type 1 diabetic patients and six healthy donors. For more detailed molecular characterisation of Tregs, we additionally compared miRNAs expression profiles of Tregs and conventional T cells. Tregs were isolated according to CD3+, CD4+, CD25(hi)+ and CD127- by flow cytometry, and miRNA expression profiling was performed using TaqMan Array Human MicroRNA Panel-1 (384-well low density array). In Tregs of diabetic patients we found significantly increased expression of miRNA-510 (p=0.05) and decreased expression of both miRNA-342 (p<0.0001) and miRNA-191 (p=0.0079). When comparing Tregs and T cells, we revealed that Tregs had significant higher expression of miRNA-146a and lower expression of eight specific miRNAs (20b, 31, 99a, 100, 125b, 151, 335, and 365). To our knowledge, this is the first study demonstrating changes in miRNA expression profiles occurring in Tregs of T1D patients and a miRNAs signature of adult Tregs.

Altered naive and memory CD4+ T-cell homeostasis and immunosenescence characterize younger patients with myelodysplastic syndrome

Response to immunosuppressive therapy (IST) in younger patients with myelodysplastic syndrome (MDS) has been linked to a T-cell-dominant autoimmune process that impairs hematopoiesis. Analysis of the age-adjusted CD4:CD8 ratio in 76 MDS patients compared with 54 healthy controls showed that inadequate CD4+, rather than expansion of CD8+ T cells, was associated with a lower ratio in a group that included both lower and higher risk MDS patients defined by the International Prognostic Scoring System. In younger MDS patients, naive and memory phenotypes defined by CD45RA and CD62L display showed depletion of naive CD4+ and CD8+ T cells, suggesting a possible relationship to IST responsiveness. To determine the correlation between T-cell subset distribution, T-cell turnover and autoimmunity, a cohort of 20 patients were studied before and after IST. The CD4:CD8 ratio correlated inversely with the proliferative T-cell index before treatment in IST-responsive patients, suggesting that proliferation may be linked to accelerated CD4+ T-cell turnover and hematopoietic failure. Our data show seminal findings that both CD4+ and CD8+ T-cell subsets are dysregulated in MDS. Association between these T-cell defects and response to IST suggests that aberrant T-cell homeostasis and chronic activation are critical determinants influencing autoimmune hematopoietic suppression in younger patients.

Characterization of regulatory T cells identified as CD4(+)CD25(high)CD39(+) in patients with active tuberculosis

Forkhead box P3 (FoxP3) is a transcription factor whose expression characterizes regulatory T cells (T(reg)), but it is also present on activated T cells, thus hindering correct T(reg) identification. Using classical markers for T(reg) recognition, discordant results were found in terms of T(reg) expansion during active tuberculosis (TB) disease. Recently CD39 has been shown to be an accurate marker for T(reg) detection. The objectives of this study were: (i) to identify T(reg) expressing CD39 in patients with TB and to compare the results with those obtained by the standard phenotypic markers; (ii) to evaluate if T(reg) are expanded in vitro by exogenous interleukin (IL)-2 or by antigen-specific stimulation; and (iii) to characterize T(reg) function on the modulation of antigen-specific responses. We enrolled 13 patients with pulmonary TB and 12 healthy controls. T(reg) were evaluated by flow cytometry ex vivo and after antigen-specific in vitro stimulation using CD25, FoxP3, CD127 and CD39 markers. Results indicate that CD39(+) cells within the CD4(+)CD25(high) cells have T(reg) properties (absence of interferon-gamma production and transforming growth factor-beta1 release upon stimulation). Ex vivo analysis did not show significant differences between TB patients and controls of T(reg) by classical or novel markers. In contrast, a significantly higher percentage of T(reg) was found in TB patients after antigen-specific stimulation both in the presence or absence of IL-2. Depletion of CD39(+) T(reg) increased RD1-specific responses significantly. In conclusion, CD39 is an appropriate marker for T(reg) identification in TB. These results can be useful for future studies to monitor Mycobacterium tuberculosis-specific response during TB.