What are effector T cell?
T cells that have been activated
What are 5 functions of effector T cells?
- kill infected cells
- make cytokines
- enhance innate immune system
- support antibody production
- remember the antigen for next time
CD4 T cells recognise antigen in the context of…
MHC II
CD8 T cells recognise antigen in the context of…
MHC I
What is the main job of CD4 T cells? Do CD8 T cells do this too?
CD4 T cells make cytokines to support other immune cells. So do CD8
What is the main job of CD8 T cells? Do CD4 T cells do this as well?
CD8 t cells make cytotoxic molecules to kill infected cells. So do CD4 t cells (less common but they do it)
What cells get activated in response to cytokines produced by effector T cells?
Phagocytes
T cells
B cells
Non-immune cells
What is the response of the effector T cell to cytokines produced by antigen presenting cells (e.g. dendritic cells)?
They produce: more cytokines
Killing enzymes
chemokines
metabolic products (T cells)
survival proteins
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
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
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
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
What do t cells produce in response to Il-23
Il-17
What do t cells produce in response to IL-12
Interferon gamma
Describe the Th17 immune response
CD4 t cells respond to IL-17 by producing Il-22 to kill fungi
Neutrophils also respond to IL-17 by increasing inflammation
CD8 T cells are usually Th…
Th1
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
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
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
- respond very quickly
- express restricted alpha and beta TCR and NK markers
- recognise lipid antigen on MHC-like molecules
- innate like
