Intracellular IFN-gamma production and IL-12 serum levels in latent autoimmune diabetes of adults (LADA) and in type 2 diabetes

Altered serum levels of cytokines in patients with myasthenia gravis

Background

Myasthenia gravis (MG) is an autoimmune disease characterized by generalized skeletal muscle contraction weakness due to autoantibodies targeting neural-muscular junctions. Here, we investigated the relationship between key cytokines and MG type, disease course, antibodies, and comorbidities.

Method

Cytokine levels in serum samples collected from MG (n = 45) and healthy control (HC, n = 38) patients from January 2020 to June 2022 were quantified via flow cytometry.

Results

Levels of IL-6 were higher in the MG group versus healthy individuals (p = 0.026) and in patients with generalized versus ocular MG (p = 0.019). IL-6 levels were positively correlated with QMG score. In patients with MG with both AChR and Titin antibodies, serum levels of sFas and granulysin were higher than in those with AChR alone (p = 0.036, and p = 0.028, respectively). LOMG had a reduction in serum levels of IL-2 compared to EOMG (p = 0.036). LOMG patients with diabetes had lower serum levels of IL-2, IL-4, and IFN-γ (p = 0.044, p = 0.038, and p = 0.047, respectively) versus those without diabetes. sFas in the MG with Abnormal thymus were reduced compared to those in MG with Normal thymus (p = 0.008).

Conclusions

This study revealed a positive correlation between IL-6 level and MG status. Serum cytokine levels of the AChR + Titin MG group differed from those of the AChR group. LOMG had a lower IL-2 level. Comorbidities affect some cytokines in peripheral blood in MG serum.

Differential Expression of Suppressor of Cytokine Signaling and Interferon Gamma in Lean and Obese Patients with Type 2 Diabetes Mellitus

BACKGROUND

The model of obesity-induced insulin resistance has long been used to explain the development of type 2 diabetes mellitus (T2DM) in obese individuals (body mass index (BMI) > 25 kg/m²), but this model failed to explain the development of the disease in lean individuals (BMI < 18.5 kg/m²). Defects in the insulin signaling pathway have been postulated to play a role in these patients, particularly in suppressors of cytokine signaling (SOCS) proteins, which are involved in the downregulation of insulin transduction. The expression of SOCS is also known to be induced by cytokines such as interferon gamma (IFN-γ). It is still not clear whether these pathways operate differently in lean versus obese patients with T2DM. Therefore, this pilot study was designed to study the expression of SOCS1, SOCS3, and IFN-γ in lean and obese patients with T2DM.

OBJECTIVES

The levels of IFN-γ in serum and the messenger RNA (mRNA) expression of SOCS (SOCS1 and SOCS3) and IFN-γ genes in whole blood in lean and obese patients with T2DM.

METHODS

Sixty newly diagnosed T2DM patients (not on any pharmacotherapy) were enrolled and divided into 2 groups of lean (BMI < 18.5 kg/m²) and obese (BMI > 25 kg/m²) patients (n = 30 per group). Serum IFN-γ was measured by enzyme-linked immunosorbent assay (ELISA), and mRNA expression of IFN-γ, SOCS1, and SOCS3 was measured by real-time polymerase chain reaction (PCR) using the ∆∆ Ct method.

RESULTS

Serum IFN-γ levels were 10.83 ± 5.81 pg/mL in the lean group and 9.35 ± 5.14 pg/mL in the obese group (P = 0.02). Fasting serum insulin levels were 16.07 ± 8.39 µIU/mL in the lean group and 27.11 ± 4 .91 µIU/mL in the obese group (P = 0.001). There was a 3.16-fold increase in mRNA expression of IFN-γ and a 1.3-fold increase in mRNA expression of SOCS1 in the lean group compared to the obese group. mRNA expression of SOCS3 was similar in both groups.

CONCLUSIONS

The level of IFN-γ increased at both transcriptional and translational levels, and mRNA expression of SOCS1 was higher in the lean group than in the obese group. The SOCS protein is a known negative regulator in insulin signaling pathways. Thus, our findings and available scientific literature suggest that IFN-γ might impair the insulin signaling pathway to a greater extent in lean patients than in obese patients via induction of SOCS1. This signaling pathway could be a major contributing factor to hyperglycemia in lean patients with T2DM compared with obese counterparts. This suggests that different therapeutic approaches to these groups might be of greater benefit in the treatment of T2DM.

Proinflammatory cytokine polarization in type 2 diabetes

Subclinical inflammatory reaction is associated with non-insulin dependent diabetes. Therefore, the aim of the present study is to describe the effect of the three cytokines: interferon γ (IFN-γ), interleukin (IL)-4 and IL-5 on the development of type 2 diabetes (T2D). Forty-five volunteers (after their permission) were participated in this work; according to their clinical examination and laboratory investigations (fasting blood sugar, 2 hours postprandial, HbA1c and lipid profile), they were divided into thirteen control (non-diabetic) (five females and eight males) and thirty-two diabetic patients (twenty-one females and eleven males). Thereafter, their sera were evaluated for C-reactive protein (CRP), IFN-γ, IL-4 and IL-5. The results revealed an increasing trend of CRP and a significant increase of IFN-γ in diabetic patients with no sex difference. A positive correlation between IFN-γ and both IL-4 and IL-5 in control, and a positive correlation between IL-4 and IL-5 in diabetic patients had been visualized. These results denoted that there may be an association of the pro-inflammatory cytokines in the etiology of diabetes mellitus type 2.

T-Natural Killers and Interferon Gamma/Interleukin 4 in Augmentation of Infection in Foot Ulcer in Type 2 Diabetes

BACKGROUND

The link between immune system and type 2 diabetes mellitus (T2DM) pathogenesis attracted attention to demonstrate the role of immune cells and their secreted cytokines in T2DM development and its subsequent foot complications.

OBJECTIVE

To investigate the relation between T Natural killer cell (TNK) %, Interleukin 4 (IL4) and Interferon gamma (IFN-γ) and diabetic foot infection (DFI) development in patients with diabetic foot ulcer (DFU).

PATIENTS AND METHODS

Ninety patients with diabetes were included in this work, divided as T2DM group (n=30), DFU group (n=30), and DFI group (n=30). TNK% was detected using flow cytometry. Serum IL4 and IFN-γ were measured by ELISA. Diabetes biochemical parameters were also analyzed.

RESULTS

Significant decrease was detected in TNK% and IFN-γ in DFI group compared to other 2 groups (P<0.001). Significant decrease was detected in serum levels of IL4 in DFI group compared to T2DM group (P=0.006). IFN-γ/IL4 was significantly decreased in DFI compared to DFU group (P=0.020). There was a significant correlation of TNK% with both IL4 and IFN-γ (r=0.385, P<0.001; r=0.534, P<0.001, respectively). Significant negative correlation of TNK% with HbA1c and LDL was revealed (r=-0.631, P<0.001; and r=-0.261, P=0.013, respectively), while a positive correlation was seen with HDL (r=0.287, P=0.006). A significant negative correlation of IL4 with HbA1c  was found (r=-0.514, P<0.001;. As for IFN-γ, a significant negative correlation with HbA1c and LDL was detected (r=-0.369, P< 0.001; r=-0.229, P=0.030). TNK % and IFN-γ level showed negative correlations with disease duration/year (r=-0.546, P< 0.001; r=-0.338, P=0.001,respectively).

CONCLUSION

Decline in TNK frequency has essential role in T2DM pathogenesis and subsequent foot complications. Downregulation of TNK% and IFN-γ level have potential roles in predicting infection of diabetic ulcer and are correlated with disease duration.

Downregulation of T-Cell Transcription Factors in Adult Latent Autoimmune Diabetes with High-Titer Glutamic Acid Decaroxylase Antibody

INTRODUCTION

Latent autoimmune diabetes in adults (LADA) shows a heterogeneous clinical profile that is dependent on the glutamic acid decaroxylase antibody (GADA) titer. We speculated that LADA patients with a high or low GADA titer may have distinct T-lymphocyte subset profiles and distinct expression patterns of transcription factors involved in T-cell immunomodulation.

METHODS

Patients with LADA (n = 40) and type 2 diabetes (T2DM; n = 14) were recruited to the study, and peripheral blood mononuclear cells were isolated. The proportions of T-lymphocyte subsets (Th1 [T helper type 1], Th2 [T helper type 2], Treg [regulatory T], and Th17 [T helper type 17] cells) were determined by flow cytometry. Real-time polymerase chain reaction (PCR) was performed to estimate mRNA expression levels of the T-cell subtype-enriched transcription factors T-bet (Th1), GATA3 (Th2), transcription factor forkhead box protein 3 (FOXP3) (Treg), and RORC (Th17).

RESULTS

The frequency of Th1 (as a percentage of total CD4⁺T cells) was greater in the LADA patients with high-titer GADA than in the LADA patients with low-titer GADA (11.06 ± 1.62 vs. 7.05 ± 0.86, P = 0.030). Compared to the T2DM group, in the low-titer GADA group the frequency of Th1 was significantly reduced (7.05 ± 0.86 vs. 16.75 ± 3.73, P = 0.017) and the frequency of Th17 frequency was signficantly increased (1.11 ± 0.09 vs. 0.74 ± 0.16, P = 0.017). Compared to T2DM patients, in the high-titer GADA group there was a significantly reduced expression of FOXP3 (0.35 ± 0.13 vs. 1.75 ± 0.54, P = 0.002), RORC (0.53 ± 0.19 vs. 2.00 ± 0.77, P = 0.046), and GATA3 (0.74 ± 0.17 vs. 2.31 ± 0.91, P = 0.046). Similarly, the high-titer GADA group expressed reduced levels of FOXP3 and RORC compared to the low-titer GADA group (0.35 ± 0.13 vs. 1.50 ± 0.41, P = 0.027; 0.53 ± 0.19 vs. 1.35 ± 0.21, P  = 0.027, respectively). There was a negative correlation between FOXP3 expression level and GADA titer for the entire cohort (r = - 0.0433, P = 0.015) and a stronger negative correlation in LADA patients (r = - 0.606, P = 0.008).

CONCLUSION

LADA patients with high-titer GADA express lower levels of T-cell transcription factors, including the Treg transcription factor FOXP3, which may contribute to differences in the clinical profile compared to LADA patients with low-titer GADA.

TRIAL REGISTRATION

ClinicalTrials.gov identifier, NCT01159847.

Analysis of inflammatory cytokine and TLR expression levels in Type 2 Diabetes with complications

The pathogenesis and complications of type 2 diabetes (T2DM) are closely linked with defective glucose metabolism, obesity, cardiovascular disease and an inability to mount an effective immune response to certain pathogenic organisms. Perturbations in key innate immune receptors known as Toll-like receptors (TLRs) and inflammatory mediators such as IL-6, TNFα and IL-1β have been linked with T2DM. Herein, we sought to establish whether patients with T2DM and underlying complications exhibit perturbations in cytokine and TLR expression. Serum cytokine and mRNA levels of cytokines/TLRs in monocytes (M) and neutrophils (N) were measured in a cohort of 112 diabetic patients: good glycaemic control without complications (GC), good glycaemic control with complications (GCC), poor glycaemic control without complications (PC) and poor glycaemic control with complications (PCC) and compared them with 34 non-diabetic volunteers (NGT). Serum cytokine levels were normal in all study participants. In the GC group, cytokine and TLR gene expression were enhanced compared to NGT. In contrast, suppressed cytokine and TLR gene expression were evident in PC, GCC & PCC groups when compared to the GC. In conclusion, whereas serum pro-inflammatory cytokine levels are unaltered in T2DM patients, differences in inflammatory gene profiles exist among the T2DM patient groups.

Study of IL4-590C/T and IL6-174G/C Gene Polymorphisms in Type 2 Diabetic Patients With Chronic Kidney Disease in North Indian Population

To explore the associations between potential functional promoter polymorphisms in pro-inflammatory and anti-inflammatory (IL-4(-590C/T) and IL-6(-174G/C) cytokine genes, and kidney dysfunction in North Indian type 2 diabetic subjects with chronic kidney disease. A total of 150 subjects aged 25-75 year were included in this study. The glomerular filtration rate (GFR) and serum creatinine were estimated. PCR was performed to analyse genotype distribution in IL-4 (-590T/C) and IL-6 (-174G/C) among healthy, type 2 diabetic patients with or without CKD. The genotype distributions were determined by Hardy-Weinberg equilibrium. CKD patients showed lower GFR (59.36 ± 1.33 ml/min/1.73 m² ) and higher serum creatinine (1.93 ± 0.99% mg) level in comparison to diabetic patients without CKD and healthy subjects. Genotypic distribution of the different genotypes among the study groups in IL-4 gene was genotype CC = 30, TC = 12, and TT = 8 in CKD patients. In type 2 diabetic patients without CKD, genotype distribution was CC = 38, TC = 10, and TT = 2. In healthy subjects, distribution of genotype was CC = 35, TC = 14, and TT = 1. The distribution of different genotype among the study groups for IL-6 gene was GG = 27, GC = 20, and CC = 3 in healthy subjects; GG = 28, GC = 19, and CC = 3 in diabetic patients without CKD and GG = 38, GC = 11, and CC = 1 in diabetic patients with CKD. There was no significant difference in the distribution of genotype frequencies between healthy subjects and diabetic patients without CKD but a significant difference was found in diabetic patients with CKD. The functional promoter polymorphisms IL4-590C/T and IL6-174G/C, which affect the IL-4 and IL-6 levels in north Indian subjects, were associated with kidney dysfunction and CKD. J. Cell. Biochem. 118: 1803-1809, 2017. © 2016 Wiley Periodicals, Inc.

Significance of CXCL12 in type 2 diabetes mellitus and its associated complications

Immune responses are extensively accepted as primitive etiological leading causes involved in immune system diseases. It is now well established that chemokines as the main arms of the immune system play critical roles in the regulation of immune responses in the pathogenesis of different diseases. Several environmental and genetic elements of the immune system are also believed to potentially affect both the onsets of immunological diseases. The stromal cell-derived factor-1 alpha (SDF-1α) which in new nomenclature is nominated as C-X-C motif ligand 12 (CXCL12) is involved in the development and progression of immune responses. The CXCL12 is an extensively active chemokine that serves as a recruiter for migration and trafficking of leukocytes and hematopoietic progenitor cells. Patients suffering type 2 diabetes (T2D) that ascribe heterozygous SDF-1 3'A genotype (801G/A in the 3' untranslated region) have increased insulin-dependent mobilization of adult progenitor cells, which are known to participate in angiogenesis and vascular repair. Conversely, homing of progenitor cells contributes to the diabetes vascular complications. Because carriers of the SDF-1 3'A genotype show increased levels of the CXCL12 messenger RNA (mRNA) in their peripheral blood mononuclear cells. Genetic variations of CXCL12 gene might affect trafficking of inflammatory cells or defected precursors and hence induced tendency to diabetic complications. The SDF-1 3'A genetic variation of CXCL12 influences the development of late vascular diabetic complications, and previous studies reported that this genetic variation regulates the expression of CXCL12. Therefore, the main goal of the present study was to collect the most recent reports regarding the relation between serum concentrations and SDF-1 3'A genetic variation of CXCL12 in T2D.

Latent autoimmune diabetes of the adult: current knowledge and uncertainty

Patients with adult-onset autoimmune diabetes have less Human Leucocyte Antigen (HLA)-associated genetic risk and fewer diabetes-associated autoantibodies compared with patients with childhood-onset Type 1 diabetes. Metabolic changes at diagnosis reflect a broad clinical phenotype ranging from diabetic ketoacidosis to mild non-insulin-requiring diabetes, also known as latent autoimmune diabetes of the adult (LADA). This latter phenotype is the most prevalent form of adult-onset autoimmune diabetes and probably the most prevalent form of autoimmune diabetes in general. Although LADA is associated with the same genetic and immunological features as childhood-onset Type 1 diabetes, it also shares some genetic features with Type 2 diabetes, which raises the question of genetic heterogeneity predisposing to this form of the disease. The potential value of screening patients with adult-onset diabetes for diabetes-associated autoantibodies to identify those with LADA is emphasized by their lack of clinically distinct features, their different natural history compared with Type 2 diabetes and their potential need for a dedicated management strategy. The fact that, in some studies, patients with LADA show worse glucose control than patients with Type 2 diabetes, highlights the need for further therapeutic studies. Challenges regarding classification, epidemiology, genetics, metabolism, immunology, clinical presentation and treatment of LADA were discussed at a 2014 workshop arranged by the Danish Diabetes Academy. The presentations and discussions are summarized in this review, which sets out the current ideas and controversies surrounding this form of diabetes.

Nontuberculous mycobacterial osteomyelitis

Osteomyelitis caused by nontuberculous mycobacteria (NTM) can have severe consequences and a poor prognosis. Physicians therefore need to be alert to this condition, especially in immunocompromised patients. Although the pathogenesis of NTM osteomyelitis is still unclear, studies in immunodeficient individuals have revealed close relationships between NTM osteomyelitis and defects associated with the interleukin-12-interferon-γ-tumor necrosis factor-α axis, as well as human immunodeficiency virus infection, various immunosuppressive conditions, and diabetes mellitus. Culture and species identification from tissue biopsies or surgical debridement tissue play crucial roles in diagnosing NTM osteomyelitis. Suitable imaging examinations are also important. Adequate surgical debridement and the choice of appropriate, combined antibiotics for long-term anti-mycobacterial chemotherapy, based on in vitro drug susceptibility tests, are the main therapies for these bone infections. Bacillus Calmette-Guerin vaccination might have limited prophylactic value. The use of multiple drugs and long duration of treatment mean that the therapeutic process needs to be monitored closely to detect potential side effects. Adequate duration of anti-mycobacterial chemotherapy together with regular monitoring with blood and imaging tests are key factors determining the recovery outcome in patients with NTM osteomyelitis.

Oxidative stress and its association with TNF-α-308 G/C and IL-1α-889 C/T gene polymorphisms in patients with diabetes and diabetic nephropathy

Diabetic nephropathy is one of the major complications of type 2 diabetes and it is currently the leading cause of end-stage renal disease. The stimulus for the increase in inflammation in diabetes is still under investigation; however, reactive oxygen species might be a primary source. This study was conducted in four groups in West Indian population: control (235), type 2 diabetes (DM) (214), nephropathy with diabetes (DN) (188) and nephropathy without diabetes (NDN) (196). Oxidative stress markers such as malondialdehyde (MDA), glutathione (GSH), superoxide dismutase and catalase were measured in all the groups. TNF-α-308 G/C and IL-1α-889 C/T polymorphisms were analyzed using PCR-RFLP method. Correlations between genotype frequency and the level of oxidative stress markers were examined. MDA was significantly increased in the patient group in comparison to control group. GSH and SOD were significantly decreased in the patient group in comparison to control group. There was no significant difference observed in genotype frequency of TNF-α in the patient group compared with control group. IL-1α-889 C/T polymorphism may be associated with diabetic nephropathy. Moreover there was no association of TNF-α-308 G/C polymorphism with diabetic nephropathy in West Indian population. The higher serum levels of oxidative stress markers in diabetic patients with nephropathy suggest the possible role of oxidative stress.

The MDM2 inhibitor Nutlin-3 attenuates streptozotocin-induced diabetes mellitus and increases serum level of IL-12p40

Besides its well-established oncosuppressor activity, a key function of p53 in regulating metabolic pathways has been recently identified. Nevertheless, the role of p53 with respect to diabetes mellitus (DM) appears highly controversial. To address this issue, we have used the cis-imidazoline compound Nutlin-3, an inhibitor of MDM2/p53 interaction, which represents a potent and selective non-genotoxic activator of the p53 pathway both in in vivo and in vitro experimental settings. Experimental DM was induced by intraperitoneal injections of low concentrations of streptozotocin (STZ) in C57BL/6N mice (n = 20). A group of control vehicle-injected mice (n = 10) and of STZ-treated mice (n = 10) was co-injected with Nutlin-3. Mice co-injected with STZ + Nutlin-3 exhibited attenuated features of DM with respect to animals treated with STZ alone. Indeed, STZ + Nutlin-3-treated mice were characterized by significantly (p < 0.05) lower levels of hyperglycemia, reduced weight loss, and increased spleen weight. In addition, STZ alone promoted a marked decrease in the levels of several circulating cytokines, including interleukin-12 (IL-12)p40. On the other hand, co-injection of STZ + Nutlin-3 significantly (p < 0.01) counteracted IL-12p40 down-modulation. In vitro experiments performed on the RAW264.7 macrophagic cell line model, used as cellular source of IL-12p40, demonstrated that Nutlin-3 treatment increased IL-12p40 release, strongly suggesting a direct effect of Nutlin-3 on the immune system. Overall, these data demonstrate that systemic administration of Nutlin-3 ameliorates the severity of STZ-induced DM and increases the levels of circulating IL-12p40.

Interleukin (IL)-10 gene polymorphisms are associated with type 2 diabetes with and without nephropathy: a study of patients from the southeast region of Iran

The impact of several environmental and genetic factors on diabetes and its complications is well documented. It has also been established that cytokines play a key role in the regulation of immune responses which have been shown to be important in the pathogenesis of diabetes. Studies showed that single-nucleotide polymorphisms within the -592 region of interleukin-10 (IL-10) are associated with the regulation of its expression. In this study, we aimed to find polymorphisms of this region that may be associated to type 2 diabetic (T2D) patients with and without nephropathy. In this study, peripheral blood samples were collected from 100 T2D patients without nephropathy, 100 T2D patients with nephropathy, and 100 healthy controls. DNA was extracted, and a polymerase chain reaction-restriction fragment length polymorphism technique was performed to examine the polymorphisms within the -592 region of the IL-10 gene. Our results showed a significant difference between the genotypes and alleles of the -592 region of IL-10 in nephropathic and non-nephropathic patients in comparison to the healthy controls. The differences between the two patient groups in relation to genotypes and alleles were not significant. Results of this study suggest that the functional gene polymorphism of IL-10 reported here may play an important role in the pathogenesis of diabetes, but it seems that these polymorphisms do not have an effect on the nephropathic complications of the disease.

State of the union between metabolism and the immune system in type 2 diabetes

Lymphocytes and myeloid cells (monocyte/macrophages) have important roles in multiple types of diseases characterized by unresolved inflammation. The relatively recent appreciation of obesity, insulin resistance and type 2 diabetes (T2D) as chronic inflammatory diseases has stimulated interest in understanding the role of immune cells in metabolic imbalance. Myeloid cells regulate inflammation through cytokine production and the adipose tissue remodeling that accompanies hyper-nutrition, thus are critical players in metabolic homeostasis. More recently, multiple studies have indicated a role for T cells in obesity-associated inflammation and insulin resistance in model organisms, with parallel work indicating that pro-inflammatory changes in T cells also associate with human T2D. Furthermore, the expansion of T cells with similar antigen-binding sites in obesity and T2D indicates these diseases share characteristics previously attributed to inflammatory autoimmune disorders. Parallel pro-inflammatory changes in the B-cell compartment of T2D patients have also been identified. Taken together, these studies indicate that in addition to accepted pro-inflammatory roles of myeloid cells in T2D, pro-inflammatory skewing of both major lymphocyte subsets has an important role in T2D disease pathogenesis. Basic immunological principles suggest that alterations in lymphocyte function in obesity and T2D patients are an integral part of a feed-forward pro-inflammatory loop involving additional cell types. Importantly, the pro-inflammatory loop almost inevitably includes adipocytes, known to respond to pro-inflammatory, pro-diabetogenic cytokines originating from the myeloid and lymphoid compartments. We propose a model for inflammation in T2D that functionally links lymphocyte, myeloid and adipocyte contributions, and importantly proposes that tools for B-cell ablation or regulation of T-cell subset balance may have a place in the endocrinologist's limited arsenal.

Elevated proinflammatory cytokine production by a skewed T cell compartment requires monocytes and promotes inflammation in type 2 diabetes

An appropriate balance between proinflammatory (Th17 and Th1) and anti-inflammatory (regulatory T cells [Tregs] and Th2) subsets of T cells is critical to maintain homeostasis and avoid inflammatory disease. Type 2 diabetes (T2D) is a chronic inflammatory disease promoted by changes in immune cell function. Recent work indicates T cells are important mediators of inflammation in a mouse model of T2D. These studies identified an elevation in the Th17 and Th1 subsets with a decrease in the Treg subset, which culminates in inflammation and insulin resistance. Based on these data, we tested the hypothesis that T cells in T2D patients are skewed toward proinflammatory subsets. Our data show that blood from T2D patients has increased circulating Th17 cells and elevated activation of Th17 signature genes. Importantly, T cells required culture with monocytes to maintain Th17 signatures, and fresh ex vivo T cells from T2D patients appeared to be poised for IL-17 production. T cells from T2D patients also have increased production of IFN-γ, but produce healthy levels of IL-4. In contrast, T2D patients had decreased percentages of CD4(+) Tregs. These data indicate that T cells in T2D patients are naturally skewed toward proinflammatory subsets that likely promote chronic inflammation in T2D through elevated cytokine production. Potential therapies targeted toward resetting this balance need to be approached with caution due to the reciprocal relationship between Th17 cells and Tregs. Understanding the unique aspects of T2D T cells is essential to predict outcomes of such treatments.

Interaction between immunoglobulin allotypes and NK receptor genes in diabetes post-hepatitis C virus infection

Genetic interactions between natural killer (NK) cells immunoglobulin-like receptor (KIR) genes and immunoglobulin allotypes have been previously reported in type 2 diabetes mellitus (DM) patients. Puerto Rican Americans with a history of intravenous drug use who developed DM following HCV infection (n=32) were compared to individuals infected with HCV without diabetes (n=121) and to DM non-infected individuals (n=95). Subjects were genotyped for KIRs and immunoglobulin allotypes. We found interactions of immunoglobulin allotypes KM3/KM3 with NK inhibitory receptors 2DL3/2DL3, 2DL1 in the absence of 2DS4 associated with susceptibility to DM in HCV infected individuals. These data suggest the possibility that a subset of patients with HCV could have an immune-mediated component contributing to the development of DM.

Differential regulation of TLR4 expression in human B cells and monocytes

Toll-like receptor 4 (TLR4) is an innate immune receptor that is constitutively and inducibly activated in monocytes. Although TLR4 is expressed at very low levels on human B cells from healthy individuals, recent reports showed that TLR4 expression and function is elevated in B cells from inflammatory disease patients. New data showed that TLR4 expression on B cells is increased upon stimulation through surface Igμ and CD40 in combination with IL-4. In contrast, monocyte stimulation through CD40 and IL-4 receptors decreased TLR4 surface expression. Analysis of molecular signatures of TLR4 activation in stimulated B cells suggested that TLR4 is regulated by different mechanisms in B cells compared to monocytes. PU.1 and interferon regulatory factor association with the TLR4 promoter are sufficient for TLR4 transcription, but are not sufficient for surface TLR4 expression on B cells. In contrast, the PU.1/IRF combination is sufficient for surface TLR4 expression on monocytes. These data identify mechanisms that can activate B cell TLR4 expression in inflammatory disease patients, and demonstrate that B cells have additional layers of TLR4 regulation absent in monocytes.

Decreased prevalence of lymphatic filariasis among diabetic subjects associated with a diminished pro-inflammatory cytokine response (CURES 83)

Epidemiological studies have shown an inverse correlation between the incidence of lymphatic filariasis (LF) and the incidence of allergies and autoimmunity. However, the interrelationship between LF and type-2 diabetes is not known and hence, a cross sectional study to assess the baseline prevalence and the correlates of sero-positivity of LF among diabetic subjects was carried out (n = 1416) as part of the CURES study. There was a significant decrease in the prevalence of LF among diabetic subjects (both newly diagnosed [5.7%] and those under treatment [4.3%]) compared to pre-diabetic subjects [9.1%] (p = 0.0095) and non-diabetic subjects [10.4%] (p = 0.0463). A significant decrease in filarial antigen load (p = 0.04) was also seen among diabetic subjects. Serum cytokine levels of the pro-inflammatory cytokines—IL-6 and GM-CSF—were significantly lower in diabetic subjects who were LF positive, compared to those who were LF negative. There were, however, no significant differences in the levels of anti-inflammatory cytokines—IL-10, IL-13 and TGF-β—between the two groups. Although a direct causal link has yet to be shown, there appears to be a striking inverse relationship between the prevalence of LF and diabetes, which is reflected by a diminished pro-inflammatory cytokine response in Asian Indians with diabetes and concomitant LF.

Childhood helminth infections can reduce the risk and severity of allergies and autoimmune diseases, by means of immunomodulation, and a decrease in helminth infections could potentially account for the increased prevalence of these diseases in the western world (hygiene hypothesis). We hypothesized that the same immunomodulatory effect can have an impact on metabolic diseases like obesity, diabetes, hypertension and atherosclerosis, wherein inflammation plays a crucial role (extended hygiene hypothesis). To test this hypothesis, we examined the prevalence of lymphatic filariasis (LF) among diabetic, pre-diabetic and non-diabetic subjects who were part of the CURES (Chennai Urban Rural Epidemiology Study) study. In accordance with our hypothesis, we found reduced prevalence of LF among diabetic subjects compared to non-diabetic and pre-diabetic subjects. This was associated with decreased filarial antigen load and anti-filarial antibody levels. The association remained significant even after adjusting for socioeconomic status, age and gender. Interestingly, within the diabetic subjects, those who were filarial positive had reduced levels of pro-inflammatory markers (TNF-α, IL-6 and GM-CSF) compared to those who were filarial negative. In light of these findings, the decreasing incidence of filarial infection due to mass drug administration could potentially have an unexpected adverse impact on the prevalence of diabetes in India.

B cells as under-appreciated mediators of non-auto-immune inflammatory disease

B lymphocytes play roles in many auto-immune diseases characterized by unresolved inflammation, and B cell ablation is proving to be a relatively safe, effective treatment for such diseases. B cells function, in part, as important sources of regulatory cytokines in auto-immune disease, but B cell cytokines also play roles in other non-auto-immune inflammatory diseases. B cell ablation may therefore benefit inflammatory disease patients in addition to its demonstrated efficacy in auto-immune disease. Current ablation drugs clear both pro- and anti-inflammatory B cell subsets, which may unexpectedly exacerbate some pathologies. This possibility argues that a more thorough understanding of B cell function in human inflammatory disease is required to safely harness the clinical promise of B cell ablation. Type 2 diabetes (T2D) and periodontal disease (PD) are two inflammatory diseases characterized by little autoimmunity. These diseases are linked by coincident presentation and alterations in toll-like receptor (TLR)-dependent B cell cytokine production, which may identify B cell ablation as a new therapy for co-affected individuals. Further analysis of the role B cells and B cell cytokines play in T2D, PD and other inflammatory diseases is required to justify testing B cell depletion therapies on a broader range of patients.

Nephropathic complication of type-2 diabetes is following pattern of autoimmune diseases?

The impact of several environmental and genetic factors on diabetes and its complications is well documented. The present study was aimed to examine the serum levels of IL-17A and IFN-gamma as antagonistic cytokines in nephropathic and non-nephropathic type-2 diabetic patients. In this experimental study, serum samples were obtained from 180 type-2 diabetic patients, 100 nephropathic type-2 diabetic patients and 100 healthy controls. Serum levels of IL-17A and IFN-gamma was detected by ELISA. Results of this study showed that the serum level of IFN-gamma was higher in both diabetic patients (nephropathic and non-nephropathic) in comparison to the controls. In terms of IL-17A, while non-nephropathic type-2 diabetic patients showed an increased serum level of it, the other patients group had a lower serum level. Based on these findings, it can be concluded that the lower serum level of IL-17A is possibly associated with nephropathic complications of type-2 diabetes.

Correlations of sleep disturbance with the immune system in type 2 diabetes mellitus

AIMS

The circadian rhythm and immune system are thought to be associated with the pathological state of diabetes. The aim of this study was to examine the correlation of circadian rhythm disturbance including sleep disturbance with the immune state in patients with type 2 diabetes compared to healthy controls.

METHODS

Nineteen patients with type 2 diabetes (11 males and 8 females; aged 46-85 years) and 19 healthy controls (7 males and 12 males; aged 45-85 years) were recruited, and the presence of circadian rhythm disturbance including sleep disturbance was examined using an actigraph. Immunological parameters were also measured.

RESULTS

Sleep and circadian rhythm disturbances were more frequently noted in diabetic patients than in healthy controls. Higher fasting plasma glucose and hemoglobin A1c levels were correlated with stronger sleep and circadian rhythm disturbances. The levels of B lymphocytes, helper T lymphocytes, natural killer cells, natural killer activity, and several cytokines were increased in diabetic patients compared to healthy controls. Correlations were shown among sleep disturbance (circadian rhythm disturbance), immunological measures, and diabetic indices.

CONCLUSION

The exacerbation of diabetes was related to the level of sleep disturbance, circadian rhythm disturbance, and activation of the immune system.

Augmentation of Megakaryocyte Expression of FcγRIIa by Interferon γ

Objective— The purpose of this study was to identify factors that alter expression of FcγRIIa by megakaryocytes.

Methods and Results— Effects of selected cytokines and growth factors on megakaryocyte expression of FcγRIIa were assessed with phorbol 12-myristate 13-acetate (PMA)-differentiated human erythroleukemia (HEL) cells and with thrombopoietin-differentiated CD34 stem cells and compared with those obtained with myelocytic cell lines and a monocytic cell lines. Expression of FcγRIIa was quantified with the use of Western blots and real-time reverse transcriptase-polymerase chain reaction. Megakaryocyte differentiation was identified by expression of CD41, CD42, and von Willebrand factor with the use of flow cytometry. Interferon (IFN) γ increased protein expression of FcγRIIa by HEL cells and CD34 stem cells after megakaryocyte differentiation (maximal ≈4-fold, P <0.001 for each). IFNγ did not increase expression of FcγRIIa by undifferentiated HEL and CD34 cells. Expression of FcγRIIa mRNA was increased (2-fold, P <0.001) in megakaryocyte-differentiated HEL cells. IFNγ did not increase expression of FcγRIIa by undifferentiated myelocytic or monocytic cell lines.

Conclusions— IFNγ appears to selectively increase expression of FcγRIIa by cells exhibiting characteristics of megakaryocytes. This effect of IFNγ may contribute to greater platelet expression of FcγRIIa in patients with atherosclerotic vascular disease.

Evaluation of IFN-gamma serum level in nephropatic type 2 diabetic patients

The present study was aimed to examine the serum level of IFN-gamma in type 2 diabetic patients with nephropatic complications. In this experimental study, serum samples were obtained from 100 type 2 diabetic patients suffering from nephropathy and 100 healthy controls. Serum level of IFN-gamma was analyzed by ELISA. Results of this study showed that the mean serum level of IFN-gamma was 16.09 +/- 2.04 and 4.03 +/- 1.00 pg mL(-1) in nephropathic patients and healthy controls, respectively. Statistical analysis of data showed that the difference in the IFN-gamma serum level was significant between nephropathic patients and controls. Due to the elevated level of IFN-gamma in nephropathic patients, it can be possibly concluded that IFN-gamma is involved in nephropathy complication of type 2 diabetes.

Glycine treatment decreases proinflammatory cytokines and increases interferon-gamma in patients with type 2 diabetes

BACKGROUND

Amino acids have been shown to stimulate insulin secretion and decrease glycated hemoglobin (A1C) in patients with Type 2 diabetes. In vitro, glycine reduces tumor necrosis factor (TNF)-alpha secretion and increases interleukin-10 secretion in human monocytes stimulated with lipopolysaccharide. The aim of this study was to determine whether glycine modifies the proinflammatory profiles of patients with Type 2 diabetes.

MATERIALS/SUBJECTS AND METHODS

Seventy-four patients, with Type 2 diabetes were enrolled in the study. The mean age was 58.5 yr, average age of diagnosis was 5 yr, the mean body mass index was 28.5 kg/m2, the mean fasting glucose level was 175.5 mg/dl and the mean A1C level was 8%. They were allocated to one of two treatments, 5 g/d glycine or 5 g/d placebo, po tid, for 3 months.

RESULTS

A1C levels of patients given glycine were significantly lower after 3 months of treatment than those of the placebo group. A significant reduction in TNF-receptor I levels was observed in patients given glycine compared with placebo. There was a decrease of 38% in the interferon (IFN)-gamma level of the group treated with placebo, whereas that of the group treated with glycine increased up to 43%. These data showed that patients treated with glycine had a significant decrease in A1C and in proinflammatory cytokines and also an important increase of IFN-gamma.

CONCLUSION

Treatment with glycine is likely to have a beneficial effect on innate and adaptive immune responses and may help prevent tissue damage caused by chronic inflammation in patients with Type 2 diabetes.

The role of interferon-gamma in the increased tuberculosis risk in type 2 diabetes mellitus

As patients with diabetes mellitus are at increased risk of developing tuberculosis, we hypothesized that this susceptibility to mycobacterial infection is due to a defective Th1-cytokine response. To explore this hypothesis, we examined four groups of subjects in Indonesia: 23 patients with tuberculosis, 34 patients with tuberculosis and diabetes, 32 patients with diabetes only and 36 healthy controls. Ex-vivo production of interferon (IFN)gamma, tumour necrosis factor-alpha and interleukin (IL)-1beta, 6, 10, -12 and -4 was measured following stimulation with Mycobacterium tuberculosis, Escherichia coli lipopolysaccharide and phytohaemagglutinin. Patients with active tuberculosis were found to have lower IFNgamma levels and a higher production of other pro-inflammatory cytokines and IL-4, both in the presence and absence of diabetes. Diabetes patients without tuberculosis, however, showed strongly reduced non-specific IFNgamma production, which is essential for inhibition of the initial growth of M. tuberculosis. Our data suggest that a defective non-specific immune response in diabetes may contribute to an increased susceptibility to develop tuberculosis.