Lecture 21

Question 1

What are effector T cell?

Answer 1

T cells that have been activated

Question 2

What are 5 functions of effector T cells?

Answer 2

1. kill infected cells
2. make cytokines
3. enhance innate immune system
4. support antibody production
5. remember the antigen for next time

Question 3

CD4 T cells recognise antigen in the context of…

Answer 3

MHC II

Question 4

CD8 T cells recognise antigen in the context of…

Answer 4

MHC I

Question 5

What is the main job of CD4 T cells? Do CD8 T cells do this too?

Answer 5

CD4 T cells make cytokines to support other immune cells. So do CD8

Question 6

What is the main job of CD8 T cells? Do CD4 T cells do this as well?

Answer 6

CD8 t cells make cytotoxic molecules to kill infected cells. So do CD4 t cells (less common but they do it)

Question 7

What cells get activated in response to cytokines produced by effector T cells?

Answer 7

Phagocytes

T cells

B cells

Non-immune cells

Question 8

What is the response of the effector T cell to cytokines produced by antigen presenting cells (e.g. dendritic cells)?

Answer 8

They produce: more cytokines

Killing enzymes

chemokines

metabolic products (T cells)

survival proteins

Question 9

Describe the Th1 immune response

• what activates the T cell
• what does the T cell produce
• what cells does this activate
• what is the outcome

Answer 9

Th1 response

Dendritic cell recognises PAMP (intracellular bacteria or virus)

DC makes IL-12

IL-12 is recognised on the IL-12 receptor on the T cell

T cell starts producing IFNgamma

IFNgamma is recognised on B cells, macrophages and CD8 T cells

B cells- make antibody to enhance phagocytoisis

CD8 T cells- kill infected cells

Macrophage- increase phagocytosis

Question 10

Describe the Th2 immune response

• what activates the T cell
• what does the T cell produce
• what cell do the T cells activate
• what is the outcome

Answer 10

Th2 response

Dendritic cell recognises pathogen (extracellular worm or parasites) and creates IL4

IL4 binds to receptor on T cell

T cell starts producing more IL4 (positive feedback loop) and IL5 and IL13

Mast cells and esonophils are activated along with CD4 t cells and B cells

Mast cells and esonophils- kill parasites

CD4 T cells- produce more IL4, IL5, IL13

B cells make antibody to bind to pathogens

Question 11

What do t cells produce in response to Il-23

Answer 11

Il-17

Question 12

What do t cells produce in response to IL-12

Answer 12

Interferon gamma

Question 13

Describe the Th17 immune response

Answer 13

CD4 t cells respond to IL-17 by producing Il-22 to kill fungi

Neutrophils also respond to IL-17 by increasing inflammation

Question 14

Answer 14

Question 15

CD8 T cells are usually Th…

Answer 15

Th1

Question 16

Gamma-delta T cells

• where are they found
• what is different about their receptors
• whats different about their need for MHC
• are they more like an adaptive or an innate response

Answer 16

Found within the epithelium (esp in gut)
Are made up of gamma and delta subunits of the TCR instead of alpha and beta

Recognise antigen directly without MHC

Innate like

Question 17

Natural killer T cells

• how fast is their response
• what is different about their receptors
• what do they recognise
• are they more like an innate or adaptive cell

Answer 17

• respond very quickly
• express restricted alpha and beta TCR and NK markers
• recognise lipid antigen on MHC-like molecules
• innate like