Antibodies to HLA class I promoter-binding proteins in sera from patients with systemic lupus erythematosus.
Antibodies directed against human cell nuclear factors (HLA-F1 and HLA-F2) that bind to the interferon consensus sequence (ICS) in the promoter region of the HLA-A2 class I gene can be detected in the serum of some patients with systemic lupus erythematosus (SLE). Such antibodies, in gel-shift assays, inhibited the formation of the retarded band corresponding to the HLA-F1/F2-ICS complex irrespective whether purified factors or crude nuclear extracts were used. This inhibitory effect was due to IgG since the SLE serum activity bound to and could be eluted from a protein A-Sepharose column. This effect still persisted after absorption of SLE serum on a DNA-affinity column which removed antibodies directed against protein-free HLA-A2-ICS nucleotide sequence also present in such sera. Western blot analysis further confirmed that SLE serum recognized both HLA-F1 (65 kDa) and HLA-F2 (88 kDa) polypeptides, independently of the presence of the HLA-A2-ICS nucleotidic sequence, as well as other proteins. These results suggest that human sera from some patients with SLE may be used as a convenient source of antibodies directed against DNA-binding proteins regulating gene transcription.
Le Bouteiller
P
P
Centre d'Immunologie, INSERM-CNRS de Marseille-Luminy, France.
Auphan
N
N
Weill
B
B
Lemonnier
F A
FA
D004268:DNA-Binding Proteins / Q000276:immunology*; D004587:Electrophoresis, Agar Gel; D015234:HLA-A Antigens / Q000235:genetics*; D006367:HeLa Cells; D006801:Humans; D066298:In Vitro Techniques; D008180:Lupus Erythematosus, Systemic / Q000276:immunology*; D008970:Molecular Weight; D009841:Oligonucleotides; D011401:Promoter Regions, Genetic; D014157:Transcription Factors / Q000276:immunology*
D004268:DNA-Binding Proteins; D015234:HLA-A Antigens; D009841:Oligonucleotides; D014157:Transcription Factors