Role of HLA-B*5101 binding nonamer peptides in formation of the HLA-Bw4 public epitope.
HLA-Bw4 is one of two HLA-B public epitopes which are discriminated by specific alloantisera and mAb. It is believed that the 77-83 of HLA-B molecules form the Bw4 epitope recognized by specific antibodies. This epitope is also recognized by NKB1 receptors on NK cells. We investigated the role of a peptide bound to HLA-B molecules on the formation of the Bw4 epitope recognized by two HLA-Bw4-specific mAb, TU109 and TU48, which recognized the difference of the Bw4 epitope among HLA-B52, -B52 and -B53. Recognition of the HLA-B*5101-peptide complex by these mAb was examined using a panel of HLA-B*5101 binding nonamer peptides. The sequence of HLA-B*5101 binding peptides has a minimum influence on the binding of TU48 mAb to HLA-B*5101 molecules. In contrast, the binding of TU109 mAb to HLA-B*5101 molecules was critically influenced by the sequence of a peptide bound to HLA-B*5101 molecules. TU109 mAb did not recognize HLA-B*5101 binding peptides carrying small or negatively charged residues at P8. The results were confirmed by a panel of mutant peptides at P8. Taken together, these results indicate that a positively charged or neutralized side chain of P8 is critical for the epitope formation of Bw4 recognized by this mAb.
Takamiya
Y
Y
Department of Tumor Biology, Institute of Medical Science, University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108, Japan.
Sakaguchi
T
T
Miwa
K
K
Takiguchi
M
M
D000818:Animals; D000911:Antibodies, Monoclonal / Q000737:chemistry; D001704:Biopolymers / Q000276:immunology; D002460:Cell Line; D000939:Epitopes / Q000096:biosynthesis* / Q000737:chemistry; D005434:Flow Cytometry; D015235:HLA-B Antigens / Q000096:biosynthesis / Q000737:chemistry / Q000502:physiology*; D007739:L Cells; D051379:Mice; D010455:Peptides / Q000737:chemistry / Q000276:immunology* / Q000502:physiology*; D011485:Protein Binding / Q000276:immunology
D000911:Antibodies, Monoclonal; D001704:Biopolymers; D000939:Epitopes; D015235:HLA-B Antigens; C035270:HLA-B5 antigen; C042388:HLA-Bw4 antigen; D010455:Peptides