Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0011849 (diabetes)
 277,896 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Dendritic cells (DCs) not only induce but also modulate T cell activation. 1,25-Dihydroxyvitamin D(3) [1,25-(OH)(2)D(3)] induces DCs with a tolerogenic phenotype, characterized by decreased expression of CD40, CD80, and CD86 co-stimulatory molecules, low IL-12, and enhanced IL-10 secretion. We have found that a short treatment with 1,25-(OH)(2)D(3) induces tolerance to fully mismatched mouse islet allografts, and that this tolerance is stable to challenge with donor-type spleen cells and allows acceptance of donor-type vascularized heart grafts. This effect is enhanced by co-administration of mycophenolate mofetil (MMF), a selective inhibitor of T and B cell proliferation, that also has effects similar to 1,25-(OH)(2)D(3) on DCs. Graft acceptance is associated with impaired development of type 1 CD4(+) and CD8(+) cells and an increased percentage of CD4(+)CD25(+) regulatory cells expressing CD152 in the spleen and in the draining lymph node. Transfer of CD4(+)CD25(+) cells from tolerant mice protects 100% of the syngeneic recipients from islet allograft rejection. CD4(+)CD25(+) cells that are able to inhibit the T cell response to a pancreatic autoantigen and to significantly delay disease transfer by pathogenic CD4(+)CD25(-) cells are also induced by treatment of adult nonobese diabetic (NOD) mice with a selected vitamin D receptor (VDR) ligand. This treatment arrests progression of insulitis and Th1 cell infiltration, and inhibits diabetes development at non-hypercalcemic doses. The enhancement of CD4(+)CD25(+) regulatory T cells able to mediate transplantation tolerance and to arrest type 1 diabetes development by a short oral treatment with small organic compounds that induce tolerogenic DCs, like VDR ligands, suggests possible clinical applications of this approach.
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PMID:Tolerogenic dendritic cells induced by vitamin D receptor ligands enhance regulatory T cells inhibiting autoimmune diabetes. 1272 48

In the nonobese diabetic (NOD) mouse, pathogenic and suppressor CD4(+) T cells can be distinguished by the constitutive expression of CD25. In this study, we demonstrate that the progression of autoimmune diabetes in NOD mice reflects modifications in both T cell subsets. CD4(+)CD25(+) suppressor T cells from 8-, but not 16-wk-old NOD mice delayed the onset of diabetes transferred by 16-wk-old CD25-depleted spleen cells. These results were paralleled by the inhibition of alloantigen-induced proliferation of CD4(+)CD25(-) cells, indicating an age-dependent decrease in suppressive activity. In addition, CD4(+)CD25(-) pathogenic T cells became progressively less sensitive to immunoregulation by CD4(+)CD25(+) T cells during diabetes development. CD4(+)CD25(-) T cells showed a higher proliferation and produced more IFN-gamma, but less IL-4 and IL-10, whereas CD4(+)CD25(+) T suppressor cells produced significantly lower levels of IL-10 in 16- compared with 8-wk-old NOD mice. Consistent with these findings, a higher frequency of Th1 cells was observed in the pancreas of 16-wk-old compared with 8-wk-old NOD mice. An increased percentage of CD4(+)CD25(-) T cells expressing CD54 was present in 16-wk-old and in diabetic NOD, but not in BALB/c mice. Costimulation via CD54 increased the proliferation of CD4(+)CD25(-) T cells from 16-, but not 8-wk-old NOD mice, and blocking CD54 prevented their proliferation, consistent with the role of CD54 in diabetes development. Thus, the pathogenesis of autoimmune diabetes in NOD mice is correlated with both an enhanced pathogenicity of CD4(+)CD25(-) T cells and a decreased suppressive activity of CD4(+)CD25(+) T cells.
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PMID:Dynamics of pathogenic and suppressor T cells in autoimmune diabetes development. 1453 Mar 24

Although T helper (T(H)) cell-mediated immunity is required to effectively eliminate pathogens, unrestrained T(H) activity also contributes to tissue injury in many inflammatory and autoimmune diseases. We report here that the T(H) type 1 (T(H)1)-specific Tim-3 (T cell immunoglobulin domain, mucin domain) protein functions to inhibit aggressive T(H)1-mediated auto- and alloimmune responses. Tim-3 pathway blockade accelerated diabetes in nonobese diabetic mice and prevented acquisition of transplantation tolerance induced by costimulation blockade. These effects were mediated, at least in part, by dampening of the antigen-specific immunosuppressive function of CD4(+)CD25(+) regulatory T cell populations. Our data indicate that the Tim-3 pathway provides an important mechanism to down-regulate T(H)1-dependent immune responses and to facilitate the development of immunological tolerance.
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PMID:Tim-3 inhibits T helper type 1-mediated auto- and alloimmune responses and promotes immunological tolerance. 1458 21

Thymic-derived dysregulated tolerance has been suggested to occur in type 1 diabetes via impaired generation of CD4(+)CD25(+) T regulatory cells, leading to autoimmune beta cell destruction. In this study, we demonstrate that Notch3 expression is a characteristic feature of CD4(+)CD25(+) cells. Furthermore, streptozotocin-induced autoimmune diabetes fails to develop in transgenic mice carrying the constitutively active intracellular domain of Notch3 in thymocytes and T cells. The failure to develop the disease is associated with an increase of CD4(+)CD25(+) T regulatory cells, accumulating in lymphoid organs, in pancreas infiltrates and paralleled by increased expression of IL-4 and IL-10. Accordingly, CD4(+) T cells from Notch3-transgenic mice inhibit the development of hyperglycemia and insulitis when injected into streptozotocin-treated wild-type mice and display in vitro suppressive activity. These observations, therefore, suggest that Notch3-mediated events regulate the expansion and function of T regulatory cells, leading to protection from experimental autoimmune diabetes and identify the Notch pathway as a potential target for therapeutic intervention in type 1 diabetes.
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PMID:Expression of activated Notch3 in transgenic mice enhances generation of T regulatory cells and protects against experimental autoimmune diabetes. 1456 23

Autoimmune diabetes progression in NOD mice is under the control of CD4+ regulatory T cells. In the thymus these regulatory cells are CD25+-like CD4+ cells shown to control physiologic organ-specific autoimmunity. In contrast, in the periphery, both CD4+CD25+ and CD4+CD25- cells exhibit regulatory capacities. We have accumulated evidence showing an important role of transforming growth factor beta (TGFbeta) in this T cell-mediated regulation in vivo. Additionally, onset of autoimmune diabetes was preceded by a functional abnormality of CD4+CD25+ regulatory T cells as assessed by their inability to suppress in vitro the proliferation of polyclonally activated CD25- T cells. Antibodies to CD3 are potent immunosuppressants now generally applied as non Fc-receptor (FcR) binding monoclonals (F(ab')2 fragments in mice and humanized Fc-mutated monoclonals in humans). They were shown to induce durable regression of overt diabetes in NOD mice by restoring self-tolerance. The data from our laboratory were the first to show that in NOD mice anti-CD3 antibodies could reverse recent onset of disease by restoring tolerance to beta cell antigens. Thus in NOD mice presenting full-blown diabetes, a five consecutive day treatment with low doses of the hamster anti-CD3 monoclonal antibody 145 2C11 induced complete and durable disease remission, within 2-4 weeks in the absence of insulin treatment. This result has led to clinical trials, presently ongoing, in recent onset type 1 diabetic patients using non FcR binding monoclonal antibodies to CD3 that are well tolerated since they are devoid of the mitogenic activity that was a hallmark of first generation CD3 antibodies such as OKT3. Concerning the mechanistic aspects, data from the NOD mouse model indicate that CD3 antibodies promote (1) immediate clearance of insulitis, followed by (2) 'resetting' of specialized subsets of immunoregulatory CD4+ T cells mediating active tolerance similar to those that control the onset of spontaneous diabetes. Our recent data show that in CD3-treated NOD mice, these immunoregulatory T cells concentrate in the CD4-CD62L+ compartment and part of the population shares the CD25 marker. Furthermore, we also obtained evidence in CD3-treated NOD for a significant increase (in the pancreatic and mesenteric lymph nodes but not in the spleen) in the proportion of CD4+CD25+CTLA4+ T cells which produce TGFbeta.
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PMID:CD3 antibody treatment stimulates the functional capability of regulatory T cells. 1460 25

Depletion of selected regulatory CD4+ T cell subsets induces the spontaneous onset of various immune or autoimmune disorders. It is not clear, however, whether a given subset, notably CD4+CD25+ regulatory T cells, protects from a wide spectrum of immune disorders, or whether specialized subsets of regulatory T cells control each given disease or group of diseases. We report here, using diabetes prone nonobese diabetic (NOD) mice, that depending on the regulatory T cells that are depleted, i.e., CD25+, CD62L+, or CD45RB(low), distinct immune diseases appear after transfer into NOD severe combined immunodeficiency (SCID) recipients. Thus, reconstitution of NOD SCID mice with CD25- T cells induces major gastritis and late-onset diabetes, but no or mild colitis. Reconstitution with CD62L- T cells induces fulminant diabetes with no colitis or gastritis. Reconstitution with CD45RB(high) T cells induces major colitis with wasting disease and no or very moderate gastritis and diabetes. Major differences among the three regulatory T cell subsets are also seen in vitro. The bulk of suppressor cells inhibiting the proliferation of CD4+CD25- T cells in coculture is concentrated within the CD25+ but not the CD62L+ or CD45RB(low) T cell subsets. Similarly, cytokine production patterns are significantly different for each regulatory T cell subset. Collectively, these data point to the diversity and organ selectivity of regulatory T cells controlling distinct autoimmune diseases whatever the underlying mechanisms.
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PMID:Diversity of regulatory CD4+T cells controlling distinct organ-specific autoimmune diseases. 1467 94

The use of soluble class II MHC tetramers has enabled the identification of autoantigen-specific T cells in the peripheral blood of type 1 diabetes patients. Our approach takes advantage of the appearance of highly activated T cells expressing a CD25(+)/CD4(high+) phenotype induced by immobilized class II MHC monomer containing the GAD65 peptide. Almost all T cells that stain with the specific tetramer reside in this population and, since this activation profile is not present in normal subjects, it may provide a useful tool for analysis of the T cell response in autoimmune diabetes. The utilization of tetramer techniques in the detection of autoreactive T cells is a powerful tool to gain insight into mechanisms of the molecular basis of autoimmunity. The phenotyping of T cells should provide useful markers for progression of immune-mediated beta cell reactivity and can be utilized in clinical trials to evaluate the efficacy of the immunomodulatory therapies targeting intervention/prevention of autoimmune diseases.
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PMID:Detection of CD4+ autoreactive T cells in T1D using HLA class II tetramers. 1467 42

The wide diversity of the T and B Ag receptor repertoires becomes even more extensive postneonatally due to the activity of TdT, which adds nontemplated N nucleotides to Ig and TCR coding ends during V(D)J recombination. In addition, complementarity-determining region 3 sequences formed in the absence of TdT are more uniform due to the use of short sequence homologies between the V, D, and J genes. Thus, the action of TdT produces an adult repertoire that is both different from, and much larger than, the repertoire of the neonate. We have generated TdT-deficient nonobese diabetic (NOD) and MRL-Fas(lpr) mice, and observed a decrease in the incidence of autoimmune disease, including absence of diabetes and decreased pancreatic infiltration in NOD TdT(-/-) mice, and reduced glomerulonephritis and increased life span in MRL-Fas(lpr) TdT(-/-) mice. Using tetramer staining, TdT(-/-) and TdT(+/+) NOD mice showed similar frequencies of the diabetogenic BDC 2.5 CD4(+) T cells. We found no increase in CD4(+)CD25(+) regulatory T cells in NOD TdT(-/-) mice. Thus, TdT deficiency ameliorates the severity of disease in both lupus and diabetes, two very disparate autoimmune diseases that affect different organs, with damage conducted by different effector cell types. The neonatal repertoire appears to be deficient in autoreactive T and/or B cells with high enough affinities to induce end-stage disease. We suggest that the paucity of autoreactive specificities created in the N region-lacking repertoire, and the resultant protection afforded to the newborn, may be the reason that TdT expression is delayed in ontogeny.
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PMID:Terminal deoxynucleotidyltransferase deficiency decreases autoimmune disease in diabetes-prone nonobese diabetic mice and lupus-prone MRL-Fas(lpr) mice. 1503 81

Immunization with heat-shock protein (HSP) gp96 elicits protective immunity to the cancer or virus-infected cells from which it is derived. Low doses of gp96 generate immunity, while doses 10 times the immunizing dose do not. We show here that injection of high doses of gp96 generates CD4(+) T cells that down-regulate a variety of ongoing immune responses. Immunization with high doses of gp96 prevents myelin basic protein- or proteolipid protein-induced autoimmune encephalomyelitis in SJL mice and the onset of diabetes in non-obese diabetic mice. The suppression of immune response can be adoptively transferred with CD4(+) cells and does not partition with the CD25 phenotype. The immunomodulatory properties of gp96 (and possibly other HSP) may be used for antigen-specific activation or suppression of cellular immune responses. The latter may form the basis for novel immunotherapies for autoimmune diseases.
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PMID:Immune modulation with high-dose heat-shock protein gp96: therapy of murine autoimmune diabetes and encephalomyelitis. 1503 92

CD4+CD25+ regulatory T cells are essential in the protection from organ-specific autoimmune diseases. In the pancreas, they inhibit actions of autoreactive T cells and thereby prevent diabetes progression. The signals that control the generation, the maintenance, or the expansion of regulatory T cell pool in vivo remain poorly understood. Here we show that a transient pulse of transforming growth factor beta (TGF-beta) in the islets during the priming phase of diabetes is sufficient to inhibit disease onset by promoting the expansion of intraislet CD4+CD25+ T cell pool. Approximately 40-50% of intraislet CD4+ T cells expressed the CD25 marker and exhibited characteristics of regulatory T cells including small size, high level of intracellular CTLA-4, expression of Foxp3, and transfer of protection against diabetes. Results from in vivo incorporation of BrdUrd revealed that the generation of a high frequency of regulatory T cells in the islets is due to in situ expansion upon TGF-beta expression. Thus, these findings demonstrate a previously uncharacterized mechanism by which TGF-beta inhibits autoimmune diseases via regulation of the size of the CD4+CD25+ regulatory T cell pool in vivo.
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PMID:TGF-beta regulates in vivo expansion of Foxp3-expressing CD4+CD25+ regulatory T cells responsible for protection against diabetes. 1507 Jul 59


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