The DR3(w18),DQw4 Haplotype Differs from DR3(w17),DQw2 Haplotypes at Multiple Class II Loci
Abstract
The polymorphism of HLA class II molecules in man is particularly evident when comparisons between population groups are made. This study describes a DR3 haplotype commonly present in the American black population. Unlike the Northern European population, in which almost all DR3 individuals are DQw2, approximately 50% of DR3-positive American blacks express a DQw4 allelic product. This study characterizes the DR subregion of that haplotype. cDNA sequence analysis has revealed a DR Beta gene which differs at several positions from previously described DR3 Beta I genes. It is postulated that a gene-conversion-like event with a DRw52 Beta gene as donor has generated some of these differences. The haplotype carries a DRw52A allele as defined by oligonucleotide hybridization studies. DNA restriction fragment analysis using a family and several unrelated individuals has allowed us to identify DR alpha and Beta fragments associated with the DR3(w18), DQw4 haplotype. The most striking observation is that the DR3(w18),DQw4 haplotype differs from DR3(w17), DQw2 haplotypes at multiple class II loci. Several genetic mechanisms including reciprocal recombination gene conversion, and point mutation were involved in generating the differences between these haplotypes. Once established, the DR3(w18),DQw4 haplotype appears to be relatively stable in the population. Keywords: B-LCL (B-lymphoblastoid cell line); HTC (Homozygous typing cell); Histocompatibility leukocyte; Antigen; Major histocompatibility complex; Polymorphism; Immunology; Immunogenetics; Transplantation; Reprints.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1989
- Accession Number
- ADA209815
Entities
People
- Armead H. Johnson
- Carolyn K. Hurley
- Fu M. Robbins
- Jack Gorski
- Jack Silver
- Noriko Steiner
- Peter K Gregersen
- Robert Hartzman
Organizations
- Naval Medical Research Center