Brainscape's Knowledge GenomeTM

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


See full index

Block 1 - Week 5 > T-Cell Activation and Effector Function > Flashcards

T-Cell Activation and Effector Function Flashcards

1
Q

Activation of Naive T-Cells (General Process)

A

Antigen Presenting Cell (APC) delivers 3 signals to activate T-cell:

  • TCR binds appropriate MHC/peptide complex
  • B7 (AKA CD80 or CD86) on APC binds CD28 on T-Cell
  • APC releases different cytokines which determine specific differentiation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Which cells are the professional antigen presenting cells (APCs)?

Which APC delivers the best co-stimulation for activating naive T-Cells?

A
  • Dendritic Cells
  • Macrophages
  • B-Cells

Dendritic Cells offer the best co-stimulation for activating naive T-Cells

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

What are the 5 different subsets of CD4+ T-Cells?

A
  • T helper 1 (Th1)
  • T helper 2 (Th2)
  • T helper 17 (Th17)
  • T follicular helper (Tfh)
  • T regulatory cells (CD25+Foxp3+ or Treg)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Th1 Differentiation

A
  • Response To: Intracellular Microbes
  • Chemokine Activators: IL-12 and INF-y
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Th2 Differentiation

A

Response To: Parasites/Helminths

Chemokine Activators: IL-4

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

Th17 Differentiation

A

Response To: Extracellular Fungi/Bacteria

Chemokine Activators: IL-1, IL-6, IL-23, and TGF-B

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

Where do T-cellls differentiated into CD4+ or CD8+ T-cells?

A

In the Thymus

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

Where do Helper T-Cells get actived into the different types of Helper T-Cells (Th1, Th2, Th17, Treg)

A

In the Lymph Node

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

Th1 Role

A

Releases:

  • IFN-y: Activates Macrophages to kill intracellular microbes
  • IL-2: Activates Cytotoxic T-Cells and clonal expansion of CD4+ and CD8+ T-Cells

Activation of Macrophages to kill intracellulsar microbes:

  • TCR binds specific MHC II/Peptide on Macrophage
  • CD40L on Th1 binds CD40 on Macrophage
  • IFN-y released by Th1 binds to receptor on Macrophage
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Th2 Role

A

Releases:

  • IL-4: Activates B-cells to produce IgE antibodies
    • IgE Ab coats parasites
    • IgE also leads to Mast Cell Degranulation
  • IL-5: Activates Eosinophils which bind Ab coated parasite and release enzymes that destroy the parasite
  • IL-4 and IL-13:
    • Alternative macrophage activation (enhanced fibrosis/tissue repair)
    • Intestinal mucus secretion and peristalsis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Th17 Role

A

Releases:

  • IL-17: Inflammation and Neutrophil Recruitment/Activation
  • IL-22: Increased Epithelial barrier integrity

IL-17 and IL-22 both cause Epithelial cells to release Anti-Microbial Peptides

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

IL-2

A

Action: T-Cell proliferation; regulatory T-Cell survival

Source: Activated T-Cells

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

IFN-y

A

Action: Activate Macrophages (classical pathway)

Source: Th1, Cytotoxic T-Cells, NK Cells

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

IL-4

A

Action:

  • Causes B-Cells to make IgE
  • Macrophage activation (alternative pathway/tissue repair)

Source: Th2 and Mast Cells

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

IL-5

A

Action: Activates Eosinophils

Source: Th2 and Mast Cells

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

IL-13

A

Action:

  • Causes B-Cells to make IgE
  • Macrophage activation (alternative pathway/tissue repair)

Source: Th2 and Mast Cells

17
Q

IL-17

A

Action: Stimulates acute inflammation

Source: Th17

18
Q

IL-21

A

Action:

  • B-Cell Activation
  • Tfh differentiation

Source: Tfh

19
Q

IL-22

A

Action: Maintenance of epithelial barrier function

Source: Th17 and NK Cells

20
Q

CD8+ T-Cell (Cytotoxic T-Cell) Activation

A
  • MHC I on APC binds specific TCR
  • B7 on APC binds CD28 on T-Cell

A very good interaction of the above leads to activation; helper T-cells can assist with this process:

  • Helper T-Cells produce cytokines (e.g. IL-2) that promotes CTL differentiation
  • Helper T-Cells also enhance the ability of APCs to stimulate CTL differentiation

This licenses the CTL (Cytotoxic T-Lymphocyte) to kill

21
Q

How do activated Cytotoxic T-Lymphocytes kill their targets?

A
  • TCR binds specific MHC I/Peptide complex
  • This activates granule exocytosis
  • These granules signal to the infected cell to undergo apoptosis
22
Q

How do CD4+ and CD8+ T-Cells cooperate to destroy intracellular microbes?

A
  • Th1 activates macrophages to kill ingested microbes
  • Cytotoxic T-Cells cause virally infected cells to undergo apoptosis
23
Q

T follicular helper (Tfh) role

A

Releases:

  • IL-21: Leads to B-Cell and Tfh differentiation
24
Q

What can occur if Th2 cells become unregulated?

A
  • Allergies
25
Q

What can occur if Th1 cells become unregulated?

A
  • Autoimmunity
  • Chronic inflammation
26
Q

What can occur if Th17 cells become unregulated?

A
  • Autoimmunity
27
Q

Foxp3+ T regulatory cells (Treg) differentiation

A

TGF-B and IL-2 help CD4+ cells differentiate into Treg cells

28
Q

Treg role

A
  • Suppress over-active T-Cell response
  • Limit innate/inflammatory response
  • Prevent autoimmunity

Releases:

  • IL-10: Supresses macrophage function
  • TGF-B: Induces generation of more Treg cells
29
Q

Memory CD4+ and CD8+ (General Concept)

A
  • Can undergo rapid recall expansion in re-infection
  • Immune memory is the principle for vaccine development

Block 1 - Week 5 (10 decks)

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