Generation and characterization of genetically modified pigs with GGTA1/β4GalNT2/CMAH knockout and human CD55/CD47 expression for xenotransfusion studies.

Pig red blood cells (pRBCs) represent a promising alternative to address the shortage in transfusion medicine. Nonetheless, a major obstacle to their clinical implementation is immunological rejection. In this study, we generated transgenic pigs expressing human CD47 (hCD47) and CD55 (hCD55) in α1,3-galactosyltransferase KO/β-1,4-N-acetyl-galactosaminyl transferase 2 KO/cytidine monophosphate-N-acetylneuraminic acid hydroxylase KO (TKO) pigs using CRISPR/Cas9 technology. Compared to wild-type pRBCs, TKO/hCD47/hCD55 pRBCs exhibit significantly reduced human IgG/IgM antibody binding. Moreover, when transfused into Cynomolgus monkeys, TKO/hCD47/hCD55 pRBCs remained detectable for 2 h post-transfusion, whereas wild-type pRBCs were eliminated within 20 min. This study demonstrates the potential of multi-gene edited pigs to provide immunologically compatible pRBCs.