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A single amino acid exchange shifts the serological reactivity of the novel HLA‐B*4442 allele product from HLA‐B44 to HLA‐B21
Author(s) -
Mrazek F.,
Fae I.,
Ambruzova Z.,
Raida L.,
Kriegova E.,
Indrak K.,
Fischer G. F.,
Petrek M.
Publication year - 2006
Publication title -
international journal of immunogenetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.41
H-Index - 47
eISSN - 1744-313X
pISSN - 1744-3121
DOI - 10.1111/j.1744-313x.2006.00596.x
Subject(s) - typing , biology , allele , serology , human leukocyte antigen , locus (genetics) , hla a , hla b , genetics , hla b antigens , epitope , microbiology and biotechnology , hla c , polymerase chain reaction , virology , antigen , gene , antibody
Summary 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.