Innate Immunity

Question 1

Why is an innate immune response important ?

Answer 1

The adaptive immune response is too slow to protect from pathogens therefore following infection by unknown pathogens

Question 2

Describe the innate immune system

Answer 2

This is a non specific antigen recognition system

It involved recognition of broadly conserved features of different classes of pathogens

Question 3

What are PAMPs?

Answer 3

These are pathogen-associated molecular patterns

These molecules are only found on pathogens and not host cells

They are essential for the survival of pathogens

Invariant structures shared by entire class of pathogens

Question 4

Provide some examples of PAMPS

Answer 4

Gram-negative bacteria :lipopolysaccharides (LPS) found in outer membrane
Gram-positive bacteria ;teichoic acid, lipoteichoic acid, peptiodlycan found in outer membrane
Bacterial flagellin
Abnormal protein glycosylation
Abnormal nucleic acid-viruses

Question 5

What are Pattern recognition receptors(PRRS) ?

Answer 5

Host factors which will recognise a particular type of PAMP.

Germ-line encoded (No rearrangements)

Question 6

What are the different classes of PRR?

Answer 6

These classes are:
Extracellular -recognise PAMP outside of a cell and trigger co-ordinated response to the pathogen

Intracellular (cytoplasmic )-they recognise PAMPS inside a cell and act to co-ordinate a response to the pathogen

Secreted-They act to tag a circulating pathogens for elimination

Question 7

What are the components of the innate system ?

Answer 7

The inflammatory response 
Phagocytes 
Complement 
Cytokines,chemokines and anti-microbial peptides (AMPS)
Natural killer cells

Question 8

What is the inflammatory response ?

Answer 8

A non-specific defence mechanism which localises and eliminates injurous agents and removes damaged tissue components

Enhanced permeability and extravasation

Neutrophil recruitment

Enhanced cell adhesion

Enhance clotting