Glycosylation Restores Survival of Chilled Blood Platelets

Abstract

Cooling of blood platelets clusters the von Willebrand factor receptor complex. Macrophage α M β 2 integrins bind to the GPIbα subunit of the clustered complex, resulting in rapid clearance of transfused, cooled platelets. This precludes refrigeration of platelets for transfusion, but the current practice of room temperature storage has major drawbacks. We document that α M β 2 is a lectin that recognizes exposed β- N -acetylglucosamine residues of N-linked glycans on GPIbα. Enzymatic galactosylation of chilled platelets blocks α M β 2 recognition, prolonging the circulation of functional cooled platelets. Platelet-associated galactosyltransferase produces efficient galactosylation when uridine diphosphate–galactose is added, affording a potentially simple method for storing platelets in the cold.