Tuesday 1 - Dirty D - Antigen presenting and processing Flashcards
CD 28
on what
binds what
starts production of waht
on mature naieve T cell
binds CD80,86 on apc
IL-2
CTLA-4-
related to and competes with CD 28. if it binds to CD80,86, T cell does not activate.
comes to peak expression on the surface of T cells in about 2-3 days post activation
prevents overstimulation, makes sure that you only get a quick burst of T cells.
what cells have to be induced to express CD80,86
macrophages and b cells
anergy
when t cells fail to recognize their specific antigen, they die
which cells constitutively express MHC II
immature dendritic - low levels
mature dendritic - high levels
macrophages - MUST BE ACTIVATED
B - cells constitutively expressed, but increases with activation
which cells constitutively express CD80,86
immature dendritic - low levels
mature dendritic - high levels
macrophages - must be activated
B cells - must be activated
TAP
heterodimer of TAP 1 and TAP 2
Transporter of Antigen Processing
proteins that are broken down by a proteosome attach to this – allows for transport of protein through the rough endoplasmic reticulum to bind with MHC class I
Expressed in the same locus as MHC genes!!
this was defective in the case study
ERAAP
trims off excess peptide once it is bound to MHC I
normal differential of CD4 to CD9 t cells
2:1 CD4:CD8
what happens if, by pure chance, you are homozygous from all of your HLA loci
You are more likely to have a defect in one of you HLA proteins DUH
what makes b cell immortal
EBV
describe the function of the invariant peptide chain with regards to MHC Class II
it binds to the binding site of the MHC class II molecule, gets some excess cut off and turns into a CLIP, is then exchanged with a surface antigen, and then the MHC molecule is displayed on the surface
what do non-classical MHC molecules do? two example names
take the clip off of the classical MHC molecule so that the surface antigen can bind
HLA-DO, HLA-DM
CD 40 where what
on T cells
binds CD40l on b cells for class switching
describe the process of cross presentation of exogenous antigen
once a dendritic cell shows its MHC class II to CD 4 t cells, the T cells tell the dendritic cell to display that same antigen on MHC I as well
