Dr(a-) polymorphism of decay accelerating factor. Biochemical, functional, and molecular characterization and production of allele-specific transfectants.
Journal Article
The Dra antigen belongs to the Cromer-related blood group system, a series of antigens on decay accelerating factor (DAF), a glycosyl-phosphatidylinositol-anchored membrane protein that protects host cells from complement-mediated damage. We studied the rare inherited Dr(a-) phenotype to ascertain the associated biochemical and functional changes in DAF and to characterize the basis for this polymorphism. Radioimmunoassay assay and flow cytometric analysis of Dr(a-) erythrocytes demonstrated 40% of normal surface expression of DAF but normal levels of several other glycosyl-phosphatidylinositol-anchored proteins, distinguishing this phenotype from that of paroxysmal nocturnal hemoglobinuria. Western blots confirmed this reduced DAF expression and indicated a slightly faster mobility of the molecule on SDS-PAGE. Despite the reduced DAF expression, Dr(a-) erythrocytes functioned normally in the complement lysis sensitivity assay. Utilization of the polymerase chain reaction to amplify mononuclear cell genomic DNA from three unrelated Dr(a-) individuals demonstrated that a point mutation underlies the Dr(a-) phenotype: a C to T change in nucleotide 649 resulting in a serine165 to leucine change. This defines the Drb allele of DAF, which can be distinguished from Dra by a Taq I restriction fragment length polymorphism. We created transfected Chinese hamster ovary cell lines expressing either the Dra or the Drb allelic form of DAF. These allele-specific transfectants were tested by inhibition of hemagglutination or flow cytometry and confirmed the specificity of anti-Dra alloantisera. The allele-specific transfectants could form the basis of a new serological approach to immunohematology.
Full Text
Duke Authors
Cited Authors
- Lublin, DM; Thompson, ES; Green, AM; Levene, C; Telen, MJ
Published Date
- June 1991
Published In
Volume / Issue
- 87 / 6
Start / End Page
- 1945 - 1952
PubMed ID
- 1710232
Pubmed Central ID
- 1710232
International Standard Serial Number (ISSN)
- 0021-9738
Digital Object Identifier (DOI)
- 10.1172/JCI115220
Language
- eng
Conference Location
- United States