Anti-peptide antibodies that recognize conformational differences of HLA class I intracytoplasmic domains.
Rabbit antibodies were raised against both long and short peptides derived from exon 7 sequences of human leukocyte antigen (HLA) class I alpha chains; anti-A/B against a 13-mer shared by most HLA-A alpha and HLA-B alpha chains, anti-C against a 15-mer characteristic of HLA-C alpha chains, anti-ACT against a 6-mer specific to HLA-A alpha chains, and anti-CCT against a 5-mer specific to HLA-C alpha chains. Binding activity of the antibodies was determined with peptides by enzyme-linked immunoabsorbent assay (ELISA) and with HLA class I transfectants and the parental cells by FACS analysis. Anti-A/B and anti-C were to a greater or lesser extent crossreactive with the long and short peptides, whereas anti-ACT and anti-CCT were specific to the corresponding short peptides. No binding was seen for anti-ACT and anti-CCT with HLA class I transfectants, C1R-A2, C1R-B7, and 221-Cw1 and the parental cells, C1R (Cw4, E) and 721.221 (E, F). Anti-A/B and anti-C were substantially protein-reactive and the binding order was C1R-B7 > C1R-A2, 721.221 > C1R, 221-Cw1 for anti-A/B, and C1R-B7 > 721.221 > C1R, 221-Cw1, C1R-A2 for anti-C. Thus, anti-A/B and anti-C bound better to HLA-B and HLA-E rather than to HLA-A and HLA-C. Computer modeling of the three-dimensional structure of the intracytoplasmic domains demonstrated that this may be due to structural differences despite the sequence similarities.
Chersi
Alberto
A
Regina Elena Institute for Cancer Research, Rome, Italy.
Galati
Rossella
R
Ogino
Takeshi
T
Butler
Richard H
RH
Tanigaki
Nobuyuki
N
D000595:Amino Acid Sequence; D000818:Animals; D000918:Antibody Specificity; D000937:Antigen-Antibody Reactions; D002460:Cell Line; D003198:Computer Simulation; D003593:Cytoplasm / Q000276:immunology; D015395:Histocompatibility Antigens Class I / Q000737:chemistry* / Q000235:genetics / Q000276:immunology*; D006801:Humans; D051379:Mice; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D021122:Protein Subunits; D011817:Rabbits; D014162:Transfection
D015395:Histocompatibility Antigens Class I; D021122:Protein Subunits