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Corynebacterium parvum prevented the development of encephalomyocarditis virus-induced diabetes in mice, when it was given 3-14 days before the virus infection. This treatment inhibited virus replication in the pancreas of the infected mice at an early stage of the infection. [ABSTRACT FROM AUTHOR]

Tyrosine kinase 2 (TYK2), a member of the JAK family, has attracted attention as a potential therapeutic target for autoimmune diseases. However, the role of TYK2 in CD8 + T cells and autoimmune type 1 diabetes (T1D) is poorly understood. In this study, we generate Tyk2 gene knockout non-obese diabetes (NOD) mice and demonstrate that the loss of Tyk2 inhibits the development of autoreactive CD8 + T-BET + cytotoxic T lymphocytes (CTLs) by impairing IL-12 signaling in CD8 + T cells and the CD8 + resident dendritic cell-driven cross-priming of CTLs in the pancreatic lymph node (PLN). Tyk2-deficient CTLs display reduced cytotoxicity. Increased inflammatory responses in β-cells with aging are dampened by Tyk2 deficiency. Furthermore, treatment with BMS-986165, a selective TYK2 inhibitor, inhibits the expansion of T-BET + CTLs, inflammation in β-cells and the onset of autoimmune T1D in NOD mice. Thus, our study reveals the diverse roles of TYK2 in driving the pathogenesis of T1D., (© 2024. The Author(s).)

There is an association between nonalcoholic fatty liver disease (NAFLD) and atherosclerosis, but the genetic risk of atherosclerosis in NAFLD remains unclear. Here, a single-nucleotide polymorphism (SNP) of the heat shock 70 kDa protein 8 ( HSPA8 ) gene was analyzed in 123 NAFLD patients who had been diagnosed using a liver biopsy, and the NAFLD phenotype including the maximum intima-media thickness (Max-IMT) of the carotid artery was investigated. Patients with the minor allele (A/G or G/G) of rs2236659 showed a lower serum heat shock cognate 71 kDa protein concentration than those with the major A/A allele. Compared with the patients with the major allele, those with the minor allele showed a higher prevalence of hypertension and higher Max-IMT in men. No significant associations between the HSPA8 genotype and hepatic pathological findings were identified. In decision-tree analysis, age, sex, liver fibrosis, and HSPA8 genotype were individually associated with severe carotid artery atherosclerosis (Max-IMT ≥ 1.5 mm). Noncirrhotic men aged ≥ 65 years were most significantly affected by the minor allele of HSPA8 . To predict the risk of atherosclerosis and cardiovascular disease, HSPA8 SNP genotyping might be useful, particularly for older male NAFLD patients.

Aims/introduction: The need for antiserum for immunohistochemical (IHC) detection of enterovirus (EV) in formaldehyde-fixed and paraffin-embedded samples is increasing. The gold standard monoclonal antibody (clone 5D8/1) against EV-envelope protein (VP1) was proven to cross-react with other proteins. Another candidate marker of EV proteins is 2A protease (2A pro ), which is encoded by the EV gene and translated by the host cells during EV replication, and participates processing proproteins to viral capsid proteins., Materials and Methods: We raised polyclonal antiserum by immunizing a rabbit with an 18-mer peptide of Coxsackievirus B1 (CVB1)-2A pro , and examined the specificity and sensitivity for EV on formaldehyde-fixed and paraffin-embedded tissue samples., Results: Enzyme-linked immunosorbent assay study showed a high titer of antibody for 18-mer peptide of CVB1-2A pro , cross-reacting with CVB3-2A pro peptide. IHC showed that antiserum against 2A pro reacted with CVB1-infected and VP1-positive Vero cells. Confocal laser scanning microscopy showed that antigen stained by the 2A pro antibody located in the same cell with VP1 stained by 5D8/1. IHC using 2A pro antiserum showed dense staining in the islets of EV-associated fulminant type 1 diabetes pancreas and that located in the same cell stained positive for VP1 (5D8/1). Specificity of 2A pro antiserum by IHC staining was confirmed by negative 2A pro in 14 VP1-negative non-diabetes control pancreases., Conclusions: Our study provides a new polyclonal antiserum against CVB1-2A pro , which might be useful for IHC of EV-infected human tissues stored as archive of formaldehyde-fixed and paraffin-embedded tissue samples., (© 2021 The Authors. Journal of Diabetes Investigation published by Asian Association for the Study of Diabetes (AASD) and John Wiley & Sons Australia, Ltd.)

SARS-CoV-2 infection primarily causes pulmonary symptoms; however, accumulating reports indicate that some patients with COVID-19 have multiple organ dysfunction or failure. Although diabetes is considered a risk factor for severe COVID-19, SARS-CoV-2 infection may also be a causal factor for diabetes mellitus in patients with COVID-19. According to the research reviewed in this paper, the pancreas and pancreatic β cells appear to be targets of SARS-CoV-2 and are damaged by direct or indirect effects of the infection. However, controversial results have been reported between study groups, mainly due to the limited number of cases with diabetes precipitated by COVID-19. In this review, we comprehensively discuss the published findings on the potential association between SARS-CoV-2 infection or COVID-19 and pancreatic β-cell damage leading to diabetes onset. These findings will further contribute to our understanding of the pathogenesis of diabetes mellitus.

Accumulating evidence has suggested that viral infection causes type 1 diabetes due to direct β-cell damage and the triggering of autoimmune reactivity to β cells. Here, we elucidated that the tyrosine kinase 2 (Tyk2 ) gene, encoding an interferon receptor signaling molecule, is responsible for virus-induced diabetes in mice, and its promoter variant confers a risk of type 1 diabetes in humans. This study investigated the relationship between a TYK2 promoter variant (TYK2PV) and insulin secretion in type 2 diabetes patients. TYK2PV status was determined using direct DNA sequencing and its associations with fasting insulin, C-peptide, and homeostatic model assessment of insulin resistance (HOMA-IR) were evaluated in type 2 diabetes patients without sulfonylurea or insulin medication. Of the 172 patients assessed, 18 (10.5%) showed TYK2PV -positivity. Their body mass index (BMI) was significantly lower than in those without the variant (23.4 vs. 25.4 kg/m 2 , p = 0.025). Fasting insulin (3.9 vs. 6.2 μIU/mL, p = 0.007), C-peptide (1.37 vs. 1.76 ng/mL, p = 0.008), and HOMA-IR (1.39 vs. 2.05, p = 0.006) were lower in those with than in those without the variant. Multivariable analysis identified that TYK2PV was associated with fasting insulin ≤ 5 μIU/mL (odds ratio (OR) 3.63, p = 0.025) and C-peptide ≤ 1.0 ng/mL (OR 3.61, p = 0.028), and also lower insulin resistance (HOMA-IR ≤ 2.5; OR 8.60, p = 0.042). TYK2PV is associated with impaired insulin secretion and low insulin resistance in type 2 diabetes. Type 2 diabetes patients with TYK2PV should be carefully followed in order to receive the appropriate treatment including insulin injections.

Enteroviruses, especially Coxsackie B viruses, are among the candidate environmental factors causative of type 1 diabetes. Host genetic factors have an impact on the development of virus-induced diabetes (VID). Host background, in terms of whether the host is prone to autoimmunity, should also be considered when analyzing the role of target genes in VID. In this review, we describe the genetic susceptibility of the host based on studies in humans and VID animal models. Understanding the host genetic factors should contribute not only to revealing the mechanisms of VID development, but also in taking measures to prevent VID.

Sodium-glucose cotransporter 2 inhibitors (SGLT2is) have been reported to improve obesity, diabetes, and nonalcoholic fatty liver disease (NAFLD) in addition to exercise training, whereas the combined effects remain to be elucidated fully. We investigated the effect of the combination of the SGLT2i canagliflozin (CAN) and exercise training in high-fat diet-induced obese mice. High-fat diet-fed mice were housed in normal cages (sedentary; Sed) or wheel cages (WCR) with or without CAN (0.03% of diet) for 4 wk. The effects on obesity, glucose metabolism, and hepatic steatosis were evaluated in four groups (Control/Sed, Control/WCR, CAN/Sed, and CAN/WCR). Numerically additive improvements were found in body weight, body fat mass, blood glucose, glucose intolerance, insulin resistance, and the fatty liver of the CAN/WCR group, whereas CAN increased food intake and reduced running distance. Exercise training alone, CAN alone, or both did not change the weight of skeletal muscle, but microarray analysis showed that each resulted in a characteristic change of gene expression in gastrocnemius muscle. In particular, in the CAN/WCR group, there was acceleration of the angiogenesis pathway and suppression of the adipogenesis pathway compared with the CAN/Sed group. In conclusion, the combination of an SGLT2i and exercise training improves obesity, insulin resistance, and NAFLD in an additive manner. Changes of gene expression in skeletal muscle may contribute, at least in part, to the improvement of obesity and insulin sensitivity.

Viral infection is a putative causal factor for the development of type 1 diabetes, but the exact pathogenic mechanism of virus-induced diabetes (VID) remains unclear. Here, to identify the critical factors that regulate VID, we analyzed encephalomyocarditis D (EMC-D) VID-sensitive DBA/2 mice in comparison with resistant B6 mice. EMC-D virus-induced cell death occurred more frequently in DBA/2 β-cells than in B6 β-cells with 100U/ml IFN-β priming in vitro. We therefore purified β-cells using flow cytometry from mice two days after EMC-D virus infection and subjected them to microarray analysis. As a results, innate immune response pathway was found to be enriched in B6 β-cells. The signal transducer and activator of transcription 2 (Stat2) gene interacted with genes in the pathway. Stat2 gene expression levels were lower in DBA/2 mice than in B6 mice, restrictive to β-cells. Moreover, administration of IFN-β failed to upregulate Stat2 gene in DBA/2 β-cells than in those of B6 in vivo. The viral titer significantly increased only in the DBA/2 pancreas. Thus, these provided data suggest that impaired upregulation of Stat2 gene restrictive to β-cells at the early stage of infection is responsible for VID development in DBA/2 mice., (Copyright © 2019 The Authors. Published by Elsevier Inc. All rights reserved.)

Objective: Type 1 diabetes (T1D) is known to be caused by Th1 cell-dependent autoimmunity. Recently, we reported that TYK2 promoter variant serves as a putative virus-induced diabetes susceptibility gene associated with deteriorated interferon-dependent antiviral response. TYK2 is also related to HIES, that is, Th2 cell-dependent. Therefore, TYK2 promoter variant may be also associated with the pathogenesis of T1D, modulating Th1/Th2 balance., Research Design and Methods: We assessed the association between anti- GAD Ab, IgE levels, and TYK2 promoter variant among 313 T1D patients, 184 T2D patients, and 264 YH controls in the Japanese., Results: T1D patients had elevated IgE (median, 56.7U/ml; p<0.0001) compared with T2D patients (22.5U/ml) and controls (43.3U/ml). Contrary to our expectations, there was no correlation between TYK2 promoter variant and IgE levels. We found that T1D could be subtyped as four groups based on anti-GAD Ab and IgE profile: Subtype 1, anti-GAD Ab positive and non-elevated IgE (47.0%); Subtype 2, anti-GAD Ab negative and non-elevated IgE (35.1%); Subtype 3, anti-GAD Ab positive and elevated IgE (10.9%); and Subtype 4, anti-GAD Ab negative and elevated IgE (7.0%). In Subtype 2, a significantly higher incidence was observed in T1D cases carrying the TYK2 promoter variant (OR, 2.60; 95%CI, 1.03-6.97; p=0.032), and also showing a flu-like syndrome at diabetes onset (OR, 2.34; 95%CI, 1.27-4.35; p=0.003)., Interpretation: Anti-GAD Ab and IgE profiling helps classifying T1D into four groups that recognize variable pathogenic bases of T1D., (Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.)

Diabetes is manifested predominantly in males in experimental models, and compelling evidence suggests that 17β-estradiol (E2) supplementation improves hyperglycemia in humans. We previously generated a severely diabetic transgenic (Tg) mouse model by β-cell–specific overexpression of inducible cAMP early repressor (ICER) and found that male but not female ICER-Tg mice exhibit sustained hyperglycemia and develop major clinical and pathologic features of human diabetic nephropathy (DN). Thus, we hypothesized that differences in circulating hormone levels have a key role in determining susceptibility to diabetes. Here, we examined whether DN in male ICER-Tg mice is rescued by adjusting the androgen-to-E2 ratio to approximate that in normoglycemic female ICER-Tg mice. We treated hyperglycemic male ICER-Tg mice with orchiectomy (ORX), E2 pellet implantation, or both. E2 pellet implantation at an early stage of DN with or without ORX caused a rapid drop in blood glucose and a dramatic increase in β-cell number, and it markedly inhibited DN progression [namely, E2 reduced glomerulosclerosis, collagen 4 deposition and albuminuria, and prevented hyperfiltration]. Furthermore, E2 pellet implantation was more effective than ORX alone and induced a remarkable improvement, even when initiated at advanced-stage DN. In contrast, induction of normoglycemia by islet transplant in ICER-Tg mice eliminated albuminuria but was less effective than E2 + ORX in reducing glomerulosclerosis, collagen 4 deposition, and hyperfiltration. These findings indicate that E2 treatment is effective, even after establishment of DN, whereas glucose normalization alone does not improve sclerotic lesions. We propose that E2 intervention is a potential therapeutic option for DN., (Copyright © 2016 by the American Society of Nephrology.)

Aim: We investigated the effect of prebiotics on the immunological response after influenza vaccination in enterally fed elderly individuals. The intervention group was given an enteral formula containing lactic acid bacteria-fermented milk products. In addition, two different types of other prebiotics, galacto-oligosaccharide and bifidogenic growth stimulator, were also given. The two prebiotics improved intestinal microbiota differently. In a control group, a standard formula without prebiotics was given., Methods: An enteral formula with (intervention group [F]) or without (control group [C]) prebiotics was given through percutaneous endoscopic gastrostomy to elderly participants for 10 weeks. Influenza vaccine was inoculated at week 4. Nutritional and biochemical indices, intestinal micro bacteria and immunological indices were analyzed., Results: The Bifidobacterium count in groups F and C at week 0 was 6.4 ± 1.9 and 6.6 ± 3.0 (log10 [count/g feces]), respectively. Although the count in group C decreased at week 10, the count in group F increased. The Bacteroides count in group F increased from 10.7 ± 0.9 to 11.4 ± 0.5, but decreased in group C from 11.2 ± 0.2 to 10.7 ± 0.4. Although the enhanced titers of H1N1, H3N2 and B antigens against the vaccine decreased thereafter in group C, these enhanced titers in group F could be maintained., Conclusion: Our findings suggest that prebiotics affect the intestinal microbiota and might maintain the antibody titers in elderly individuals., (© 2015 Japan Geriatrics Society.)

We investigated the effect of a formula containing two different prebiotics (bifidogenic growth stimulator and galacto-oligosaccharide) and fermented milk products on intestinal microbiota and antibody responses to an influenza vaccine in enterally fed elderly in-patients. Patients were administered either formula containing prebiotics and fermented milk products (group F: n = 12, 79.9 ± 9.5 years old) or standard formula (group C: n = 12, 80.7 ± 10.1 years old) via percutaneous endoscopic gastrostomy during a 14-week intervention period. Subjects were immunized with an influenza vaccine (A/H1N1, A/H3N2, and B) at week 4 of the intervention. Blood biochemical indices, intestinal bacteria populations and antibody titers were analyzed. Bifidobacterium counts increased significantly in group F compared with group C. The enhanced antibody titers against A/H1N1 were maintained in group F for a longer period compared with group C. The titers against A/H3N2 were unchanged between both groups, and those against B were significantly lower in group F than in group C, although few subjects had seroprotective titers against A/H3N2 and B. These results suggest that administration of the formula containing prebiotics and fermented milk products may maintain antibody titers for longer periods through the improvement of intestinal microbiota.

Background: Recently, natural mutation of Tyrosine kinase 2 (Tyk2) gene has been shown to determine susceptibility to murine virus-induced diabetes. In addition, a previous human genome-wide study suggested the type 1 diabetes (T1D) susceptibility region to be 19p13, where the human TYK2 gene is located (19p13.2)., Methods: Polymorphisms of TYK2 gene at the promoter region and exons were studied among 331 healthy controls, and 302 patients with T1D and 314 with type 2 diabetes (T2D) in the Japanese., Findings: A TYK2 promoter haplotype with multiple genetic polymorphisms, which are in complete linkage disequilibrium, named TYK2 promoter variant, presenting decreased promoter activity, is associated with an increased risk of not only T1D (odds ratio (OR), 2.4; 95% confidence interval (CI), 1.2 to 4.6; P = 0.01), but also T2D (OR, 2.1; 95% CI, 1.1 to 4.1; P = 0.03). The risk is high in patients with T1D associated with flu-like syndrome at diabetes onset and also those without anti-glutamic acid decarboxylase autoantibody., Interpretation: The TYK2 promoter variant is associated with an overall risk for diabetes, serving a good candidate as a virus-induced diabetes susceptibility gene in humans., Funding: Ministry of Education, Culture, Sports, Science and Technology and of Health, Labor and Welfare of Japan.

Accumulating evidence suggests that viruses play an important role in the development of diabetes. Although the diabetogenic encephalomyocarditis strain D virus induces diabetes in restricted lines of inbred mice, the susceptibility genes to virus-induced diabetes have not been identified. We report here that novel Tyrosine kinase 2 (Tyk2) gene mutations are present in virus-induced diabetes-sensitive SJL and SWR mice. Mice carrying the mutant Tyk2 gene on the virus-resistant C57BL/6 background are highly sensitive to virus-induced diabetes. Tyk2 gene expression is strongly reduced in Tyk2-mutant mice, associated with low Tyk2 promoter activity, and leads to decreased expression of interferon-inducible genes, resulting in significantly compromised antiviral response. Tyk2-mutant pancreatic β-cells are unresponsive even to high dose of Type I interferon. Reversal of virus-induced diabetes could be achieved by β-cell-specific Tyk2 gene expression. Thus, reduced Tyk2 gene expression in pancreatic β-cells due to natural mutation is responsible for susceptibility to virus-induced diabetes.

We herein demonstrate the immune-regulatory effect of embryonic stem cell-derived dendritic cells (ES-DCs) using two models of autoimmune disease, namely non-obese diabetic (NOD) mice and experimental autoimmune encephalomyelitis (EAE). Treatment of pre-diabetic NOD mice with ES-DCs exerted almost complete suppression of diabetes development during the observation period for more than 40 weeks. The prevention of diabetes by ES-DCs was accompanied with significant reduction of insulitis and decreased number of Th1 and Th17 cells in the spleen. Development of EAE was also inhibited by the treatment with ES-DCs, and the therapeutic effect was obtained even if ES-DCs were administrated after the onset of clinical symptoms. Treatment of EAE-induced mice with ES-DCs reduced the infiltration of inflammatory cells into the spinal cord and suppressed the T cell response to the myelin antigen. Importantly, the ES-DC treatment did not affect T cell response to an exogenous antigen. As the mechanisms underlying the reduction of the number of infiltrating Th1 cells, we observed the inhibition of differentiation and proliferation of Th1 cells by ES-DCs. Furthermore, the expression of VLA-4α on Th1 cells was significantly inhibited by ES-DCs. Considering the recent advances in human induced pluripotent stem cell-related technologies, these results suggest a clinical application for pluripotent stem cell-derived dendritic cells as a therapy for T cell-mediated autoimmune diseases.

Although mutations of autoimmune regulator (AIRE) gene are responsible for autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED), presenting a wide spectrum of many characteristic and non-characteristic clinical features, some patients lack AIRE gene mutations. Therefore, something other than a mutation, such as dysregulation of AIRE gene, may be a causal factor for APECED or its related diseases. However, regulatory mechanisms for AIRE gene expression and/or translation have still remained elusive. We found that IL-2-stimulated CD4(+) T (IL-2T) cells showed a high expression of AIRE gene, but very low AIRE protein production, while Epstein-Barr virus-transformed B (EBV-B) cells express both AIRE gene and AIRE protein. By using microarray analysis, we could identify miR-220b as a possible regulatory mechanism for AIRE gene translation in IL-2T cells. Here we report that miR-220b significantly reduced the expression of AIRE protein in AIRE gene with 3'UTR region transfected 293T cells, whereas no alteration of AIRE protein production was observed in the open reading frame of AIRE gene alone transfected cells. In addition, anti-miR-220b reversed the inhibitory function of miR-220b for the expression of AIRE protein in AIRE gene with 3'UTR region transfected cells. Moreover, when AIRE gene transfected cells with mutated 3'UTR were transfected with miR-220b, no reduction of AIRE protein production was observed. Taken together, it was concluded that miR-220b inhibited the AIRE gene translation through the 3'UTR region of AIRE gene, indicating that miR-220b could serve as a regulator for human AIRE gene translation., (© 2013.)

Although the autoimmune regulator (Aire) knockout (KO) mouse model has been reported to present various organ-specific autoimmune diseases depending on genetic background, autoimmune pancreatitis in mice of BALB/c background has not yet been reported. Here, we report that Aire KO mice with BALB/cAnN background showed significant lymphoid cell infiltration in the pancreas and stomach. To examine whether the phenotype in the pancreas and stomach is due to autoimmune reaction associated with autoantibody production, indirect immunofluorescence staining followed by Western blot analysis was performed. Consequently, the autoantibody against pancreas and stomach was detected in the sera of Aire KO mice, and the target antigen of the autoantibody was identified as protein disulfide isomerase-associated 2 (Pdia2), which was reported to be expressed preferentially in the pancreas and stomach. Thus, Aire KO mice of BALB/cAnN background can serve as a useful animal model for autoimmune gastro-pancreatitis with anti-Pdia2 autoantibody production.

Introduction: Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is a rare autosomal recessive disorder caused by monogenic mutations in the autoimmune regulator (AIRE) gene. No attention has been paid to muscle manifestations in this disorder. We aimed to uncover whether progressive myopathy is a component of this disorder., Methods: A case description and literature search for APECED cases presenting with myopathy and analysis of AIRE gene expression in biopsied muscles from 4 healthy volunteers and the patient by reverse transcriptase polymerase chain reaction., Results: A 52-year-old woman with APECED caused by AIRE gene mutations developed progressive myopathy involving proximal limb and paraspinal muscles. Muscle biopsy specimens showed myopathic changes without inflammatory cell infiltrate. We detected AIRE gene expression in all muscle tissues examined. An extensive literature search uncovered 5 cases of APECED with myopathy, all of whom had similar features., Conclusions: Progressive myopathy involvement could be a hitherto unknown manifestation of APECED., (Copyright © 2012 Wiley Periodicals, Inc.)

In the mechanism of thymus-induced central tolerance, the transcription factor Aire has been demonstrated to promote the expression of a wide range of peripheral organ-specific antigens (Ags) in the medullary thymic epithelial cells (mTECs), which serve as self-Ags in negative selection. We examined the expression of desmoglein 3 (Dsg3), the autoantigen in pemphigus vulgaris (PV), in mouse thymus and the involvement of Aire in tolerance to Dsg3. Immunofluorescence and in situ hybridization revealed Dsg3 in single cells or in clusters in ∼3% of mTECs near the cortico-medullary junction of the thymus in C57BL/6 mice. Dsg3-expressing mTECs also expressed some Ags of skin-unrelated peripheral organs simultaneously. In contrast, Dsg3-positive mTECs were not detected in the Aire(-/-) thymus. Adoptive transfer of splenocytes from Aire(-/-) mice immunized with Dsg3 did not induce anti-Dsg3 IgG production or PV phenotype in Rag2(-/-) recipient mice. However, Aire(-/-) CD4(+) T cells, but not Aire(+/+) CD4(+) T cells, induced low levels of anti-Dsg3 IgG production when transferred with Dsg3(-/-) B cells. These findings indicate that Aire has an important role in Dsg3 expression as well as in selection of T cells that help B cells to produce anti-Dsg3 IgG in thymus.

Recently, accumulating evidence has suggested that B cell depletion therapy with rituximab is effective not only in autoantibody-associated, but also in T cell-mediated, autoimmune diseases. It is likely that B cells play an important role in regulating the extent of immune response in both physiological and pathological conditions. When a severe infection occurs, pathogens spread throughout the bloodstream. B cells in the blood capture the pathogens, via their specific antigen receptors (surface immunoglobulins), then present the specific antigen to T cells in the spleen, thus increasing the degree of T-cell immune responses to systemic infection. Similarly, in the exacerbation stage of autoimmunity, a large amount of autoantigens may be released into the blood and be captured by autoantigen specific B cells, and this may be followed by presentation of the antigen to CD4 positive autoreactive T cells resulting in extensive activation and proliferation of autoreactive T cells. Thus, it has been suggested that B-cell depletion therapy for autoimmune diseases is most useful for the "vicious cycle" phase of autoreactive immune response. The recognition of this paradigm for the role of B cells in regulating the magnitude of immune response will help to facilitate both basic and clinical research on the regulation of immune responses.

In order to clarify the significance of protective mechanisms against encephalomyocarditis (EMC) virus-induced diabetes in mice, we studied the relative importance of T cells, B cells, antibodies and macrophages in the prevention of virus-induced diabetes. Neither T cell-deficient athymic nude mice nor B cell-deficient microMT/microMT mice showed an enhanced clinical course of EMC-D virus-induced diabetes, indicating that neither T cells nor B cells played a major role in the protection against EMC-D-virus-induced diabetes. Transfer of a large amount of antiserum to EMC-D-virus-infected mice protected the development of diabetes only when transferred within 36 h of infection, the timing of which was earlier than that for the production of natural neutralizing antibodied. Since pretreatment of mice with the macrophage-activating immunopotentiator Corynebacterium parvum (CP) completely prevented the development of diabetes, we studied the clinical outcome of EMC-D-virus-infected mice pretreated with CP. Mice treated with CP showed reduced proliferation of EMC-D virus in the affected organs, including the pancreas, while the levels of development of neutralizing antibody and serum interferon were not enhanced compared with the controls. Finally, we studied the macrophages derived from mice pretreated with CP and found that they inhibited the growth of EMC-D virus in vitro more than those derived from non-treated and thioglycolate-treated mice. Taken together, it can be suggested that neither T cells nor B cells, which have to do with adaptive immunity, play a significant role in the pathogenesis of EMC-D-virus-induced diabetes, while innate immunity, which is dependent on activated macrophages, contributes to in vivo resistance against EMC-D-virus-induced diabetes.

It has recently been reported that insulin resistance is prevalent in patients with dilated cardiomyopathy (DCM); however, it remains unclear whether insulin resistance is directly induced by DCM or if it is caused by congestive heart failure associated with DCM. We evaluated homeostasis model assessment insulin resistance (HOMA-R) in 14 patients with DCM in comparison with 9 patients with valvular heart diseases (VHD). We also measured the level of serum tumor necrosis factor (TNF)-alpha as a possible causative factor for inducing insulin resistance. Even after the adjustment for age, body mass index, and cardiac function, HOMA-R was significantly higher in patients with DCM than in those with VHD (P = 0.012) (mean +/- SEM: 3.51 +/- 0.59, and 0.80 +/- 0.64, respectively). The serum TNF-alpha level tended to be higher in patients with DCM than in those with VHD; however, the difference was not significant. In conclusion, patients with DCM possess insulin resistance independently of the severity of cardiac dysfunction or serum TNF-alpha, suggesting that insulin resistance in patients with DCM may be closely associated with the pathogenic condition of DCM itself.

The autoimmune regulator (AIRE) gene is a gene responsible for autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy. Here we show that AIRE is expressed in human peripheral CD4-positive T-cells, and most highly in antigen-and interleukin 2-stimulated T (IL-2T) cells. Mitogen-activated protein kinases (MAPKs), including MAPK kinase (MEK) 1/2 and p38 MAPK, were phosphorylated in IL-2T cells and the expression of the AIRE gene was inhibited by a specific p38 MAPK inhibitor (SB203580), thereby indicating that AIRE gene expression is controlled by the MAPK pathway in IL-2T cells. These data suggested the possible significance of the AIRE gene in the peripheral immune system.

Here we report the capacity of human cord blood (CB)-derived cells to generate insulin-producing cells. To investigate in vivo capacity of human CB-derived cells, T cell-depleted mononuclear cells were intravenously transplanted into nonobese diabetic/severe combined immunodeficient/beta2-microglobulinnull mice within 48 hours of birth. At 1-2 months post-transplantation, immunofluorescence staining for insulin and fluorescence in situ hybridization (FISH) analysis using a human chromosome probe indicated that human CB-derived cells generated insulin-producing cells at a frequency of 0.65%+/-0.64% in xenogeneic hosts. Reverse transcription-polymerase chain reaction analysis confirmed the transcription of human insulin in the pancreatic tissue of the recipient mice. To clarify the mechanism underlying CB-derived insulin-producing cells, double FISH analysis using species-specific probes was performed. Almost equal proportions of human chromosome+ murine chromosome- insulin+ cells and human chromosome+ murine chromosome+ insulin+ cells were present in recipient pancreatic islets. Taken together, human CB contains progenitor cells, which can generate insulin-producing cells in recipient pancreatic tissues across a xenogeneic histocompatibility barrier by fusion-dependent and -independent mechanisms.

A 61-year-old man was diagnosed with obesity, diabetes mellitus, and hyperlipidemia associated with insulin resistance in 1988. His condition was complicated with asymptomatic coronary artery disease in 1992. His coronary artery disease gradually progressed during the subsequent 13 years of observation, and he underwent percutaneous coronary intervention four times and also received a coronary artery bypass graft. This is a case of metabolic syndrome with multiple risk factors for arteriosclerosis as visceral obesity, insulin resistance, diabetes, hypertension and hyperlipidemia, in which the recent rapid progression of coronary artery disease might be associated with the discontinuation of statin after coronary artery bypass graft, accompanied with hyper-LDL-choleterolemia. Patients with metabolic syndrome require most comprehensive and strict therapies against multiple risk factors.

Autoimmune regulator (AIRE) gene is a responsible gene for the rare autosomal recessive autoimmune disease: autoimmune-polyendocrinopathy-candidiasis ectodermal dystrophy (APECED). Although it has been reported that AIRE is expressed in the thymic epithelial cells and monocyte-dendritic cell lineage, the regulatory mechanisms of AIRE gene expression have as yet been poorly understood. Here we show that the expression of AIRE gene was induced in granulo-monocyte colony stimulating factor (GM-CSF)-stimulated myelomonocytic leukemia OTC-4 cells. In GM-CSF-stimulated OTC-4 cells, stat5 was not phosphorylated, while mitogen-activated protein kinases (MAPKs), including MAPK kinase (MEK) 1/2 and p38 MAPK, were phosphorylated, indicating activation of MAPK pathway. In addition, the expression of AIRE gene was inhibited by specific p38 MAPK inhibitor (SB203580), whereas the expression was rather enhanced by the MEK1/2 inhibitor (U0126), suggesting that AIRE gene expression is regulated by mitogen-activated protein kinase pathway.

The levels and types of immune responses are determined dependent on the extent of pathogen invasion, reactions to antigens mediated by macrophage-dendritic cells, T cells and antibodies. Recently, accumulating evidence suggests that B cells also play an important role in the regulation of immune responses. Here we have made a review to present a role of B cells in determining the level of immune responses and discussed about the clinical significance of B cell-targeted therapy in patients with autoimmune diseases. Type 1 diabetes is a T cell-mediated autoimmune disease characterized by the destruction of insulin-producing pancreatic beta cells. We and other groups have elucidated that B cells play a critical role in the development of insulitis and diabetes, as B-cell-deficient NOD mice are protected from developing type 1 diabetes. B cells are essential for the T cell receptor clonotype spreading of islet-infiltrating T cells, indicating that B cells may play a role in determining the level of immune responses by antigen presentation to antigen specific T cells. There are now numerous case reports and small series of clinical trials regarding rituximab therapy in autoimmune diseases, such as refractory autoimmune hemolytic anemia, IgM antibody-associated polyneuropathy, systemic lupus erythematosus and rheumatoid arthritis. Rituximab is a genetically engineered chimeric anti-CD 20 monoclonal antibody that is approved for the treatment of lymphoma. CD20 is a B-cell surface antigen that is expressed only on pre- B and mature B cells. Thus, rituximab causes a selective transient depletion of the CD20+ B -cell subpopulation. Rationale and strategy for targeting B cells in the treatment of autoimmune diseases consist of the inhibition of antigen-presentation and co-stimulation that induces T cell expansion and activation. Further careful mechanistic studies are required to develop therapies in patients with autoimmune diseases.

With islet transplantation having grown in popularity since the introduction of the Edmonton protocol, how to secure an unlimited source of islets has become an urgent problem. To resolve this problem, techniques to induce or proliferate islets are urgently required. To achieve this goal, gene expression analysis using a cDNA microarray in islets of partially pancreatectomized mice, in which the remaining islets regenerate and proliferate with insulin secretion and glucose responsiveness, provides us with valuable information. However, those experiments have two critical problems: first, how to selectively collect the regenerating or proliferating islets, and second, the shortage of total RNA extracted from one islet for a microarray analysis. A useful system was thus designed which combined laser microdissection, cDNA amplification by SMART PCR, which can maintain the relative expression profile of transcripts throughout reactions, and a cDNA microarray. Furthermore, this system is expected to contribute to future studies regarding not only islet regeneration but also the function of the islet itself, and this system may also be applicable to many other types of endocrine tissue. In this review, the details of this system are presented and discussed.

The significance of a delayed type hypersensitivity skin reaction to hepatitis B surface antigen (HBsAg) (HBs-DTH) in type B viral hepatitis (VHB) and in intradermal hepatitis B (HB) vaccination is reviewed. HBs-DTH could be developed by the intradermal injection of HB vaccine in anti-HBs positive people and also in persons immunized with HB vaccine. Thus, HBs-DTH could serve as a useful marker for the acquisition of an active Th1 type immunoreactivity to HBsAg. HBs-DTH was absent in patients with chronic VHB. In contrast, HBs-DTH developed early in the convalescent phase of the acute VHB, whereas the production of anti-HBs was significantly delayed, thus suggesting that HBs-DTH may be involved in the recovery mechanisms of acute VHB. Intradermal HB vaccination is useful not only in lowering the cost, but also in the rapid development of anti-HBs, reversing non-responsiveness, improving postexposure prophylaxis and in immunizing immunosuppressed people. A similar vaccination strategy should prove to be useful in prevention and control of not only other infectious diseases but also malignant neoplasms.

The gene encoding interferon (IFN)-gamma, IFNG, is known as one of the candidate susceptibility genes for type 1 diabetes. In addition, cytokines, including IFN-gamma, play important roles in the pathogenesis of type 1 diabetes. Therefore, we focused on the Th1-specific T-box transcription factor gene (T-bet), which contributes to the induction of the hallmark Th1 cytokine, IFN-gamma. We first screened for polymorphisms in the T-bet gene and detected two microsatellite repeat polymorphisms located in intron 1 and the 3'- flanking region, and two single nucleotide polymorphisms, including a His33Gln substitution within the coding region. By association studies, the Gln-positive phenotype and (CA)14 allele in 3'-flanking region of T-bet were found to be associated with type 1 diabetes in the Japanese population. Furthermore, Gln33 T-bet showed a significantly higher transcriptional activity of the IFNG gene via a dual luciferase reporter assay. Our study suggests the first evidence of an association between type 1 diabetes and polymorphisms in the T-bet gene, and that variation in T-bet transcriptional activity may play a role in the development of type 1 diabetes, possibly through the effect on IFN-gamma production in Th1 cells., (Copyright 2004 Springer-Verlag)

The manipulation of a specific gene in NOD mice, the best animal model for insulin-dependent diabetes mellitus (IDDM), must allow for the precise characterization of the functional involvement of its encoded molecule in the pathogenesis of the disease. Although this has been attempted by the cross-breeding of NOD mice with many gene knockout mice originally created on the 129 or C57BL/6 strain background, the interpretation of the resulting phenotype(s) has often been confusing due to the possibility of a known or unknown disease susceptibility locus (e.g., Idd locus) cosegregating with the targeted gene from the diabetes-resistant strain. Therefore, it is important to generate mutant mice on a pure NOD background by using NOD-derived embryonic stem (ES) cells. By using the NOD ES cell line established by Nagafuchi and colleagues in 1999 (FEBS Lett., 455, 101-104), the authors reexamined various conditions in the context of cell culture, DNA transfection, and blastocyst injection, and achieved a markedly improved transmission efficiency of these NOD ES cells into the mouse germ line. These modifications will enable gene targeting on a "pure" NOD background with high efficiency, and contribute to clarifying the physiological roles of a variety of genes in the disease course of IDDM.

In the present study, full length of feline bax, bcl-2, bcl-xL and caspase 3 genes were sequenced and the expression of these mRNAs were also investigated in FIV-infected lymphocytes. The full length cDNA sequence of bax (646 bp), bcl-2 (1423 bp), bcl-xL (1163 bp) and caspase 3 genes (1208 bp) contained a single open reading frame of 579 bp coding 193 amino acids, 708 bp coding 236 amino acids, 702 bp coding 234 amino acids and 834 bp coding 278 amino acids, respectively. Number of apoptotic Kumi-1 cells gradually increased after FIV infection and approximately 70% were apoptotic and 30% were viable in the cells infected with FIV after 8-day incubation, though approximately 80% were non-apoptotic and 20% were dead in non-infected cells. The expression of bcl-2 mRNA in lymphocytes of established cell line was increased by FIV. The amounts of mRNAs of bax, caspase 3 and bcl-xL in FIV-infected cells were not different from those in uninfected control cells., (Copyright 2004 Elsiever B.V.)

Type 2 diabetes mellitus is a heterogeneous disorder, and the development of type 2 diabetes mellitus is associated with both insulin secretion defect and insulin resistance. The primary metabolic defect leading to type 2 diabetes mellitus has been thought to be varied among populations, especially in Japanese and Caucasians. Here, we have done the genome-wide scan for type 2 diabetes mellitus using 102 affected Japanese sib-pairs to identify the genetic factors predisposing to type 2 diabetes mellitus. Nonparametric linkage analysis showed one suggestive evidence for linkage to 11p13-p12 [D11S905: two-point maximum LOD score (MLS) of 2.89 and multipoint MLS of 2.32] and one nominally significant evidence for linkage to 6q15-q16 (D6S462: two-point MLS of 2.02). Interestingly, the 11p13-p12 region was reported to be a susceptibility locus for Japanese type 2 diabetes mellitus with suggestive evidence of linkage, and D11S905 was within 5 cM to D11S935 with the highest MLS in the previous linkage analysis reported. The only overlapped susceptibility region with suggestive evidence of linkage for Japanese type 2 diabetes mellitus was D11S935-D11S905 among the three reports including this study. These results taken together suggest that a susceptibility gene for type 2 diabetes mellitus in Japanese will reside in 11p13-p12.