T cell activation Flashcards

immunology 3 (52 cards)

1
Q

catabolism of protein to peptides inside a host cell, some peptides bind to MHC molecules

A

processing

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2
Q

peptide + MHC on surface of host cell interacts with TCR

A

presenting

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3
Q

pathogens- harmless antigens are taken up by specialized APC

A

exogenous antigens

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4
Q

come from inside a host cell, generally result from an infection

A

endogenous antigens

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5
Q

difference btw. exo/endo -genous antigens

A

different MHC interactions

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6
Q

MHC II pathway were antigen is taken up by acid vesicles and borken down to peptides

A

exogenous antigen

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7
Q

newly synthesized MHC, from ER to golgi will intersect with the acid vesicle forming a

A

MHC II molecule

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8
Q

antigen is catabolized in cytoplasm where peptides will be transported to the ER and associate with MHC I

A

endogenous pathway

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9
Q

peptides to MHC I are generally _____ long

A

8-9

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10
Q

MHC II peptides are generally _______ long

A

20-22

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11
Q

influences the interaction between peptides and MHC class

A

gamma

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12
Q

processed peptides will contain different properties leading to

A

peptide binding to MHC is selective

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13
Q

one HLA groove

A

per molecule

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14
Q

many peptides can bind to MHC?

A

yes, but only one at a time

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15
Q

some HLA alleles are associated with autoimmune syndromes leading us to theorize that

A

certain pathological tendencies are a result from theses interactions

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16
Q

antigen specific interaction, necessary but not sufficient

A

signal 1

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17
Q

not antigen specific, invoked by co-stimulating pairs one on host and one on T cell

A

signal 2

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18
Q

Costimulator Host:

B7

A

CD28

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19
Q

Costimulator Host:

CD40

A

CD40 ligand

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20
Q

key APC for the activation of naive T cells

A

Dendritic cell

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21
Q

DC express _____ and high levels of

A

PRR and high levels of MHC II molecules

22
Q

immature properties, low resting levels of MHC II molecules and co-stimulators,

23
Q

extended star quality, can now, leave the tissue and travel to the lymph node “homing property” MHC class II upregulated, B7 upregulated and cytokines production is available

24
Q

can be processed and presented to self- Tcells

A

self-proteins

25
self can be processed but
it does not trigger T-cell activation
26
required interaction of at least ____ hours for activation of T cell to occur
8 hr
27
the intracellular pathway in T-cell activation build up signal transduction complex and activation of
tyrosine kinase
28
necessary for T -cell activation
Zap70
29
cyclosporen A what does it does? and what is the results
preventing transplant rejection by preventing T -cell activation
30
stimulator needed for T -cell activation because if not present IL-2 is not sufficiently made
CD28
31
synthesis of cytokines and cytokine receptor especially
IL-2 and IL-2R
32
changes in expression of adhesion molecules leads to _____ leaves node, moves into tissues to combat pathogen
effector T cell
33
are polyclonal activators
superantigens
34
T cell turn off signals: CTLA4
B7 (APC)
35
T cell turn off signals: | PD1
PDL1 or PDL2
36
type of interaction when turning off the t cell signal
negative interaction
37
CTL4 competes with ___ for binding to B7
CD28
38
interaction with B7 turns off activated T cell
CTLA-4
39
expressed on "exhausted" (several rounds of replication, cell cant carry on) activated T cells, in chronic conditions such as cancer
PD1
40
anti PD-1 or anti PDL1 blocks interaction between tumor cell and T cell
checkpoint therapy
41
Key steps in processing an exogenous antigen in the MHC class II pathway
1. Antigen taken into acid vesicles 2. Broken into peptides 3. Peptides associate with newly synthesized MHC class II 4. MHC-peptide complex is presented on the surface
42
Key steps in processing of an indigenous antigen MHC class I pathway
1. Antigen broken down in cytoplasm 2. Peptides transported to ER 3. Peptides associate with MHC class I 4. MHC peptide complex is presented on the surface
43
Co stimulator pairs
B7 and CD 28 (to activate naive T -cell) CD40 and CD40L (B-cell interaction with T-cells)
44
Pathogens bind to the PRR _____ in immature DC cells to activate them
TLR4
45
_______ are not processed and presented. They bind ______ the MHC class II peptide groove and crosslink ____ and _______
Superantigens are not processed and presented. They bind outside the MHC class II peptide groove and crosslink MHC II and TCR-beta
46
Upon activation by super antigens there is a cytokine storm in which there is a huge production of ____. _____, and _____
IFN-gamma, IL-1, IL-6
47
The cytokine storm can result in ______
Toxic shock syndrome
48
CTLA-4 is induced _____ after activation
24 hrs
49
CTLA-4 competes with _____ for binding to ______
competes with CD28 for binding in to B7
50
PD-1 is expressed on ______ T-cells, after __________
PD-1 is expressed on exhausted T-cells, after multiple rounds of activation
51
Example of checkpoint therapy
mAbs
52
T-cell growth factor
IL-2