Immune Signaling

Question 1

What does immune signalling do?

Answer 1

coverts external stimuli to effective immune responces

Question 2

How does medicine use immune signalling?

Answer 2

• engage and manipulate cell surface signalling molecules on host immune cells to modulate antigen specific T cell and B cell receptor signals to control the direction and magnitude of lymphocyte responses.

Question 3

What are examples of the signalling pathways?

Answer 3

• JAK/STAT pathway (cytokines)
• NFkB pathway (inflammation)
• MAPK/ERK pathway (inflammation, cell proliferation/death)
• TLR pathway (innate immune activation)

Question 4

How does the JAK/STAT pathway work?

Answer 4

• Primary signalling cascade in response to cytokines
• JAKs are associated with cell surface receptors that lack kinase activity - residues on itself and receptor tail
• STAT proteins contain SH2 domains and bind to phosphorylated tyrosine residues on the receptor
• JAK phosphorylates STATS tyrosine residues
• STAT proteins form dimers and translocate the nucleus to initiate gene transcription

Question 5

How does the NF-KB pathway work?

Answer 5

• NF-KB is a protein complex which controls gene transcription - central to inflammation- rapid acting primary transcription factor
• In steady state NF-KB proteins repressed by IkB
  -Upon litigation of upstream receptors signal cascades result in activation
• NF-KB is translocated to nucleus to initiate gene transcription

Question 6

How does the MAPK/ERK pathway work?

Answer 6

• 3-teir kinase pathways initiated by an activator and a terminating transcription factor
• activated by hormones, growth factors, differentiation factors, oncogenic substances

Question 7

How does the TLR pathway work?

Answer 7

• found on innate immune cells
• Recognise a wide range of molecular patterns
• signal through Toll/IL-1 receptor domains on the intracellular proportion to complex with and TIR containing adaptor proteins