Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Immunology > Differentiation And Functions Of CD4+ T Cells > Flashcards

Differentiation And Functions Of CD4+ T Cells Flashcards

1
Q

Alpha beta TCRs recognize and bind to __.

A

Peptides presented within the MHC molecules and MHC itself.

These cells also express either CD4 or CD8 co-receptors.

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

Where does activation of T cells occur?

A

In the lymph nodes.

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

What are langerhans cells?

A

Immature dendritic cells which do not express high levels of B7.

They stimulate naive T cells.

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

What does Ag recognition involve?

A

Clustering of TCRs.

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

What is the activation of T cells initiated by?

A

A signaling cascade after TCRs recognize specific Ag.

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

What is needed to activate a T cell?

A

TCR, CD4 or CD8 and CD3.

CD4 for T helper cells

CD8 for CTLs

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

When the TCR is engaged and activates T cells, the T cell must:

A

Receive a co-stimulatory signal.

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

____ can be considered as an “amplifier” that improves signaling of T cells.

A

Co-stimulation.

This involves B7 and CD28.

With co-stimulation, 100 fold fewer of clustered TCRs are needed for activation.

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

Once T cells are Ag-activated, what do they produce?

A

IL-2 and IL-2R, which leads to cell proliferation.

The result is the expansion of the clone of T cells that are specific for the Ag.

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

What do T cells differentiate into?

A

Effector cells or memory cells.

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

What drives proliferation of T cells, and is also called the “T cell growth factor”?

A

IL-2

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

True or false: naive T cells do not have IL-2 receptor (IL-2R) expressed on their surface.

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

True or false: activted T cells produce a large amount of IL-2 and express IL-2R.

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

___ enhances resistance of activated T cells to apoptosis.

A

IL-2

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

How do effector T cells migrate through blood vessels in peripheral tissues?

A

They bind to endothelial cells that have been activated by cytokines produced in response to infection in these tissues.

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

CD4+ cells recruit and activate phagocytes. What do the phagocytes destroy?

A

Microbes

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

What do CD8+ lymphocytes kill?

A

Infected cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

True or false: each subset of T helper clls tends to oproduce a set of particular cytokines.

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What do Th1 cells activate?

A

A cell-mediated immune response.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What do Th2 cells activate?

A

An Ab-mediated immune response.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are Th17 cells involved in?

A

Inflammation and anti-bacterial response.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Why are PRRs important for innate and adaptive immunity?

A

Pathogen recognition by immature DCs through PRRs is an important bridge between innate and adaptive immunity.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the result of PRR signaling?

A

Activation and maturation of antigen-presenting cells (APCs)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

APC processed antigen is presented to what cells?

A

Naive Th0 cells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Secreted IL-12 assists the development and differentiation of what type of helper cell?
Th1 cell
26
What are four main classes of CD4+ cells?
Treg Th1 Th2 Th17
27
What causes differentiation of Treg cells?
IL-2 + TGF beta
28
What are the functions of Treg cells?
Suppresses tumor immunity Promotes immune tolerance Maintains lymphocyte homeostasis
29
What cytokine activates Th1?
IL-12
30
What are the functions of Th1?
Promotes tumor immunity Intracellular pathogens Drives autoimmunity
31
What acitvates Th2?
IL-4
32
What are the functions of Th2?
Extracellular pathogens Allergy Asthma
33
What activates Th17?
TGF-beta IL-6 IL-21
34
What are the functions of Th17?
Tumor immunity Breaks immune tolerance Extracellular bacteria Autoimmunity
35
What immune reactions are stimulated by Th1 cells?
Macrophage activation IgG production
36
What immune reaction is associated with Th2?
Mast cell, eosinophil activation, IgE production Alternative macrophage activation
37
What immune reactions are associated with Th17?
Neutrophilic Monocytic inflammation
38
What is the host defense associated with Th1 cells?
Intracellular microbes
39
What is the host defense associated with Th2 cells?
Helminthic parasites
40
What is the host defense associated with Th17?
Extracellular bacteria; fungi
41
What is the function of TGF-beta?
It functions mainly as an inhibitor of immune responses
42
What is involved in the development of a Th1 cell?
IL-12 and IFN-gamma activate a T cell. T-bet, STAT4 and STAT1 activate a Th1 cell
43
What is involved in the development of a Th2 cell?
IL-4 activates a T cell. GATA-3 and STAT6 activate a Th2 cell
44
What is involved in the development of a Th17 cell?
A dendritic cell uses IL-1, IL-6, IL-23 and TGF-beta to activate a T cll. ROR gamma t and STAT3 activate a Th17 cell.
45
What is IL-12 produced by?
DC and macrophages.
46
In the development of Th1 cells, what produces IFN-gamma?
NK cells
47
What is the function of IFN gamma in the development of Th1 cells?
It amplifies the Th1 repsonse and inhibits the development of Th2 and Th17 cells.
48
In the development of Th2 cells, what produces IL-4?
Activated T cells or by mast cells and eosinophils. These activate GATA-3 and STAT6, which stimulate the differentiation of naive CD4+ T cells to the Th2 subset.
49
What is the function of IL-4 during the development of Th2 cells?
It amplifies the response (development of Th2 cells) and inhibits the development of Th1 and Th17 cells.
50
What transcription factors are activated by IL-1, IL-6 and TGF beta?
ROR gamma t and STAT3. These stimulate the differentiation of Th17 subset.
51
What do ROR gamma t and STAT3 regulate the production of?
IL-21. This amplifies generation of Th17 cells.
52
What cytokine is very important in the differentiation of Th17 cells?
IL-23
53
What is the function of IL-17?
It protects from extracellular pathogens and is involved in tissue inflammation and autoimmunity.
54
How does TGF-beta promote the Th17 response?
By suppressing Th1 and TH2 cells, both of which inhibit the Th17 differentiation.
55
What is the role of oxygen species, nitric oxide, and increased lysosomal enzymes in cell-mediated immunity?
Killing of microbes in phagolysosomes
56
What is the role of the secretion of cytokines and chemokines in cell-mediated immunity?
Leukocyte recruitment Th1 differentiation, IFN gamma production
57
What is the role of increased expression of B7 costimulators and MHC molecules?
Increased T cell activation (amplification of T cell response).
58
What are functions of Th2 cells?
Mast cell degranulation Intestinal mucus secretion and peristalsis Eosinophil activation Alternative macrophage activation (tissue repair)
59
What is the funciton of ROS, NO and l ysosomal enzymes?
Phagocytosis and killing of many bacteria and fungi.
60
What is the role of chemokines (IL-1, IL-12, IL-23)?
Inflammation
61
What are the roles of IL-10 and TGF beta?
Anti-inflammtory effects, wound repair and fibrosis
62
What are the functions of Th17 cells?
Inflammation, neutrophil response Increased barrier function
63
True or false: CD8+ T cells are activated by mechanisms that involve cross presentation of antigens to CD8+ T cells.
True
64
Where are CD8+ T cells activated?
In the LN by dendritic cells loaded with Ags exactly as CD4+ T cells are.
65
True or false: CD4+ helper T cells produce cytokines that stimulate CTL differentiation.
True
66
True or false: CD4+ helper T cells enhance the ability of APCs to stimulate CTL differentiation.
True
67
True or false: CD8+ T cells recognize antigen + costimulators on professional APCs, which results in CTL differentiation without helper T cells.
True
68
CTLs are activated to release their granule contents. What are in the granules?
Perforin and granzyme
69
What do CD8+ T lymphocytes secrete, and what does it activate?
They secrete IFN-gamma, which activates macrophages.
70
What do nontraditional gamma delta T cells have?
Gamma delta TCRs and CD3. Most of them do not express CD4 or CD8 co-receptors.
71
Where are nontraditional gamma delta T cells most abundant in?
The intestine, uterus and the tongue
72
What are the functions of gamma detla T cells?
First line of defense Regulatory cell Bridging between innate and adaptive responses
73
Gamma delta T cells are considered a component of what type of immunity?
Adaptive immunity.
74
Rearrangement of TCR genes produces __.
Junctional diversity.
75
True or false: NKT cells share properties and CD markers of both T cells and NK cells.
True
76
What do NKT cells recognize?
Self- and foreign lipids and glycolipids.
77
What is the role of activated NKT cells?
They produce large quantities of IFN-gamma, IL-4 and GM-CSF, as well as other cytokines and chemokines. They also rapidly release cytokines. They also promote or suppress different immune responses.
78
What occurs when there is a dysfunction or deficiency of NKT cells?
Autoimmunity (diabetes or atherosclerosis) Cancers Progression of asthma.
79
Over 90 - 95% of T cells in the circulation have ___.
Alpha beta TCRs.

Immunology (17 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions