Autoimmune antibodies to hnRNPG protein in dogs with systemic lupus erythematosus: epitope mapping of the antigen.
We previously reported the presence of circulating autoantibodies to hnRNPG protein in dogs with systemic lupus erythematosus (Soulard et al. 1993, 1994). These antibodies appeared to be specifically limited to German shepherd dog species. In the present report, we have analysed the nature of the hnRNPG epitopes responsible for autoantibody specificity. By using a set of 11 dog sera selected for their strong reactivity to hnRNPG protein, we have found that these sera had the ability to recognize two epitopes: (1) within a stretch of 33 amino acids located around the central part of protein, that is readily detected by immunoblotting; (2) a N-terminal conformation of the protein close to the RNA binding domain (RBD), that is revealed by immunoprecipitation. Our data strongly support the notion that the dog autoimmune response against hnRNPG protein is antigen-driven.
Centre de Biologie Vétérinaire de l'Arche, 110 rue Jean Jaurès, 92800, Puteaux, France.
Michel
M
Soulard
Véronique
V
Della Valle
Christian-Jacques
CJ
Larsen
D000595:Amino Acid Sequence; D000818:Animals; D001323:Autoantibodies / Q000097:blood*; D001324:Autoantigens / Q000737:chemistry / Q000235:genetics; D001483:Base Sequence; D018076:DNA, Complementary / Q000235:genetics; D004283:Dog Diseases / Q000235:genetics / Q000276:immunology*; D004285:Dogs; D018604:Epitope Mapping; D006367:HeLa Cells; D034441:Heterogeneous-Nuclear Ribonucleoproteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000235:genetics / Q000276:immunology / Q000662:veterinary*; D008969:Molecular Sequence Data; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D017384:Sequence Deletion; D013045:Species Specificity
D001323:Autoantibodies; D001324:Autoantigens; D018076:DNA, Complementary; D034441:Heterogeneous-Nuclear Ribonucleoproteins; D011993:Recombinant Fusion Proteins