Innate Immunity

Question 1

What does Innate immunity mean?

Answer 1

Recognition of an antigen by non-specific pattern recognition receptors. These receptors are gremlin encoded.

Question 2

What is the function of the innate immunity? Describe features of it.

Answer 2

1. Act rapidly
2. Promote acute inflammation

Microbiological- natural flora
Mechanical- skin, epithelial cells joined by tight junctions, cilia
Chemical- fatty acids, low pH, enzymes, antibacterial peptides

Question 3

Describe how antigens are recognised in the innate immune response.

Answer 3

By PAMPs (Pathogen-associated molecular patterns) which occur in lower order organisms.
These are recognised by PRR (Pattern recognition receptors)

An example would be that mannose binding ligands have an affinity to mannose and frucose residues with correct spacing.

Question 4

How do natural killer cells work?

Answer 4

Recognise antibody-coated bacteria via Fc receptors.

Question 5

What is the function of eosinophils?

Answer 5

They are important in parasitic infections
They flood the site of infections
They contain granules containing toxic elements

Question 6

Consider soluble mediators. Describe complement molecules.

Answer 6

Series of enzymes made in liver and secreted into circulation in inactive form.
One one of the enzymes is activated by antibody-antigen complex, pathogen, mannose binding ligand it sets off a ‘TRIGGERED ENZYME CASCADE’
This leads to cell lysis, secretion of inflammatory components and antibody-antigen complex clearance.

C3B will stick to pathogen in opsonisation aiding in phagocytosis

Question 7

Consider soluble mediators. Describe interferon.

Answer 7

They are produced by virally infected cells.
This causes proximal cells to slow down division and protein synthesis.
Stimulates production of anti-viral proteins

They are used in treatment against Hep-B however these effects include nausea.