[Recent advances in xenotransplantation].
Interest in xenotransplantation has dramatically increased in the past 4 years, focusing on the potential use as donors of distantly related animals such as pigs (discordant xenografts). The major barrier is hyperacute rejection. The mechanisms responsible for this rejection include: specific reaction of the recipient's natural antibodies with antigens in the donor's organ, direct activation of the recipient's complement system by endothelial cells in the donor's organ, and/or relative failure of complement inhibitory proteins in the donor's organ to impede activation of the recipient's complement system. In case of vascularized xenograft, the temporary depletion of anti-donor antibodies (anti-ABH or anti-HLA class I) from a graft recipient may allow the long term survival of the graft despite a possible return of the antibodies to the circulation. This phenomenon is called accommodation. The mechanisms involved could be: the endothelial cells in a graft develop a resistance to complement mediated injury; the antigens expressed on the blood vessels become modulated or changed; the natural antibody repertoire changes in such a way that there are fewer anti-donor antibodies. The accommodation phenomenon encourages the view that the barrier to xenotransplantation is not immutable.
Jeffrey
L
L
Platt
M D
MD
D003179:Complement C3b / Q000276:immunology; D003165:Complement System Proteins / Q000276:immunology*; D004727:Endothelium / Q000276:immunology / Q000502:physiology; D006084:Graft Rejection / Q000276:immunology*; D006801:Humans; D014183:Transplantation, Heterologous / Q000379:methods*
D003179:Complement C3b; D003165:Complement System Proteins
Progrès récents en xénotransplantation.