Innate Immune System

Question 1

What are the components of the innate immune system?

Answer 1

Macrophafes
Neutrophils
Interferons
Natural killer cells

Question 2

How does the innate immune systme recognise pathogens?

Answer 2

Macrophages have TLR which recognise PAMPS (not present on human cells)

Question 3

What are the 3 main responses triggered by macrophages recognising a pathogen?

Answer 3

PHAGOCYTOSIS

• carried out by macrophages 1st (due to being present in the tissues) and then by neutrophils once been recruited (also eosinophils)
• involves attachment/ingestion/killing/degradation

INFLAMMATION

• release of cytokines i.e. interleukins/TNF/GF
• leads to recruitment of more macrophages, neutrophils and NK cells + opsonins to help with identification of pathogens

INTERFERONS

• block viral entry + replication in cell
• activate macrophages + NK cells

NATURAL KILLER CELLS
-lymphocytes which are NOT specific to one antigen
-recognise abnormal cells i.e. virurally-infected or tumour
-induce apoptosis or cell lysis
-secrete IFN-gamma to activate more macrophages
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