Studies On Prolonging The Life-time Of Cool Platelets By Glycosylation

Preservation of platelets at 4°C is one of the major obstacles in blood storage.Previous studies revealed that platelets transfused after refrigeration at 4°C are rapidlycleared from the circulation due to the expression of the clusters of glycoprotein(GP)I bαwhich trigger their phagocytosis by macrophages thus reduce their survival aftertransfusion.In this study, UDP-Gal was used to modigy the platelet for blocking theβ-N-GlcNAc residues of GP I bαand prevent the recognition by liver macrophages and prolong the circulation times of refrigerated platelets.The morphology, ultra-structure and function of the glycosylated platelets were detected by means of light microscope, electron microscope, flow cytometry, and so on. And the inhibitory effects of glycosylation on the phagocytosis of chilled platelets by differentiated THP-1 cells in vitro were also investigated.Animal models were established for evaluatin the survival of the glycosylated murine and human platelets after transfusion.The results showed that glycosylated platelet maintained their intact morphology,ultra-structure as well as the aggregation ability.We also demonstrated that enzymatic galactosylation inhibited the phagocytosis of chilled platelets by THP-1 cells and the rapid clearance of chilled platelets after transfusion into mice.These datas suggested that masking ofβ-N-GlcNAc residues by enzymatic galactosylation is a promising approach to storing platelets at 4°C without affecting platelet function.