Innate Immunity 1

Question 1

What are the cellular mechanisms of innate immunity?

Answer 1

Phagocytosis
Cytokine secretion
Antigen presentation
Tissue remodelling

Question 2

What are the humeral mechanisms ?

Answer 2

Neutralisation of toxin action
Precipitation into insoluble form
opsonisation - make more accessible to phagocytes
Direct killing

Question 3

How does recognition occur?

Answer 3

All microbes have conserved PAMPs
Host cells have PRRs ( Pattern Recognition Receptors ) for recognition of PAMPs
Upon sensing pathogens, PRRs trigger innate immune responses to;
Eliminate pathogens
Activate and shape adaptive immune responses via antigen presenting cells
Activation of signalling PRRs triggers intracellular signalling cascades leading to activation of transcription and secretion of pro-inflammatory cytokines and anti-microbial peptides

Question 4

Give some examples of PAMPs

Answer 4

Peptidoglycan
Lipopolysaccharide
Lipoteichoic acids

Question 5

What are the phases of inflammation?

Answer 5

Acute phase - changes in local blood flow, accumulation of inflammatory cells (macrophages, neutrophils) , oedema
Middle phase - resolution of initial insults
Final phase - termination of inflammation and tissue repair

Question 6

What is innate immunity?

Answer 6

Innate (natural) immunity produces non-specific responses
The innate immune system performs a valuable delaying function, keeping pathogen numbers in check while the adaptive immune system gears up for action

Question 7

What are the benefits of innate immunity?

Answer 7

Allows to detect and protect against a broad spectrum of pathogens
Non-specific for a particular antigen or pathogen
Allows perfect discrimination between self and non-self