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Transplantation of Tissues and Organs

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Presentation on theme: "Transplantation of Tissues and Organs"— Presentation transcript:

1 Transplantation of Tissues and Organs
Chapter 15 Transplantation of Tissues and Organs Immune response against grafted cells, tissues, or organs

2 Lymphocyte activation
Signal 1-3 Lymphocyte activation Innate immunity Effector response

3

4 The transplant patient is already inflamed before transplantation
Donation program Safety Living healthy donors Donated organ may also be inflamed Ischemia 局部缺血

5 Donor

6 Major histocompatibility complex (MHC)
Identity of transplantation antigens Major histocompatibility complex (MHC) MHC Ag Class I Class II Autograft Isograft Allograft Xenograft

7 Identity of transplantation antigens Erythrocyte Ag : ABO, Rh, etc.
Blood transfusion Erythrocyte Ag : ABO, Rh, etc. 15.3 A RHD- The most widespread kind of transplantation in clinical medicine

8 Type of immune response in rejection of solid organs
Hyperacute rejection (within 24h) Acute rejection (first few weeks) Chronic rejection (months - years)

9 Hyperacute rejection Pre-existing Ab e.g. Anti-MHC, A/B/O ABO/MHCI Ag
C’, blood clotting Immediate graft death

10 Source of pre-existing antibody
Repeated blood transfusions Repeated pregnancies Previous graft Sensitization Panel reactive antibody (PRA) A representative HLA panel of individuals from the population The higher the PRA value , the more difficult to find a suitable transplant donor 15.5

11 The prevention of hyperacute rejection
Blood typing Cross-matching test 移植前 Serum D Ab

12 Cell-mediated immunity (CMI)
Acute rejection (first few weeks) Cell-mediated immunity (CMI) Th1 response Macrophages (Type IV hypersensitivity) CTLs Cross reactivity MHC polymorphism Allogeneic T cells The frequency of T cells specific for any non-self MHC molecules is relatively high

13 Affinity Cross reactivity High frequency of allogeneic T cells
Self Cross reactivity High affinity to non-self MHC Ag

14 Acute rejection Anti-CD3 Donor DC 15.9

15 In vitro mixed lymphocyte reaction (MLR)
15.10 T: recipient APC: donor

16 The prevention of acute rejection Tissue typing of HLA-I/II
Blood typing Tissue typing of HLA-I/II Serological typing DNA analysis Immunosuppressive agents

17 15.14

18 Immunosuppressive agents
Steroids 15.17

19 15.18

20 Killing of proliferating cells
Immunosuppressive agents Cytotoxic drugs Killing of proliferating cells Pro-drug 15.25 Side effect: liver, kidney, etc

21 Inhibition of T-cell activation
Immunosuppressive agents Cyclosporin A (CsA) Tacrolimus (FK506) Inhibition of T-cell activation 15.19 Anti-T antibody

22 mTOR: mammalian target of rapamycin Activated by associated proteins
Reduce T-cell proliferation G1 phase arrest Promote apoptosis Increase Treg number Kinase Activated by associated proteins

23 Increase the risk of cancer and infection
Immunosuppressive agents Increase the risk of cancer and infection

24 Chronic rejection (months - years) FcR Antibody against HLA-I:
Infiltration of CD40 B cells and CD40L TH cells

25 Chronic rejection (months - years) Antibody against HLA-I:
Infiltration of CD40 B cells and CD40L TH cells Fig

26 Major type of Ag presentation in transplantation rejection
Chronic rejection Dead cells Acute rejection 15.12

27 Minor histocompatibility Ag
HLA matching Minor histocompatibility Ag Male Ag 15.40

28 Transplantation that not requiring tissue typing of HLA-I/II
No immunosuppressive therapy 15.29 Liver

29 Bone marrow transplantation
Genetic diseases of blood cells Cancer therapy Intravenous infusion Chemotherapy Repopulation Reconstitution of the patient’s immune system and also their red cells and platelets

30 Genetic diseases of blood cells
15.32

31 15.34

32 移植相容性 Genetics of MHC 遺傳

33 移植 相容性 Transplantation

34 HLA-haploidentical family members

35 T cells : thymus MHC restriction
Positive selection

36 MHCa MHCaxb Hematopoiesis MHCb APC MHCa MHCaxb MHCb

37 Thymic non-lymphoid stroma: MHC restriction Bone marrow-derived APC
Bone marrow chimera Blood type Thymic non-lymphoid stroma: MHC restriction Bone marrow-derived APC The more HLA allotypes they share, the better it works

38 Colonization of HSC in the bone of recipient
Engraftment: Colonization of HSC in the bone of recipient Myeloablative therapy Enrichment Niche Fig. 1.13

39 Stringent T-cell depletion
15.35 Stringent T-cell depletion

40 Activation of allogeneic T cells
膽紅素 15.36 Tissue inflammation Cytokine storm Acute GVHD: First few months Activation of allogeneic T cells

41 Graft-versus-leukemia effect
Graft-versus-tumor effect

42 graft-specific tolerance
Hematopoietic cell transplantation can induce tolerance to solid organ transplants Induction of graft-specific tolerance 15.44

43 A non-immunogenic tissue barrier An immune privileged site
Fetus Natural allograft A non-immunogenic tissue barrier An immune privileged site


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