Cytotoxic T Lymphocytes Flashcards
1
Q
What activates CD8+ cells?
A
MHC I
2
Q
What costimulatory ligands are needed?
A
CD28 on CTLs binds to B7.1/B7.2 but not mature CD8s
3
Q
What causes the immunological synapse?
A
ICAM1 and leukocyte function associated antigen 1
4
Q
What do granules contain?
A
Perforin and Granzymes
5
Q
What does perforin do?
A
Polymerases 16nm diatameter holes in cell membrane. Water and ions flow out and granzymes can enter.
6
Q
What granzymes do CTLs release?
A
A, B H and K.
7
Q
What do granzymes do?
A
Proteolytic and apoptotoic
8
Q
How do granzymes induce apoptosis?
A
Granzyme B converts BID to tBID which causes mitochondrial memdisruption and DNA fragmentation
9
Q
What 3 cytokines do CTLs release?
A
IFN-gamma, TNF alpha and beta
