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Flashcards in Transplant Immunology - Bailey Deck (42)
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1

In regards to transplants, what is the primary reason for morbidity and mortality?

Immune response

2

________ means transplanting cell or tissue to the same anatomical site.

Orthotopic

3

_______ means transplanting cell or tissue to a different anatomical site.

Heterotopic

4

______ means transfer of circulating cells.

transfusion

5

_____ is graft transplanted from one individual to the same individual.

Autologous graft

6

______ is graft transplanted between two genetically identical (or very similar) individuals.

Syngeneic graft

7

______ is graft transplanted between two genetically identical (or very similar) individuals.

Syngeneic graft (Twins or siblings)

8

_______ is graft between two genetically diverse individuals.

Allogeneic graft

9

Rejection of Graft is due to ________ mismatch.

MHC mismatch

10

How are T cells activated?

T cells recognize antigen that is presented to them in the context of MHC.

11

______ require antigen + MHC2 to be activated.

CD4+

12

______ require antigen + MHC1 to be activated.

CD8+

13

If a T cell has high avidity binding to self peptide and MHC, what happens?

Apoptosis of the T cell.
* this is how the body prevents the full development of auto reactive T cells.

14

Can Alloreactive T cells recognize Allogeneic MHC + Self Peptide?

Some can.

15

______ T cells will kill the target.

CD8+

16

____ T cells will produce cytokines to help propagate the immune response.

CD4+

17

What is direct Alloantigen recognition?

When T cells recognize allogeneic MHC directly

18

What is indirect Alloantigen recognition?

When APC is used to present antigen to T cell.

19

What are the 3 ways Allogeneic T cells lead to Graft Rejection?

1. Hyperacute rejection
2. Acute Rejection
3. Chronic Rejection

20

What is Hyper acute Rejection?

Characterized by thrombosis (Blood clot) formation that begins within minutes to hours and graft dies.
*Antibodies lead to activation of complement cascade.

21

What is Acute Reaction?

Alloreactive T cells become activated (after about a week) produce cytokines to:
1. Activate CD8+ T cells
2. Activate B cells to produce antibodies
3. Inflammation damages blood endothelial cells.
4. Inflammation leads to thrombosis (clot) formation.
5. Parenchymal cells can also be affected by CD8+ cells.

22

What is Chronic Rejection?

Grafts that survive for 6 months or more can eventually develop blood vessel thickening due to intimal smooth muscle formation.
*Growth factors induce intimal thickening

23

What ultimately leads to the death of a graft?

Loss of vascularization

24

What is the mechanism of action for Rapamycin?

Blocks lymphocyte proliferation by inhibiting IL-2 signaling.

25

What is the mechanism of action for Anti-CD3 monoclonal antibody?

depletes T cells by binding to CD3 and promoting phagocytosis or complement mediated lysis.

26

What is the Mechanism of action for Anti-IL-2 receptor?

Inhibits T cell proliferation by blocking IL-2 binding and depletes activated T cells that express CD25

27

What is the Mechanism of action for CTLA-4lg?

Inhibits T cell activation by blocking B7 costimulator binding to T cell.

28

_________ Is a treatment for hematological disease.

Bone marrow transplant.

29

What is one of the additional risks to bone marrow transplant?

Graft can attack the host. (Graft Versus Host disease)

30

_____ can produce IFN-gamma.

Natural killer cells