ISSN:
1432-1211
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Abstract Two-dimensional (2D) gel electrophoresis of immunoprecipitated HLA-DR antigens from eight homozygous typing cells (HTC) expressing the HLA-DRw8 specificity revealed a clustering of polymorphic β chain patterns into distinct electrophoretic variants. The variant patterns correlate with three discrete HLA-D clusters that are defined in the mixed leukocyte culture reaction (MLR) using DRw8-positive HTC. These HLA-D clusters have been provisionally designated Dw“8.1”, detected primarily in Caucasoids, Dw“8.2”, detected primarily in American Indians, and Dw“8.3”, detected predominantly in Orientals. All three HLA-Dw“8.1” cell lines express a single DR-locus product as defined by immunoprecipitation with a DR-specific monoclonal antibody, P4.1. This DR β chain is identical among the Dw“8.1” cell lines and different from the DR β chains of the Dw“8.2” and Dw“8.3” cell lines. Two separate Dw“8.2” HTC express a shared DR β chain that is slightly more basic than the 8.1 DR molecule; interestingly, one of these lines also expresses an additional DR-like β chain not found in the other cells. Thus, the two lines defining the Dw“8.2” cluster share one distinct class 11 molecule, but differ in another and therefore are not biochemically HLA-identical. Cells from the Dw“8.3” cluster are likewise distinct from all other Dw8 clusters. One additional DRw8-positive HTC has been analyzed and found to be distinct from the Dw“8.1”, “8.2” and “8.3” clusters by both MLR and 2D gels. lmmunoprecipitates using monoclonal antibody 1B5 [anti-DR and anti-DQ(DS)] identify additional polymorphic class II variants among the cell lines tested. These data indicate that HLA-DRw8 is a public serologic specificity present on class II molecules expressed on multiple distinct haplotypes. These haplotypes differ from each other in expression of polymorphic class II molecules encoded by at least two HLA loci. They also differ in HLA-D, even though they all type as HLA-DRw8 homozygous. In Dw“8.2”, variation in expressed β chains is not reflected in variation in HLA-D, indicating that MLR, as well as serologic typing, does not detect the full degree of allelic polymorphism within HLA.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00372241
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