Cross-reactivity of the B/B' subunit of the Sm ribonucleoprotein autoantigen with proline-rich polypeptides.
Using recombinant fusion proteins representing different regions of the human Sm B/B' polypeptide, the 4B4 monoclonal anti-Sm antibody was found to bind a C-terminus epitope that is proline-rich. 4B4 cross-reacted with the p24 gag protein of HIV-1 and with other polypeptides rich in proline residues, including collagen. BALB/c mice immunized with human collagen not only produced antibodies to the immunizing antigen but also antibodies to Sm. This immune mouse serum also recognized C-terminus B/B' fusion proteins. These data suggest that the Sm B/B' antigen contains a poly-Pro epitope that is shared by several autoantigens and retroviral proteins. These sites may be important in the induction of autoantibodies through molecular mimicry.
De Keyser
F
F
Clinical Immunology Section, Audie L. Murphy Memorial Veterans Hospital, San Antonio, Texas.
Hoch
S O
SO
Takei
M
M
Dang
H
H
De Keyser
H
H
Rokeach
L A
LA
Talal
N
N
D000818:Animals; D000911:Antibodies, Monoclonal; D001324:Autoantigens / Q000276:immunology*; D003094:Collagen / Q000276:immunology; D003429:Cross Reactions; D000939:Epitopes / Q000737:chemistry / Q000276:immunology; D005260:Female; D006801:Humans; D046911:Macromolecular Substances; D051379:Mice; D008807:Mice, Inbred BALB C; D010455:Peptides / Q000737:chemistry / Q000276:immunology*; D011392:Proline / Q000032:analysis; D011489:Protein Denaturation; D012261:Ribonucleoproteins / Q000276:immunology; D017411:Ribonucleoproteins, Small Nuclear; D055517:snRNP Core Proteins
D000911:Antibodies, Monoclonal; D001324:Autoantigens; D000939:Epitopes; D046911:Macromolecular Substances; D010455:Peptides; D012261:Ribonucleoproteins; D017411:Ribonucleoproteins, Small Nuclear; C526416:Snrpb protein, mouse; D055517:snRNP Core Proteins; D003094:Collagen; D011392:Proline