title: Selective antibody reactivity with peptides from human endogenous retroviruses and nonviral poly(amino acids) in patients with systemic lupus erythematosus.
abstract: OBJECTIVE
  To investigate antibody responses to a broad panel of peptides derived from human endogenous retroviruses (HERVs) among unselected patients with systemic lupus erythematosus (SLE).
  
  
  METHODS
  In sera obtained from 69 patients with SLE and healthy blood donors, immunoassay was used to measure levels of antibody against synthetic peptides derived from HERVs, exogenous retroviruses, and nonviral poly(amino acids).
  
  
  RESULTS
  Measurement by immunoassay revealed increased frequencies of antiretroviral antibodies against 2 peptides derived from the env gene of the type C-like class, which includes ERV-9 and HERV-H, and against 2 peptides from the gag region of human T lymphotropic virus type I-related endogenous sequence 1, in patients with SLE. Antibodies to 2 nonviral peptides, polyhistidine and polyproline, were also overrepresented in patient sera. In 1 patient, longitudinal data obtained over a period of 12 years indicated that the concentrations of certain antiretroviral antibodies varied according to disease activity.
  
  
  CONCLUSIONS
  Reactivity to certain type C HERV-derived antigens was found among patients with SLE. This reactivity could be explained by increased exposure to cross-reactive epitopes from essentially complete type C HERVs.
authors.affiliation: Lund University, Sweden.
authors.forename: A
authors.initials: A
authors.lastname: Bengtsson
authors.forename: J
authors.initials: J
authors.lastname: Blomberg
authors.forename: O
authors.initials: O
authors.lastname: Nived
authors.forename: R
authors.initials: R
authors.lastname: Pipkorn
authors.forename: L
authors.initials: L
authors.lastname: Toth
authors.forename: G
authors.initials: G
authors.lastname: Sturfelt
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000276:immunology*; D000818:Animals; D000914:Antibodies, Viral / Q000276:immunology*; D000918:Antibody Specificity; D001323:Autoantibodies / Q000097:blood; D006224:Cricetinae; D003429:Cross Reactions; D000939:Epitopes / Q000276:immunology; D005260:Female; D015686:Gene Products, env / Q000737:chemistry / Q000276:immunology; D015683:Gene Products, gag / Q000737:chemistry / Q000276:immunology; D015684:Gene Products, pol / Q000737:chemistry / Q000276:immunology; D006801:Humans; D008137:Longitudinal Studies; D008180:Lupus Erythematosus, Systemic / Q000276:immunology* / Q000821:virology*; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D010455:Peptides / Q000276:immunology; D012190:Retroviridae / Q000276:immunology*; D014764:Viral Proteins / Q000737:chemistry / Q000276:immunology*
chemical_list: D000596:Amino Acids; D000914:Antibodies, Viral; D001323:Autoantibodies; D000939:Epitopes; D015686:Gene Products, env; D015683:Gene Products, gag; D015684:Gene Products, pol; D010455:Peptides; D014764:Viral Proteins