Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0011854 (type 1 diabetes)
 20,749 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Active T cell recognition of islet antigens has been postulated as the pathogenic mechanism in human type 1 diabetes, but evidence is scarce. If T cells are engaged, they are expected to display increased clonal size and exhibit a T helper (Th)1/Th2 differentiation state. We used a peptide library that covers tyrosine phosphatase IA-2, a target antigen expressed in pancreatic beta cells, to probe 8 diabetic patients and 5 HLA-matched controls. When tested in a high resolution IFNgamma/IL-4 double color ELISPOT assay directly ex vivo, the number of IA-2-reactive IFNgamma producing cells was 17-fold higher in patients than in controls and IL-4 producing cells were not present. An average of 9 peptides was recognized in the patients vs. one in the controls. Determinant recognition primarily involved CD4+ cells and showed high variability among the patients. Furthermore, anti-CD28 antibody signal enhances quantitative assessment of effector T cells in T1D patients. In vitro expansion with peptides and IL-2 results in detection of responding cells in the controls and loss of disease specificity of the T cell response. Together these data provide strong evidence for the active targeting of IA-2 by Th1 memory effector cells in human type 1 diabetes.
 ...
PMID:Increased in vivo frequency of IA-2 peptide-reactive IFNgamma+/IL-4- T cells in type 1 diabetic subjects. 1523 52

The B7-1/2-CD28 system provides the critical signal for the generation of an efficient T cell response. We investigated the role played by B7-2 in influencing pathogenic autoimmunity from islet-reactive CD4 T cells in B7-2 knockout (KO) NOD mice which are protected from type 1 diabetes. B7-2 deficiency caused a profound diminishment in the generation of spontaneously activated CD4 T cells and islet-specific CD4 T cell expansion. B7-2 does not impact the effector phase of the autoimmune response as adoptive transfer of islet Ag-specific BDC2.5 splenocytes stimulated in vitro could easily induce disease in B7-2KO mice. CD4 T cells showed some hallmarks of hyporesponsiveness because TCR/CD28-mediated stimulation led to defective activation and failure to induce disease in NODscid recipients. Furthermore, CD4 T cells exhibited enhanced death in the absence of B7-2. Interestingly, we found that B7-2 is required to achieve normal levels of CD4+CD25+CD62L+ T regulatory cells because a significant reduction of these T regulatory cells was observed in the thymus but not in the peripheral compartments of B7-2KO mice. In addition, our adoptive transfer experiments did not reveal either pathogenic or regulatory potential associated with the B7-2KO splenocytes. Finally, we found that the lack of B7-2 did not induce a compensatory increase in the B7-1 signal on APC in the PLN compartment. Taken together these results clearly indicate that B7-2 plays a critical role in priming islet-reactive CD4 T cells, suggesting a simplified, two-cell model for the impact of this costimulatory molecule in autoimmunity against islets.
 ...
PMID:B7-2 (CD86) controls the priming of autoreactive CD4 T cell response against pancreatic islets. 1535 7

Idd9.3, a locus that determines susceptibility to the autoimmune disease type 1 diabetes (T1D) in the nonobese diabetic (NOD) mouse, has been mapped to the distal region of chromosome 4. In the current report we reduce the size of the Idd9.3 interval to 1.2Mb containing 15 genes, including one encoding the immune signaling molecule, 4-1BB, which shows amino acid variation between diabetes sensitive and resistant strains. 4-1BB, a member of the TNF receptor superfamily expressed by a variety of immune cells, mediates growth and survival signals for T cells. Functional analyses demonstrate that purified T cells from NOD congenic mice with the C57BL/10 (B10) allele at Idd9.3 produce more IL-2 and proliferate more vigorously in response to anti-CD3 plus immobilized 4-1BB ligand than T cells from NOD mice with the NOD allele at Idd9.3. In contrast, the response to anti-CD3 plus anti-CD28 costimulation was indistinguishable between the congenic strains, pinpointing the differences in NOD versus NOD.B10 Idd9.3 T cell responses to the 4-1BB costimulatory pathway. These data provide evidence in support of Idd9.3 as the locus encoding 4-1BB and suggest that the 4-1BB signaling pathway could have a primary function in the etiology of autoimmune disease.
 ...
PMID:Genetic and functional association of the immune signaling molecule 4-1BB (CD137/TNFRSF9) with type 1 diabetes. 1599 81

Costimulatory signals regulate T-cell activation. To investigate the role of costimulation in autoimmunity and transplantation, we studied the BB rat model of type 1 diabetes. Diabetes-prone BB (BBDP) rats spontaneously develop disease when 55-120 days of age. We observed that two anti-CD28 monoclonal antibodies (mAb) with different functional activities completely prevented diabetes in BBDP rats. Anti-CD154 mAb delayed diabetes, whereas treatment with CTLA4-Ig or anti-CD80 mAb accelerated disease. Anti-CD86 or anti-CD134L mAbs had no effect. Diabetes resistant BB (BBDR) rats are disease-free, but >95% of them develop diabetes after treatment with polyinosinic-polycytidylic acid and an mAb that depletes Treg cells. In the induced BBDR model, anti-CD154 mAb delayed onset of diabetes, whereas CTLA4-Ig, anti-CD134L or either of the anti-CD28 mAbs had little or no effect. In contrast, blockade of the CD134-CD134L pathway was highly effective for preventing autoimmune recurrence against syngeneic islet grafts in diabetic BBDR hosts. Blockade of the CD40-CD154 pathway was also effective, but less so. These data suggest that the effectiveness of costimulation blockade in the treatment of type 1 diabetes is dependent on both the costimulatory pathway targeted and the mechanism of induction, stage, intensity and duration of the pathogenic process.
 ...
PMID:Costimulation and autoimmune diabetes in BB rats. 1661 20

NOD.Idd3/5 congenic mice have insulin-dependent diabetes (Idd) regions on chromosomes 1 (Idd5) and 3 (Idd3) derived from the nondiabetic strains B10 and B6, respectively. NOD.Idd3/5 mice are almost completely protected from type 1 diabetes (T1D) but the genes within Idd3 and Idd5 responsible for the disease-altering phenotype have been only partially characterized. To test the hypothesis that candidate Idd genes can be identified by differential gene expression between activated CD4+ T cells from the diabetes-susceptible NOD strain and the diabetes-resistant NOD.Idd3/5 congenic strain, genome-wide microarray expression analysis was performed using an empirical Bayes method. Remarkably, 16 of the 20 most differentially expressed genes were located in the introgressed regions on chromosomes 1 and 3, validating our initial hypothesis. The two genes with the greatest differential RNA expression on chromosome 1 were those encoding decay-accelerating factor (DAF, also known as CD55) and acyl-coenzyme A dehydrogenase, long chain, which are located in the Idd5.4 and Idd5.3 regions, respectively. Neither gene has been implicated previously in the pathogenesis of T1D. In the case of DAF, differential expression of mRNA was extended to the protein level; NOD CD4+ T cells expressed higher levels of cell surface DAF compared with NOD.Idd3/5 CD4+ T cells following activation with anti-CD3 and -CD28. DAF up-regulation was IL-4 dependent and blocked under Th1 conditions. These results validate the approach of using congenic mice together with genome-wide analysis of tissue-specific gene expression to identify novel candidate genes in T1D.
 ...
PMID:Genome-wide microarray expression analysis of CD4+ T Cells from nonobese diabetic congenic mice identifies Cd55 (Daf1) and Acadl as candidate genes for type 1 diabetes. 1817 47

The 620Trp variant of the LYP protein, encoded by the lymphoid tyrosine phosphatase 22 gene (PTPN22), is associated with autoimmunity. In this study we aimed at characterising the role of this variant on lymphocyte activation. We analysed cytokine secretion and proliferation of peripheral blood mononuclear cells (PBMCs) and CD4(+)T cells in a cohort of clinically non-diabetic, multiple autoantibody-positive children, healthy controls and in children with type 1 diabetes (T1D). We found a decreased proliferation and IL-2 production of CD4(+)T cells after anti-CD3/anti-CD28 stimulation (p=0.04 for IL-2) among T1D patients. In addition, a profoundly decreased intracellular calcium flux in CD4(+)T cells after PHA stimulus was detected among 620Trp carriers. In contrast, no effect of this polymorphism on tuberculin and tetanus toxoid induced PBMC proliferation and cytokine secretion was observed in autoantibody positive children, healthy controls and children with newly-diagnosed T1D. In conclusion, the LYP 620Trp variant is associated with reduced activation, proliferation and IL-2 production in CD4(+)T cells among T1D patients. In accordance with our previous findings on the key role of this variant on disease progression, this mechanism is likely to contribute to the development of beta-cell specific autoimmunity.
 ...
PMID:Reduced CD4+T cell activation in children with type 1 diabetes carrying the PTPN22/Lyp 620Trp variant. 1829 86

We sought to determine whether Litomosoides sigmodontis, a filarial infection of rodents, protects against type 1 diabetes in non-obese diabetic (NOD) mice. Six-week-old NOD mice were sham-infected or infected with either L3 larvae, adult male worms, or adult female worms. Whereas 82% of uninfected NOD mice developed diabetes by 25 weeks of age, no L. sigmodontis-infected mice developed disease. Although all mice had evidence of ongoing islet cell inflammation by histology, L. sigmodontis-infected mice had greater numbers of total islets and non-infiltrated islets than control mice. Protection against diabetes was associated with a T helper type 2 (Th2) shift, as interleukin-4 (IL-4) and IL-5 release from alpha-CD3/alpha-CD28-stimulated splenocytes was greater in L. sigmodontis-infected mice than in uninfected mice. Increased circulating levels of insulin-specific immunoglobulin G1, showed that this Th2 shift occurs in response to one of the main autoantigens in diabetes. Multicolour flow cytometry studies demonstrated that protection against diabetes in L. sigmodontis-infected NOD mice was associated with significantly increased numbers of splenic CD4(+) CD25(+) FoxP3(+) regulatory T cells. Interestingly, injection of crude worm antigen into NOD mice also resulted in protection against type 1 diabetes, though to a lesser degree than infection with live L. sigmodontis worms. In conclusion, these studies demonstrate that filarial worms can protect against the onset of type 1 diabetes in NOD mice. This protection is associated with a Th2 shift, as demonstrated by cytokine and antibody production, and with an increase in CD4(+) CD25(+) FoxP3(+) regulatory T cells.
 ...
PMID:Inhibition of type 1 diabetes in filaria-infected non-obese diabetic mice is associated with a T helper type 2 shift and induction of FoxP3+ regulatory T cells. 1901 10

Islet specific CD4 cells expressing inhibitory receptors may be a useful therapeutic tool for treating type 1 diabetes (T1D). Engagement of transgenic Ly49A inhibits CD4 cell activation and delays onset of T1D in mice. However, in vitro studies suggest the inhibitory effect of Ly49A is incomplete. Here we report that following simultaneous TCR and Ly49A engagement, phosphorylation of Zap70, Erk1/2 and c-Jun were significantly diminished. Kinetic studies indicated that Ly49A did not simply delay activation but had a long-lasting effect. In contrast, when only costimulatory signals were provided through CD28, Ly49A engagement did not block p38 MapK or Akt phosphorylation. Likewise, expression of the downstream targets Bcl-xl and Baff were unaffected. Together these data suggest that engagement of Ly49A selectively inhibits signals downstream of the TCR but spares those unique to CD28. These results suggest that when considering its use as an immunotherapy, the potency of inhibitory receptors such as Ly49A may be further improved by pairing them with costimulatory blockade.
 ...
PMID:Engagement of transgenic Ly49A inhibits mouse CD4 cell activation by disrupting T cell receptor, but not CD28, signaling. 1936 13

Type 1 diabetes mellitus (T1D) and multiple sclerosis (MS) are organ-specific autoimmune diseases leading to an attack of auto-aggressive lymphocytes against the pancreatic beta-cells and central nervous system, respectively. Using four-colour flow cytometry, T-lymphocyte populations having an important function in autoimmune processes were analyzed. T-regulatory cells (Treg) CD4(+)CD25(+)CD127(low), T-suppressor cells (Ts) CD8(+)CD28(-), activated helper CD4(+)CD25(+)CD127(+) and cytotoxic CD8(+)CD25(+) T-cells and also naive CD4(+)CD45RA(+) and memory T-cells CD4(+)CD45RO(+) were compared in the group of patients with T1D (n=30), MS (n=31) and in the group of healthy controls (n=29). Significant differences in Ts cells, activated helper and cytotoxic cells and also memory T-cells were recognized in the group of T1D patients compared to healthy controls. Ts population was significantly lowered in MS patients as well. However, no significant differences were noticed in Treg population. The observed data demonstrate significant differences among patients with T1D and MS in comparison to healthy individuals.
 ...
PMID:Numerical defects in CD8+CD28- T-suppressor lymphocyte population in patients with type 1 diabetes mellitus and multiple sclerosis. 2021 85

Diabetes-prone BioBreeding (DP-BB) rats spontaneously develop type 1 diabetes mellitus (T1DM) on grounds of their MHC haplotype RT1(u) and a point mutation in the Gimap5 gene. In this study, we report that DP-BB rats exhibit an increasingly severe imbalance, in particular between Th17 and regulatory T (T(reg)) cells, within the first months of age. This can be assigned to an excess in effector T cells because neither the percentage nor the function of the T(reg) cells is compromised. Flow cytometric analysis of Vbeta segment usage and CDR3 spectratyping further suggest that the disturbed repertoire of peripheral T cells may also contribute to the development of T1DM in DP-BB rats. Importantly, expansion of T(reg) cells in vivo by means of a CD28 superagonistic Ab as well as adoptive transfer of T(reg) cells efficiently interferes with the development of T1DM in DP-BB rats, whereas treatment with conventional Th cells does not afford protection. Using a newly generated strain of enhanced GFP transgenic rats, we could further demonstrate that the transferred T(reg) cells persist in the recipient rats for several months and partially correct the imbalance between Th17 and T(reg) cells. Thus, our data support the hypothesis that unchecked effector T cell action and a disturbed T cell repertoire contribute to the development of T1DM in DP-BB rats, which may also have implications for a better understanding of the human disease.
 ...
PMID:Type 1 diabetes in BioBreeding rats is critically linked to an imbalance between Th17 and regulatory T cells and an altered TCR repertoire. 2124 65


<< Previous 1 2 3 4 5 6 Next >>