Reactions to Porcine Cells With or Without β4GalNT2

β-1,4-acetyl-galactosaminyltransferase 2 (β4GalNT2)-knockout (KO) pigs have been produced and reveal less antigenicity to both humans and nonhuman primates (NHP). In this study, we checked the antibody response of human and NHP sera to pig cells with or without this gene. The β4GalNT2-KO porcine endothelial cell (PEC), clone #11, was first established using the plasmid pX330 expressing hCas9 and sgRNA for β4GalNT2. The glycoantigen feature on the PEC was then studied. The Sd^a antigen, synthesized by β4GalNT2, was slightly ascertained on wild-type (WT)-PEC, and it became null in clone #11. The PEC response to lectins was also assessed, such as Dolichos biflorus agglutinin, soybean agglutinin, and Wisteria floribunda agglutinin. All of these lectins reduced the binding reaction to clone #11 as compared with WT-PEC. Next, several human and cynomolgus sera were checked for their natural antibody reaction to both WT-PEC and clone #11. In addition, human monocyte-mediated PEC phagocytosis was assessed. However, the reduction in phagocytosis to clone #11 was not significant. Human sera showed less reactivity to the changes in antigenicity of PEC by knocking out the β4GalNT2 than cynomolgus sera.