Molecular characterization of HLA-C incompatibilities in HLA-ABDR-matched unrelated bone marrow donor-recipient pairs. Sequence of two new Cw alleles (Cw*02023 and Cw*0707) and recognition by cytotoxic T lymphocytes.
While the influence of HLA-AB and -DRB1 matching on the outcome of bone marrow transplantation (BMT) with unrelated donors is clear, the evaluation of HLA-C has been hampered by its poor serological definition. Because the low resolution of standard HLA-C typing could explain the significant number of positive cytotoxic T lymphocyte precursor frequency (CTLpf) tests found among HLA-AB-subtype, DRB1/B3/B5-subtype matched patient/donor pairs, we have identified by sequencing the incompatibilities recognized by CD8+ CTL clones obtained from such positive CTLpf tests. In most cases the target molecules were HLA-C antigens that had escaped detection by serology (e.g. Cw*1601, 1502 or 0702). Direct recognition of HLA-C by a CTL clone was demonstrated by lysis of the HLA class I-negative 721.221 cell line transfected with Cw*1601 cDNA. Because of the functional importance of Cw polymorphism, a PCR-SSO oligotyping procedure was set up allowing the resolution of 29 Cw alleles. Oligotyping of a panel of 382 individuals (including 101 patients and their 272 potential unrelated donors, 5 related donors and 4 platelet donors) allowed to determine HLA-C and HLA A-B-Cw-DRB1 allelic frequencies, as well as a number of A-Cw, B-Cw, and DRB1-Cw associations. Two new HLA-Cw alleles (Cw*02023 and Cw*0707) were identified by DNA sequencing of PCR-amplified exon 2-intron 2-exon 3 amplicons. Furthermore, we determined the degree of HLA-C compatibility in 287 matched pairs that could be formed from 73 patients and their 184 potential unrelated donors compatible for HLA-AB by serology and for HLA-DRB1/ B3/B5 by oligotyping. Cw mismatches were identified in 42.1% of these pairs, and AB-subtype oligotyping showed that 30% of these Cw-incompatible pairs were also mismatched for A or B-locus subtype. The degree of HLA-C incompatibility was strongly influenced by the linkage with B alleles and by the ABDR haplotypes. Cw alleles linked with B*4403, B*5101, B18, and B62 haplotypes were frequently mismatched. Apparently high resolution DNA typing for HLA-AB does not result in full matching at locus C. Since HLA-C polymorphism is recognized by alloreactive CTLs, such incompatibilities might be as relevant as AB-subtype mismatches in clinical transplantation.
Grundschober
C
C
Transplantation Immunology Unit, Hôpitaux Universitaires de Genève, Switzerland.
Rufer
N
N
Sanchez-Mazas
A
A
Madrigal
A
A
Jeannet
M
M
Roosnek
E
E
Tiercy
J M
JM
D000017:ABO Blood-Group System; D000483:Alleles; D000595:Amino Acid Sequence; D001483:Base Sequence; D016026:Bone Marrow Transplantation; D018076:DNA, Complementary; D005787:Gene Frequency; D015236:HLA-C Antigens / Q000235:genetics / Q000276:immunology*; D006684:HLA-DR Antigens / Q000235:genetics; D059811:HLA-DRB1 Chains; D059826:HLA-DRB3 Chains; D059847:HLA-DRB5 Chains; D006239:Haplotypes; D006650:Histocompatibility Testing; D006801:Humans; D015810:Linkage Disequilibrium; D008969:Molecular Sequence Data; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*
D000017:ABO Blood-Group System; D018076:DNA, Complementary; D015236:HLA-C Antigens; D006684:HLA-DR Antigens; D059811:HLA-DRB1 Chains; D059826:HLA-DRB3 Chains; D059847:HLA-DRB5 Chains