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Flashcards in 13 MHC and transplantation Deck (10):
1

How many MHC molecules are there on the average mammalian cell?

50-100,000

2

Where on the chromosome is the HLA complex?

6p21.3

3

The HLA complex has three regions, which antigens does each encode?

1: HLA-A/ B/ C
2: HLA-DR/ DQ/ DP
3: HSP70, TNF, C4A, C4B, C2, BF, CYP21

4

The two classes of antigens are found on different cells, which is where?

1: all nucleated cells
2: B lymphocytes (may be induced on T lymphocytes)

5

The two classes of antigens have different structures - distinguish between them.

1: 45kd heavy chain and B2 microblobulin
2: 31kd a chain and 26kd B chain

6

How is the HLA complex inherited?

En-bloc from each parental chromosome. Codominant expression - all inherited antigens are displayed (HLA phenotype).

7

What is the difference between direct and indirect MHC recognition?

Direct: white blood cells from donor present directly to recipient T cells.
Indirect: foreign proteins are broken down and presented to T cells by MHCII of self APC's

8

What is sensitisation? Name three examples.

Any event which elicits an HLA directed immune response.
Pregnancy, blood transfusion, transplantation.

9

How are the chances of an organ transplant determined by immunologically?

Blood group.
HLA type.
Sensitisation.

10

What is hyper-acute rejection of an organ transplant?

Activation of the clotting cascade and complement system leading to loss of vascular integrity and DIC. Results in death.

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