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

IgG fractions were purified on a protein G-agarose column from sera of both systemic lupus erythematosus (SLE) patients and healthy donors. All IgG fractions, after elution with 0.5 M acetic acid, reacted with histones in an anti-histone ELISA assay, and IgG anti-histone activity was in all instances higher in the IgG fraction than in the corresponding whole serum. This was shown to be due to the presence in serum of histone-binding components that inhibited IgG binding to histones. Both normal human and SLE patients' sera had these histone-binding components, and disparity between serum-positive and -negative anti-histone antibody (AHA) tests was not dependent on differences in the blocking capacity but on IgG antibody levels and avidity. Interaction of normal serum IgG fraction with all five histones was of low avidity, whereas interaction of IgG from AHA-positive SLE sera with both H1 and H2B had high avidity. Low-affinity antibodies to every histone fraction, but also high-affinity anti-H1 antibodies, were preferentially inhibited. Our data indicate that several serum protein components are inhibiting histone/anti-histone interaction and may play a protective role against both high-affinity anti-H1 antibodies present in SLE patients, and natural, low-affinity, anti-histone antibodies. As some acute phase proteins, notably C-reactive protein, bind to histones, it is conceivable that they play such a role. High-affinity anti-H2B antibodies, present in some SLE patients, and not inhibited by these serum components, may, on the other hand, participate in the pathogenesis of the disease.
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PMID:Inhibition of histone/anti-histone reactivity by histone-binding serum components; differential effect on anti-H1 versus anti-H2B antibodies. 813 38

The mechanism of attachment of circulating immune complexes (CIC) to glomerular basement membranes (GBM) in systemic lupus erythematosus (SLE) has not yet been elucidated. One difficulty is that CIC must be strongly cationic for such deposition to occur, which is opposite to the anionic nature of putative DNA-anti-DNA immune complexes (DNA-IC). The strongly cationic histone has been proposed as a potential "planted antigen"; it would decorate the GBM to function as a ligand for DNA in the DNA-IC. However, DNA-IC, aggregated IgG and most of the IgG "anti-histone antibodies" in SLE patient sera bind to histone on a solid phase not through DNA, but through the Fcgamma. Here, we investigated the nature of the anti-histone "antibody" in sera of 18 patients with SLE and 57 with drug-induced lupus (DIL). The binding to nucleosomes of IgG from these patients was mainly pepsin-resistant and F(ab')(2)-dependent, whereas the binding to histone was mainly pepsin-sensitive and Fcgamma-dependent. Surprisingly, after molecular sieving of 12 of these sera, the pepsin-sensitive histone-binding IgG was located mainly in the 150-kDa monomeric IgG peak. The binding to nucleosomes was only in the 150-kDa peak. These findings are consistent with the existence of an anomalous IgG in SLE and DIL sera, capable, like aggregated IgG, DNA-IC and other CIC, of binding to histone-decorated structures. We propose that this anomalous IgG plays an essential role in the pathogenesis of lupus nephritis and other related inflammatory conditions. These observations also explain the large discrepancies in the reports on anti-histone autoantibodies in autoimmune conditions.
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PMID:Binding to histone of an anomalous IgG from patients with SLE and drug-induced lupus. 1500 11

The Sle2c1rec1c (rec1c) sublocus is derived from the mouse lupus susceptibility 2 (Sle2) locus identified in the NZM2410 model. Our current study dissected the functional characters and the genetic basis of the rec1c locus relative to lupus when co-expressed with the Fas lpr mutation, an established inducer of autoimmunity. The rec1c.lpr mice exhibited mild expansion of lymph nodes and had a normal T cell cellularity, but developed significantly kidney and lung inflammation, indicating that the rec1c amplifies lpr-induced autoimmune pathogenesis. A variant of somatic nuclear autoantigenic sperm protein (sNASP) was identified from the rec1c interval as a substitution of two consecutive amino acid residues in the histone-binding domain, resulting in an increased binding affinity to histone H4 and H3.1/H4 tetramer. To determine the role of the sNASP rec1c allele in mouse lupus, a novel strain was generated by introducing the rec1c mutations into the B6 genome. In this transgenic model, the sNASP allele synergized with the lpr mutation leading to moderate autoimmune phenotypes and aggravating inflammatory pathology alterations in kidney and lung that were similar to those observed in the rec1c.lpr mice. These results establish that the sNASP allele is a pathogenic genetic element in the rec1c sublocus, which not only promotes autoimmunity, but also exacerbates the inflammation reaction of end organs in mouse lupus pathogenesis. It also shows the complexity of the Sle2c locus, initially mapped as the major locus associated with B1a cell expansion. In addition to Cdkn2c, which regulates this expansion, we have now identified in the same locus a protective allele of Csf3r, a variant of Skint6 associated with T cell activation, and now a variant of sNASP that amplifies autoimmunity and tissue damage.
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PMID:A Variant of the Histone-Binding Protein sNASP Contributes to Mouse Lupus. 3100 Dec 59

Objective To prepare inducible lupus model mice and investigate the effect of nuclear autoantigenic sperm protein (NASP) gene mutation on the autoimmune response of mice with induced systemic lupus erythematosus (SLE). Methods The 3-month wild-type B6 (B6-WT) mice were used as a control group and the NASP mutant B6 (B6-NASPM) mice as an experimental group. Mouse spleen lymphocytes were activated with concanavalin A (ConA), and the DNA was extracted as autoantigen. B6-WT mice and B6-NASPM mice were immunized three times. Serum anti-double stranded DNA (dsDNA) IgG levels were detected by ELISA. Renal lesions were detected by HE staining. Immunohistochemical staining was performed to detect the deposition of IgG and complement C3 in the renal tissues. Flow cytometry was applied to compare the spleen lymphocyte subsets in B6-WT and B6-NASPM mice and to explore the mechanism of NASP gene mutation affecting the immune response in mice. Results Compared with B6-WT mice, B6-NASPM mice showed no significant changes in body weight, kidney index and spleen index; serum anti-dsDNA IgG levels significantly increased; glomerular cell proliferation was obvious and the deposition of IgG and C3 in the renal tissues increased. The proportion of spleen CD3+ T cells and natural killer (NK) cells decreased, while the proportion of CD19+ B cells and regulatory B cells (Breg) increased. Conclusion Mutation in the NASP gene can increase the levels of anti-dsDNA IgG antibodies, promote cell proliferation in the glomerulus of the kidney, deposition of IgG antibodies and complement C3, alter the proportion of immune cells in the spleen and aggravate the autoimmune response in lupus model mice.
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PMID:[Mutation of nuclear autoantigenic sperm protein (NASP) gene aggravates autoimmune response in induced lupus model mice]. 3175 Aug 17