Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0751781 (NOD)
 6,696 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Activated insulin-specific CD8(+) T cells (IS-CD8(+) cells) home to the pancreas, destroy beta cells, and cause rapid diabetes upon transfer into diabetes-prone NOD mice. Surprisingly, they also cause diabetes in mouse strains that are free of preexistent inflammation. Thus, we hypothesized that islet-specific homing may be in part dependent on IS-CD8(+) cells' recognition of the cognate major histocompatibility complex (MHC)/peptide complexes presented by pancreatic endothelial cells, which acquire the antigen (insulin) from beta cells. In fact, islet-specific homing was abrogated in mice that lack MHC class I expression, or presentation of the specific peptide, or have impaired insulin secretion. Moreover, we found that IS-CD8(+) cells directly recognized pancreatic endothelial cells in islet organ cultures. Triggering of IS-CD8(+) cells' T cell receptor (TCR) led to activation of integrins expressed by these cells. In addition, chemokines, particularly SLC (CCL21), were also required for IS-CD8(+) cells' adhesion to endothelial monolayers and for successful homing in vivo. Thus, signaling through TCR and chemokine receptors work in concert to assure firm adhesion of T cells to the pancreatic endothelium. The antigen cross-presentation ability of endothelia may therefore contribute to the specificity of homing of activated T lymphocytes to the tissues where antigens are generated by other cell types.
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PMID:Presentation of antigen by endothelial cells and chemoattraction are required for homing of insulin-specific CD8+ T cells. 1261 5

Human natural killer (NK) and NK T cells play an important role in allogeneic bone marrow (BM) transplantation and graft-versus-leukemia (GVL) effect. The mechanisms by which these cells home to the BM and spleen are not well understood. Here we show that treatment of these cells with pertussis toxin and neutralizing antibodies to the chemokine receptor CXCR4 inhibited homing of the cells to the BM, but not the spleen, of NOD/SCID mice. The retention of NK and NK T cells within the spleen and BM was dependent on Galphai signaling and CXCR4 function. The chemokine receptors CXCR4 and CXCR3 are expressed predominantly on the cell surface of NK T cells. Following activation with interleukin-2 (IL-2), the levels of CXCR4 on NK and NK T cells decreased significantly. Treatment of cells with IL-2 inhibited their migration in response to CXCL12 and their homing and retention in the BM and spleen of NOD/SCID mice. In contrast to CXCR4, the expression levels of the chemokine receptor CXCR3 and the migration of cells in response to CXCL9 and CXCL10 increased after IL-2 treatment. Thus, down-regulation of CXCR4 and up-regulation of CXCR3 may direct the trafficking of cells to the site of inflammation, rather than to hematopoietic organs, and therefore may limit their alloreactive potential.
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PMID:Involvement of CXCR4 and IL-2 in the homing and retention of human NK and NK T cells to the bone marrow and spleen of NOD/SCID mice. 1273 Jan 2

Hematopoietic stem cells rarely contribute to hepatic regeneration, however, the mechanisms governing their homing to the liver, which is a crucial first step, are poorly understood. The chemokine stromal cell-derived factor-1 (SDF-1), which attracts human and murine progenitors, is expressed by liver bile duct epithelium. Neutralization of the SDF-1 receptor CXCR4 abolished homing and engraftment of the murine liver by human CD34+ hematopoietic progenitors, while local injection of human SDF-1 increased their homing. Engrafted human cells were localized in clusters surrounding the bile ducts, in close proximity to SDF-1-expressing epithelial cells, and differentiated into albumin-producing cells. Irradiation or inflammation increased SDF-1 levels and hepatic injury induced MMP-9 activity, leading to both increased CXCR4 expression and SDF-1-mediated recruitment of hematopoietic progenitors to the liver. Unexpectedly, HGF, which is increased following liver injury, promoted protrusion formation, CXCR4 upregulation, and SDF-1-mediated directional migration by human CD34+ progenitors, and synergized with stem cell factor. Thus, stress-induced signals, such as increased expression of SDF-1, MMP-9, and HGF, recruit human CD34+ progenitors with hematopoietic and/or hepatic-like potential to the liver of NOD/SCID mice. Our results suggest the potential of hematopoietic CD34+/CXCR4+cells to respond to stress signals from nonhematopoietic injured organs as an important mechanism for tissue targeting and repair.
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PMID:HGF, SDF-1, and MMP-9 are involved in stress-induced human CD34+ stem cell recruitment to the liver. 1286 5

Viruses can cause but can also prevent autoimmune disease. This dualism has certainly hampered attempts to establish a causal relationship between viral infections and type 1 diabetes (T1D). To develop a better mechanistic understanding of how viruses can influence the development of autoimmune disease, we exposed prediabetic mice to various viral infections. We used the well-established NOD and transgenic RIP-LCMV models of autoimmune diabetes. In both cases, infection with the lymphocytic choriomeningitis virus (LCMV) completely abrogated the diabetic process. Interestingly, such therapeutic viral infections resulted in a rapid recruitment of T lymphocytes from the islet infiltrate to the pancreatic draining lymph node, where increased apoptosis was occurring. In both models this was associated with a selective and extensive expression of the chemokine IP-10 (CXCL10), which predominantly attracts activated T lymphocytes, in the pancreatic draining lymph node, and in RIP-LCMV mice it depended on the viral antigenic load. In RIP-LCMV mice, blockade of TNF-alpha or IFN-gamma in vivo abolished the prevention of T1D. Thus, virally induced proinflammatory cytokines and chemokines can influence the ongoing autoaggressive process beneficially at the preclinical stage, if produced at the correct location, time, and levels.
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PMID:Cure of prediabetic mice by viral infections involves lymphocyte recruitment along an IP-10 gradient. 1470 11

The chemokine stromal cell-derived factor-1 (SDF-1) and its receptor CXCR4 participate in the retention of normal hematopoietic stem cells within the bone marrow (BM) and their release into the circulation. Homing and engraftment of human stem cells in immunodeficient mice are dependent on cell surface CXCR4 expression and the production of BM SDF-1, which acts also as a survival factor for both human and murine stem cells. However, the role of SDF-1/CXCR4 interactions in the control of human acute myelogenous leukemia (AML) cell trafficking and disease progression is poorly understood. In this study, we report that although some AML cells do not express surface CXCR4, all AML cells tested express internal CXCR4 and SDF-1. Culture of AML cells with SDF-1 promoted their survival, whereas addition of neutralizing CXCR4 antibodies, SDF-1 antibodies, or AMD3100 significantly decreased it. Pretreatment of primary human AML cells with neutralizing CXCR4 antibodies blocked their homing into the BM and spleen of transplanted NOD/SCID/B2m(null) mice. Furthermore, weekly administrations of antihuman CXCR4 to mice previously engrafted with primary AML cells led to a dramatic decrease in the levels of human AML cells in the BM, blood, and spleen in a dose- and time-dependent manner. Interestingly, the same treatment did not affect significantly the levels of normal human progenitors engrafted into NOD/SCID mice. Taken together, our findings demonstrated the importance of the SDF-1/CXCR4 axis in the regulation of in vivo motility and development of human AML stem cells and identified CXCR4 neutralization as a potential treatment for AML.
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PMID:CXCR4 regulates migration and development of human acute myelogenous leukemia stem cells in transplanted NOD/SCID mice. 1537 5

The mechanism that regulates the preferential accumulation of NKT cells in the BM is unknown. The BM endothelium constitutively expresses selectins, the integrin ligands VCAM-1 and ICAM-1, and the chemokine CXCL12. Both NK and NKT subsets of cells exhibited similar tethering and rolling interactions on both P-selectin and E-selectin and expressed similar levels of the integrins, VLA-4 and LFA-1. Although NKT cells express higher levels of CXCR4 than NK cells, CXCL12 (the ligand for CXCR4) rapidly stimulates similar levels of adhesion of NK and NKT cells to VCAM-1 and ICAM-1. In both subsets, the arrest on VCAM-1 was dependent on high affinity VLA-4 and the homing of these cells to the BM of NOD/SCID was VLA-4-dependent. However, as opposed to the situation for NK cells, CXCL12 preferentially triggers, under shear flow, the rolling on VCAM-1 and transendothelial migration of NKT cells. Moreover, over-expression of high levels of CXCR4 on the YT NK cell line enables them to migrate in response to CXCL12. This study therefore suggests an important role for CXCR4 levels of expression and for VLA-4 in regulating the accumulation of NKT cells in the BM.
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PMID:Differential usage of VLA-4 and CXCR4 by CD3+CD56+ NKT cells and CD56+CD16+ NK cells regulates their interaction with endothelial cells. 1511 66

Type 1 diabetes (T1D) is an autoimmune disease characterized by leukocyte infiltration into the pancreatic islets, and we have previously shown that treatment of adult NOD mice with a vitamin D analog arrests the progression of insulitis, blocks Th1 cell infiltration into the pancreas, and markedly reduces T1D development, suggesting inhibition of chemokine production by islet cells. In this study, we show that all TLRs are expressed by mouse and human islet cells, and their engagement by pathogen-derived ligands markedly enhances proinflammatory chemokine production. The vitamin D analog significantly down-regulates in vitro and in vivo proinflammatory chemokine production by islet cells, inhibiting T cell recruitment into the pancreatic islets and T1D development. The inhibition of islet chemokine production in vivo persists after restimulation with TLR ligands and is associated with up-regulation of IkappaBalpha transcription, an inhibitor of NF-kappaB and with arrest of NF-kappaBp65 nuclear translocation, highlighting a novel mechanism of action exerted by vitamin D receptor ligands potentially relevant for the treatment of T1D and other autoimmune diseases.
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PMID:A vitamin D analog down-regulates proinflammatory chemokine production by pancreatic islets inhibiting T cell recruitment and type 1 diabetes development. 1529 40

Type 1 diabetes appears to progress not as an uncontrolled autoimmune attack on the pancreatic islet beta-cells, but rather in a highly regulated manner. Leukocytic infiltration of the pancreatic islets by autoimmune cells, or insulitis, can persist for long periods of time before the terminal destruction of beta-cells. To gain insight on the final stage of diabetogenesis, we have studied progression to diabetes in a CD4(+) T-cell receptor transgenic variant of the NOD mouse model, in which diabetes can be synchronously induced within days by a single injection of cyclophosphamide. A time-course analysis of the gene expression profiles of purified islets was performed using microarrays. Contrary to expectations, changes in transcripts subsequent to drug treatment did not reflect a perturbation of gene expression in CD4(+) T-cells or a reduction in the expression of genes characteristic of regulatory T-cell populations. Instead, there was a marked decrease in transcripts of genes specific to B-cells, followed by an increase in transcripts of chemokine genes (cxcl1, cxcl5, and ccl7) and of other genes typical of the myelo-monocytic lineages. Interferon-gamma dominated the changes in gene expression to a striking degree, because close to one-half of the induced transcripts issued from interferon-gamma-regulated genes.
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PMID:Progression to islet destruction in a cyclophosphamide-induced transgenic model: a microarray overview. 1533 40

We have shown that neutralization of IFN-inducible protein 10/CXCL10, a chemokine for Th1 cells, breaks Th1 retention in the draining lymph nodes, resulting in exacerbation in Th1-dominant autoimmune disease models induced by immunization with external Ags. However, there have been no studies on the role of CXCL10 neutralization in Th1-dominant disease models induced by constitutive intrinsic self Ags. So, we have examined the effect of CXCL10 neutralization using a type 1 diabetes model initiated by developmentally regulated presentation of beta cell Ags. CXCL10 neutralization suppressed the occurrence of diabetes after administration with cyclophosphamide in NOD mice, although CXCL10 neutralization did not significantly inhibit insulitis and gave no influence on the trafficking of effector T cells into the islets. Because both CXCL10 and CXCR3 were, unexpectedly, coexpressed on insulin-producing cells, CXCL10 was considered to affect mature and premature beta cells in an autocrine and/or paracrine fashion. In fact, CXCL10 neutralization enhanced proliferative response of beta cells and resultantly increased beta cell mass without inhibiting insulitis. Thus, CXCL10 neutralization can be a new therapeutic target for beta cell survival, not only during the early stage of type 1 diabetes, but also after islet transplantation.
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PMID:CXC chemokine ligand 10 neutralization suppresses the occurrence of diabetes in nonobese diabetic mice through enhanced beta cell proliferation without affecting insulitis. 1555 99

Immunization with autoantigenic peptides skews T cell responses in type 1 diabetes (T1D), yet the gene-expression signature characterizing this change is unclear. We used cDNA microarray technology to identify genes differentially regulated in splenocytes of T1D prone NOD mice after immunization with a disease protective glutamic acid decarboxylase 65 (GAD(65) P14) peptide. We identified 96 genes involved in cytokine secretion, humoral immune response, T cell activation, signal transduction, cell proliferation, complement activation and inflammatory responses. Up-regulation of seven chemokine and cytokine genes confirmed our previous findings of increased interferon-gamma (IFN-gamma) secretion, which may lead to a protective response in T1D. Hierarchical clustering was used to organize treated and control groups on the basis of their overall similarity in gene-expression patterns, suggesting association or co-regulation. Semi-quantitative RT-PCR was used to confirm the expression of selected genes in spleen and pancreatic draining lymph nodes. These findings can be used to compare other immunization strategies affecting the expression of these genes and explore their mechanisms of action. This microarray-based study, thus, unravels the molecular mechanism of beta-cell associated autoantigenic peptide immunization in T1D prone NOD mice, paving the way for identification of diagnostic markers and drug targets for modulating immune responses in T1D.
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PMID:Gene expression profiling in type 1 diabetes prone NOD mice immunized with a disease protective autoantigenic peptide. 1557 25


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