Identification of FAM234A as a novel non-Gal antigen in xenotransplantation

  Objective   To investigate whether FAM234A is a novel non-Gal antigen in xenotransplantation.

  Methods  Cynomolgus monkeys were immunized with primary porcine aorta endothelial cells (PAEC) from α-1, 3-galactosyltransferase gene-knockout (GTKO) minipigs.The serum samples of immunized monkeys were incubated with PAEC.After immunization, the monkey anti-pig cell antibodies were able to recognize and bind with the unknown antigens on the PAEC surface.Flow cytometry was adopted to determine the mean fluorescence intensity (MFI) of monkey anti-pig cell antibodies binding with the PAEC surface to characterize the content of PAEC surface antigen.Lentivirus-mediated short hairpin ribonucleic acid (shRNA) was utilized to knock down the FAM234A gene in PAEC to detect whether the content of the cell-bound monkey anti-pig cell antibody was reduced and determine if this gene was a potential transplant antigen.

  Results  The non-Gal antigen in PAEC could trigger a large quantity of monkey anti-pig cell antibodies in monkeys.After knock down of the FAM234A gene with shRNA in the PAEC of the GTKO miniature pigs, the monkey IgG antibody binding with PAEC was declined.

  Conclusions   FAM234A is a novel non-Gal antigen in xenotransplantation.