A2 Innate

Question 1

Innate 4 point summary

Answer 1

1. Inflammatory response
2. Complement
3. Interferons
4. Leukocytes

Question 2

Inflammation

Answer 2

recognition: PAMPs bind to PRR e.g. TLR,CLR, NOD
Activation innate: macrophages/ mast cells
inflammatory mediators: mast cells

Question 3

5 signs of inflammation

Answer 3

1. Heat 2. Redness 3.Pain 4. Swelling 5.Loss of function

Question 4

example innate recognition by TLR

Answer 4

TLR-3 Ligand:ds RNA (found only in virus)

TLR-4 dimer: LPS (gram-ve bacteria)

Question 5

TLR stimulation can = cell activation, activates…

Answer 5

cell secretes cytokine & chemokines

• inflammation
• recruitment more phagocytes (increases intracellular killing)

Question 6

Acidification mechanism in pattern recognition

Answer 6

pH= ~3.5-4, bacteriostatic or bactericidal

Question 7

Toxic oxygen derived products mechanism in pattern recognition

Answer 7

superoxide O2-, H2O2, singlet oxygen 102, Hydroxy radical *OH, hypophalite OCl-

Question 8

Antimicrobial proteins mechanism in pattern recognition

Answer 8

defensins & cationic proteins

Question 9

Enzymes mechanism in pattern recognition

Answer 9

lysozyme: dissolves cell walls of some gram+ve bacteria. Acid hydrolases: further digest bacteria

Question 10

Competitors mechanism in pattern recognition

Answer 10

Lactoferrin (binds Fe) & VitB12 - binding protein

Question 11

Steps of phagocytosis

Answer 11

Recognition: TLR - binding to PAMP present on pathogen

1. chemotaxis & adherence of microbe to phagocyte
2. Pseudopod formation
3. Ingestion of microbe by phagocyte
4. Phagosome:
5. Phagolysosome formation
6. Digestion: of ingested microbes of enzymes
7. formation of residual body containing digestible material
8. Discharge of waste materials

Question 12

Complement (Alternative & MBL pathway

Answer 12

Bacterium is coated w/ complement by alternative & MBL pathways
When only C3b binds CR1, bacteria are not phagocytosed
C5a can activate macrophages to phagocyose via CR1

Question 13

Complement C5b onwards

Answer 13

C5b binds C6 & C7, C5b67 complexes bind to membrane via C7, C8 binds to complex & inserts into cell membrane, C9 molecules bind to complex & polymerise, 10-16 moelcules of C9 bind to form a pore in membrane

Question 14

3. results of PRR

Answer 14

1. Cell activation 2. Cell recruitment 3. Bacteria killing