Innate Immunity

Question 1

Describe innate immunity

Answer 1

From birth
Fast
Recognises patterns
Not specific

Question 2

3 ways of pathogen recognition

Answer 2

PAMPs pathogen structure e.g. peptidoglycan, lipoproteins
DAMPs cell injury e.g. ATP, DNA, collagen
Detect self using NK
- NK use MHC class I receptors
- infected cells downregulate self molecules

Question 3

Characteristics of neutrophils

Answer 3

Multi lobed
Primary granules with enzymes
Secondary granules supply primary

Question 4

Upon infection what do neutrophils do?

Answer 4

Enter tissue
Bind to pathogen
Phagocytosis
Kill

Question 5

What is opsonisation?

Answer 5

Coating of pathogen in either antibodies or complement protein to make phagocytosis easier

Question 6

Characteristic of monocytes

Answer 6

Differentiate into macrophages
Have lysozymes and pattern recognition receptors
Signal infection by releasing cytokines

Question 7

IL 1
IL 6
IL8

Answer 7

Fever
Acute phase protein, acts over long distance
Chemotactic for neutrophils

Question 8

Bacterial septic shock

Answer 8

Release of IL1 and TNF alpha by macrophages drop in both

Question 9

What is a complement ?

Answer 9

Glycoproteins help defence when antigen and antibody bind

Trigger enzyme cascade reaction

Question 10

3 ways complement is activated

Answer 10

Classical = antigen and antibody bind
Lectin is a pattern recognition receptor that binds to carbohydrates on pathogen only
Alternative = activation by surface of pathogen

All activate C3b and form membrane attach complex

Question 11

Function of complements?

Answer 11

Active inflammation response

• degranulation of mast cell
• clearing of antibody antigen complex

Question 12

Mast cells

Answer 12

Secret histamine 
Phagocytotic
2 types: mucosal and connective
Activated by anaphylatoxin
Causes vasodilation

Question 13

Describe the local acute inflammation response

Answer 13

Pattern recognition receptor on macrophage binds to PAMP
Macrophages secret alarm cytokines and chemokine
Neutrophils and lymphocytes to find pathogen
Complement activated by pathway
Produce anaphylatoxins
Bind to receptor on mast cell = degranulation
Vasodilation

Question 14

Characteristic of NK

Answer 14

Cytotoxic
Secret interferons
Granulated
Bind to antibody coated cells
Defence against rumours and viruses

Question 15

Missing self recognition

Answer 15

NK recognise MCG class I on cells
They are normal cells
NK inhibitory receptors recognise
Not to be killed

Question 16

Induced self

Answer 16

Cell giving off stress patterns
NK activating receptors regencies
Kill