Therapeutics and Immunology: Lecture 5: Transplantation and immunosuppression

Question 1

How does transplanted rejection occur

Answer 1

Transplanted organ has different T cell antigen profile

Each individual has dramatically different major histamine tissue complex (MHC) which leads to allorecognition (activation of CD8 and CD4 lymphocytes in body)

Defends itself against foreign antigens

Question 2

What is the role of MHC complex

Answer 2

Presents peptides to T lymphocytes

T lymphocyte can recognise abnormal MHC and attack them

Question 3

Give some examples of mechanisms of rejection

Answer 3

Type 2 hypersensitivity:
Antibody mediated cell killing
T cell mediated cell killing

Type 4 hypersensitivity:
T cell mediated inflammation

Question 4

What is allorecognition

Answer 4

The random activation of up to 10% or more of all CD8 and CD4 lymphocytes in the body

Question 5

What are the interventions that can be done for transplantation

Answer 5

Remove antigens and find perfect MHC match from donor/recipient (identical twin)

Question 6

What are the two MHC types and how many total MHC genes are there

Answer 6

3 x MHC 1 (x2)

4 x MHC 2 (x2)

14 MHC genes altogether

Question 7

Give the three examples of inhibitors of the adaptive immune system and their roles

Answer 7

Anti-proliferative drugs: METHOTREXATE and AZATHIOPRINE

Inhibitors of Lymphocyte signalling: CYCLOSPORIN (calcineurin inhibitors) and Tacrolimus

Biologic inhibitors of lymphocyte signalling: Abatacept

Question 8

Give examples of opportunistic infections that kill aids patients

Answer 8

Oral Thrush - candida fungal infection

Mycobacterium tuberculosis- latent infection

Shingles- VZV

Herpes

Pneumonia

Cancer infections
Karposi’s sarcoma
B cell lymphoma