Lecture 14. Major Histocompatability Comple (MHC) Molecules

Question 1

What are the two types of MHC molecule ?

Answer 1

1. Human leucocyte class I antigens
2. Human leucocyte class II antigens

Question 2

What are MHC molecules coded for by ?

Answer 2

Genes in the MHC complex on chromosome 6 in humans

Question 3

What are the two main functions of MHC molecules ?

Answer 3

1. Present peptides
2. Restrict T lymphocytes

Question 4

When does transplant rejection not occur ?

Answer 4

If its autologous

Question 5

When does transplant rejection happen ?

Answer 5

Allogenic

Question 6

What is meant by congenic ?

Answer 6

Identical except for the genes that code for rejection

Question 7

What do all nucleated cells produce ?

Answer 7

Class I MHC

Question 8

Where are class II MHC restricted to ?

Answer 8

Antigen presenting cells

Question 9

What can nucleated cells become ?

Answer 9

Cancerous

Question 10

What is the immunoglobulin domain ?

Answer 10

Beta sheets held together by two disulphide bonds

Question 11

What is essential for class I ?

Answer 11

B2m

Question 12

What is the structure of an alpha helix in a class I MHC ?

Answer 12

Ends are close

Question 13

What is the structure of a class II alpha helix ?

Answer 13

The ends are open

Question 14

What is meant by hypervariable ?

Answer 14

Lots of mutation resulting in different amino acids

Question 15

What sort of MHC does complement have ?

Answer 15

Class III

Question 16

What is the structure of MHC II molecule ?

Answer 16

1. alpha one
2. alpha two
3. beta one
4. beta two
5. peptide binding groove

Question 17

What do MHC class II binding peptides bind into ?

Answer 17

A beta sheet

Question 18

Where are dendritic cells found ?

Answer 18

Anywhere there are macrophages

Question 19

Where does MHC I present to ?

Answer 19

CD8+ T-cells

Question 20

What is the structure of HC I ?

Answer 20

Alpha chain with three domains, non covalently associated beta-2 microglobulin

Question 21

What forms the peptide binding groove that is recognised by TCR ?

Answer 21

Alpha one and alpha two

Question 22

What does alpha three do in MHC I ?

Answer 22

Binds CD8 Co-receptor

Question 23

How would you describe the process of class I antigen processing and presentation ?

Answer 23

Endogenous

Question 24

What does MHC I bind ?

Answer 24

Short peptides (8-10 amino acids long)

Question 25

What is binding of the peptide stabilised by ?

Answer 25

Contacts between atoms at carboxy and amino terminal ends of peptide and invariant sites on end of MHC I peptide binding groove

Question 26

What is the story with each MHC I binding ?

Answer 26

Binds many different peptides byt with common anchor residues