What is the difference between recognition of antigens in innate immunity and Adaptive Immunity? (2)
Innate Immunity: Recognise antigen by non-specific PATTERN RECOGNITION RECEPTORS ( recognise pathogen-associated molecular patterns). These receptors are ‘germline’ encoded (genetic).
In Adaptive Immunity (B-cells, T-cells): Random Somatic Recombination is used clonally select receptors so they are antigen-specific.
What are the functions of Innate Immunity? (3)
- Prevents Infection
- Promotes Acute Inflammation
- Rapid response
What are the innate barriers to Infection? (5)
- Skin - Epithelial cells, Normal Flora, Antibacterial peptides.
- Lungs - Cilia to move mucus, Antibacterial peptides, Flow of air
- Gut - Normal Flora, pH, Enzymes, Antibacterial peptides.
- Eyes/Nose - Enzymes, epithelial cells.
What two examples of Pattern Recognition Receptors? (2)
- Toll-like receptors.
2. Mannose Binding Ligand - binds to mannose and fructose residues with certain spacing.
What cells are part of the Innate Immunity system?
- Mast Cells and basophils
- Natural Killer Cell
How do Cytokines cause Systematic Inflammation, consider:
- Bone Marrow
- Fat Muscle cells
In Liver - Release of C-reactive proteins and Mannose binding lectin, which activate opsonisation and complement.
In Bone Marrow - Increase production of leukocytes for phagocytosis.
In Hypothalamus - Increases body temperature
In fat and muscle cells - Increases energy use.
Increasing body temp, helps reduce pathogen replication and increases immune response.
What are the 4 soluble mediators released in innate immunity?
What is Complement in Immune system?
- These are circulating inactive enzymes in the bloodstream, produced from the liver.
- When one of these enzymes are activated, triggers a cascade of reactions to trigger Cell lysis. (destroying membrane of pathogen cell).
What is the role of complement in opsonisation?
- Complement component C3b sticks to pathogens
- Then binds to phagocyte receptor alongside antigen.
What is an Interferon and what is its role in immune response? (2)
- Interferon can be alpha or beta. They are produced by virus infected cells.
- They work locally around cell, interfering with metabolic activity e.g stops cell division, protein synthesis and production of anti viral proteins.