Three types of blood group I specificity among monoclonal anti-I autoantibodies revealed by analogues of a branched erythrocyte glycolipid.
Blood group I activities of the purified glycosphingolipid lacto-N-iso-octaosyl ceramide (Fromula: see text) and 8 of its analogues have been evaluated with 11 anti-I sera including 5 anti-I sera previously tested. All but one of the antisera were inhibited by the lacto-N-iso-octaosyl structure. Three types of I-specificity could be distinguished although none of the anti-I sera was identical in its inhibition patterns with the nine glycophingolipid analogues. The anti-I sera Ma and Woj represent the first type and require an intact Galbeta1 leads to 4GlcNAcbeta1 leads to 6 chain, the anti-I sera Step, Gra, Ver, and Ful represent the second type which requires Galbeta1 leads to 4GlcNAcbeta1 leads to 3 chain with branching, and the anti-I sera Phi, Da, Sch, and Low belong to the third type which requires both branches to be intact. Anti-I antibodies varry in their ability to react with their antigenic determinants in the presence of external substitutions with alpha-linked galactose or sialic acid.
D000918:Antibody Specificity; D001323:Autoantibodies; D001666:Binding Sites, Antibody; D001789:Blood Group Antigens; D002999:Clone Cells / Q000276:immunology; D004912:Erythrocytes / Q000276:immunology*; D006017:Glycolipids / Q000097:blood / Q000276:immunology*; D006028:Glycosphingolipids / Q000097:blood / Q000276:immunology; D006801:Humans; D007048:I Blood-Group System; D007518:Isoantibodies; D013329:Structure-Activity Relationship
D001323:Autoantibodies; D001789:Blood Group Antigens; D006017:Glycolipids; D006028:Glycosphingolipids; D007048:I Blood-Group System; D007518:Isoantibodies