Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0024141 (systemic lupus erythematosus)
 44,322 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

CD40 ligand (CD40L, CD154) is overexpressed on T and B cells in systemic lupus erythematosus (SLE). Monocytes have been shown to contribute to immune-mediated pathology in SLE and to express CD40L under certain conditions. Therefore, we studied CD40L expression on lupus monocytes ex vivo, as well as after activation in vitro. A highly significant sevenfold increase in the frequency of CD40L-expressing peripheral monocytes from 23 SLE patients, compared to 16 healthy individuals (mean percentage of CD40L(+)CD14(+) among CD14(+) cells, 11.7 versus 1.6), was found by flow cytometry. Increased CD40L expression on monocytes correlated significantly with disease activity, elevated gamma-globulin serum levels, as well as increased CD40L expression on T cells. CD40L expression by lupus monocytes was verified at both the mRNA and protein levels, while LPS stimulation was found to upregulate CD40L mRNA accumulation and surface protein expression. CD40L expression on activated lupus monocytes within anti-CD3-stimulated, mononuclear cell cultures was also enhanced compared to control-derived monocytes. These novel findings underscore the multiplicity of pathways through which monocytes may contribute to SLE pathology and suggest that T cell-independent CD40L-mediated cell to cell interactions may be also involved in humoral immune activation in SLE.
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PMID:Aberrant expression of the costimulatory molecule CD40 ligand on monocytes from patients with systemic lupus erythematosus. 1198 85

To explore the regulatory defects underlying the overexpression of CD40 ligand (CD40L, CD154) in human lupus we studied the effects of cyclosporin-A (CsA), which blocks Ca2+/calcineurin-dependent CD40L gene expression, on peripheral blood-derived T cells and monocytes. In contrast to control subjects, CsA failed to inhibit the prolonged CD40L expression observed in vitro on anti-CD3-activated lupus T cells. Resistance to CsA was not restricted to CD4+ or CD8+ T cell subsets and was disease activity-independent. Experiments assessing the effects of dexamethasone on CD40L expression, as well as of CsA on the early activation marker CD69 expression and on surface CD40L cleavage, confirmed the unique regulation of CD40L in lupus T cells. On the other hand, co-culture with anti-CD3-activated T cells caused surface CD40L expression on monocytes, which was not an Fc receptor-mediated event. Lupus monocytes clearly overexpressed CD40L comparing to healthy and disease-control monocytes, and, similarly to lupus T cells, displayed a prominent resistance to CsA inhibitory effects. These findings indicate that, besides Ca2+/calcineurin-dependent mechanisms, other pathways are involved in the dysregulation of CD40L in SLE immune cells, dissection of which may have important therapeutic implications.
Lupus 2002
PMID:CD40L overexpression on T cells and monocytes from patients with systemic lupus erythematosus is resistant to calcineurin inhibition. 1213 75

Monocytes/macrophages activated by Th1 stimulation such as interferon-gamma (IFN-gamma) and CD40 ligand (CD40L) infiltrate the kidney and play a critical role in the progression of lupus nephritis (LN). We examined the monocyte response to Th1 stimulation and their effector function toward activating renal resident cells in patients with LN. Following stimulation with IFN-gamma granulocyte macrophage-colony stimulating factor (GM-CSF)/recombinant CD40L the production of tumor necrosis factor-alpha and IL-12 p70 by PBMC was significantly higher in LN patients. In coculture experiments employing activated monocytes and human mesangial cells, there was a trend toward higher monocyte chemoattractant protein-1 production by lupus monocytes compared to normal controls. Basal expression of CD40, ICAM-1, and STAT-1 was significantly higher in monocytes from LN patients, suggesting ongoing activation. Monocyte response to IFN-gamma, as accessed by intercellular adhesion molecule-1 upregulation and phosphorylation of STAT-1, was comparable between the two groups. Thus, in contrast to earlier reports, Th1-dependent monocyte activation is not impaired. In this disease activated monocytes appear to be fully capable of inducing renal injury.
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PMID:Monocyte response to Th1 stimulation and effector function toward human mesangial cells are not impaired in patients with lupus nephritis. 1258 53

The potential cross-reactivity of normal T and B cells to nuclear antigens is vast, probably due to their "education" by apoptotic cell antigens in generative lymphoid organs. Despite this "nucleocentric repertoire," as we call it, the peripheral immune system normally remains tolerant or ignorant of the products of apoptosis. However, the T helper (Th) cells, and also B cells of lupus, have a regulatory defect in the expression of CD40 ligand (CD40L). A sustained hyper-expression of CD40L by lupus T cells can be triggered by sub-threshold stimuli, and is associated with impaired phosphorylation of Cbl-b, a critical downregulatory molecule in T cell signal transduction. This CD40L hyper-expression abnormally prolongs co-stimulatory signals to autoimmune B cells, and it probably instigates APC (dendritic cells, resting anti-DNA B cells, and macrophages) to present apoptotic cell autoantigens in an immunogenic fashion. We have identified the dominant nucleosomal epitopes that are critical for cognate interactions between autoimmune Th cells and anti-DNA B cells in lupus. By scanning of overlapping synthetic peptides, and by mass spectrometry of naturally processed peptides, five major epitopes in nucleosomal histones were localized, namely H1'(22-42), H2B(10-33), H3(85-105), H4(16-39), and H4(71-94). The autoimmune T cells as well as B cells of lupus recognize these epitopes, and with age, autoantibodies against the peptide epitopes cross-react with nuclear autoantigens. Moreover, the peptide autoepitopes can be promiscuously presented and recognized by lupus T cells in the context of diverse MHC alleles. This cross-reactivity opens up the possibility of developing "universally" tolerogenic peptides for therapy of lupus in humans despite their MHC diversity. Indeed, tolerogenic therapy with a single histone peptide epitope can halt the progression of established glomerulonephritis in lupus-prone mice by "tolerance spreading" that inactivates a broad spectrum of autoimmune T and B cells in concert.
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PMID:Major peptide autoepitopes for nucleosome-centered T and B cell interaction in human and murine lupus. 1272 26

CD40 ligand (CD40L, also known as CD154 or gp39) is a member of the tumor necrosis superfamily of transmembrane proteins. The interaction of CD40L on activated T cells with its receptor, CD40 on B cells, is necessary for normal immune function, including B cell differentiation, germinal center formation, and antibody isotype switching. Abnormal expression of CD40L in patients with systemic lupus erythematosus (SLE) may contribute to autoantibody production and disease pathogenesis. Although murine models of monoclonal antibodies directed against CD40L initially showed promise, human trials either have failed to demonstrate efficacy or have been associated with adverse events. This review will summarize in vitro and murine model data and human clinical trials involving anti-CD40L monoclonal antibody.
Lupus 2004
PMID:The role of CD40 ligand in systemic lupus erythematosus. 1523 Feb 96

Costimulation between T cells and APC is required for productive immune responses. A number of receptor/ligand pairs have been shown to mediate costimulation, including CD28/B7 molecules (CD80 and CD86), CD40/CD40 ligand (CD40L, CD154), and LFA-1 (CD18)/ICAM-1 (CD54). T-B cell costimulation also plays a significant role in autoimmune diseases such as systemic lupus erythematosus. Murine HgCl2-induced autoimmunity (mHgIA) is a T cell-dependent systemic autoimmune disease that shares a number of common pathogenic mechanisms with idiopathic lupus. In this report, the significance of costimulation in mHgIA is examined by attempting to induce disease in mice deficient in either CD40L, CD28, or ICAM-1. Unlike absence of ICAM-1, homozygous deficiencies in either CD40L or CD28 significantly reduced the development of mHgIA. CD40L displayed a gene dosage effect as heterozygous mice also showed reduction of autoantibody responses and immunopathology. Markers of T cell activation such as CD44 and CTLA-4 were associated with disease expression in wild-type and ICAM-1-deficient mice but not in CD40L- or CD28-deficient mice. Absence of CTLA-4 expression in CD40L-/- mice suggests that signaling via both CD28 and CD40L is important for T cell activation and subsequent autoimmunity in mHgIA. Attempts to circumvent the absence of CD40L by increasing CD28 signaling via agonistic Ab failed to elicit CTLA-4 expression. These findings indicate that breaking of self-tolerance in mHgIA requires signaling via both the CD28/B7 and CD40/CD40L pathways.
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PMID:Costimulation requirements of induced murine systemic autoimmune disease. 1549 42

Patients with rheumatoid arthritis (RA) have a two to five times increased risk of developing premature cardiovascular disease that shortens life expectancy by 5-10 years. Traditional risk factors known to promote and accelerate the progression of atherosclerotic lesions however, are often absent in patients with RA. Many similarities have emerged between the paradigm of inflammation in the pathogenesis of atherosclerosis and the well-established mechanisms of inflammation in the pathogenesis of RA. Hence it is intriguing to speculate that inflammation in RA is not confined to the joints but also present in the vessel wall. Indeed, low-grade inflammation and endothelial dysfunction play pivotal roles in the initiation, progression and propagation of the atherosclerotic process. While the healthy endothelium prevents adhesion of mononuclear cells, the defence mechanisms cease under the influence of cardiovascular risk factors and inflammation and they express adhesion molecules (selectins, vascular adhesion molecule-([VCAM-]1, intercellular adhesion molecule-[ICAM-]1) that promote the adherence of monocytes. This expression is induced by pro-inflammatory cytokines such as interleukin-(IL-)1beta and tumor necrosis factor-(TNF-)alpha, by C-reactive protein (CRP), and CD40/CD40 ligand interactions. As all of these factors are present at increased levels in the systemic circulation in RA, it appears possible that they might impact the endothelium as well. Further similarities include proteolytic enzymes such as matrix metalloproteinases (MMPs) that play a role in joint destruction as well as in destabilization and rupture of vulnerable atherosclerotic plaques. In addition, coagulation factors such as increased levels of tissue factor (TF), van Willebrand factor (vWF) and plasminogen activator inhibitor-(PAI-)1 are important in both, RA and CAD. Endothelial dysfunction has shown to correlate with cardiovascular prognosis in several studies, which indicates its clinical relevance. Endothelial function measurement is performed in the coronary or peripheral circulation (by venous occlusion plethysmography or flow-mediated dilation). Recent studies have demonstrated impaired endothelial function in patients with RA, already at early stages of the disease. Similar results are found in patients with systemic lupus erythematosus (SLE), indicating that inflammation per se may impair altering vascular function. This and more evidence supports the notion that inflammation plays a pivotal role in vascular dysfunction and may by these mechanisms explain at least part of the excess morbidity and mortality observed in RA and SLE. In light of the growing evidence of increased cardiovascular morbidity and mortality mostly independent of traditional risk factors, treatment strategies in RA should not only aim at relieving symptoms and inhibiting joint destruction but should have a beneficial effect on the vasculature to reduce cardiovascular events. Indeed, an improvement in endothelial function in RA was recently demonstrated by anti-TNF-alpha therapy and statins. Whether and to what degree the effects of anti-inflammatory strategies to improve endothelial function, which although clinically well established is still a surrogate, translate into clinical benefit for our patients with rheumatologic diseases needs to be determined in large-scale clinical trials some of which are now already under way.
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PMID:[Rheumatoid arthritis, inflammation, and atherosclerosis]. 1559 72

CD40 ligand (CD40L) is expressed not only on activated T cells but also on activated platelets. A soluble CD40 ligand (sCD40L) is released from the activated T cells and platelets by ill-defined proteolytic process in vitro. It has been reported that sCD40L is elevated in the serum of patients with systemic lupus erythematosus, unstable angina, essential thrombocythemia, and autoimmune thrombocytopenic purupura. However, source of sCD40L in vivo remains to be elucidated. We investigated the serial sCD40L in the serum in patients undergoing allogeneic stem cell transplantation and compared with the platelets number and soluble IL2R, which is a marker of activated T cells. The value of sCD40L was well correlated with platelet number or thrombopoiesis. In cases of severe graft vs. host disease with markedly increased sIL2R, sCD40L was not increased in vivo. These results indicate that sCD40L in vivo is released mainly from the platelets or in the process of platelet production but not from the activated T cells.
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PMID:Analysis of serum soluble CD40 ligand (sCD40L) in the patients undergoing allogeneic stem cell transplantation: platelet is a major source of serum sCD40L. 1561 7

Many tissue injuries and immune mediated pathologies such as graft allo-rejections were found to involve CD40-CD40 ligand (CD40L, CD154) signaling pathway. The disruption of this pathway in many animal models led to the improvement of graft survival in these models. CD40-CD154 interactions were also shown to play a significant role in the maintenance of autoimmunity, and the production of auto-antibodies in systemic lupus erythematosus (SLE). High-level expression of CD154 has been detected on T cells from patients with active SLE, rheumatoid arthritis (RA) and other autoimmune diseases, indicating that such cells could account for the high-level expression of immune accessory molecules on B cells of patients with active disease. An increased serum level of soluble CD154 was also reported in SLE, RA, and Sjogren's disease in correlation with the relevant auto-antibodies and with the clinical disease activity. Anti-CD154 antibody therapy prevents auto-antibody production and renal immune complex deposition in lupus nephritis, indicating that disruption of this pathway could be a beneficial treatment in SLE. However, the etiology of the higher than expected number of thromboembolic events in anti-CD154 treated SLE patients should be investigated and preventive measures should be considered.
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PMID:The role of CD40-CD154 interactions in autoimmunity and the benefit of disrupting this pathway. 1562 72

Large increases in mortality related to premature atherosclerosis with coronary artery disease and stroke have been reported during the last few years in patients with systemic lupus erythematosus (SLE). Studies found relative risks of 5 to 7 for myocardial infarction in SLE patients. The traditional risk factors fail to fully account for accelerated atherosclerosis in SLE and APS, in addition prolonged glucocorticoid therapy and long duration of SLE seem to be of importance. The disease SLE per se is an independent risk factor. The current pathogenic hypothesis for atherosclerosis involves an inflammatory response, autoantibodies, immune complexes (containing antibodies to phospholipids, to oxidized LDLs, and to endothelial cells), CD40/CD40 ligand interactions, and bacterial or viral infections responsible for an immune response. The determination of classic and new risk factors, together with specific autoantibody titers and the use of Doppler carotid ultrasound, are useful methods to detect early atherosclerosis. Therapeutic strategies, including early risk factor intervention and effective control of inflammation, are essential to reduce morbidity and mortality and should be incorporated into the management of connective tissue disease with the goal of protecting patients against atherosclerosis.
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PMID:[Accelerated atherosclerosis in rheumatic systemic diseases as an example of systemic lupus erythematosus--what is the consequence?]. 1590 83


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