MHC structure and diversity

Question 1

What prompted MHC discovery?

Answer 1

Transplant rejection

Question 2

MHC mechanism

Answer 2

Epitopes recognised by T cell receptors are often buries; antigen must be broken down into fragments
Epitope peptide binds to MHC molecule; T cell receptor binds to MHC-epitope complex

Question 3

HLA genes

Answer 3

Found on human chromosome 6 and often referred to as MHC gene locus
Polygenic
Highly polymorphic

Question 4

Why do we have the MHC system?

Answer 4

VIRUSES

Question 5

MHC restriction

Answer 5

CD8+ cells induced by a virus infection w a mouse from MHC genotype A would recognise and kill MHC A +ve infected cell but not those of MHC B infected with the same virus, or the MHC A with a different virus

Question 6

Altered self model

Answer 6

Assumes one T cell receptor recognised the MHC molecule to have been modified by the virus.

Question 7

Role of the MHC

Answer 7

To present pathogen proteins to the immune system