Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Immuno 2 Self > 12 T Cell Tolerance > Flashcards

12 T Cell Tolerance Flashcards

1
Q

True or false? self reactive t cells are controlled by central but not peripheral tolerance?

A

false—they are by both

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

True or false? self reactive t cells are controlled by central but not peripheral tolerance?

A

false—they are by both

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What do medullary epithelial cells express?

A

self peptides in the context of MHCI and MHCII

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What drives thymocyte selection?

A

affinity for MHC/antigen complex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What locations all play roles in thymocyte selection?

A

cortical epithelial cells, medullary epithelial cells and resident dendritic cells—(basically anywhere in the thymus when there is a functional TCR alpha and beta presented)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Mice with deficient MHC class II can’t produce what?

A

CD4 Tcells–defects in ability to activate CD4 thymocytes during selection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What area of the thymus presents the largest number of proteins from the human body for selection?

A

Medullary thymic epithelial cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What drives the promiscuous expression of proteins for thymocyte selection?

A

transcriptional regulator AIRE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What picks up proteins from blood stream for thymocyte selection?

A

thymus resident dendritic cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What presents periphery self antigens to the thymus?

A

Peripheral dendritic cells (food antigens and commensal bacteria antigens too)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Most important mechanisms of peripheral tolerance? [3]

A

immune privilege
costimulation —>anergy and cell death
regulatory T-cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What mechanisms drive immune privilege? [5]

A
  1. Physical barriers
  2. low expression of MHC
  3. Expression of suppressive cytokines
  4. Expression of Fas ligands
  5. Increased number of regulatory T-cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What mechanisms drive immune privilege? [5]

A
  1. Physical barriers
  2. low expression of MHC
  3. Expression of suppressive cytokines
  4. Expression of Fas ligands
  5. Increased number of regulatory T-cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What do medullary epithelial cells express?

A

self peptides in the context of MHCI and MHCII

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What drives thymocyte selection?

A

affinity for MHC/antigen complex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What locations all play roles in thymocyte selection?

A

cortical epithelial cells, medullary epithelial cells and resident dendritic cells—(basically anywhere in the thymus when there is a functional TCR alpha and beta presented)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Infections and inflammation leads to up regulation of what in antigen presenting cells? [costimulatory protein with CD28]

A

B7

18
Q

What area of the thymus presents the largest number of proteins from the human body for selection?

A

Medullary thymic epithelial cells

19
Q

What drives the promiscuous expression of proteins for thymocyte selection?

A

transcriptional regulator AIRE

20
Q

What picks up proteins from blood stream for thymocyte selection?

A

thymus resident dendritic cells

21
Q

What presents periphery self antigens to the thymus?

A

Peripheral dendritic cells (food antigens and commensal bacteria antigens too)

22
Q

Most important mechanisms of peripheral tolerance? [3]

A

immune privilege
costimulation —>anergy and cell death
regulatory T-cells

23
Q

Damage to an immune privileged organ can cause what?

A

autoimmunity

24
Q

What mechanisms drive immune privilege? [5]

A
  1. Physical barriers
  2. low expression of MHC
  3. Expression of suppressive cytokines
  4. Expression of Fas ligands
  5. Increased number of regulatory T-cells
25
Q

What 3 signals are required for Tcell full activation?

A

1: TCR/co-receptors–specificity
2: costimulatory receptors—-suppress auto-reactivity
3: cytokines—differentiation

26
Q

What signal in absence of the what other signal causes cell death or anergy in the T cell?

A

signal 1 in absence of signal 2.

27
Q

What is the primary costimulatory molecule for naive T cells?

A

CD28–activated upon binding B7-1 and B7-2

28
Q

What happens to mice deficient in CD28?

A

normal early responses to infection, but do not have T cell expansion, differentiation and function

29
Q

Infections and inflammation leads to up regulation of what in antigen presenting cells? [costimulatory protein with CD28]

A

B7

30
Q

The simultaneous activation of both the TCR and CD28?

A

cytokine production, proliferation, and protein expression

31
Q

What protein is expressed several days after initial TCR/CD28 activation, binds B7, and inhibits CD28 function?

A

CTLA-4

32
Q

What happens in over expression of CTLA-4?

A

immune evasion of several types of cnacer

33
Q

What happens in defects of CTLA-4?

A

autoimmunity

34
Q

what are critical for suppressing T cell responses before and following infection, control auto reactive tells and shut down pathogen specific T cell responses?

A

Regulatory T cells

35
Q

Do naive CD4 T cells or Regulatory T cells have a stronger reactivity to self peptide- MHC class II?

A

regulatory T cells

36
Q

Do naive CD4 T cells or regulatory T cells make cytokines IL-10 and TGF beta?

A

Regulatory—Naive make IL-2

37
Q

What is the key transcriptional regulator for regulatory T cells?

A

FOXP3- epigenetically

38
Q

When are regulatory T cells produced?

A

during positive and negative selection in the thymus—T cells with a moderate level of self reactivity differentiate into regulatory T cells

39
Q

What is the purpose of inducible regulatory T cells?

A

limit damage to surrounding tissue

40
Q

What are the 6 mechanisms regulatory T cells suppress effector T cell function?

A
  1. direct inhibition of DC via CTLA4
  2. Production of suppressive cytokines
  3. Binding of IL-2 by CD25
  4. Direct lysis of effector T cells
  5. Eliminate extracellular ATP, produce adenosine
  6. Forming Gap junctions with effector T cells
41
Q

Overexpression of inflammatory cytokines or under expression of suppressive cytokines can cause??

A

multiple autoimmune disorders

42
Q

Defects in proteins required for controlling central and peripheral tolerance can also drive the initiation and progression of what?

A

autoimmune disorders

Immuno 2 Self (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions