7. 第一节 同种异体器官移植排斥的机制(Chapter 1 Mechanism of allograft rejection)
8. Target antigens of allograft rejectionMajor histocompatibility antigens(MHC)
Minor histocompatibility antigens
Other target antigens in allograft rejection:
Human ABO blood group antigen
tissue specific antigen
13. Mechanisms in alloantigen recognition of T cellsDirect recognition
Indirect reconition
14. 二、T细胞识别同种抗原的机制(一)直接识别
(二)间接识别
15. Direct recognitionAlloreactive T cells of recipient directly recognize peptide-allo-MHC complex on donor’s APC surface and generate immune response.
The principal mechanism of acute rejection in the early period of transplantation.
19. Indirect recognitionCast-off cells or MHC antigen from the donor’s graft are captured and processed by recipient’s MHC to form peptide-donor’s MHC complexes which are presented to recipient’s T cells for recognition and activation.
The principal mechanism of acute rejection in the late period of transplantation and chronic rejection.
30. Allograft rejectionAfter transplantation, recipient’s immune system recognize graft antigen and generate immune response. On the other hand, the immune cells in graft recognize tissue antigens and generate immune response. The former is called host versus graft Reaction, the latter is called graft versus host Reaction.
34. Host versus graft ReactionHyperacute rejection
Acute rejection
Chronic rejection
The host immune system launch attack on the graft and result in rejection of the graft.
36. Hyperacute rejectionDefinition: Rejection after transplanted organ cut-in recipient’s blood vessels for only several minutes to 24 hours. It is seen in repeated transfusion, multiple pregnancy, long-term hemodialysis and retransplantation individuals.
Reason: There are antibodies against donor’s tissue antigen pre-exist in recipient.
39. Acute rejectionDefinition: It is the most frequentrejection in allogenic organ transplantation. It occur after transplantation for about several days to 2 weeks.
Mechanism: cell mediated immunologic rejection play major roles.
42. Chronic rejectionIt occur after transplantation for several weeks, or several months even several years. It’s process is similar to chronic nephritis. The normal kidney tissue disappear gradually and renal function decrease progressively even lost completely.
Mechanism: Relate to damage and hyperplasia of blood vessel endothelium in transplanted organs.
45. Graft versus host Reaction, GVHRDefinition: Antigen specific lymphocyte in the graft recognize the recipient’s tissue antigen and result in rejection.