title: Cross-reactivity of anti-nDNA antibodies with nuclear envelope proteins. Isolation of a cDNA encoding the 70 kDa annular protein recognized by autoantibodies from patients with systemic lupus erythematosus.
abstract: OBJECTIVE
  To determine whether annular rDNA is complexed with the nuclear envelope proteins.
  
  
  METHODS
  From a batch of lupus sera with anti-nDNA, we selected a lupus serum containing annular anti-nDNA autoantibodies resistant to DNase digestion and used it to isolate several cDNA clones from a lambda gt11 HeLa cell library.
  
  
  RESULTS
  The cloned fusion protein immunoadsorbed the annular anti-nDNA autoantibodies, and the immunoaffinity autoantibodies eluted from the recombinant filters produced an annular pattern around the nucleus in fluorescent assays on HEp-2 cells; by Western blot, they also recognized a 70 kDa protein from HEp-2 cell extracts. Annular-lambda gt11 lysogens generated in E. coli Y1089 produced a fusion protein that recognized annular anti-nDNA autoantibody-containing lupus sera by Western blot. The recombinant filters and annular fusion protein were also recognized by a prototype anti-lamin serum. To determine whether the annular recombinant protein bound DNA, an interaction assay was performed in vitro using DNA minicircles and DNA from HEp-2 cells; this assay resulted in a slowing of the electrophoretic mobility of the DNA.
  
  
  CONCLUSIONS
  1) The annular DNA in eukaryotic cells is complexed with nuclear envelope proteins. 2) Annular anti-nDNA autoantibodies from lupus patients cross-react with perinuclear proteins. 3) Perinuclear proteins recognized by anti-nDNA are lamins. 4) An interaction between DNA and the 70 kDa protein is inducible in vitro. Whether this interaction affects cell function is still unknown.
authors.affiliation: Department of Immunology, Universidad Autónoma de Zacatecas, Mexico. herrerar@cantera.reduaz.mx
authors.forename: R
authors.initials: R
authors.lastname: Herrera-Diosdado
authors.forename: E
authors.initials: E
authors.lastname: Avalos-Diaz
authors.forename: R
authors.initials: R
authors.lastname: Herrera-Esparza
mesh_terms: D000974:Antibodies, Antinuclear / Q000276:immunology*; D001323:Autoantibodies / Q000276:immunology; D003429:Cross Reactions; D004247:DNA / Q000276:immunology*; D018076:DNA, Complementary / Q000235:genetics / Q000302:isolation & purification; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000276:immunology; D008970:Molecular Weight; D009685:Nuclear Envelope / Q000378:metabolism*; D009687:Nuclear Proteins / Q000737:chemistry / Q000276:immunology*; D011994:Recombinant Proteins
chemical_list: D000974:Antibodies, Antinuclear; D001323:Autoantibodies; D018076:DNA, Complementary; D009687:Nuclear Proteins; D011994:Recombinant Proteins; D004247:DNA