Sialylation and fucosylation changes of cytidine monophosphate-Nacetylneuraminic acid hydroxylase (CMAH) and glycoprotein, alpha1,3-galactosyltransferase(GGTA1) knockout pig erythrocyte membranes

The recent GGTA1 and CMAH DKO pigs have made it possible to resolve the immune barriers which are duo to xenoantigens on RBC such as Gal and Neu5Gc. Nevertheless, it still requires the detection of glycosylation alternation on the pig RBCs because even the minor changes would be unexpected xenoantigens. DKO RBC immune reactivity with human serum was assessed by hemagglutination assay. Glycosylation alteration of RBC membranes was characterized by NanoLC-Q-TOF-MS system and lectin blotting assay. Twelve GGTA1/CMAH DKO piglets were successfully produced. The immunoreactivity with human serum was remarkably reduced in DKO (less than 1:2 dilution), whereas wild type(WT) pigs showed agglutination (the least 1:256 dilution). The MS results showed that DKO increased neutral N-glycans as well as decreased total sialylated N-glycans, especially suggesting significant decrease of di-sialylated N-glycans (P < 0.05). Moreover, lectin blotting assay revealed that DKO pigs reduced the binding signals with AAL, AOL, LCA and SNA and increased the binding signal with MAL. DKO pigs decreased the expression of total fucosylation and sialylated N-glycans on the erythrocyte membrane. Our findings will support further investigation into DKO pig RBC glycosylation and contribute to uncover the roles of glycan changes for xenotransfusion. Summary statementTo detect glycosylation changes in red blood cells(RBC) of GGTA1/CMAH double knockout(DKO) pigs, comparative analysis of the glycan profiling was done.