A novel TNFR2 agonist antibody expands highly potent regulatory T cells.

Regulatory T cells (Treg cells) restrict immune system activity, such as in response to self-antigens, and are switched on by tumor necrosis factor receptor 2 (TNFR2). Therapeutic activation of TNFR2, thereby expanding Treg cells and suppressing immune activity, may be beneficial to patients with various inflammatory diseases. Here, we characterized a new human TNFR2-directed antibody agonist isolated from mice. We found that the antibody agonist expanded the number of Treg cells within cultures of primary human CD4+ T cells from healthy donors and patients with type 1 diabetes or Sézary syndrome. These Treg cells had increased metabolic gene expression and intracellular itaconate concentrations, characteristics associated with maximally suppressive, anti-inflammatory Treg cells. Furthermore, antibody-expanded Treg cells repressed the activity of primary human CD8+ effector T cells (Teff cells). Epitope mapping suggested that the antibody bound to TNFR2 through a natural cross-linking surface and that Treg cell expansion was independent of the antibody Fc region. In addition, Treg cell expansion was not increased by adding either supplemental TNF ligand or a cross-linking reagent, suggesting that the antibody agonist by itself can elicit maximal activity, a notion that was confirmed by increased secretion of soluble TNFR2. Pending in vivo tests, these features indicate that this TNFR2 antibody agonist has the potential to safely and effectively treat various inflammatory disorders.

Efficacy and safety of once-weekly exenatide after switching from twice-daily exenatide in patients with type 2 diabetes.

AIMS/INTRODUCTION: To evaluate the efficacy and safety of once-weekly (q.w.) extended-release exenatide after switching from twice-daily (b.i.d.) exenatide in patients with type 2 diabetes. MATERIALS AND METHODS: This was an investigator-initiated, prospective, single-arm, multicenter study. Individuals with type 2 diabetes who had been treated with exenatide b.i.d. for at least 3 months were enrolled and switched to exenatide q.w. for 24 weeks. The primary end-point was change in HbA1c at week 24 to test the glucose-lowering effect of exenatide q.w. versus exenatide b.i.d. RESULTS: A total of 58 Japanese individuals with type 2 diabetes completed the study. Glycated hemoglobin was reduced by 0.2% at week 24 (7.2 ± 1.2% vs 7.0 ± 1.2% [56 ± 13 vs 53 ± 13 mmol/mol], 95% confidence interval -0.4 to -0.03%, P < 0.005 for non-inferiority, P = 0.01 for superiority). Fasting plasma glucose was reduced by 12 mg/dL at week 24 (154 ± 46 vs 142 ± 46 mg/dL, P = 0.02). ß-Cell function assessed by homeostasis model assessment of ß-cell function and C-peptide index was significantly improved at week 24. The incidence of self-reported hypoglycemia was reduced, and treatment satisfaction assessed by the Diabetes Treatment Satisfaction Questionnaire and Diabetes Medication Satisfaction Questionnaire was improved at week 24, with no change in body weight. There was no serious adverse event related to the study drug. CONCLUSIONS: Switching from exenatide b.i.d. to exenatide q.w. resulted in a reduction in glycated hemoglobin, fasting plasma glucose and the incidence of hypoglycemia, and improvement in ß-cell function and treatment satisfaction in patients with type 2 diabetes. These findings will be useful for selecting optimal treatment in individuals with type 2 diabetes.

Targeting TNFR2 with antagonistic antibodies inhibits proliferation of ovarian cancer cells and tumor-associated Tregs.

Major barriers to cancer therapy include the lack of selective inhibitors of regulatory T cells (Tregs) and the lack of broadly applicable ways to directly target tumors through frequently expressed surface oncogenes. Tumor necrosis factor receptor 2 (TNFR2) is an attractive target protein because of its restricted abundance to highly immunosuppressive Tregs and oncogenic presence on human tumors. We characterized the effect of TNFR2 inhibition using antagonistic antibodies. In culture-based assays, we found that two TNFR2 antagonists inhibited Treg proliferation, reduced soluble TNFR2 secretion from normal cells, and enabled T effector cell expansion. The antagonistic activity occurred in the presence of added TNF, a natural TNFR2 agonist. These TNFR2 antibodies killed Tregs isolated from ovarian cancer ascites more potently than it killed Tregs from healthy donor samples, suggesting that these antibodies may have specificity for the tumor microenvironment. The TNFR2 antagonists also killed OVCAR3 ovarian cancer cells, which have abundant surface TNFR2. The antibodies stabilized antiparallel dimers in cell surface TNFR2 that rendered the receptor unable to activate the nuclear factor κB pathway and trigger cell proliferation. Our data suggest that, by targeting tumor cells and immunosuppressive tumor-associated Tregs, antagonistic TNFR2 antibodies may be an effective treatment for cancers positive for TNFR2.

Strategies for Utilizing Neuroimaging Biomarkers in CNS Drug Discovery and Development: CINP/JSNP Working Group Report.

Despite large unmet medical needs in the field for several decades, CNS drug discovery and development has been largely unsuccessful. Biomarkers, particularly those utilizing neuroimaging, have played important roles in aiding CNS drug development, including dosing determination of investigational new drugs (INDs). A recent working group was organized jointly by CINP and Japanese Society of Neuropsychopharmacology (JSNP) to discuss the utility of biomarkers as tools to overcome issues of CNS drug development.The consensus statement from the working group aimed at creating more nuanced criteria for employing biomarkers as tools to overcome issues surrounding CNS drug development. To accomplish this, a reverse engineering approach was adopted, in which criteria for the utilization of biomarkers were created in response to current challenges in the processes of drug discovery and development for CNS disorders. Based on this analysis, we propose a new paradigm containing 5 distinct tiers to further clarify the use of biomarkers and establish new strategies for decision-making in the context of CNS drug development. Specifically, we discuss more rational ways to incorporate biomarker data to determine optimal dosing for INDs with novel mechanisms and targets, and propose additional categorization criteria to further the use of biomarkers in patient stratification and clinical efficacy prediction. Finally, we propose validation and development of new neuroimaging biomarkers through public-private partnerships to further facilitate drug discovery and development for CNS disorders.

Treg activation defect in type 1 diabetes: correction with TNFR2 agonism.

Activated T-regulatory cells (aTregs) prevent or halt various forms of autoimmunity. We show that type 1 diabetics (T1D) have a Treg activation defect through an increase in resting Tregs (rTregs, CD4(+)CD25(+)Foxp3(+)CD45RA) and decrease in aTregs (CD4(+)CD25(+)Foxp3(+)CD45RO) (n= 55 T1D, n=45 controls, P=0.01). The activation defect persists life long in T1D subjects (T1D=45, controls=45, P=0.01, P=0.04). Lower numbers of aTregs had clinical significance because they were associated with a trend for less residual C-peptide secretion from the pancreas (P=0.08), and poorer HbA1C control (P=0.03). In humans, the tumor necrosis factor receptor 2 (TNFR2) is obligatory for Treg induction, maintenance and expansion of aTregs. TNFR2 agonism is a method for stimulating Treg conversion from resting to activated. Using two separate in vitro expansion protocols, TNFR2 agonism corrected the T1D activation defect by triggering conversion of rTregs into aTregs (n=54 T1D, P<0.001). TNFR2 agonism was superior to standard protocols and TNF in proliferating Tregs. In T1D, TNFR2 agonist-expanded Tregs were homogeneous and functionally potent by virtue of suppressing autologous cytotoxic T cells in a dose-dependent manner comparable to controls. Targeting the TNFR2 receptor for Treg expansion in vitro demonstrates a means to correct the activation defect in T1D.

Strategic internal covalent cross-linking of TNF produces a stable TNF trimer with improved TNFR2 signaling.

BACKGROUND: Soluble TNF superfamily (TNFSF) ligands are less stable and less active than their transmembrane (tm) analogues. This is a problem for the therapeutic use of recombinant TNFSF ligands in diverse diseases including cancer and autoimmunity. Creating TNFSF ligand analogues with improved targeting of their respective receptors is important for research and therapeutic purposes. FINDINGS: Covalent internal cross-linking of TNF monomers by double mutations, S95C/G148C, results in stable trimers with improved TNFR2 function. The resulting mutein induced the selective death of autoreactive CD8 T cells in type-1 diabetic patients and demonstrates targeted proliferation and expansion of human CD4 Tregs. CONCLUSIONS: Stable TNF trimers, created by internal covalent cross-linking, show improved signaling. The high structural homology within the TNF superfamily provides an opportunity to extend internal cross-linking to other TNF superfamily proteins to produce active trimers with improved stability and receptor signaling, and with potential applications for cancer, autoimmunity, infections, and transplantation.

Homogeneous expansion of human T-regulatory cells via tumor necrosis factor receptor 2.

T-regulatory cells (T(regs)) are a rare lymphocyte subtype that shows promise for treating infectious disease, allergy, graft-versus-host disease, autoimmunity, and asthma. Clinical applications of T(regs) have not been fully realized because standard methods of expansion ex vivo produce heterogeneous progeny consisting of mixed populations of CD4 + T cells. Heterogeneous progeny are risky for human clinical trials and face significant regulatory hurdles. With the goal of producing homogeneous T(regs), we developed a novel expansion protocol targeting tumor necrosis factor receptors (TNFR) on T(regs). In in vitro studies, a TNFR2 agonist was found superior to standard methods in proliferating human T(regs) into a phenotypically homogeneous population consisting of 14 cell surface markers. The TNFR2 agonist-expanded T(regs) also were functionally superior in suppressing a key T(reg) target cell, cytotoxic T-lymphocytes. Targeting the TNFR2 receptor during ex vivo expansion is a new means for producing homogeneous and potent human T(regs) for clinical opportunities.

Proof-of-concept, randomized, controlled clinical trial of Bacillus-Calmette-Guerin for treatment of long-term type 1 diabetes.

BACKGROUND: No targeted immunotherapies reverse type 1 diabetes in humans. However, in a rodent model of type 1 diabetes, Bacillus Calmette-Guerin (BCG) reverses disease by restoring insulin secretion. Specifically, it stimulates innate immunity by inducing the host to produce tumor necrosis factor (TNF), which, in turn, kills disease-causing autoimmune cells and restores pancreatic beta-cell function through regeneration. METHODOLOGY/PRINCIPAL FINDINGS: Translating these findings to humans, we administered BCG, a generic vaccine, in a proof-of-principle, double-blind, placebo-controlled trial of adults with long-term type 1 diabetes (mean: 15.3 years) at one clinical center in North America. Six subjects were randomly assigned to BCG or placebo and compared to self, healthy paired controls (n = 6) or reference subjects with (n = 57) or without (n = 16) type 1 diabetes, depending upon the outcome measure. We monitored weekly blood samples for 20 weeks for insulin-autoreactive T cells, regulatory T cells (Tregs), glutamic acid decarboxylase (GAD) and other autoantibodies, and C-peptide, a marker of insulin secretion. BCG-treated patients and one placebo-treated patient who, after enrollment, unexpectedly developed acute Epstein-Barr virus infection, a known TNF inducer, exclusively showed increases in dead insulin-autoreactive T cells and induction of Tregs. C-peptide levels (pmol/L) significantly rose transiently in two BCG-treated subjects (means: 3.49 pmol/L [95% CI 2.95-3.8], 2.57 [95% CI 1.65-3.49]) and the EBV-infected subject (3.16 [95% CI 2.54-3.69]) vs.1.65 [95% CI 1.55-3.2] in reference diabetic subjects. BCG-treated subjects each had more than 50% of their C-peptide values above the 95(th) percentile of the reference subjects. The EBV-infected subject had 18% of C-peptide values above this level. CONCLUSIONS/SIGNIFICANCE: We conclude that BCG treatment or EBV infection transiently modified the autoimmunity that underlies type 1 diabetes by stimulating the host innate immune response. This suggests that BCG or other stimulators of host innate immunity may have value in the treatment of long-term diabetes. TRIAL REGISTRATION: ClinicalTrials.gov NCT00607230.

Pioglitazone may accelerate disease course of slowly progressive type 1 diabetes.

BACKGROUND: It has been reported that intervention with insulin in slowly progressive type 1 diabetic (SPIDDM) patients delays the progression to an insulin-dependent state compared to that with sulfonylureas. However, the rate of progression to SPIDDM with the use of insulin-sensitizing agents is unknown. The aim of this study was to determine the effect of insulin-sensitizing agents on SPIDDM patients. METHODS: The enrolled SPIDDM patients were randomly allocated to a pioglitazone or metformin group. When the haemoglobin A1C level was more than 8% on two consecutive occasions, the case was considered to reach the end point. RESULTS: By 4 years post-intervention, all patients had reached the end point in the pioglitazone group, whereas only 20% of patients had reached the end point in the metformin group (p<0.05). CONCLUSIONS: Pioglitazone may accelerate the disease course of SPIDDM.

A mimic of viral double-stranded RNA triggers fulminant type 1 diabetes-like syndrome in regulatory T cell-deficient autoimmune diabetic mouse.

Human fulminant type 1 diabetes (FT1D) is an extremely aggressive disease. The delay of proper diagnosis results in high mortality. However, the pathophysiology of this disease remains unclear. We took advantage of CD28-deficient NOD (CD28(-/-) NOD) mice, which have limited numbers of regulatory T cells and develop aggressive autoimmune diabetes, to create a FT1D model that mimicked the disease in humans. Young CD28(-/-) NOD mice were injected with polyinosinic-polycytidylic acid to activate innate immunity in an effort to induce diabetes onset. In this model, innate immune cell activation precedes the onset of diabetes similar to ∼70% of FT1D patients. Eighty-three percent of CD28(-/-) NOD mice developed diabetes within 1-6 d after injection of polyinosinic-polycytidylic acid. Moreover, T cells infiltrated the pancreatic exocrine tissue and destroyed α cells, an observation characteristic of human FT1D. We conclude that an FT1D-like phenotype can be induced in the background of autoimmune diabetes by a mimic of viral dsRNA, and this model is useful for understanding human FT1D.

Proatherogenic effect of interleukin-18 is exerted with high-fat diet, but not with normal diet in spontaneously hyperlipidemic mice.

AIM: It has been considered that interleukin (IL)-18, a T helper 1(Th1) type cytokine, has a promoting effect on atherosclerosis development. A previous mouse study demonstrated that short-term exogenous IL-18 promoted atherosclerosis through a Th1 type immune response; however, the serum IL-18 may have increased greatly beyond its physiological range, and the effect of increased serum IL-18 on atherosclerosis development has not been investigated under different conditions of dietary fat content. The purpose of this study was to reveal the effect of increased serum IL-18 within its physiological fluctuations on atherosclerosis development under different conditions of dietary fat content. METHODS: Spontaneously hyperlipidemic (SHL) mice were systemically supplied with IL-18 for 10 weeks by means of an in vivo gene transfer system with a high-fat diet containing 0.15% cholesterol or a normal diet. RESULTS: Serum IL-18 steadily elevated within its physiological fluctuations. An atherosclerotic lesion area in the aortic root significantly increased with a high-fat diet. Systemic cytokine balance shifted to a Th1-dominant state, and IL-12 mRNA in the arterial wall significantly increased with a high-fat diet; however, these findings were not observed with a normal diet. CONCLUSIONS: It was suggested that the proatherogenic effect of IL-18 is physiologically exerted exclusively with a high-fat diet through Th1 type immune responses, but not with a normal diet.

Novel automated blood separations validate whole cell biomarkers.

BACKGROUND: Progress in clinical trials in infectious disease, autoimmunity, and cancer is stymied by a dearth of successful whole cell biomarkers for peripheral blood lymphocytes (PBLs). Successful biomarkers could help to track drug effects at early time points in clinical trials to prevent costly trial failures late in development. One major obstacle is the inaccuracy of Ficoll density centrifugation, the decades-old method of separating PBLs from the abundant red blood cells (RBCs) of fresh blood samples. METHODS AND FINDINGS: To replace the Ficoll method, we developed and studied a novel blood-based magnetic separation method. The magnetic method strikingly surpassed Ficoll in viability, purity and yield of PBLs. To reduce labor, we developed an automated platform and compared two magnet configurations for cell separations. These more accurate and labor-saving magnet configurations allowed the lymphocytes to be tested in bioassays for rare antigen-specific T cells. The automated method succeeded at identifying 79% of patients with the rare PBLs of interest as compared with Ficoll's uniform failure. We validated improved upfront blood processing and show accurate detection of rare antigen-specific lymphocytes. CONCLUSIONS: Improving, automating and standardizing lymphocyte detections from whole blood may facilitate development of new cell-based biomarkers for human diseases. Improved upfront blood processes may lead to broad improvements in monitoring early trial outcome measurements in human clinical trials.

CXC chemokine ligand 10 DNA vaccination plus Complete Freund's Adjuvant reverses hyperglycemia in non-obese diabetic mice.

OBJECTIVE: Complete Freund's Adjuvant (CFA) is known to arrest autoimmune diabetes development in non-obese diabetic (NOD) mice. However, CFA alone cannot induce effective remission in diabetic NOD mice. Previously, we reported that anti-CXC chemokine ligand 10 (CXCL10) antibody can promote beta-cell proliferation in NOD mice. In the present study, we aimed to examine whether anti-CXCL10 plus CFA treatment can effectively reverse autoimmune diabetes development. METHODS: Systemic supply of anti-CXCL10 antibody by CXCL10 DNA vaccination in combination with CFA injection was performed in new-onset diabetic NOD mice. Remission rate of diabetes, histological characteristics of residual insulitis lesions, residual beta-cell mass, and regulatory T cell population in local pancreas were examined. RESULTS: A high frequency of diabetes reversal was observed after combination treatment with anti-CXCL10 plus CFA. In mice showing diabetes reversal, residual beta-cell mass was significantly increased, and some beta-cells were in a proliferative state. Although systemic cytokine profiles were unaffected, the frequency of "hybrid regulatory T cells", i.e. regulatory T cells expressing CXCR3, was significantly increased in local pancreatic lesions. This was possibly associated with the regulation of anti-islet autoimmunity. CONCLUSIONS: Anti-CXCL10 plus appropriate immune adjuvant therapy arrested, and reversed, type 1 diabetes development.

Proteomics identifies multipotent and low oncogenic risk stem cells of the spleen.

The adult spleen harbors a population of naturally occurring multipotent stem cells of non-lymphoid lineage (CD45-). In animal models, these splenic stem cells can directly or indirectly contribute to regeneration of bone, inner ear, cranial nerves, islets, hearts and salivary glands. Here we characterize the CD45- stem cell proteome to determine its potential broader multipotency versus its protection from malignant transformation. Using state-of-the-art proteomics and in vivo testing, we performed functional analyses of unique proteins of CD45- (non-lymphoid) splenic stem cells, as compared with CD45+ (lymphoid) cells. CD45- stem cell-specific proteins were identical to those in iPS, including OCT3/4, SOX2, KLF4, c-MYC and NANOG. They also expressed Hox11, Gli3, Wnt2, and Adam12, the benchmark transcription factors of embryonic stem cells. These transcription factors were functional because their mRNA was upregulated in the spleen in association with ongoing damage to the pancreas and salivary glands, organs to which they normally contribute stem cells. We also show low likelihood of malignant transformation. Our proteomic and functional analyses reveals that naturally occurring CD45- stem cells of the spleen are the first-ever candidates for naturally occurring population of embryonic and iPS cells with low oncogenic risk. Given their presence in normal humans and mice, splenic stem cells are poised for translational research.

The role of the CXCL10/CXCR3 system in type 1 diabetes.

Despite intervention with insulin, type 1 diabetes gradually deteriorates the patients' quality of life. The disease is characterized by an immune-mediated destruction of pancreatic beta-cells. Its etiology, however, remains controversial. Some studies argue that glutamic acid decarboxylase (GAD) antigen and GAD-reactive T cells are critical players in the development of diabetes by affecting the Th cell balance. A T-helper 1 (Th1)-dominant immune response is considered to be important in beta-cell failure in both human and animal models of type 1 diabetes. The Th1-type chemokine, CXCL10, and its receptor, CXCR3, are involved not only in the immune response, but also in the suppression of beta-cell proliferation. Thus, understanding the CXCL10/CXCR3 system may be important for finding a cure. In this short review, we discuss the role of the CXCL10/CXCR3 system in type 1 diabetes and propose relevant treatment options.

Induction of anti-whole GAD65 reactivity in vivo results in disease suppression in type 1 diabetes.

Most type 1 diabetes mellitus is caused by autoimmune pancreatic beta-cell destruction. Several antigens such as insulin, glutamic acid decarboxylase (GAD) and islet-specific glucose-6-phosphatase catalytic subunit related protein (IGRP) are considered to take part in the autoimmune destructive process. Because the role of GAD in the disease process of type 1 diabetes is still controversial, we investigated the disease phenotype upon in vivo induction of whole GAD65 reactivity using a GAD65 homo knockout NOD splenocytes to NOD-scid transfer system. Splenocytes from 8 to 10-week-old female GAD65 homo knockout (=KOT splenocytes) or age-matched wild type (=WTT splenocytes) NOD mice were transferred into female NOD-scid recipients. As compared to recipients of WTT splenocytes, the onset of diabetes in recipients of KOT splenocytes was significantly delayed (p<0.001). Moreover, TGF-beta expression was enhanced in the pancreas from recipients of KOT splenocytes. Splenocytes from recipients of KOT splenocytes produced IL-10 (/IFN-gamma) upon GAD65 stimulation, whereas those from recipients of WTT splenocytes did not. Based upon these results, we propose that anti-whole GAD65-reactive T cells have the ability to regulate the development of type 1 diabetes.

FOXP3/Scurfin gene polymorphism is associated with adult onset type 1 diabetes in Japanese, especially in women and slowly progressive-type patients.

PURPOSE: Some reports have shown that the cause of type 1 diabetes is associated with dysfunction of regulatory T cells (Tregs). The FOXP3/Scurfin gene is known to be a master gene of Tregs. Therefore, we tried to analyze the relation between the gene polymorphism and adult onset type 1 diabetes and its subtype in the Japanese population. METHODS: In this study, we recruited 316 Japanese patients with type 1 diabetes (155 male and 161 female, mean onset age 35.4 years) and 432 healthy Japanese controls (263 male and 169 female, mean age 44.4 years). Then we subdivided the patients by onset type, sex, and islet-associated autoantibody positivity. RESULTS: The genotype frequency of (GT)(16)/(GT)(16) in female patients with overall type 1 diabetes was especially lower than that in controls (19.9% vs. 38.5%, p = 0.0002). Moreover, the genotype frequency of (GT)(16)/(GT)(16) in female patients with slowly progressive type 1 diabetes was significantly lower than that in controls (15.4% vs. 38.5%, p = 0.002). CONCLUSION: Our data showed that the (GT)n microsatelloite polymorphism in the FOXP3/Scrufin gene was associated with Japanese adult onset type 1 diabetes, especially in females, and slowly progressive type 1 diabetes.

Hyperplastic islets observed in "reversed" NOD mice treated without hematopoietic cells.

At the onset of type 1 diabetes, most of the insulin-producing pancreatic beta cells are destroyed by effector cells, and therefore, the following two factors, at a minimum, are necessary for "reversing" hyperglycemia in autoimmune diabetes; depletion of effector cells and enhancement of beta cell regeneration. In this study, we tried a novel approach for "reversing" autoimmune diabetes in a murine model. Here we show that remission could be achieved with a combination therapy of a single injection of complete Freund's adjuvant (CFA) and a single intraperitoneal injection of a pancreatic beta cell line, MIN6N-9a, in recent-onset diabetic NOD (non-obese diabetic) mice. Five out of seven mice (71%) receiving MIN6N-9a and CFA became normoglycemic within 120 days after treatment, whereas only two of nine (22%) receiving vehicle instead of MIN6N-9a achieved remission. Histological examination of pancreatic specimens from "reversed" mice showed decreased islet number, but each islet was markedly hyperplastic; being about six times larger than those from controls. Although it has been reported that hematopoietic cells such as splenocytes differentiate into insulin-producing cells and play a key role, our data indicate that they are not an absolute requirement for the "reversal" of autoimmune diabetes.

Frequency of CTLA-4 gene CT60 polymorphism may not be affected by vitamin D receptor gene Bsm I polymorphism or HLA DR9 in autoimmune-related type 1 diabetes in the Japanese.

One of the CTLA-4 SNPs, +6230G>A (CT60), has recently been reported to be related to susceptibility to type 1 diabetes and autoimmune thyroid disease. We have previously reported an association between acute-onset type 1 diabetes in Japanese and the Vitamin D receptor (VDR) gene Bsm I large B polymorphism, which is related to the Th1-type response. Moreover, we found a significant correlation between autoimmune-related type 1 diabetes with HLA DR9 and detection of GAD-reactive Th1 (T helper 1)-type cells. In the present article, we tried to clarify whether the frequency of one of the CTLA-4 SNPs, +6230G>A (CT60), is affected by the VDR gene Bsm I polymorphism or by HLA DR9 in Japanese type 1 diabetics. The frequency of the CT60 GG genotype did not appear to be affected by either the VDR gene Bsm I large B polymorphism or HLA DR9.

Thiazolidinediones may not reduce diabetes incidence in type 1 diabetes.

Thiazolidinediones improve glycemic control by reducing insulin resistance. Some studies have demonstrated that troglitazone had a preventative effect on diabetes in NOD (non-obese diabetic) mice. One of the mechanisms proposed for the prevention of diabetes by thiazolidinediones is an effect on T-helper 1/T-helper 2 (Th1/Th2) balance. In this article, we attempted to clarify whether pioglitazone is also effective in preventing diabetes as compared to metformin, which has no immunological effect. Female NOD mice were administered pioglitazone or metformin orally, and the insulitis score, cytokines secreted from splenocytes, cytokine expression levels in the pancreas, and the incidence of diabetes after acceleration by cyclophosphamide were analyzed. We could not find any advantage of pioglitazone in preventing Th1 skewing and the development of diabetes over metformin. Therefore, further research should take place before the application of thiazolidinediones to human slowly progressive insulin-dependent diabetes mellitus (SPIDDM) patients.