Sequence of a new HLA-DR4 allele with an unusual residue at position 88 that does not seem to affect T-cell allo recognition.
New HLA alleles can be identified by unorthodox patterns observed during low-resolution typing performed with sequence specific oligonucleotide probes (SSOP). One of the best examples is locus DRB1, where allelic subtypes are characterized by a combination of a limited number of residues located in three hypervariable regions of exon 2. HLA-DR oligotyping analysis of a female caucasoid bone marrow donor led to the identification of an individual that typed as DRB1*11, DRB3*02, DRB4*01, DQB1*0301-0302. This donor was, however, typed by serology as DR11 DR4, DR52, DR53, DQ7 DQ8. PCR-SSP typing for DR4 subtype revealed an amplification pattern typical for DRB1*0404. After sequencing the entire exon 2, a new DRB1 allele was identified: DRB1*04var that is identical to DRB1*0404, except for one nucleotide at codon 88 resulting in a Ser-->Arg exchange. This mutation had prevented amplification with the DR generic primers. Cellular typing by three HTCs-DRB1*0404/DW14 from the 9th Workshop showed that this DRB1*04var typed exactly like a DW14 cell. This suggests that residue 88 does not affect T cell recognition.
Histocompatibility Laboratory, Blood Transfusion Center, Lyon, France.
L
L
Gebuhrer
N
N
Adami
F
F
Javaux
A C
AC
Freidel
M
M
Jeannet
H
H
Betuel
J M
JM
Tiercy
D000483:Alleles; D000595:Amino Acid Sequence; D001483:Base Sequence; D005260:Female; D015804:HLA-DR4 Antigen / Q000737:chemistry / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D013601:T-Lymphocytes / Q000276:immunology*
D015804:HLA-DR4 Antigen