Frequent occurrence of anti-tRNAHis autoantibodies that recognize a conformational epitope in sera of patients with myositis.
To investigate the incidence of autoantibodies directed to deproteinized transfer RNAHis (tRNAHis) in anti-Jo-1 positive myositis patients and to determine the major B cell epitope.
One hundred sixty-seven myositis sera were screened by immunoblotting and enzyme-linked immunosorbent assay for the presence of anti-Jo-1 antibody.
Autoantibodies directed to deproteinized RNA were detected by immunoprecipitation.
Ribonuclease cleavage experiments were performed to determine the tRNAHis-specific features important for recognition.
Approximately one-third of the anti-Jo-1 positive sera also contained autoantibodies recognizing tRNAHis.
This recognition was independent of modified bases, but the presence of stabilizing Mg2+ions appeared to be essential for efficient immunoprecipitation.
Transfer RNAHis-specific features in the anticodon loop were not protected from ribonuclease cleavage by bound antibodies, while protection of bases located in the D and T loops was observed.
A significant number of anti-Jo-1 positive myositis sera contain anti-tRNAHis activity.
Formation of the major autoepitope on tRNAHis is strongly dependent on proper folding of this molecule mediated by an interaction between D and T loops which is stabilized by either modified residues or Mg2+ions.
Mots-clés Pascal : Polymyosite, Idiopathique, Inflammation, Epidémiologie, Incidence, Lymphocyte B, Anticorps, Autoanticorps, Déterminant antigénique, Technique ELISA, Sérum, RNA transfert, Homme, Immunoprécipitation, In vitro, Muscle strié pathologie, Maladie système, Antigène Jo-1
Mots-clés Pascal anglais : Polymyositis, Idiopathic, Inflammation, Epidemiology, Incidence, B-Lymphocyte, Antibody, Autoantibody, Antigenic determinant, ELISA assay, Serum, tRNA, Human, Immunoprecipitation reaction, In vitro, Striated muscle disease, Systemic disease
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 98-0409987
Code Inist : 002B07. Création : 25/01/1999.