Innate Immune System

Question 1

Understand the importance of innate immunity as the first line of defence when encountering new pathogens

Answer 1

• immediate reaction to detecting pathogens.
• recognise PAMPs allows process of removing pathogenic material before adaptive response
• phagocytes: monocytes, granulocytes, neutrophils
• NK-cells: interrogate loss of MHC = loss of self
• chemokines and cytokines
• pro-inflammation = ⬆️clotting ⬆️cytokine release, ⬆️adhesion and cell adhesion and localisation of infection site.

Question 2

Know the general principles of recognition of pathogens and the role of pattern recognition receptors in the innate immune system

Answer 2

PAMPs:
- flagella
- abnormal protein glycosylation => β-glucan dectin-1 => ficolins=>
- asymmetric phospholipid membrane => pentraxins => cq1=> classic pathway

• no host control (loss of self) = detection via NK-cells => IFN ɑ/β = ⬆️ procaspase activation/cleaving
  increased recruitment of CD8

Question 3

Describe the importance of innate immunity in triggering an appropriate adaptive immune response

Answer 3

• highly conserved microbial ligands in evolution
• germ line encoded receptors used to detect for loss of self and instruct ⬆️ transcription into ‘hostile anti-viral’ cells and alert site of infection using cyto/chemokines

Question 4

Compare and contrast innate and adaptive immune system

Answer 4

INNATE:
- immediate: no previous exposure needed
- no memory / no change in magnitude of response before and after exposure
- limited variation of receptors

ADAPTIVE:
- repeated exposure ⬆️ magnitude and quality of response
- responding to a newly presented pathogen take several days for antigen specific antibody production and humoral and adaptive response
- memory