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Query: UMLS:C0409974 (lupus)
 22,386 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A qualitative impairment of natural killer (NK) function and the presence of circulating DNA have been independently reported in clinical situations such as cancer and lupus. The existence of receptors for chromatin fragments at the leukocyte membrane raised the question of the relation between the presence of chromatin fragments in the extracellular medium and the impairment of NK function. The present study shows that plasmas from patients with metastatic cancer and with pathological DNA concentrations inhibited significantly the NK activity of normal lymphocytes as compared to cancer plasmas with DNA concentrations in the normal range. In vitro, it was demonstrated that chromatin fragments inhibited the NK-mediated cytotoxicity in a dose-dependent manner. Inhibitory concentrations of nucleosomes (2.5-10 micrograms/ml) were lower than those of DNA and histones alone (100 micrograms/ml). Inhibitory effects of nucleosomes, DNA and histones differed also according to the effector population used: nucleosomes were effective whatever the CD56+ cell enrichment of the effector population, while DNA inhibition needed T cells, and histone inhibition probably resulted from a subtoxic effect, prevented by the presence of adherent cells. Finally we found that nucleosomes could inhibit the NK function only when they were present in the extracellular medium. Taken together, these data suggest that the persistence of nucleosomal DNA at sites of cell death or in the blood might be responsible, at least partly, for the NK activity impairment observed in pathological circumstances characterized by a high rate of cell death phenomena such as cancer.
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PMID:In vitro inhibition of natural-killer-mediated lysis by chromatin fragments. 792 49

To investigate the structural contribution of the light chain of anti-DNA antibodies to fine specificity, the VKappa genes of two monoclonal anti-DNA antibodies, termed H241 and H102, were cloned and sequenced. H102 and H241 are independently derived from MRL-lpr/lpr mice and differ in their fine specificity: H241 binds dsDNA and normal glomeruli in vitro and deposits in the kidney in vivo, whereas H102 binds only ssDNA and does not deposit in the kidney. Both are encoded by nearly identical VH genes but different N and D regions. Our previous results have demonstrated that the VH gene for H102 and H241 encodes eight other anti-DNA antibodies that also differed in fine specificity. This suggested that the gene product encoded by the VH 102/241 gene, may have intrinsic affinity for DNA, but is unlikely to determine fine specificity or nephritogenicity. In the present study we examined whether the VKappa gene might account for the difference in nephritogenicity. The complete nucleotide and deduced amino acid sequence of VK 102 and VK241 revealed that they are very dissimilar to each other (< 60% homology). VK 241 defined a new member of the VKappa gene family and was moderately homologous to two other VK genes encoding anti-DNA antibodies and to one VK gene encoding an anti-histone antibody all from lupus strains of mice. In addition, sequence diversity in the VK CDR1 region and position 96 of the CDR3 region was observed that may be of significance in determining fine specificity. VK 102 was highly homologous to two other VKappa genes, VKs17.2 and VK C8.5, both encoding anti-DNA antibodies and members of the VK20 gene family. It was striking that all three members of the VK 20 gene family code for DNA reactivity. This suggests that certain VKappa genes may also be used to repeatedly code for anti-DNA reactivity.
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PMID:The role of VL gene structural determinants in the fine specificity of anti-DNA antibodies. 799 57

In lupus diseases products of chromatin catabolism released from dead cells might be involved in the induction of autoantibody and in the development of glomerulonephritis. While the pathogenic role of anti-DNA antibodies is recognized, the role of antibodies directed against structural proteins of chromatin is still questioned. IgG antibodies to histones, ubiquitin, and ubiquitinated histone H2A (UH2A) have been investigated both in plasma and in glomerular eluates of NZB x NZW and MRL-lpr/lpr mice. In NZB x NZW mice, anti-ubiquitin and anti-UH2A antibodies were detected at 8 weeks of age, simultaneously with anti-double-stranded DNA antibodies, whereas anti-histone antibodies appeared later. In MRL-lpr/lpr mice, anti-DNA antibodies were detected at 4 weeks, whereas anti-histone, anti-ubiquitin, and anti-UH2A antibodies were not detected at that age but appeared in plasma rapidly thereafter. In both strains, increased anti-histone activity was found in IgG eluted from glomeruli. These results support the suggestion that anti-histone antibodies are likely to play a pathogenic role in lupus nephritis. They also indicate that, like human lupus, murine lupus is characterized by the production of anti-ubiquitin and anti-UH2A antibodies.
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PMID:Autoimmunity to histones, ubiquitin, and ubiquitinated histone H2A in NZB x NZW and MRL-lpr/lpr mice. Anti-histone antibodies are concentrated in glomerular eluates of lupus mice. 808 47

Ten percent of human lupus syndromes occur in patients as a result of treatment with certain medications. H-2s mice can produce autoantibodies following treatment with various drugs or heavy metals and they are a potential animal model of drug-induced lupus. We have examined nine anti-chromatin monoclonal antibodies (mAb) from A.SW mice that had been treated with either D-penicillamine or quinidine, two lupus-inducing drugs in humans. These mAb are specific either for DNA or histone-DNA complexes corresponding to nucleo-specific either for DNA or histone-DNA complexes corresponding to nucleosomes or subnucleosome particles. Only one mAb reacts with an unknown chromatin antigen. The V region sequences of six of these mAb were studied and are notable by several features. As previously observed in spontaneous autoantibodies to DNA or histone-DNA complexes, arginine or asparagine residues are found at critical locations throughout the V regions. Many of these residues, potentially important for binding to DNA or DNA-histone complexes, result either from somatic mutations or atypical VH-D-JH rearrangements. Another significant characteristic is that the VH genes of several D-penicillamine- or quinidine-induced mAb are most similar to those of anti-nucleolar mAb obtained from mercury-injected A.SW mice. The implications of these findings for the pathogenesis of spontaneous or induced autoimmunity are discussed.
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PMID:D-penicillamine- and quinidine-induced antinuclear antibodies in A.SW (H-2s) mice: similarities with autoantibodies in spontaneous and heavy metal-induced autoimmunity. 812 39

The production of pathogenic anti-DNA autoantibodies in mice with lupus nephritis is dependent on special autoimmune Th cells that can also transfer the disease into preautoimmune mice. In previous work, these pathogenic Th cells were cloned and their TCR beta-chains were sequenced to reveal a recurrent motif of anionic residues in their CDR3 loops. Accordingly, approximately half of the Th clones were found to be specific for nucleosomal Ag that contain cationic residues. Herein, we analyzed the TCR alpha-chain repertoire of 15 of these pathogenic Th clones and found them to be heterogeneous, even among the nucleosome-specific Th clones. Most of these autoimmune TCR alpha-chains contained anionic residues in their CDR3 in addition to cationic residues. Therefore, these pathogenic Th clones of lupus probably recognize epitopes with mixed charge runs that are derived from autoantigens, such as histone-DNA complexes. Interestingly, the V alpha gene segments used by 10 of these Th clones derived from the (SWR x NZB)F1 lupus mice differed from previously reported sequences indicating that they were new members or alleles of the respective V alpha gene family. One of the Th clones used a gene from an entirely new murine V alpha gene family, identified here as V alpha 23, which consisted of approximately two members that were conserved among strains with different V alpha haplotypes. Knowledge of the primary structure of the TCR expressed by these pathogenic Th clones of lupus would help in the analysis of their antigenic specificities and also would be essential for studying their regulation in transgenic mice carrying these autoimmune TCR genes.
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PMID:T cell receptor alpha-chain repertoire of pathogenic autoantibody-inducing T cells in lupus mice. 830 Nov 46

The histone H2A-H2B dimer is a component of nucleosomes in chromatin and a frequent target of autoantibodies in spontaneous and drug-induced lupus. We obtained a panel of several lgG mAbs reacting with H2A-H2B or DNA from MRL mice which develop a spontaneous lupus-like syndrome. Several of these antibodies do not react with individual histones, but bind strongly to the H2A-H2B dimer and some bind even more strongly to the H2A-H2B-DNA complex. Moreover, these antibodies not only bind to H2A-H2B dimers in the absence of DNA, but also exhibit significant binding to DNA in the absence of histones, indicating an overlap between the anti-histone and anti-DNA specificities. The analysis of the variable region gene sequences of these antibodies shows a recurrent usage of similar VH genes, suggesting a dominant role for the heavy chain in determining binding specificity. The heavy chain third complementarity determining regions of these antibodies are also remarkable for their frequency of D-D fusions and of D segments read in unusual reading frames and for many arginine residues that may contribute to DNA binding. In addition, several antibodies obtained from an individual mouse are clonally related and some differ through somatic mutations, indicating that autoreactive clones are positively selected by nuclear antigens.
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PMID:Relationships among antinuclear antibodies from autoimmune MRL mice reacting with histone H2A-H2B dimers and DNA. 831 54

Sheep, either naturally or experimentally infected with visna virus, were examined for the production of autoantibodies. Elevated titres of IgM and IgG antiglobulins and rheumatoid factors as well as antibodies to ssDNA, cardiolipin or histones were found in serum of both groups of animals using ELISA techniques. IgA autoantibodies were usually absent or present in low titres. The specificity of the autoantibody reactivities was confirmed by inhibition assays, affinity chromatography, Western blotting and agglutination methods. Antiglobulin titres were slightly elevated in synovial fluids, although the levels of the other autoantibodies were not raised. No significant correlations were observed between autoantibody and immunoglobulin concentrations. In a separate group of sheep infected experimentally, small but significant rises in the levels of all IgM autoantibodies, except anti-histone antibodies, were observed during and subsequent to the primary immune response to the virus. The autoantibody profiles tended to parallel each other, suggesting a common stimulus for their induction and/or a high degree of polyreactivity. The results thus show that the visna retrovirus induces, either directly or indirectly, autoimmune reactivities that are commonly observed in human autoimmune diseases such as rheumatoid arthritis or systemic lupus erythematosis.
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PMID:Autoimmune reactivity in sheep induced by the visna retrovirus. 838 56

Only a fraction (12%) of 268 "autoreactive" T cell clones derived from lupus-prone mice can selectively induce the production of pathogenic anti-DNA autoantibodies in vitro and accelerate the development of lupus nephritis when transferred in vivo. The CDR3 loops of T cell receptor beta chains expressed by these pathogenic T helper (Th) clones contain a recurrent motif of anionic residues suggesting that they are selected by autoantigens with cationic residues. Herein, we found that approximately 50% of these pathogenic Th clones were specific for nucleosomal antigens, but none of them responded to cationic idiopeptides shared by variable regions of pathogenic anti-DNA autoantibodies. Nucleosomes did not stimulate the T cells as a nonspecific mitogen or superantigen. Only the pathogenic Th cells of lupus responded to nucleosomal antigens that were processed and presented via the major histocompatibility class II pathway. Although the presentation of purified mononucleosomes to the Th clones could be blocked by inhibitors of endosomal proteases, neither of the two components of the nucleosomes--free DNA or histones by themselves--could stimulate the Th clones. Thus critical peptide epitopes for the Th cells were probably protected during uptake and processing of the nucleosome particle as a whole. The nucleosome-specific Th clones preferentially augmented the production of IgG autoantibodies to histone-DNA complex in vitro. In vivo, nucleosome-specific, CD4+ T cells were not detectable in normal mice, but they were found in the spleens of lupus-prone mice as early as 1 mo of age, long before other autoimmune manifestations. Immunization of young, preautoimmune lupus mice with nucleosomes augmented the production of autoantibodies and markedly accelerated the development of severe glomerulonephritis. Previously, crude preparations containing nucleosomes were shown by others to have polyclonal mitogenic activity for B cells from normal as well as lupus mice. Identification here of pure mononucleosome as a lupus-specific immunogen for the Th cells that selectively help the pathogenic anti-DNA autoantibody producing B cells of lupus could lead to the design of specific therapy against this pathogenic autoimmune response.
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PMID:Nucleosome: a major immunogen for pathogenic autoantibody-inducing T cells of lupus. 847 12

We have evaluated the autoantibody profiles in the sera of 117 patients with systemic lupus erythematosus (SLE) and compared and contrasted the clinical and laboratory features of the disease of patients segregated according to an autoantibody profile. Using this approach we are able to demonstrate that autoantibody profiles identified subsets of patients with SLE. Patients with a negative autoantibody profile had fewer clinical and laboratory features of their disease when compared to the other subsets of patients. In contrast, patients with profile A (anti-nDNA and/or anti-Sm antibodies) had a statistically significant increase in malar rash, renal and hematologic involvement and hypocomplementemia when compared to patients with a negative profile. Patients with profile B (anti-nRNP antibodies) had a clinical pattern of disease different from that of patients with profile A and had a statistically significant increase in Raynaud's phenomenon when compared to patients with a negative profile. Patients with profile C (anti-SSA and/or anti-SSB antibodies) had a statistically significant increase in lupus-related rashes and photosensitivity. None of the lupus patients reviewed in this study has profile D (antibodies to centromere and/or Scl-70), this profile being seen largely in patients with scleroderma or one of its variants. Both patients with profile E (anti-histone antibodies) had drug-induced lupus. We conclude that the use of autoantibody profiles defines subsets of patients with lupus that may have clinical, therapeutic and prognostic implications.
Lupus 1993 Feb
PMID:The clinical significance of autoantibody profiles in patients with systemic lupus erythematosus. 848 55

Current clinical practice relies heavily on serologic testing for the prompt and accurate diagnosis of rheumatic diseases. Serologic testing should be used to support the findings of the history and physical examination, and, in some cases, to monitor disease activity. The inflammation of the rheumatoid arthritis (RA), polymyalgia rheumatica, and temporal arteritis can be assessed by the erythrocyte sedimentation rate (ESR). The C-reactive protein (CRP, an acute-phase protein) test, which is newer, correlates more closely than ESR with clinical and radiographic parameters of RA inflammation. The rheumatoid factor test is nonspecific as a screen for RA, and some argue that it is also insensitive (accounting for the existence of "seronegative" RA). High titers of rheumatoid factor are associated with progressive joint inflammation, erosions, and disability. Antinuclear antibody (ANA) tests are likewise nonspecific, but ANA subtypes have proved to be very specific for subtypes of connective tissue diseases. Examples are the presence of anti-DNA antibody in systemic lupus erythematosus; anti-centromere antibody in the CREST syndrome of scleroderma; anti-histone antibody in drug-induced lupus; and anti-Ro antibody in neonatal lupus. Anti-neutrophil cytoplasmic antibodies (ANCA) are a new group of auto-antibodies seen in Wegener's granulomatosis. Brief case descriptions are presented to illustrate appropriate selection of these antibody tests as well as tests for antiphospholipid antibodies and cryoglobulins.
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PMID:Selection and use of laboratory tests in the rheumatic diseases. 860 22


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