Complement

Question 1

consists of a group of around

Answer 1

40 proteins

Question 2

which paper talks about complement

Answer 2

sousa 2011

Question 3

where are complement proteins synthesised

Answer 3

the liver

Question 4

main roles of complement

Answer 4

1) inflammation
2) opsonisation
3) Lysis

Question 5

innate immunity kills…

Answer 5

bacteria, fungi, virus’ and parasites

Question 6

main components of complement

Answer 6

C1-C9

Question 7

complement proteins are named in

Answer 7

order that they were discovered, not the order that they act

Question 8

cell lysis mediated by the

Answer 8

membrane attack complex…

Question 9

name the three pathways

Answer 9

classical
lectin
alternative

Question 10

complement and phagocytosis

Answer 10

phagocytes have complement recpetors- these receptors bind to pathogens opsonised with complement (C3b and C4b).

Question 11

MAC formation

Answer 11

C5b bind sC6 and C6

• C5b67 complex binds to pathogen membrane via C7
• C8 binds to the complex and inserts into the cell membrane
• C9 molecules binds to the complex and polymerises
• 10-16 C9 molecules form a pore resulting in osmotic lysis and cell death

Question 12

classical pathway activated by

Answer 12

antigen-antibody complies (IgG and IgM)

Question 13

alternative pathway activated by

Answer 13

microbial survives e.g. polysaccharide

Question 14

lectin pathway activated by

Answer 14

mannose-binding lectin

Question 15

classical pathway activation occurs when

Answer 15

C1q/r/s molecule binds to Fc portion of Ab

Question 16

binding of C1q/r/s causes

Answer 16

conformational change

Question 17

conformational change to C1qrs

Answer 17

cleaves C1s to an active serum protease

Question 18

C1s cleaves

Answer 18

C4 to C4a and C4b

Question 19

C4b

Answer 19

cleaves C2 to C2a and C2b

Question 20

C2a binds to

Answer 20

C4b

Question 21

C4bC2a complex

Answer 21

C3 convertase

Question 22

C3 converts

Answer 22

cleaves C3

Question 23

C3 cleaved to … by C3 convertase

Answer 23

C3a and C3b

Question 24

C3b, C5a and C5b

Answer 24

C5 convertasse

Question 25

C5 converts cleaves C5 to

Answer 25

C5a and C5b

Question 26

C3a and C5a

Answer 26

inflammation

Question 27

C5a

Answer 27

chemoattractant for macrophage and neutrophils

Question 28

C3a and C5a bind to

Answer 28

mast cells- cause them to degranulate- releasing histamines –> inflammation

Question 29

C3b and C4b

Answer 29

opsonisation

Question 30

MAC complex

Answer 30

lyse bacteria

• C5b binds with C6-9
• formation of large (10nm) pore

Question 31

pore causes

Answer 31

water, ions and small molecules to enter the cell–> lysis