Identification of potential platelet alloantigens in the Equidae family by comparison of gene sequences encoding major platelet membrane glycoproteins

Authors

  • Mary K. Boudreaux,

    Corresponding author
    1. Department of Pathobiology, College of Veterinary Medicine, Auburn University, Auburn, AL, USA
    • Correspondence

      Dr. Mary K. Boudreaux, Department of Pathobiology, 166 Greene Hall, College of Veterinary Medicine, Auburn University, Auburn, AL 36849-5519, USA

      E-mail: boudrmk@auburn.edu

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  • Drew M. Humphries

    1. Department of Pathobiology, College of Veterinary Medicine, Auburn University, Auburn, AL, USA
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Abstract

Background

Platelet alloantigens in horses may play an important role in the development of neonatal alloimmune thrombocytopenia (NAIT).

Objective

The objective of this study was to evaluate genes encoding major platelet glycoproteins within the Equidae family in an effort to identify potential alloantigens.

Methods

DNA was isolated from blood samples obtained from Equidae family members, including a Holsteiner-Oldenburg cross, a Quarter horse, a donkey, and a Plains zebra (Equus burchelli). Gene sequences encoding equine platelet membrane glycoproteins IIb, IIIa (integrin subunits αIIb and β3), Ia (integrin subunit α2), and Ibα were determined using PCR. Gene sequences were compared to the equine genome available on GenBank. Polymorphisms that would be predicted to result in amino acid changes on platelet surfaces were documented and compared with known alloantigenic sites documented on human platelets.

Results

Amino acid differences were predicted based on nucleotide sequences for all 4 genes. Nine differences were documented for αIIb, 5 differences were documented for β3, 7 differences were documented for α2, and 16 differences were documented for Ibα outside the macroglycopeptide region.

Conclusions

This study represents the first effort at identifying potential platelet alloantigens in members of the Equidae Family based on evaluation of gene sequences. The data obtained form the groundwork for identifying potential platelet alloantigens involved in transfusion reactions and neonatal alloimmune thrombocytopenia (NAIT). More work is required to determine whether the predicted amino acid differences documented in this study play a role in alloimmunity, and whether other polymorphisms not detected in this study are present that may result in alloimmunity.

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