Adaptive Immunity 3 Flashcards
Which are the antigen presenting cells?
Dendritic cells
Macrophages
B cells
Endogenous antigens are presented on which class molecules?
class 1 MHC to CD8 T cells
Exogenous antigens are presented where?
On Class 2 MHC molecules to CD4 T cells
Peptides produced in cytoplasm are transported into Endoplasmic reticulum
TAP
TAP pump preferentially transports proteins of how many amino acids?
8 -15
How to interfere with immune system to avoid killing?
Herpes simplex virus protein ICP47 can selectively bind to TAP and inhibit the transfer of peptides into ER
How are endosomal protease activated?
Acidification of vesicles
Where are MHC 2 a and b class molecules produced?
Golgi
Where are MHC class 2 molecules loaded into vesicles?
Trans golgi
Why does MHC 2 not bind to self peptide?
MHC class 2 are bound to invariant chain
In vesicles invariant is cleaved leaving clip fragment. It blocks binding of peptides to MHC 2 in vesicles.
HLA DM facilitates release of CLIP allowing peptide to bind
Adenovirus interferes with?
Class 2 upregulation in APCS
How does HSV evade?
Viral protein envelope, glycoproteins B reduces MHC class processing and inhibits production of invariant chain peptide
HIV interferes with?
Class 2 processing
Which pathogens evade lysosomes?
Leishmania and mycobacterium (tuberculosis) prevent phagosome- lysosome fusion
Control of loading happens through accessory proteins?
Class 1- TAP, tapasin
Class 2- require low pH to remove invariant chain
