Lecture 16 - Antigen processing

Question 1

What are professional APC’s? what do they do?

Answer 1

• express MHC class 2 molecules
• dendritic cells, macrophages, and B cells
• they are able to convert a naive T cell into a effector T cell through antigen presentation
• note professional APC’s provide some stimuli sent into the T cells they interact with

Question 2

what is the order of best to worst professional APC’s an why?

Answer 2

1. Dendritic cells = best. This is b/c they constitutively express MHC 2 and the co-factor B7
2. B cells –> constitutively express MHC 2 but needs to be activated for B7
3. macrophages –> needs activation for both

Question 3

what does a slow off rate mean for a peptide?

Answer 3

this would be a high affinity peptide that binds its MHC molecule tightly. Slow off-rates increase the likelihood of a T cell interaction.