differentiation and functions of CD8 effector cells Flashcards Preview

immunology > differentiation and functions of CD8 effector cells > Flashcards

Flashcards in differentiation and functions of CD8 effector cells Deck (39):
0

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

Cross-presentation

1

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

class I MHC

2

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

CTL differentiation

3

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

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

4

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

peptide

5

Effector CD8+ CTLs are activated by the antigen in?

Peripheral tissues

6

activated CTLs mostly secrete this cytokine to potently activate macrophages?

IFN-gamma

7

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

transcriptional factor T-bet

8

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

Perforin, Granzyme B, and IFN-gamma

9

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

latent viral infections, organ transplants, and tumors

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?

CD4+ helper T cells

11

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

CD4+

12

activated CD4+ Th cells express?

CD40L

13

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

CD80/CD86

14

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

CD8+ T cells

15

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

alpha subunit of IL-2R

16

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

Gamma chain

17

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

effector CTLs

18

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

up-regulation of both cytokine and its receptors

19

defect in the common receptor chain Gamma

......

20

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

CD8+ T cells

21

IL-12 activates these cells

activates NK cells

22

the primary source of IL-15 is found in?

activated tissue macrophages and mature DCs

23

IFN-gamma is an important component of?

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

24

activated CTLs secrete these pro-inflammatory molecules

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

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?

Exhaustion. CTLA-4, PD-1

26

PD-1 mediated T cell exhausion may contribute to?

chronicity of HIV and Hep C viral infections

27

perforin and granzymes are secreted into?

the synapse formation to Antigen or infected cell

28

what is the purpose of the immunologic synapse?

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

29

Do all cells express Fas?

yes

30

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

apoptosis

31

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

C9 complement protein

32

granzyme B activates this enzyme to trigger apoptosis

Caspase-3

33

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

Procaspase-8. FADD adaptor. Caspase-8

34

type I T cells use caspase-8 to

directly cleave caspase-3

35

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

cytochrome c from mitochondria

36

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

caspase-3

37

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

bacteria which resist lysosomal degradation

38

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

stimulate macrophage production in the bone marrow