Structural analysis of HLA-B40 epitopes.
Two genes encoding HLA-B60 or HLA-B61 were cloned from Japanese and the exons of their genes were sequenced. One silent mutation was observed at the exon 1 between HLA-B60 (B*40012) and B*40011. Seven nucleotide substitutions were seen at the exon 3 between HLA-B61 (B*4006) and B*4002. Three substitutions at codon 95, CTC in B*4002 to TGG in B*4006, changed Leu in B*4002 to Trp in B*4006, while two substitutions at codon 97, AGC in B*4002 and ACG in B*4006, changed Ser in B*4002 to Thr in B*4006. Since B*4002 shares the epitope of alloantibodies specific for HLA-B61, two HLA-B61 subtypes are discriminated by two amino acid substitutions at residues 95 and 97. B*40012 and B*4006 differ by four amino acid substitutions on the beta sheet and five amino acid substitutions on the alpha 2 helix. Since the residues at the beta sheet seem hardly to affect the binding of alloantibody, it is suspected that the residues on the alpha 2 helix provide epitopes for alloantibodies that discriminate allospecificity between HLA-B60 and HLA-B61.
Kawaguchi
G
G
Department of Tumor Biology and Immunology, University of Tokyo, Japan.
Kato
N
N
Kashiwase
K
K
Karaki
S
S
Kohsaka
T
T
Akaza
T
T
Kano
K
K
Takiguchi
M
M
D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D003601:Cytotoxicity Tests, Immunologic; D004252:DNA Mutational Analysis; D000939:Epitopes / Q000737:chemistry / Q000276:immunology; D005802:Genes, MHC Class II; D015235:HLA-B Antigens / Q000737:chemistry* / Q000235:genetics / Q000276:immunology; D059947:HLA-B40 Antigen; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation; D017385:Sequence Homology
D000939:Epitopes; D015235:HLA-B Antigens; D059947:HLA-B40 Antigen; C079077:HLA-B61 antigen