CD8 T Cell Effects (Exam 3)

Question 1

What are the 2 main mechanisms CD8+ T cells use to kill target cells?

Answer 1

1. perforin + granzymes
2. Fas ligand

Question 2

What is the shorthand name for CD8+ T cells?

Answer 2

CTLs

Question 3

In terms of their role in CTL killing of target cells- What does perforin do? What do granzymes do?

Answer 3

perforin: forms pore in target cell
granzymes: enter pores –> apoptosis

Question 4

Fas ligand is expressed on _______ and Fas receptor on _______ which engage to cause apoptosis.

Answer 4

CTLs
target cell

Question 5

What problem occurs with chronic antigen exposure and persistent immune response?

Answer 5

CD8+ T cell exhaustion

Question 6

CD8+ T cell exhaustion leads to:

(Increased/decreased) T cell proliferation and effector function.

(Increased/decreased) IFN-y production and cytotoxicity.

(Increased/decreased) inhibitory receptors.

Answer 6

decreased
decreased
increased

Question 7

What are the 2 kinds of gamma-delta T cells?

Answer 7

peripheral g-d T cells
epithelial g-d T cells

Question 8

Which kind of cells act as a link between innate and adaptive immunity?

Answer 8

peripheral gamma-delta T cells

Question 9

Main function of peripheral gamma-delta T cells.

Answer 9

protection from bacterial infection

Question 10

Main function of epithelial gamma-delta T cells.

Answer 10

produce tissue growth factors during tissue injury & preserve epithelium integrity during stress

Question 11

Where are epithelial gamma-delta T cells located?

Answer 11

intestinal / skin epithelium

Question 12

(T/F) Gamma-delta T cells require MHC to recognize and respond to antigen.

Answer 12

False - can respond w/o MHC

Question 13

What two kinds of antigens do gamma-delta T cells respond to?

Answer 13

lipid antigens
microbial metabolites

Question 14

What are the 2 phases of signal transduction?

Answer 14

1. cytosolic phase
2. nuclear phase

Question 15

In the cytosolic phase of signal transduction, the ligand binds to the receptor which causes cytosolic region of the receptor to ________ which activates an enzyme downstream to activate ______.

Answer 15

change conformation
transcription factor

Question 16

In the nuclear phase of signal transduction, the modified ______ enters the nucleus which leads to a change in ________.

Answer 16

transcription factor
gene expression

Question 17

CD8 and CD4 T cell receptors are _______ with an alpha and a beta chain.

Answer 17

heterodimers

Question 18

Term for the variable regions on the alpha-beta chain of T cell receptors which determines the specificity to MHC-antigen.

Answer 18

CDR (complementarity determing regions)

Question 19

What two molecules attach to the alpha-beta T cell receptor which signals for T cell activation?

Answer 19

CD3
zeta proteins

Question 20

What molecules on T cell receptor complex regulates T cell responses, strengths adhesion between T cells and APCs, and mediates cellular homing?

Answer 20

accessory molecules

Question 21

CD3 and zeta proteins (covalently/noncovalently) attach to alpha-beta T cell receptors and transduce signals to activate T cells when they are (phosphorylated/dephosphorylated) when the ligand binds.

Answer 21

noncovalently
phosphorylated

Question 22

Term for area which forms a stable contact between a T cell receptor complex and MHC-peptide complex on APC.

Answer 22

immunological synapse

Question 23

What is the function of an immunological synapse?

Answer 23

stabilize contact between T cell and MHC

Question 24

What 3 structures are at the center of an immunological synapse?

Answer 24

TCR complex
coreceptors
costimulators

Question 25

What structures are present at the periphery of an immunological synapse? What purpose?

Answer 25

integrins for stabilization