| Popis: |
Xenotransplantation of porcine organs to untreated primates results in hyperacute rejection involving natural antibodies and complement. These antibodies rapidly interact with the vascular endothelium of discordant xenograft, activate the complement, and cause destruction of the vascular endothelium. The present study investigated the efficacy of two modalities to overcome the above barrier. The study was carried out on non-treated porcine hepatocytes, UV-B treated hepatocytes, and encapsulated hepatocytes which were incubated with normal human AB serum and complement-inactivated serum. Antibodymediated cytotoxicity to porcine hepatocytes was assessed by MTT (tetrazolium) assay. Complement inactivation of normal human AB serum resulted in significantly less cell lysis in comparison with normal human serum. Non-irradiated and UV-B irradiated hepatocytes did not show any difference, indicating that surface-antigenic epitopes are not altered by UV-B irradiation. Microencapsulation of hepatocytes in alginate poly-L-lysine capsules, however, provided protection against antibody-mediated cell lysis, suggesting that this immunoisolation technique may be useful in xenotransplantation. |
