Glycosylation Restores Survival of Chilled Blood Platelets

Karin M. Hoffmeister,1* Emma C. Josefsson,1,2 Natasha A. Isaac,1 Henrik Clausen,3,4 John H. Hartwig,1 Thomas P. Stossel1

Cooling of blood platelets clusters the von Willebrand factor receptor complex. Macrophage Mß2 integrins bind to the GPIb 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 Mß2 is a lectin that recognizes exposed ß-N-acetylglucosamine residues of N-linked glycans on GPIb. Enzymatic galactosylation of chilled platelets blocks Mß2 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.

1 Division of Hematology, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA. 2 Department of Rheumatology and Inflammation Research, University of Gothenburg, Gothenburg, Sweden. 3 Department of Oral Diagnostics, University of Copenhagen, School of Dentistry, Copenhagen, Denmark. 4 Zymequest, Inc., Beverly, MA 01915, U.S.A.

* To whom correspondence should be addressed. E-mail: khoffmeister@rics.bwh.harvard.edu