title: Induction of anti-Ro60/anti-La by immunisation with spectrin and induction of anti-spectrin by immunisation with Ro60 and 4-hydroxy-2-nonenal-modified Ro60 immunisation.
abstract: OBJECTIVE
  The Ro ribonucleoprotein particle, targeted in systemic lupus erythematosus (SLE) and Sjögren's syndrome (SS), includes Ro60 (SSA) and La (SSA) autoantigens. Anti-Ro60 occurs in SLE and SS. The importance of α-fodrin and spectrin as well as anti-Ro and anti-fodrin/spectrin antibodies in SS and SLE, led us to hypothesise that rabbit immunisation with Ro60 or 4-hydroxy-2-nonenal-modified Ro60 would induce anti-spectrin. In addition, we hypothesised that antibodies to Ro60 and La will develop in animals immunised with spectrin.
  
  
  METHODS
  Two NZW rabbits each were immunised with 4-hydroxy-2-nonenal-modified Ro60 or unmodified Ro60. Methods used included ELISA, including an inside-out RBC membrane ELISA, and Crithidia lucilae assays.
  
  
  RESULTS
  Commercial anti-spectrin sera bound significantly to Ro60 (OD 2.6 ± 0.1), Ro60 multiple antigenic peptides (MAPs) (3 out of 21 Ro60 MAPs), La (OD 4.4±0.5), and La fragments as well as to double stranded DNA but not to BSA (OD 0.6±0.1). Anti-spectrin binding to purified spectrin could be inhibited by spectrin (>95%), and Ro60 or La (70%). When the binding of anti-spectrin was tested against a nested set of La fragments we found that a N4 fragment representing the C-terminal 250 aa (aa 159 to 408) bound the strongest (OD=4.12) followed by a N9 fragment (the C-terminal 36aa; aa373 to 408 (OD=1.36). Also, significant anti-spectrin antibody levels were induced by Ro60 and HNE-modified Ro60 immunisation.
  
  
  CONCLUSIONS
  We found intermolecular epitope spreading from Ro60/La to spectrin and vice versa, and this may have pathological significance in these animal models of autoimmunity.
authors: Arthritis and Clinical Immunology Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA. biji-kurien@omrf.org
authors: Biji T
authors: BT
authors: Kurien
authors: Yaser
authors: Y
authors: Dorri
authors: Michael
authors: M
authors: Bachmann
authors: R Hal
authors: RH
authors: Scofield
mesh_terms: D000447:Aldehydes / Q000008:administration & dosage / Q000276:immunology*; D000818:Animals; D000974:Antibodies, Antinuclear / Q000097:blood*; D001324:Autoantigens / Q000276:immunology*; D015551:Autoimmunity; D001667:Binding, Competitive; D004247:DNA / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D018604:Epitope Mapping; D000939:Epitopes; D007114:Immunization; D011485:Protein Binding; D011817:Rabbits; D012261:Ribonucleoproteins / Q000008:administration & dosage / Q000276:immunology*; D013049:Spectrin / Q000008:administration & dosage / Q000276:immunology*; D000097585:SS-B Antigen; D000099207:SS-A Antigen
chemical_list: D000447:Aldehydes; D000974:Antibodies, Antinuclear; D001324:Autoantigens; D004247:DNA; D000939:Epitopes; D012261:Ribonucleoproteins; D013049:Spectrin; D000097585:SS-B Antigen; D000099207:SS-A Antigen; C035356:SS-A antibodies; C035357:SS-B antibodies; C027576:4-hydroxy-2-nonenal