ANTI-PEPTIDE ANTIBODIES DETECT A LUPUS-RELATED INTERSPECIES IDIOTYPE THAT MAPS TO H-CHAIN CDR2

作者：MEEK K; TAKEI M; DANG H; SANZ I; DAUPHINEE MJ; CAPRA JD; TALAL N

来源：The Journal of Immunology, 1990, 144(4): 1375-1381.

DOI：10.4049/jimmunol.144.4.1375

<jats:title>Abstract</jats:title>
<jats:p>Antibodies to the small nucleoprotein Sm occur spontaneously in human and murine systemic lupus erythematosus. Human and mouse monoclonal anti-Sm autoantibodies designated 4B4 and Y2 share an idiotype (Id) determinant located on the Ig H chain. To understand the molecular basis of this cross-reactivity, the VH regions of both antibodies were sequenced and analyzed for homology. The antibodies showed only 49.6% homology. The second complementary determining region (CDR2) was the most likely candidate for the Id site. To investigate this possibility, rabbit antiserum was made against a peptide corresponding to the CDR2 of 4B4. This antiserum was specific for the immunizing peptide and reacted weakly to a peptide corresponding to the CDR2 of Y2. Anti-CDR2 antibody bound to 4B4 and Y2 but not to other human and mouse mAb. Binding was directed at the H chain when analyzed by Western blots. Anti-CDR2 antibody blocked anti-Id antibody binding to 4B4 and Y2 by 58% and 24%, respectively. These studies suggest that this interspecies Id maps to the H chain CDR2 and that a conserved Id can occur within molecules that are otherwise radically different.</jats:p>

• 出版日期1990-2-15