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)

Isoniazid (INH) and hydralazine (HYD) are transglutaminase (TGase, E.C.2.3.2.13.) substrates containing catalytically recruitable hydrazyl groups. Since they can be expected to inhibit TGase-mediated cell functions by competing with physiological substrates, their effect upon allogeneically and lectin-induced proliferation of mononucleocytes and upon zymosan-induced chemiluminescence of phagocytes was studied. Both compounds inhibited chemiluminescence in a dose-dependent manner. ID50 of HYD was consistently below 20 microM, while that of INH was above 120 microM. Proliferation of immunocompetent cells was suppressed by HYD with an ID50 of 60 microM, INH was inhibitory only above 5000 microM. Analogs of both compounds not containing hydrazyl groups proved to be inactive. Control experiments indicated that inhibition is not due to toxicity or lipophilicity of the compounds, structural analogs lacking a hydrazyl moiety were inactive. It is suggested that, in vivo, HYD interferes with signal-induced TGase-dependent leucocyte functions essential for immunologic stability, and that the resultant dysregulation with disruption of self tolerance contributes to the HYD promoted lupus-like syndrome.
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PMID:Effects of hydrazyl group containing drugs on leucocyte functions: an immunoregulatory model for the hydralazine-induced lupus-like syndrome. 286 61

The hypothesis that autoimmune diseases might be due to a defect in immunoregulation was tested in systemic lupus erythematosus (SLE). We have applied the double immunofluorescence, flow cytometry technique to peripheral blood lymphocytes from patients with SLE. T cells were studied for their binding of the lectin Vicia villosa (VV) which is a phenotypic marker for contra-suppressor cells both in mice and humans. A significant increase in CD3+VV+ and CD8+VV+ cells was found in patients with SLE, as compared with age and sex matched controls (P less than 0.01). When the patients were divided according to the 'lupus activity criteria count', those with active disease had a significantly increased proportion of CD3+VV+ and CD8+VV+ cells, as compared with those showing no disease activity (P less than 0.001). Indeed, a sequential investigation showed that the proportion of CD8+VV+ cells changed in parallel with exacerbation and remission of disease activity. These results suggest that disease activity in SLE is associated with an increase in VV binding CD8 cells which can function as contrasuppressor cells.
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PMID:Phenotypic expression of Vicia villosa binding T cell subsets, as markers of contrasuppressor cells in systemic lupus erythematosus. 297 36

The autosomal recessive lpr (lymphoproliferation) gene is responsible for a thymus-dependent massive lymphoproliferation associated with the development of lupus-like autoimmune disease. Phenotypic analysis of adult lpr/lpr lymph nodes has demonstrated accumulation of a dull Lyt-1+, Thy-1+ population that expresses neither Lyt-2 nor L3T4 antigens. With the use of a depletion method based on complement-mediated lysis with an anti-Lyt-2 monoclonal antibody (31 M) and a new anti-L3T4 monoclonal antibody (RL 172.4), we have purified the Lyt-2- L3T4- subset from lymph nodes or spleens of C57BL/6-lpr/lpr mice and determined whether they are immunologically functional in vitro. Production of neither interleukin 2 nor interferon-gamma was detected by the double-negative subset after stimulation with concanavalin A and/or phorbol myristate acetate. The frequencies of allospecific cytotoxic T lymphocyte (CTL) precursors and lectin-induced antigen-nonspecific CTL precursors were diminished to almost undetectable levels, whereas the Lyt-2+ population from lpr/lpr mice had CTL-precursor frequencies comparable with that of +/+ mice. These results show that the major cell subset of adult lpr/lpr lymph nodes or spleens is composed of lymphocytes with markedly limited potential for lymphokine production or antigenic stimulation.
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PMID:Functional analysis of T cell subsets from mice bearing the lpr gene. 392 47

Seeking common abnormalities in mice genetically predisposed to lupus-like autoimmune disease, we investigated (1) the ontogeny of Ia antigens (I-A/I-E) on the surfaces of resident peritoneal macrophages (rpM phi) of lupus and normal mice, (2) spontaneous and lectin-induced in vitro production of M phi-stimulating factors (interferon, IFN; M phi-activating factor, MAF; M phi-Ia-inducing/recruiting factor, MIRF), and (3) responses of rpM phi from such animals to Ia-inducing signals. Indirect immunofluorescence techniques showed that Ia+ rpM phi increased numerically during the life spans of MRL/Mp lpr/lpr, while no such increase was observed in age-matched non-lpr MRL/Mp +/+ or (MRL/Mp lpr/lpr X MRL/Mp +/+)F1 hybrid mice. However, neonatal thymectomy, which prevents lymphoproliferation and autoimmune disease in MRL/Mp lpr/lpr mice, had no effect on this enhanced M phi I-A/I-E expression. NZB mice developed a similar increase with age, whereas BXSB and (NZB X NZW)F1 lupus mice, like immunologically normal controls, had low numbers of I-A/I-E+ rpM phi. Cultured splenocytes of lupus mice, including those with high percentages of I-A/I-E+ rpM phi, did not spontaneously (in the absence of mitogens) elaborate MIRF, MAF, or IFN activity. Furthermore, concanavalin A-stimulated splenocytes from lupus mice, particularly strains with early autoimmune disease manifestations [MRL/Mp lpr/lpr, male BXSB, and female (NZB X NZW)F1] produced levels of these lymphokines that were lower than normal controls. MRL/Mp lpr/lpr and NZB rpM phi, when stimulated in vitro with the supernatant of a MIRF-producing T cell hybridoma, did not hyperrespond. Our study shows that increased I-A/I-E+ rpM phi occur in some, but not all, lupus mice and this increase does not correlate with increased spontaneous or mitogen-induced production of M phi-stimulating lymphokines nor with hyperresponsiveness to Ia-inducing signals.
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PMID:Macrophage I-A/I-E expression and macrophage-stimulating lymphokines in murine lupus. 620 80

Nervous system involvement in SLE encompasses a wide array of clinical manifestations which may reflect multiple etiologic factors including autoantibodies to nervous tissue antigens. The aim of the present study was to examine the association between autoantibodies to a wide range of brain antigens and cognitive abnormalities in an unselected population of 70 SLE patients. Using a battery of standardized neuropsychological tests, cognitive impairment was identified in 15/70 (21%) SLE patients compared with 1/25 (4%) patients with rheumatoid arthritis and 1/23 (4%) healthy subjects (P = 0.04). Integral membrane proteins were isolated from dissociated brain cells by temperature-induced phase separation with Triton X-114. Synaptosomes were isolated by differential centrifugation and membrane enriched fractions were prepared by lectin affinity chromatography. Western blotting identified IgG reactivity to a wide range of proteins (MW 22-52 K) in SLE patients. The proteins identified were distinct from well-characterized intracellular antigens including ribosomal P proteins. There was no significant difference in the prevalence of anti-brain antibodies between SLE patients who were cognitively impaired and those who were not impaired. Furthermore, there was no association between the presence of autoantibodies and subsets of cognitive dysfunction. These results suggest that circulating autoantibodies to brain antigens are not responsible for the abnormalities in cognitive function in SLE patients.
Lupus 1994 Jun
PMID:Brain reactive autoantibodies and cognitive impairment in systemic lupus erythematosus. 795 5

Nervous system involvement in systemic lupus erythematosus (SLE) has been linked to the production of autoantibodies that may bind to surface antigens on neuronal cells and cause cellular dysfunction. At present, little is known of the target antigens recognized by these antibodies. The aim of the present study was to examine reactivity to rat brain synaptosomes (RBS) in sera from patients with SLE. Sera from 73 unselected SLE patients and controls were studied. Crude RBS were prepared by differential centrifugation and enriched fractions of synaptosomes (SY-E), myelin (MY-E) and mitochondria (MI-E) were obtained by sucrose density centrifugation. Rat liver (RL) was used for control antigens. Wheat-germ lectin affinity chromatography yielded membrane-enriched fractions of RBS, RL and whole rat brain (WRB). Antibody binding was examined by Western blotting. IgM reactivity was detected in 12/73 sera (16%) and was directed to proteins of 62K, 48K 37K molecular weight. IgG reactivity was present in 5/73 sera (7%) to proteins of 52K, 48K, 37K and 29K molecular weight. Except for binding to the 52K and 37K proteins these autoantibodies were not detected in control sera. Reactivity was usually absent, or present in reduced amounts, in WRB and RL. Additional experiments revealed that binding of IgM to 62K was found predominantly in SY-E and MY-E fractions, 48K in SY-E and MI-E fractions and 37K in the SY-E fraction. Binding of IgG to 48K and 29K was detected in the SY-E and MI-E, but reactivity to 52K and 37K was restricted to the SY-E fraction. Thus, sera from SLE patients contain antibodies to synaptosomal antigens that may contribute to the neuropsychiatric manifestations of the disease.
Lupus 1993 Feb
PMID:Brain synaptosomal antibodies in systemic lupus erythematosus. 848 58

The V beta 8.3-specific superantigenic lectin Urtica dioica agglutinin (UDA) was used to delete the V beta 8.3+ T cells in MRL lpr/lpr mice. In contrast to the systemic lupus erythematosus-like pathology which progresses with age in the phosphate-buffered saline-injected MRL lpr/lpr controls, UDA-treated animals did not develop overt clinical signs of lupus and nephritis. The pathogenic T cell clones thus reside within the V beta 8.3+ T cell population, which includes an expanded T cell clone described previously. Finally, UDA alters the production of autoantibodies in a sex-dependent manner.
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PMID:Urtica dioica agglutinin, a V beta 8.3-specific superantigen, prevents the development of the systemic lupus erythematosus-like pathology of MRL lpr/lpr mice. 876 10

The objectives were to provide estimates of the prevalence of autoantibody (Ab) directed to CD45 in lupus patients, identify the target autoantigen(s), and determine the ability of such reactivity to mediate neutralization of T lymphocytes. Sera from 64 patients were studied using 2 assays: Western blot and an ELISA with CD45 eluted from 3 cell lines as antigen (U937, Jurkat and Daudi). The role of carbohydrate specificity was investigated using enzyme digestion of blotted glycans, competition with sugars, and inhibition with lectins. Apoptosis was studied through annexin V binding, and cell cycle analysis using the propidium iodide method. AutoAb to CD45 were detected in 16/64 sera (25%) by Western blot, and 21/32 sera (66%) found positive in the ELISA. CD45 purified from Daudi cells was identified in the ELISA, but not in the blot. AutoAb were of the IgM and the IgG isotypes, but not specific for a particular cell type or CD45 isoform: 2 dominant specificities were recognized, one against p180, and another against high MW isoforms. Neuraminidase-induced enhancement of reactivity, together with the inhibitory effect of N-acetyl galactosamine and Dolichos diflorus lectin suggest that the epitopes are carbohydrates. AutoAb which were specific for activated CD4+T cells triggered the annexin V binding, and, in 2 of 4 cases, lymphocytes underwent apoptosis. In conclusion, carbohydrate conformational epitopes may be important as target antigens, and some CD45 autoAb have the capacity to neutralize activated T cells through anergy or apoptosis.
Lupus 2000
PMID:CD45 autoantibodies mediate neutralization of activated T cells from lupus patients through anergy or apoptosis. 1103 38

Complement is involved in inflammation and in the optimization of adaptive responses. Abnormalities in the complement system have been associated with autoimmunity, especially systemic lupus erythematosus. A paradoxic relation exits between complement and lupus. Complement-mediated tissue damage is accepted as a mechanism in disease pathophysiology. Conversely, complement exerts a protective effect in disease development. The theoretic framework explaining this protective influence involves the adequate disposal of apoptotic material by classic pathway components. Inadequate clearance of apoptotic material may evoke a proinflammatory autoimmune response. This conceptual model is substantiated by studies indicating that complement receptor genes are within major susceptibility loci of systemic lupus erythematosus, that functional and structural abnormalities in these receptors are found in lupus mouse models, and that genetic polymorphism of lectin pathway genes correlates with increased risk of disease development. Finally, new diagnostic and therapeutic modalities based on complement regulation have been described in the past year.
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PMID:Update on complement in the pathogenesis of systemic lupus erythematosus. 1219 43

The complement system consists of more than 30 proteins and has 3 types of activation pathways: classical, lectin and alternative pathways. The complement system not only has a role in innate immunity but also works as an antibody-dependent effecter to eliminate pathogens. It is useful to measure serum levels of CH50, C3 and C4 in patients with immune-mediated diseases. While increased levels of CH50 are associated with non-specific inflammation, decreased levels of CH50 in combination with normal or decreased levels of C3 and C4 are associated with specific immune-mediated diseases. Recent studies have demonstrated that the defect in the clearance of immune complexes and apoptotic cells is associated with autoimmune disease. Mice deficient in Clq show a lupus-like phenotype with the appearance of antinuclear antibodies and glomerulonephritis due to a defect in the clearance of immune complexes and apoptotic cells. This at least explains the paradox that, in humans, deficiency in an early complement component is a major risk factor for SLE. It is demonstrated that mutations in factor H, membrane cofactor protein (MCP) and factor I gene are associated with atypical hemolytic uremic syndrome. Since the complement system is a central mediator of inflammation, it is recognized as a promising therapeutic target. Anti-C5 monoclonal antibody was developed to block the final stage of complement activation. Pexelizumab is a single chain, short-acting anti-C5 antibody and is used for reperfusion after myocardial infarction, or for coronary artery bypass graft surgery with cardiopulmonary bypass. Eculizumab is a long-acting anti-C5 antibody used for paroxysmal nocturnal hemoglobinuria, rheumatoid arthritis, membranous glomerulonephritis with promising results.
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PMID:[Clinical aspects of the complement system]. 1691 67


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