Dr(a-) polymorphism of decay accelerating factor. Biochemical, functional, and molecular characterization and production of allele-specific transfectants.

Published

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

Electronic International Standard Serial Number (EISSN)

  • 1558-8238

International Standard Serial Number (ISSN)

  • 0021-9738

Digital Object Identifier (DOI)

  • 10.1172/jci115220

Language

  • eng