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Flashcards in Ppt5 Deck (75):
1

in order for the cell-mediated response to be active, what must always be present?

antigen

2

can humoral immunity be transfered to a fetus?

yes

3

can cell-mediated immunity be transfered to a fetus?

no

4

what will IL-2 do?

activate: B, NK, T helper, T cytotoxic cells

5

T helper cells help defend against?

parasites, cancer, bacteria/viruses inside host cell

6

T helper cells will regulate the proliferation and activity of these cells:

B cells, macrophages, neutrophils

7

t cells only react to antigen combined or associated with this molecules

MHC

8

how to t helper cells kill microbes?

they stimulate macrophages that have ingested the microbe to kill it

9

do natural killer cells require antigen stimulation?

no

10

are natural killer cells phagocytic?

no

11

how are macrophages activated in the cell-mediated response?

by using the CD40-CD40L interaction and through INF-y

12

what are the 2 phases of the cell-mediated response?

1) induction phase2) effector phase

13

what characterises the induction phase?

CD4+ and CD8+ T cells recognise antigen presented by dendritic cells in peripheral organs causing them to proliferate and differentiate into effector cells that enter the circulation...they bind to activated endothelial cells

14

what characterises the effector phase?

the effector t cells will recognise the antigen and release cytokines to activate phagocytes to kill the microbe or if CTL's kill it directly

15

what cells will migrate through the endothelium that has been previously activated by cytokines? what cells cannot migrate through activated endothelium?

effector t cells and memory t cellsnaive t cells cant

16

what cells are activated and retained in the sites of infection?

t cells that specifically recognize antigen

17

cells that do not recognize antigen in site of infection will...

return to circulation

18

can resting APC's that encounter antigen stimulate T cells?can they present antigen?

nope, they don't express co-stimulators, yes they can present antigen though

19

what happens if t cells are exposed to antigen without co-stimulation?

they may become unresponsive to future presentations of that antigenTHEY MAY BECOME ANERGIC

20

what receptor do naive T cells have in order to recognize B7 co-stimulators on APC's?

CD28

21

when APC presents antigen through MHC to Helper T cell, what does the T helper cell do?

T helper cell will secrete IL-12 and recognize the IL-12 causing it to proliferate

22

when the T helper cell recognizes IL-12 and proliferates, what will some of the clones become?

some are memory and others effector cells

23

what cells express the low affinity IL-2 receptor complex?

Naive T cells

24

what will activate the IL_2 receptor complex in naive T cells? what will activation of the IL-2 receptor complex in Naive T cells cause?

antigen recognition and co-stimulationit will cause expression of IL-2 cytokine

25

Once naive T cells express IL-2 cytokine, what happens to the IL-2 receptor complex?

it will become high affinity

26

how many TCR need to be cross-linked in order for a immune response to take place?

2 or more TCR

27

cells use this adhesion molecule receptor to bind to endothelial cells

LFA-1

28

LFA-1 will bind to what on endothelial cells?

ICAM-1

29

what is an ITAM?

tyrosine activating motif

30

what is used to bind to VCAM?

VLA-4

31

what are two examples of integrins?

VLA-4 and LFA-1

32

what receptor will bind to B7 in order to inhibit T cells?

CTLA-4

33

what is CD152?

CTLA-4

34

CTLA-4 will bind to naive t cells or activated t cells?

to activated t cells in order to inhibit them

35

when can we use CTLA-4?

when we have autoreactive T cells that are proliferating uncontrollably

36

When is CTLA-4 very, very, very important?

for maintaining self-tolerance

37

T helper cells that have differentiated express what? and secrete what?

CD40-L and secrete cytokines

38

T helper cells expressing CD40L will bind to what?

to macrophages with CD40 or B cells with CD40

39

When T helper cells bind to macrophages using CD40L-CD40, what will this do? is this a cell-mediated reaction?

it delivers the signal to kill microbes, and yes it is a cell-mediated reaction

40

how does effector T helper cell work in humoral immunity?

T helper cells bind to B cells using CD40L-CD40 and cause them to secrete specific antibody

41

What do T helper 1 cells do to phagocytes? and how do they do it?

they activate phagocytes by secretion of IFN-y

42

what do T helper 1 cells do to CTL's?

help them differentiate into effector CTL's

43

What do T helper 1 cells do to B cells?

make stimulate them to produce IgG

44

which subset of IgG will T helper 1 cells stimulate B cells to produce?

IgG 1 and IgG 3

45

what will T helper 2 cells cause B cells to do?

they will make B cells produce antibodies and class switch to IgG 4  or IgE

46

What do CTL's release from their granules?

perforins and gramzymes

47

what do perforins and gramzymes do?

cause the activation of apoptotic pathways

48

what accessory molecules are needed on the CTL and the target cell in order for the CTL to do its work?

LFA-1 and CD8

49

What ligand is expressed on CTL's surface that leads to apoptosis of the target cell?

FAS-L

50

What disease results from a mutation in the FAS-L receptor?

ALPS

51

What type of infection in macrophages will lead to the differentiation of T helper 1 cells?

intracellular bacteria or virus

52

what other pathway leads to differentiation of T helper cells to T helper 1 cells?

Toll-like receptors

53

infection of macrophages in innate immunity through engagement of toll-like receptors will lead to expression of what cytokine? though what cell-cell interaction and receptor engagement will the cytokine be released?

IL-12

- T helper cell and APC engage CD40-CD40L

54

what does IL-12 activate in T helper cells?

STAT 4

55

what does INF-y cause in APC's? 

 

production of more IL-12

56

what does INF-y activate in T helper cells?

Tbet

57

what does Tbet in T helper cells do?

regulates differentiation to T helper 1

58

What does STAT 4 in T helper cells do?

causes T helper cells to differentiate to T Helper 1 cells

59

On what do T helper cells depend on to differentiate to T helper 2 cells?

IL-4

60

what will IL-4 activate in T Helper cells?

STAT 6

61

In presence of antigen and while STAT 6 is activated, what transcription factor activates in T helper cells? what does it do?

GATA 3 activates and leads to T Helper 2 differentiation

62

what does TH1 cells secrete?

INF-y

TNF

IL-2

63

what do T helper 2 cells secrete?

IL-4/5/10/13

64

TH 2 cells will recruit what cells mainly?

eosinophils

65

TH 1 cells will recruit what type of cells mainly?

monocytes

66

TH 1 cells will stimulate what isotype subset of antibodies?

IgG 1 and IgG3

67

TH 2 cells will stimulate what antibody isotype mainly?

IgE

  IgG1

IgG4

68

what T helper cell subset will activate macrophages to repair tissue?

TH2

69

IL-2 secreted by TH 1 cells will increase what molecules  on macrophages and dendritic cells?

it will increase MHC 2 and co-stimulators

70

IFN-y secreted by TH 1 cells will help what 2 cells? how?

1) it helps macrophages by activating them (will kill microbes)

2) helps B cells to secrete IgG(1 and 3) antibodies that coat microbe for opsonization

71

TH 1 cells secrete TNF, what will this do?

recruit neutrophils

72

what will IL-4 secreted by TH 2 cells do to B cells? what will it do to other T helper cells?

it causes them to secrete IgE

causes other T helper cells to differentiate into TH 2

73

what will IL-5 secreted by TH 2 cells do?

activation of eosinophils 

74

What do eosinophils do?

protect against parasites (helminths)

75

cytokines from TH 2 will inhibit activation of who?

macrophages