Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0409974 (lupus)
 22,386 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

As one of the main mediators of the endoplasmic reticulum unfolded protein response, heat shock protein gp96 is also an obligate chaperone for multiple TLRs including TLR4. We demonstrated recently that enforced cell surface expression of gp96 in a transgenic (Tg) mouse (96tm-Tg) conferred hyperresponsiveness to LPS and induced TLR4-dependent lupus-like autoimmune diseases. In this study, we investigated the function of CD4(+)CD25(+) Foxp3(+) regulatory T cells (T(reg)) in these mice in light of the important roles of T(reg) in the maintenance of peripheral tolerance against self-Ag as well as the increasing appreciation of TLR signaling on the regulation of T(reg). We found that the development of T(reg) was not impaired in 96tm-Tg mice. Contrary to the prediction of dampened T(reg) activity, we discovered that the suppressive functions of T(reg) were increased in 96tm-Tg mice. Inactivation of T(reg) during the neonatal stage of life exacerbated not only organ-specific diseases but also systemic autoimmune diseases. By crossing 96tm-Tg mice into the TLR4 null background, we demonstrated the critical roles of TLR4 in the amplification of T(reg) suppressive function. These findings illustrate that gp96 plays dual roles in regulating immune responses by augmenting proinflammatory responses and inducing T(reg) function, both of which are dependent on its ability to chaperone TLR4. Our study provides strong support to the notion of compensatory T(reg) activation by TLR ligation to dampen inflammation and autoimmune diseases.
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PMID:TLR4 hyperresponsiveness via cell surface expression of heat shock protein gp96 potentiates suppressive function of regulatory T cells. 1731 70

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by autoantibodies and systemic clinical manifestations. In this study we investigated the beneficial effects on murine lupus accomplished by a peptide based on the sequence of the complementarity-determining region 1 of an anti-DNA autoantibody (hCDR1) when given alone or in combination with cyclophosphamide (CYC), and determined the mechanisms underlying those effects. SLE-afflicted (NZB x NZW) F(1) mice were treated for 12 weeks with injections of hCDR1, CYC or a combination of both drugs. We found that hCDR1 and CYC ameliorated serological and renal manifestations of the diseased mice, down-regulated interferon-gamma and interleukin-10, and up-regulated transforming growth factor-beta. These effects were associated with an increment of naive CD4(+) cells at the expense of the number of CD4(+) cells with the memory/activated phenotype. Further, the number of CD8(+) cells in the diseased mice was increased by the two drugs, resulting in a significant decrease in the CD4 : CD8 ratio. However, whereas the frequency and activity of CD4(+) CD25(+) CD45RB(low) regulatory T cells and the expression of cytotoxic T-lymphocyte antigen 4 (CTLA-4) in CD4(+) cells were up-regulated by hCDR1 treatment, they were minimally affected following treatment with CYC. CTLA-4 played an important role in the activity of the hCDR1-induced CD4(+) CD25(+) cells as manifested by down-regulation of CD28 expression, decrease of activation-induced apoptosis, and modulation of the cytokine profile in CD4(+) CD25(-) cells derived from SLE-afflicted mice. Thus, although the two drugs have similar ameliorative effects, hCDR1 but not CYC elicits regulatory pathways that are of importance for tolerance induction in SLE.
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PMID:Clinical amelioration of murine lupus by a peptide based on the complementarity determining region-1 of an autoantibody and by cyclophosphamide: similarities and differences in the mechanisms of action. 1734 82

The objective of the study was to investigate the influence of the blood concentrations of hydroxychloroquine ([HCQ]) and its derivative desethylhydroxychloroquine ([DHCQ]) on lymphocyte activation or differentiation in HCQ-treated lupus patients. We studied the correlations between [HCQ], [DHCQ], and the frequency of various lymphocyte subsets in 58 HCQ-treated lupus patients (mean HCQ dose: 4.93 +/- 1.58 mg/kg/day; mean duration of the disease: 122 +/- 64 months). [HCQ] and [DHCQ] were determined by high-performance liquid chromatography (HPLC). Lymphocyte markers were studied by flow cytometry using monoclonal anti-CD3, -CD4, -CD8, -CD25, -DR, -CD45RA, -CD45RO, -CD19, -CD38, and -CD86 antibodies. sIL2-R serum concentrations were measured by enzyme-linked immunosorbent assay (ELISA). [HCQ] and [DHCQ] were 599.9 ng/mL (median: 529.5; range: 55-1935) and 353.43 (median: 286 ng/mL; range: 118-1090). In a multiple regression analysis, [HCQ] and [DHCQ] were associated with the HCQ prescribed dose in mg/kg/day (P = 0.0002 and P = 0.03) and with compliance to the treatment (P = 0.004 and P = 0.03). We found a negative correlation between [HCQ], [DHCQ], and the CD45RO+ cell frequency among CD3+CD4+ cells (P = 0.03 and P = 0.007, respectively). Other lymphocyte subset markers (LSMs) and sIL2-R concentrations were not significantly associated with [HCQ] or [DHCQ]. In the multiple regression analysis, CD45RO+ expression was negatively influenced by [HCQ] (P = 0.005), and positively influenced by smoking habits (P = 0.005) and age (P = 0.005). Similar results were found in the multivariate model including [DHCQ]. Disease activity and taking more than 10 mg/day of corticosteroids or an immunosuppressive drug did not influence CD45RO+ expression. Lupus patients had less CD3+CD4+CD45RO+ cells than controls (P = 0.03). In lupus patients, HCQ and DHCQ may alter the generation or the blood circulation of CD4+CD45RO+ lymphocytes in a concentration-dependent pattern.
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PMID:Blood concentrations of hydroxychloroquine and its desethyl derivative correlate negatively with the percentage of CD45RO+ cells among CD4+ lymphocytes in hydroxychloroquine-treated lupus patients. 1789 69

Experimental systemic lupus erythematosus (SLE) can be induced in mice following immunization with an anti-DNA mAb expressing a major Id, 16/6Id. Treatment with a peptide, designated human CDR1 (hCDR1; Edratide), that is based on the sequence of CDR1 of the 16/6Id ameliorated disease manifestations. In the present study, we investigated the roles of apoptosis and related molecules in BALB/c mice with induced experimental SLE following treatment with hCDR1. A higher state of activation and increased rate of apoptosis were found in lymphocytes of SLE-afflicted mice as compared with healthy controls. The latter effects were associated with up-regulated caspase-8 and caspase-3, and down-regulated Bcl-x(L). The ameliorative effects of hCDR1 were associated with down-regulation of caspase-8 and caspase-3, up-regulation of Bcl-x(L), and a reduced rate of apoptosis. Treatment of diseased mice with an apoptosis-reducing compound that inhibited caspases down-regulated the secretion of the pathogenic cytokine IFN-gamma and lowered the intensity of glomerular immune complex deposits and the levels of proteinuria. Furthermore, coincubation of Bcl-x(L) inhibitors with hCDR1-treated cells abrogated the ability of hCDR1 to reduce the activation state of lymphocytes and to down-regulate the secretion of IL-10 and IFN-gamma. Moreover, the Bcl-x(L)-expressing CD4(+)CD25(+) cells from hCDR1-treated mice induced the expression of Bcl-x(L) in CFSE-labeled CD4(+)CD25(-) cells of the SLE-afflicted mice. Thus, the reduction of apoptosis and the up-regulation of Bcl-x(L), which plays an apparent role in tolerance induction, contribute to at least part of the beneficial effects of hCDR1 on lupus manifestations.
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PMID:The role of apoptosis in the ameliorating effects of a CDR1-based peptide on lupus manifestations in a mouse model. 1791 82

The Sle1 locus is a key determinant of lupus susceptibility in the NZM2410 mouse model. Within Sle1, we have previously shown that Sle1a expression enhances activation levels and effector functions of CD4(+) T cells and reduces the size of the CD4(+)CD25(+)Foxp3(+) regulatory T cell subset, leading to the production of autoreactive T cells that provide help to chromatin-specific B cells. In this study, we show that Sle1a CD4(+) T cells express high levels of ICOS, which is consistent with their increased ability to help autoreactive B cells. Furthermore, Sle1a CD4(+)CD25(+) T cells express low levels of Foxp3. Mixed bone marrow chimeras demonstrated that these phenotypes require Sle1a to be expressed in the affected CD4(+) T cells. Expression of other markers generally associated with regulatory T cells (Tregs) was similar regardless of Sle1a expression in Foxp3(+) cells. This result, along with in vitro and in vivo suppression studies, suggests that Sle1a controls the number of Tregs rather than their function on a per cell basis. Both in vitro and in vivo suppression assays also showed that Sle1a expression induced effector T cells to be resistant to Treg suppression, as well as dendritic cells to overproduce IL-6, which inhibits Treg suppression. Overall, these results show that Sle1a controls both Treg number and function by multiple mechanisms, directly on the Tregs themselves and indirectly through the response of effector T cells and the regulatory role of dendritic cells.
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PMID:Murine lupus susceptibility locus Sle1a controls regulatory T cell number and function through multiple mechanisms. 1802 88

Thymus-derived CD4(+)CD25(high)Foxp3(+) T-regulatory cells (Tregs) have an important role in the mechanisms of peripheral immune tolerance and in the prevention of pathogenic autoimmunity through the suppression of proliferation and production of pro-inflammatory cytokines in effector immune cells. Some studies have shown that in systemic lupus erythematosus (SLE) the number of circulating Tregs may be decreased during active disease, and that the extent of such decrease may correlate with severity of the disease. Recent data in murine models of lupus have suggested the possibility to target Tregs for the modulation of SLE, and Treg-based intervention has been proposed as a novel therapeutic mean for a better management of the disease. This review provides an update on the role of Tregs in SLE, discussing new findings in relation to possible targeting of Tregs for immune modulation in lupus.
Lupus 2008 May
PMID:T-regulatory cells in systemic lupus erythematosus. 1849 Apr 20

The aim of this study was to quantify and evaluate the forkhead box P3 (FoxP3) expression regulatory T cells in new-onset systemic lupus erythematosus (SLE) patients before and after treatment. Forty-four newly diagnosed and untreated SLE patients, including 24 with active disease (SLEDAI > or = 10) and 20 with inactive disease (SLEDAI < 5), were enrolled in this study. Twenty-one age- and sex-matched healthy volunteers were also included as controls. Peripheral blood samples were collected and mononuclear cells isolated. The expression of CD25 and FoxP3 in CD4(+) T cells were analysed with flow cytometry. CD4(+)CD25(+) (3.95-13.04%) and CD4(+)CD25(high) (0.04-1.34%) T cells in peripheral blood in untreated patients with new-onset active lupus were significantly lower than that in the patients with inactive lupus (7.27-24.48%, P < 0.05 and 0.14-3.07% P < 0.01 respectively) and that in healthy controls (5.84-14.84%, P < 0.05). Interestingly, the decrease in CD4(+)CD25(high) T cells was restored significantly in patients with active lupus after corticosteroid treatment. There was, however, a significantly higher percentage of CD4(+)FoxP3(+) T cells in patients with active (5.30-23.00%) and inactive (7.46-17.38%) new-onset lupus patients compared with healthy control subjects (2.51-12.94%) (P < 0.01). Intriguingly, CD25 expression in CD4(+)FoxP3(+) T cells in patients with active lupus (25.24-62.47%) was significantly lower than that in those patients with inactive lupus (30.35-75.25%, P < 0.05) and healthy controls (54.83-86.38%, P < 0.01). Most strikingly, the levels of FoxP3 expression determined by mean fluorescence intensity in CD4(+)CD25(high) cells in patients with active SLE were significantly down-regulated compared with healthy subjects (130 +/- 22 versus 162 +/- 21, P = 0.012). CD4(+)CD25(high) T cells are low in new-onset patients with active SLE and restored after treatment. Despite that the percentage of CD4(+)FoxP3(+) T cells appear high, the levels of FoxP3 expression in CD4(+)CD25(high) T cells are down-regulated in untreated lupus patients. There is a disproportional expression between CD25(high) and FoxP3(+) in new-onset patients with active SLE.
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PMID:Reduction of forkhead box P3 levels in CD4+CD25high T cells in patients with new-onset systemic lupus erythematosus. 1850 26

A global depletion of FoxP3+ CD25(bright) CD4+ regulatory T cell is observed during lupus flares. This phenomenon is not the consequence of the relocalization of Tregs in diseased organs but could be related to their specific sensitivity to Fas mediated apoptosis. Several therapeutic perspectives can be drawn taking into account these pathophysiological insights.
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PMID:[Systemic lupus erythematosus and regulatory T cells]. 1853 96

Systemic lupus erythematosus (SLE) is an autoimmune disorder characterized by the production of autoantibodies and deposition of immune complexes in various organs. T cells play a central role in driving disease progression, and multiple defects in T cells from patients with SLE have been uncovered. Notch signalling is an evolutionarily well-conserved signalling cascade involved in the proliferation, differentiation and apoptosis of T lymphocytes during development and peripheral effector functions. In this study, we investigated the correlation between expression of Notch receptor and the severity of SLE disease. On the contrary to T lymphocytes from healthy controls (n=11), Tlymphocytes from patients with active SLE (n=12) failed to upregulate Notch1 upon in-vitro stimulation as quantified by quantitative real time RT-PCR (P<or=0.025). Among patients with inactive SLE (n=10), those with late onset of flare exhibited significantly less Notch1 upregulation compared with SLE patients with remission. Expression of the Notch target genes, Hes1 and deltex, was also lower in patients with active SLE. The decrease in Notch1 mRNA expression was consistent with less Notch1 protein expression in patients with active SLE. The defects in Notch1 upregulation correlated with decreased proliferation, CD25 and Foxp3 expression upon stimulation in vitro. Taken together, the failure of T cells to upregulate Notch1 upon activation may be a key feature of active SLE and a potential therapeutic target.
Lupus 2008 Jul
PMID:Defects in Notch1 upregulation upon activation of T Cells from patients with systemic lupus erythematosus are related to lupus disease activity. 1862 37

The Sigirr gene (also known as Tir8) encodes for an orphan receptor of the Toll-like receptor (TLR)/interleukin 1 receptor family that inhibits TLR-mediated pathogen recognition in dendritic cells. Here, we show that Sigirr also inhibits the activation of dendritic cells and B cells upon exposure to RNA and DNA lupus autoantigens. To evaluate the functional role of Sigirr in the pathogenesis of systemic lupus erythematosus (SLE), we generated Sigirr-deficient C57BL/6-lpr/lpr mice. These mice developed a progressive lymphoproliferative syndrome followed by severe autoimmune lung disease and lupus nephritis within 6 mo of age as compared with the minor abnormalities observed in C57BL/6-lpr/lpr mice. Lack of Sigirr was associated with enhanced activation of dendritic cells and increased expression of multiple proinflammatory and antiapoptotic mediators. In the absence of Sigirr, CD4 T cell numbers were increased and CD4(+)CD25(+) T cell numbers were reduced. Furthermore, lack of Sigirr enhanced the activation and proliferation of B cells, including the production of autoantibodies against multiple nuclear lupus autoantigens. These data identify Sigirr as a novel SLE susceptibility gene in mice.
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PMID:Tir8/Sigirr prevents murine lupus by suppressing the immunostimulatory effects of lupus autoantigens. 1864 72


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