Immunology

Question 1

What pro-inflammatory cytokines are released by macrophages?

Answer 1

PAF
Prostaglandins
IL1
IL8
IL6
TNFa

Question 2

What effect do pro inflammatory cytokines have on endothelial cells?

Answer 2

PAF, prostaglandin, IL6 & TNFa increase permeability

PAF also induces platelet histamine release

IL1 and TNFa activate adhesion molecule expression

IL8 promotes recruitment of neutrophils and monocytes

Question 3

List 3 adhesion molecules

Answer 3

P-selectin
E-selectin
Integins

Question 4

What are the 2 types of mast cells

Answer 4

Mucosal mast cells
Connective tissue mast cells

Question 5

What does histamine do

Answer 5

It causes vasodilation and increased vascular permeability

Question 6

What does TNFa do

Answer 6

Promotes inflammation

Question 7

What do prostaglandins do

Answer 7

Vasodilation and also platelet aggregation

Question 8

What is extravasation?

Answer 8

The process of leukocytes exiting the blood vessel

Question 9

Describe the 4 steps of extravasation

Answer 9

1. Chemoattractant
   Inflammation causes cytokine release causing expression of adhesion molecules
2. Rolling adhesion
   Leukocyte binds marginally to selecting and roll along inner wall of vessel
3. Tight adhesion
   Macrophages release chemokines which causes integrin molecules to bind at high affinity (stops rolling)
4. Transmigration
   Leukocyte flattens out and squished between endothelial cells and through basement membrane, then migrated along chemotactic gradient towards site of injury

Question 10

What cytokine drives the process of extravasation?

Answer 10

IL5

Question 11

Describe the Missing Self Hypothesis

Answer 11

NK cells have both activating and inhibitory receptors. Healthy cells express both of these.

Infected cells down-regulate their expression of proteins that activate inhibitory receptors.

Without the inhibitory receptors activated, NK cells kill (only signal is the activation receptors)

Question 12

What is systemic inflammation, and what are 2 prominent cytokines that cause issues?

Answer 12

Inflammation throughout the body caused by massive release of cytokines that spreads through the blood and affects other organs.

IL1 affects the brain and causes fever, anorexia and somnolence

IL6 stimulates liver to produce acute phase proteins

Question 13

Define acute phase proteins?

Answer 13

Proteins that change plasma concentration in response to inflammation (either positive or negative acute phase proteins)

Question 14

How do acute phase proteins come about?

Answer 14

They are produced by the liver in response to IL1, IL6, IL8, TNFa etc

Question 15

List a few acute phase proteins

Answer 15

C-reactive protein
Serum amyloid P component
Complement factors
Mannon-binding lectin
Coagulation factors

Question 16

What are the 3 phases of wound healing?

Answer 16

Inflammation, proliferation and remodelling

Question 17

How long does each phase of wound healing last for and what are the characteristics of each?

Answer 17

1. Inflammation
   -4-6 days
   -controlling bleeding, preventing infection, established environment for healing with chemotaxis
2. Proliferation
   -4-24 days
   -fibroblasts depositing collagen, angiogenesis, granulation tissue formation, Re-epithelialisation, wound contraction
3. Remodelling
   -21 days - 2 years
   - collagen realigned along tension lines, apoptosis of cells no longer needed

Question 18

What receptor type do PAMPs bind to?

Answer 18

PRRs

Question 19

What receptor types do antigens bind to?

Answer 19

MHC class II, TCR, antibodies

Question 20

What receptor type do antibodies bind to

Answer 20

FcR