Platelet adhesion to decorin but not collagen I correlates with the integrin ?2 dimorphism E534K, the basis of the human platelet alloantigen (HPA)-5 system.

ABSTRACT: A single nucleotide polymorphism in the integrin ?2 gene ITGA2 (rs1801106; G1600A) creates the non-conservative amino acid substitution E534K, the basis of the human platelet alloantigen system HPA-5. Yet HPA-5 alleles do not influence binding of ?2?1 to its primary ligand collagen I, and the effect of HPA-5 on platelet function has not been determined. We used a direct platelet adhesion assay to evaluate whether differential inheritance of HPA-5 alleles influences platelet adhesion to collagen I or an alternative ligand, decorin. Platelets from donors bearing one or more minor allele HPA-5b showed attenuated adhesion to purified decorin but not collagen I. Adhesion to decorin was significantly inhibited by human alloantibodies specific for HPA-5a but not by the collagen I sequence GFOGER or ?2-specific inhibitory monoclonal antibodies. The minor allele 534K attenuates platelet adhesion to decorin but not collagen I, providing the first evidence of a functional effect of HPA-5 alleles.

SUBMITTER: Kunicki TJ 

PROVIDER: S-EPMC3342970 | biostudies-literature | 2012 May

REPOSITORIES: biostudies-literature