lecture 3

Question 1

what is produced in response to infection?

Answer 1

= pro-inflammatory cytokines

Question 2

what IL-2 cause?

Answer 2

T cell proliferation

Question 3

what does IL-10 cause?

Answer 3

anti-inflammatory

Question 4

describe the appearance of neutrophils?

Answer 4

= multi lobulated nucleus

= pink cytoplasm

Question 5

True or false.

neutrophils are long lived?

Answer 5

= false

- they are short lived

Question 6

what is main mode of movement of neutrophils used to move from blood to the tissue through the blood vessel wall?

Answer 6

= trans-endothelial migration

Question 7

what is trans-endothelial migration triggered by?

Answer 7

= triggered by po-inflammatory mediators as they promote vascular changes

Question 8

describe the process involved in trans-endothelial migration of neutrophils?

Answer 8

1) margination of neutrophils to endothelium
2) binding of neutrophils to adhesion molecules (e.g. ICAM ) on endothelial
(Histamien & TNFalpha promote the expression of adhesion molecules)
3) migration across endothelium by diapedesis
4) movement of neutrophils within tissue via chemotaxis
5) activation of neutrophils via their PAMPs via TNFalpha

Question 9

what are 3 mechanisms of neutrophil killing?

Answer 9

1) phagocytosis
2) degranulation
3) NETs
= neutrophils extracellular traps

Question 10

what does NETs stand for?

Answer 10

= neutrophils extracellular traps

Question 11

what happens in degranulation?

Answer 11

= direct killing of the extracellular pathogen
BUT
= it can lead to tissue damage and systemic inflammation

Question 12

what is the purpose of NETs?

Answer 12

= to immobilise the pathogen
- making it easier for the pathogen to be killed by phagocytosis
+
= prevents the phagocyte migrating/moving anywhere

Question 13

what is an abscess?

Answer 13

= collection of pus, surrounded by a membrane of spouting capillaries, neutrophils and fibroblasts

Question 14

what is the acute phase response driven by?

Answer 14

= pro-inflammatory mediators released by macrophages (IL-1, IL-6 and TNF)

Question 15

what is acute phase response mediated by?

Answer 15

= liver hepatocytes which produce acute phase proteins

Question 16

what is the complement system?

Answer 16

= a family of proteins that are produce din the liver but circulate in the blood

Question 17

what sort of reaction does the complete system result in?

Answer 17

= cascade reaction

Question 18

what are 3 types of pathway involve din the complement system?

Answer 18

1) classical pathway
2) alternative pathway
3) myosin binding lectin pathway

Question 19

what do all of these pathways do?

Answer 19

break down

C3 = C3a + C3b

Question 20

what is the mannose binding pathway lectin triggered by?

Answer 20

= bacteria

Question 21

what happens in the alternative pathway?

Answer 21

the C3b produced is highly UNSTABLE so binds to the cell surface resulting in;

(a) opsonisation
(b) triggering C5 = C5a + C5b

Question 22

what does C5b promote?

Answer 22

= formation of the membrane attack complex

Question 23

what do MACs do?

Answer 23

= insert themselves into pathogens membranes allowing extracellular salts and water to enter
= causing the cell to swell and burst

= LYSIS

Question 24

what is the role of C5a and C3a?

Answer 24

= inflammation