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.
Clinical Immunology Section, Audie L. Murphy Memorial Veterans Hospital, San Antonio, Texas.
F
F
De Keyser
S O
SO
Hoch
M
M
Takei
H
H
Dang
H
H
De Keyser
L A
LA
Rokeach
N
N
Talal
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