THE IMMUNOLOGICAL BARRIERS TO XENOTRANSPLANTATION

There is an increasing interest in the potential clinical application of xenotransplantation. This interest derives in part from the need to identify a more abundant source of organs for transplantation and in part from rapid progress in understanding the cellular and molecular c hanges that contribute to hyperacute and acute vascular xenograft reje ction. Recent areas of progress in understanding the immunological hur dles to xenotransplantation include the characterization of xenoreacti ve antibodies and the antigens they recognize, the role of complement regulatory proteins in immune recognition, the mechanism of complement activation in a xenograft, and the pathophysiologic changes in endoth elial cells caused by the activation of complement.