医学免疫学资料chapter22transplantationimmunology

Chapter 22 Transplantation Immunology Part I Introduction； Part II Immunology of allogeneic transplantation PartHI ClassiHcation and effector mechanisms of allograft rejection； PartIV Prevention and treatment of allograft rejection Part V Exnogtransplantaion Part I Introduction Transplantation the process of taking cells, tissues, or organs from one individual and placing them into a different individual or different site of the same individual. Graft transplanted cells, tissues, or organs； Donor the individual who provides the graft. Recipient the individual who receives the graft. Also called the host. Alexis Carrel reported the first systematic study of transplantation in 1908; he interchanged both kidneys in a series of nine cats. Some of those receiving kidneys from other cats maintained urinary output for up to 25 days. The first human kidney transplant, attempted in 1935 by a Russian surgeon, failed because there was a mismatch of blood types between donor and recipient. This incompatibility caused almost immediate rejection of the kidney, and the patient died without establishing renal function. The first successful human kidney transplant, which was between identical twins, was accomplished in Boston in 1954. Today, kidney, pancreas, heart, lung, liver, bone-marrow, and cornea transplantations are pered among nonidentical individuals with ever increasing frequency and success. Autologous graft Autograft A graft transplanted from one site to another site in the same individual. Syngeneic graft Isograft A graft transplanted between two genetically identical or syngeneic individuals. Allogeneic graft Allograft A graft transplanted between two genetically different individuals of the same species. Xenogeneic graft Xenograft A graft transplanted between individuals of different species. The most idable barrier is the immune system； Allograft Rejection Displays Specificity and Memory. Part II Immunology of allogeneic transplantation Transplantation antigens； Mechanism of allograft rejection 1. Transplantation antigens Major histocompatibility antigens MHC molecules； Minor histocompatibility antigens ABO Blood group antigens and tissue specific antigens 2. Mechanism of allograft rejection The immune responses in allogeneic transplantation T cell mediated rejection of allograft； Antibody mediated rejection of allograft NK cell mediated rejection of allograft T cell mediated rejection of allograft mechanism of cellular immunity Recognition of alloantigens Direct recognition； Indirect recognition Activation of T cells and rejection of allograft ① Direct recognition of alloantigens Recognition of an intact MHC molecule displayed by donor APC in the graft. An allogeneic MHC molecule with a bound peptide can mimic the determinant ed by a self MHC molecule plus peptide. Direct recognition is a cross-reaction of a normal TCR, which was sel