A single amino acid exchange shifts the serological reactivity of the novel HLA-B*4442 allele product from HLA-B44 to HLA-B21.
A novel HLA-B (human leukocyte antigen-B) allele, HLA-B*4442, was identified both in a Czech patient with leukaemia and in his mother. The presence of a novel allele was initially suspected because conflicting results were obtained by serological and DNA typing techniques. The HLA typing using the polymerase chain reaction-sequence-specific primers (PCR-SSP) at the two-digit level indicated an allele belonging to the HLA-B*44 group, whereas serological typing indicated HLA-B21. Typing with PCR-sequence-specific oligonucleotides (PCR-SSO) resulted in a unique reaction pattern that could not be assigned to a known allele, PCR-SSP typing at the four-digit level did not match any known B*44 allele, either. The sequencing-based typing of the HLA-B locus then revealed the novel B*4442 allele that is identical with B*4405 except a single C-->G nucleotide exchange at position 572. This exchange results in an amino acid substitution from serine to tryptophan at position 167 of the expressed HLA-B protein. The B21 serological reactivity of the novel B*4442 allele product was confirmed by employing an additional serological panel of typing sera. Our findings support previous reports claiming that serine at the position 167 in the alpha-2 domain of the HLA-B protein is a major determinant of the HLA-B44(12) serological epitope.
Mrazek
F
F
Tissue Typing Laboratory, Department of Immunology, Medical Faculty Palacky University, Olomouc, Czech Republic. mrazekf@fnol.cz
Fae
I
I
Ambruzova
Z
Z
Raida
L
L
Kriegova
E
E
Indrak
K
K
Fischer
G F
GF
Petrek
M
M
D000483:Alleles; D019943:Amino Acid Substitution / Q000276:immunology; D001483:Base Sequence; D018153:Czech Republic; D005260:Female; D015973:Gene Expression Regulation, Leukemic / Q000235:genetics / Q000276:immunology; D015235:HLA-B Antigens / Q000235:genetics* / Q000276:immunology; D059948:HLA-B44 Antigen; D006801:Humans; D007938:Leukemia / Q000235:genetics / Q000276:immunology; D008297:Male; D008969:Molecular Sequence Data; D010375:Pedigree; D017354:Point Mutation / Q000276:immunology
D015235:HLA-B Antigens; C512337:HLA-B*44:42 antigen; C063569:HLA-B21 antigen; D059948:HLA-B44 Antigen