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  • 1
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Scandinavian journal of immunology 32 (1990), S. 0 
    ISSN: 1365-3083
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Interleukin 1β(IL-1β) and tumour necrosis factor alpha (TNF-α) may be pathogenetically important in insulin-dependent diabetes mellitus (IDDM), which is associated with genes of the HLA region. Since a regulatory role of HLA region genes on monokine production may exist, we looked for an association between the monokine and prostaglandin E2 (PGE2) responses of monocytes (Mo) from 20 healthy males (18–50 years) with HLA-DR types relevant for IDDM susceptibility and resistance (DR 1,2, DR 1,3, DR 1,4, DR 3,4). Monokine assays were established and evaluated and the secretions of IL-1β, TNF-α, and PGE2 measured in Mo cultures (2 h, 6 h, 20 h) prepared by endotoxin-free techniques and stimulated by low-dose E. coli lipopolysaccharides (LPS). There were no significant associations between Mo responses and HLA-DR phenotype. Likewise, Mo from DR2 (n=5) and DR4 (n= 5) homozygous healthy males demonstrated no significant differences in monokine and PGE2 responses of Mo.In the HLA class III region a diallelic TNF-β gene Ncol polymorphism consisting of alleles of 5.5 kb and 10.5 kb was recently described and associated with susceptibility to autoimmune diseases including IDDM. We report that IL-1β and TNF-α responses of Mo from TNF-β 10.5 kb homozygous healthy individuals were significantly higher than for TNF-β 5.5/10.5 kb heterozygotes.IL-1β and TNF-α responses of Mo from males (18–35 years) with newly diagnosed (n= 10) and long-standing IDDM (n= 10) and from age- and HLA-DR-matched healthy males (n= 10) were studied. LPS, gamma interferon (IFN), and TNF-α-stimulated Mo cultures were investigated. No significant differences were found between Mo responses of IDDM patients and controls. IFN (1000 U/ml) in the presence of LPS significantly potentiated LPS-stimulated Mo TNF-α secretion and reduced the levels of IL-β immunoreactivity in Mo lysates. IFN and TNF-α did not have any effects on LPS-stimulated Mo secretion of IL-1 β immunoreactivity.We conclude that Mo IL-1β and TNF-α production is normal in patients with recent-onset and long-standing IDDM. The interindividual differences in monokine responses may be accounted for by the diallelic human TNF-β gene polymorphism rather than by HLA class II genes. This observation may be important for understanding the association of certain H LA haplotypes with autoimmune phenomena and disease.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1365-3083
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: The effects of dietary supplementation with ω-3-polyunsaturated fatty acids (ω-3-PUFA) on the proliferative response of PBMC and on the secretion of monokines and arachidonic acid metabolites from PBMC and monocytes (Mo) from healthy subjects and patients with recent-onset insulin-dependent diabetes mellitus (IDDM) were examined. Three groups of eight to nine healthy individuals were randomized to either 2.0 g/day or 4.0 g/day of ω-3-PUFA devoid of vitamins A and D, or an isocaloric amount of placebo. Furthermore, eight patients with recent-onset IDDM received 4.0 g/day of ω-3-PUFA. IL-lβ production and TNF-α secretion was determined before and after 7 weeks of treatment, and 10 weeks after withdrawal of treatment. Significant increases in platelet and PBMC membrane eicosapentaenoic acid was found in ω-3-PUFA-treated individuals. ω-3-PUFA treatment significantly reduced the content of IL-Ib in lysates of PBMC, but did not affect PBMC or Mo secretion of IL-1β, TNF-α or prostaglandin E2 (PGE2) or PBMC leukotriene B4 (LTB4) secretion in healthy subjects or in IDDM patients. A significant inhibition of the PHA-stimulated. but not the spontaneous or PPD-stimulated, proliferative response of PBMC was observed in healthy and diabetic subjects treated with (o-3-PUFA. No correlation was found between PHA-stimulated PBMC proliferation and PBMC secretion of TNF-α and IL-1β. There were no significant differences in the spontaneous or the PPD-or PHA-stimulated proliferative responses of PBMC between diabetic and healthy individuals at entry. We conclude that although dietary supplementation with 4.0 g/day of ω-3-PUFA inhibits the proliferation of PBMC and reduces IL-I immunoreactivity in PBMC and Mo, it does not alter monokine, PGE2 or LTB4, secretion in healthy or IDDM subjects.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1398-9995
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Supernatants of peripheral blood mononuclear cells from healthy human donors stimulated with recall antigen (purified protein derivative of tuberculin) or lectin (phytohaemagglutinin) markedly inhibited the insulin release from isolated human and rat islets of Langerhans, and decreased rat islet contents of insulin and glucagons in a dose-dependent manner. A maximal effect on islet function was obtained with supernatant concentrations down to 5%. Supernatants of mononuclear cells stimulated with tuberculin were more potent than supernatants produced by lectin stimulation. Culture medium reconstituted with tuberculin or phytohaemagglutinin did not impair islet function. Electron microscopy demonstrated that supernatants were cytotoxic to islet cell. The cytotoxic mononuclear cell mediator(s) was non-dialysable, sensitive to heating to 56°C, labile even when stored at -70°C, but stable when lyophilised.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Allergy 40 (1985), S. 0 
    ISSN: 1398-9995
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Cytokines are soluble, antigen non-specific, non-immunoglobulin mediators produced and secreted by blood mononuclear cells interacting in the cellular immune-response. To test the possibility that cytokines participate in the autoimmune destruction of the pancreatic beta-cells leading to insulin-dependent diabetes mellitus, isolated human or rat islets of Langerhans were incubated for 7 days with cytokine-rich, cell-free supernatants of blood mononuclear cells from healthy human donors stimulated with or without purified protein derivative of tuberculin or phytohaemagglutinin. Glucose stimulated insulin-release, and contents of insulin and glucagon in islets incubated with cytokine-rich supernatants were markedly reduced. This impairment of islet function was due to a cytotoxic effect of cytokine-rich supernatants as judged by disintegration of normal light-microscopic morphology.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Oxford, UK; Malden, USA : Blackwell Science Ltd
    Scandinavian journal of immunology 59 (2004), S. 0 
    ISSN: 1365-3083
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: CD4 is a candidate gene in autoimmune diseases, including Type 1 diabetes mellitus (T1DM), because the CD4 receptor is crucial for appropriate antigen responses of CD4+ T cells. We previously found linkage between a CD4-1188(TTTTC)5−14 promoter polymorphism and T1DM. In the present study, we screened the human CD4 promoter for mutations and identified three frequent single nucleotide polymorphisms (SNPs): CD4-181C/G, CD4-521C/G and CD4-1050T/C. The SNPs are in strong linkage disequilibrium (LD) and association with the CD4-1188(TTTTC)5−14 alleles, and we observed nine CD4 promoter haplotypes, of which four are frequent. We genotyped the SNPs in 253 Danish T1DM families (1129 individuals) and found evidence for linkage and association of a CD4 (A4-1188T-1050G-521C-181) haplotype to T1DM. In reporter studies, we show that (1) the T1DM-associated CD4 haplotype encodes high constitutive promoter activity and (2) the CD4-181G variant encodes higher stimulated promoter activity than the CD4-181C variant. This difference is in part neutralized in the frequently occurring CD4 promoter haplotypes by the more upstream genetic variants. Thus, we report functional impact of a novel CD4-181C/G SNP on stimulated CD4 promoter activity and the identification of a novel CD4 haplotype with high constitutive promoter activity that is linked and associated with T1DM.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 1043-4666
    Keywords: Aminoguanidine ; NAME ; glucagon ; insulin resistance ; leukocytes
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 1432-0428
    Keywords: Autoimmunity ; pancreatic B cells ; cytotoxicity ; Interleukin-1 ; lymphokines ; macrophages ; pancreatic islets pathogenesis ; Type 1 (insulin-dependent) diabetes mellitus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Addition of highly purified human Interleukin-1 to the culture medium of isolated rat islets of Langerhans for 6 days led to 88% inhibition of glucose-induced insulin-release, reduction of islet contents of insulin and glucagon to 31% and 8% respectively, and disintegration of the islets. These effects were dose-dependent and reproducible when using three different Interleukin-1 preparations. Highly purified human Interleukin-2, Lymphotoxin, Leucocyte Migration Inhibitory Factor and Macrophage Migration Inhibitory Factor were ineffective. These findings suggest that Interleukin-1 may play an important role in the molecular mechanisms underlying autoimmune B-cell destruction leading to Type 1 (insulin-dependent) diabetes mellitus.
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 1432-0428
    Keywords: Interleukin 1 ; pancreatic islets ; preproinsulin mRNA ; proinsulin biosynthesis ; Type 1 (insulin-dependent) diabetes mellitus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Human crude and recombinant interleukin 1 (IL-1) was found to dose- and time-dependently affect the biosynthesis of (pro)insulin in isolated rat islets of Langerhans. Incubation of rat islets with either 0.5 U/ml or 5 U/ml of crude IL-1 for 1 h had no detectable effect on (pro)insulin biosynthesis. After 24 hours of exposure 0.5 U/ml of crude or 0.6 ng/ml of recombinant IL-1 (beta) increased the (pro)insulin biosynthesis by 42% and 58%, respectively, whereas a 10-fold greater concentration of IL-1 decreased the (pro)insulin biosynthesis by 74% and 89%, respectively. The increase in (pro)insulin biosynthesis was accompanied by an increase in total protein biosynthesis indicating a nonspecific stimulatory action of low IL-1 concentrations. In contrast, high IL-1 concentrations caused a more selective decrease of the (pro)insulin biosynthesis when compared to the total protein biosynthesis. In addition, low IL-1 concentrations were found to increase and high concentrations to decrease the relative levels of pre-proinsulin mRNA suggesting that IL-1 may act both at a pre- and post-translational level of insulin biosynthesis.
    Type of Medium: Electronic Resource
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  • 9
    ISSN: 1432-0428
    Keywords: Cytokine ; interleukin-1 receptor antagonist ; insulin-dependent diabetes mellitus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The monokines interleukin-1α and -β have been implicated as effector molecules in the immune-mediated pancreatic beta-cell destruction leading to insulin-dependent diabetes mellitus. Here we investigated the effects of interleukin-1 receptor antagonism on insulin and glucagon release of rat, mouse and human islets exposed to recombinant human interleukin-1β, and on interleukin-1β induced changes in blood glucose, serum insulin and serum glucagon levels in Wistar Kyoto rats. The interleukin-1 receptor antagonist reduced the co-mitogenic effect of interleukin-1β on mouse and rat thymocytes with a 50% inhibitory concentration of 10- and 100-fold molar excess, respectively. Complete inhibition was obtained with a 100–1,000-fold molar excess. However, at a 100-fold molar excess the interleukin-1 receptor antagonist did not antagonise the potentiating effect of interleukin-1βon rat islet insulin accumulation during 3 and 6 h of exposure or of interleukin-1β-induced inhibition of insulin release after 24 h. In contrast, interleukin-1β-stimulated islet glucagon release was completely antagonised by a 100-fold molar excess of interleukin-1 receptor antagonist. A 10,000-fold molar excess of interleukin-1 receptor antagonist was needed to antagonise interleukin-1β stimulatory and inhibitory effects on rat beta-cell function in vitro. A 100-fold excess of interleukin-1 receptor antagonist could not counteract interleukin-1β effects on mouse and human beta cells, excluding species difference in the efficacy of the human interleukin-1 receptor antagonist. An anti-mouse interleukin-1 receptor type I antibody completely abolished interleukin-1β effects on isolated mouse islets. A 10–100-fold molar excess of interleukin-1 receptor antagonist antagonised interleukin-1β-induced fever, hypercorticosteronaemia and hyperglucagonaemia, but not interleukin-1β-induced reduction in insulin/glucose ratio in normal rats. In conclusion, our results suggest that antagonism of interleukin-1β effects on beta cells requires higher concentrations of interleukin-1 receptor antagonist than those necessary to block interleukin-1 action on islet alpha cells and other interleukin-1 targets in vitro and in vivo. This may contribute to the understanding of the specificity of the immunological beta-cell destruction leading to insulin-dependent diabetes.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Diabetologia 39 (1996), S. 1005-1029 
    ISSN: 1432-0428
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
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