differentiation and functions of CD8 effector cells

Question 0

Extracellular antigens are processed and presented within class II MHC via the classical pathway, but they are also presented in association with ? because of cross presentation

Answer 0

class I MHC

Question 1

CD8+ T cells are activated by mechanisms that involve_____ of antigens to CD8+ cells.

Answer 1

Cross-presentation

Question 2

CD4+ helper T cells produce cytokines (IL-2) that stimulate

Answer 2

CTL differentiation

Question 3

CD4+ helper T cells enhance the ability of APCs via______ to stimulate CTL differentiation

Answer 3

CD40L (on T cell) binding to CD40R (on APC)

Question 4

Naive CD8+ T cells recognize which kind of Antigens presented by DC’s in the Lymph nodes?

Answer 4

peptide

Question 5

Effector CD8+ CTLs are activated by the antigen in?

Answer 5

Peripheral tissues

Question 6

activated CTLs mostly secrete this cytokine to potently activate macrophages?

Answer 6

IFN-gamma

Question 7

similar to activation of Th1 cells, the molecular events in CTL differentiation involve?

Answer 7

transcriptional factor T-bet

Question 8

T-bet regulates transcription of genes encoding for which proteins?

Answer 8

Perforin, Granzyme B, and IFN-gamma

Question 9

CD4+ helper T cells are required for CD8+ T cell responses when weak innate immune reactions are evoked by?

Answer 9

latent viral infections, organ transplants, and tumors

Question 10

Which cells are more important for the generation of CD8+ memory T cells than for the differentiation of naive CD8+ T cells into effector CTLs?

Answer 10

CD4+ helper T cells

Question 11

which cells provide signal 3 by secretion of cytokines in CTL activation?

Answer 11

CD4+

Question 12

activated CD4+ Th cells express?

Answer 12

CD40L

Question 13

CD40-CD40L binding up regulate the expression of ____ on professional APCs

Answer 13

CD80/CD86

Question 14

IL-2 promotes proliferation and differentiation of ? into CTLs and memory cells

Answer 14

CD8+ T cells

Question 15

after activation of CD8+ T cells, they express high levels of?

Answer 15

alpha subunit of IL-2R

Question 16

IL-2R shares a common receptor component with IL-15 and IL-21

Answer 16

Gamma chain

Question 17

IL-12 and type I IFNs stimulate the differentiation of naive CD8+T cells into?

Answer 17

effector CTLs

Question 18

local release of IL-2 can lead to activation of T cells which results in?

Answer 18

up-regulation of both cytokine and its receptors

Question 19

defect in the common receptor chain Gamma

Answer 19

……

Question 20

without IL-12, these cells are exhausted and decrease in number

Answer 20

CD8+ T cells

Question 21

IL-12 activates these cells

Answer 21

activates NK cells

Question 22

the primary source of IL-15 is found in?

Answer 22

activated tissue macrophages and mature DCs

Question 23

IFN-gamma is an important component of?

Answer 23

anti-viral protection by up-regulating Antigen presentation of viral targets by infected cells

Question 24

activated CTLs secrete these pro-inflammatory molecules

Answer 24

TNF-beta, IFN-gamma, cytotoxic perforin and granzymes

Question 25

in chronic viral infections, responses of CD8+ T cells may be initiated but gradually extinguished. what is this phenomenon and what are the inhibitory molecules?

Answer 25

Exhaustion. CTLA-4, PD-1

Question 26

PD-1 mediated T cell exhausion may contribute to?

Answer 26

chronicity of HIV and Hep C viral infections

Question 27

perforin and granzymes are secreted into?

Answer 27

the synapse formation to Antigen or infected cell

Question 28

what is the purpose of the immunologic synapse?

Answer 28

ensures that normal bystander cells are not injured by CTLs reacting against infected cells. no collateral damage.

Question 29

Do all cells express Fas?

Answer 29

yes

Question 30

FasL is expressed on activated CTLs to engage Fas on the surface of target cells to induce?

Answer 30

apoptosis

Question 31

Perforin is a membrane-perturbing molecule that is homologous to?

Answer 31

C9 complement protein

Question 32

granzyme B activates this enzyme to trigger apoptosis

Answer 32

Caspase-3

Question 33

binding of FasL to Fas recruits ____ through the ____ to convert to the active form of the enzyme _____

Answer 33

Procaspase-8. FADD adaptor. Caspase-8

Question 34

type I T cells use caspase-8 to

Answer 34

directly cleave caspase-3

Question 35

in type II cells, like virus-infected hepatocytes, caspase 8- cleaves Bid to stimulate ?

Answer 35

cytochrome c from mitochondria

Question 36

Cytochrome c and apoptotic peptidase activating factor 1 (Apaf-1) uses ATP to activate caspase 9 which activates?

Answer 36

caspase-3

Question 37

macrophage activation by Th1 cells is an important immune mechanism in eliminating

Answer 37

bacteria which resist lysosomal degradation

Question 38

Th1 cells make IL-3 and GM-CSF, which

Answer 38

stimulate macrophage production in the bone marrow