Immuno Test II, Lecture 6 Flashcards Preview

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Flashcards in Immuno Test II, Lecture 6 Deck (75)
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0
Q

Where did the cell mediated immunity term evolve from?

A

The finding that immunity to intracellular pathogens could be transferred to other animals by immune cells from infection-recovered animal.

1
Q

What is cell mediated immunity?

A

due to the direct action of T cells

2
Q

How have T cells evolved?

A

To protect us against intracellular microbes (viruses and some bacteria)

3
Q

What do T cells have to help to mount?

A

A robust Ab-mediated humoral immune responses directed agains extracellular pathogens

4
Q

What can T cells not do?

A

Cannot directly recognize unprocessed Ags or bind to microbes

5
Q

How are Ags in host cells broken up?

A

Into…

6
Q

A

7
Q

A

8
Q

Each T cell recognizes only one specific foreign peptide, how does the body over come this?

A

but there is a large TCR repertoire generated in the body

9
Q

Where are the T cells educated?

A

thymus

10
Q

T cells are either?

A

selected for survival or eliminated if self reactive

11
Q

What is the general function of different T cells?

A

each with different functions in the immune response that are dictated by cytokines produced

12
Q

CD4+ T helper cells recognize?

A

peptide Ags in the context of MHC class II molecules that are expressed by dendritic cells, Mo, and B cells

13
Q

CD8+ cytotoxic T cells

A

recognize peptides associated with MHC class I molecules

14
Q

What does the CD4 and CD8 attach to?

A

the non-polymorphic (non variant) part of the MHC class II and MHC class I molecules, respectively.

15
Q

What needs to happen to T cells in order for them to carry our their function?

A

they need to be activated

16
Q

What is not sufficient to activate the T cells?

A

recognition of the peptide Ag by the TCR

17
Q

What are required in addition to recognition?

A

Co-stimulatory molecules, with co receptors involved in signaling events

18
Q

What does T cells activation lead to?

A

production of IL-2, which controls clonal expansion of specivic T cells

19
Q

What does IL-2 control?

A

clonal expansion of the specific T cell

20
Q

What does Th1 do?

A

helps Mo to get rid of intracellular microbes and help the development of cytotoxic T cells to kill virus infected cells

21
Q

What is IFN gamma produced by?

A

Th1 cells activates Mo

22
Q

What are Th2 cells involved in?

A

Helping B cells to develop into memory cells and plasma cells that produce antibodies

23
Q

What is IL-4 produced by?

A

Th2 cells

24
Q

What is IL-4 important for?

A

B cell proliferation

25
Q

How is B cell activated?

A

Self activated, but cannot advance without help from Th cells.

26
Q

What do B cells develop into?

A

memory cells and plasma cells

27
Q

plasma cells produce?

A

antibodies

28
Q

What is the TCR of conventional (alpha, beta T cells)?

A

It is composed of two polypeptide chains, alpha and beta, which have molecular wights of 50 and 39 kDa

29
Q

What are the genes coding for TCR polypeptide chains?

A

members of the Ig super family

30
Q

A

31
Q

A

32
Q

A

33
Q

A

..

34
Q

..

A

35
Q

What does the T cell receptor complex consist of?

A

The TCR, the alpha,beta or gamma,epsilon dimer, in association with CD3

36
Q

What is CD3?

A

A signaling complex composed of gamma, epsilon, and delta

37
Q

What is a seperate signaling molecule made up of?

A

38
Q

What does CD4 on T cells bind to?

A

nonpolymorphic region of MHC class II on APCs restricting Th cells to recognizing only peptides presented on MHC class II molecules

39
Q

CD8 on cytolytic T cells binds to?

A

the non polymorphic region of MHC class I, restricting…

40
Q

Know what TCR complex looks like

A

Slide…

41
Q

Proteasome genes structure

A

TAP1, 2

42
Q

A

43
Q

A

44
Q

A

45
Q

Look at Detailed map of Human

A

MHC

46
Q

Class I major

A

HLA-B, C, A

47
Q

Class I region minor

A

HLA G, F, E

48
Q

What is the significance of co dominant expression of both parental allels of each MHC gene are expressed?

A

increases number of different MHC molecules that can presesnt peptides to T cells

49
Q

What is the significance of polymorphic genes: many different alleles are in the population.

A

Ensures that different individuals are able to present and respond to different microbial peptides

50
Q

What is the significance of MHC expressing Cell types: Class II: dendrictic cells, macrophages, B cells

A

CD4+ helper T lymphocytes interact with dendritic cells, macrophages, B lymphocytes

51
Q

Class I all nucle

A

52
Q

What are the two classes of polymorphic MHC genes encode human leukocyte ?

A

Class I and II, that can bind peptides and are thus critical to Ag presentations

53
Q

What are class I genes?

A

HLA-A, -B, -C

54
Q

What doe class I genes do?

A

encode a polymorphic heavy chain which combines with beta2-micro-globulin and is expressed on the surfaces of all nucleated cells

55
Q

What does the heavy chains of class I genes have?

A

a binding groove for peptides to be recognized by T cells

56
Q

What are Class II genes?

A

HLA-D

57
Q

What are Class II genes encoded molecules?

A

(HLA-DP, -DR….

58
Q

A

59
Q

A

60
Q

A

61
Q

..

A

..

62
Q

.

A

.

63
Q

What is that alpha chain of the class I molecules?

A

glycosylated (carbohydrate residues are not shown)

64
Q

What does the ribbon diagram show??

A

The stucture of the ex….

65
Q

What do the anchor residues on the peptides do?

A

Bind to residues in the class I and II grooves and vary for different MHC alleles.

66
Q

What are MHC class II molecules expressed on?

A

professional APCs, only B cells, dendritic cells and macrophages

67
Q

What are MHC class I molecules expressed on?

A

all nucleated cells

68
Q

What is expression of MHC class I and II modulated by?

A

cytokines

69
Q

What are peptides that bind to class I MHC molecules derived from?

A

viruses that have infected host cells and move as the complexes to the surfac (endogenous pathway)

70
Q

What doe petides that bind to class I MHC bind to?

A

recgonized bty CD8+ cytotoxic T lymphocytes CTL

71
Q

Ags and pathogens taken from the environment primarily present on?

A

MHC class II molecules to CD4+ helper T cells

72
Q

What are professional APCs?

A

B cells macrophages, dendritic cells… They are strongly expressed on MHC class I and II

73
Q

Dendritic cells recognize?

A

antigens at the gate..

74
Q

CD28 does what?

A

Binds dendritic cell and naive T cells with the costimulator B7