Biochemical analysis of HLA-DP gene products by isoelectric focusing and comparison with cellular and molecular genetic typing results.
The polymorphism of HLA-DPA1 and HLA-DPB1 genes of 39 lymphoblastoid cell lines, representing 3 DPA1 and 14 DPB1 alleles, was studied after immunoprecipitation of DP molecules, subsequent isoelectric focusing (1D-IEF) and immunoblotting by a polyclonal DP antibody. Two 1D-IEF variants for DPA1 and 7 for DPB1 gene products were identified, including 2 new variants associated with the DPB1*1401 and DPB1*1901 alleles. The 1D-IEF polymorphism correlated clearly with molecular-genetic-defined alleles and primed lymphocyte or T cell line (PLT) specificities with exceptions observed in DUCAF (DPB1*0202) and ARBO (DPB1*0101). Both exceptional cases may reflect amino acid variations outside the hypervariable regions (HVRs) at the second exon of DPB1. The findings were supported by a comparison of HVR amino acid sequences with estimated net charges to the isoelectric points of the DPB1 molecules. 1D-IEF seems to be a valuable method for studying the expression of DPA1 and DPB1 alleles provided the molecules differ in their isoelectric points.
Rebmann
V
V
Institute of Immunology, University Hospital of Essen, Germany.
Kubens
B S
BS
Ferencik
S
S
Grosse-Wilde
H
H
D000595:Amino Acid Sequence; D015153:Blotting, Western; D005802:Genes, MHC Class II; D006682:HLA-DP Antigens / Q000737:chemistry* / Q000235:genetics; D006801:Humans; D007526:Isoelectric Point; D008969:Molecular Sequence Data
D006682:HLA-DP Antigens