Xenogeneic and Allogenic Cellular Rejection (CR)

In solid organ xenotransplantation, the humoral response of human immunity is a direct barrier due to its Abs binding to non-self-antigens of carbohydrates and proteins present in the pig vasculatures [1, 2]. During the last three decades, for the long-term solid organ survivals in xenotransplantation, vascular endothelial cells have been studied as a target for xenograft recipient immune system and grafted microvasculature has been received a great attention [3]. When antigenic deletion of α1,3Gal epitopes pigs prevents HR in recipients, instead DXR or cellular rejection (CR) becomes a secondary and major immune response as a huge barrier in xenotransplantation. To date in the xenotransplantation, the experimental and clinical evidence and process that systemic responses of host immune system cause the failure of xenotransplantation of pig xenografts in primates have largely been understood and explained. The mostly important barrier and hurdle in pig-to-human clinical xenotransplantation still remain immune-rejective response despite the animal development with the disrupted carbohydrate antigens.