Innate Immunity: Phagocytosis and Atg Presentation

Question 1

MHC proteins expressed from MHC genes

Answer 1

HLA- human leucocyte Atg
FLA- feline 
SLA- sus
ELA- equine 
BoLA -bo

Question 2

MHC polymorphism: number of inherited MHC genes - e.g for MHCI

Answer 2

Rat >60
Mouse ~ 30
Human ~20
Pig- 6
Cheetah- 1

One out of 60 selects 6- there is an MHC that can bind to the antigen– there is always a survivor

Question 3

MHC polymorphism

Answer 3

The genes are inherited in blocks
There can be a high level of polymorphism within a population (if large colonies)

Gene block exchange
High mutation rate 
Recombination
Mating preferences 
Crossing over 
Selective abortion

Question 4

Differences between MHCI, MHCII and CD1d

Answer 4

MHCI:

• CD8+ T-cell
• Has a diverse TCR
• bind e.g peptide on the APC

MHCII:

• CD4+ T-cell
• Has a diverse TCR
• bind e.g peptide on the APC

CD1d:

• NKTcell
• semi-invariant TCR! Valpha14 or Jalpha8
• binds e.g glycolipid on the APC