Wade J A, Hurley C K, Hastings A, Ehrenberg P, Johnson A H, Martell R W, du Toit E D
University of Toronto, Canada.
Tissue Antigens. 1993 Mar;41(3):113-8. doi: 10.1111/j.1399-0039.1993.tb01990.x.
Sequence analysis has identified multiple alleles at two loci that encode for the DR2 specificity. The loci, DRB1 and DRB5, are in linkage disequilibrium which can extend to alleles of the DQ loci. Serologic, cellular, and sequence-specific oligonucleotide probe (SSOP) typing techniques have been used to identify the DR2 haplotypes. In this report, we have characterized by SSOP typing and cDNA/DNA sequence analyses the combinatorial diversity of DR2 haplotypes. Cells were selected on the basis of unique serologic reactivity, unique associations of alleles of DR and DQ loci, and/or presence in populations which have not been extensively characterized for HLA diversity. An asymmetric polymerase chain reaction (PCR) amplification was applied to rapidly screen unique cells and to characterize DNA sequence in conjunction with more conventional cDNA sequence analysis. The sequence data confirm the lack of a DRB5 locus in the DR2"LUM" specificity, the unexpected association of DRB11602 and DRB5010 alleles in a nonCaucasoid population, and the association of the allele DRB11503 with DRB50101 in black African, African American and native American individuals. The DRB11503 and DRB50101 alleles were identified in an unusual haplotype, DR2,DQ2. The combinatorial diversity of the DR2 haplotypes is extended by these studies in nonCaucasoid populations.
