Complement System

Question 1

C3a

Answer 1

• soluble

- stimulates inflammation by acting as a chemoattractant for neutrophils

Question 2

C3B

Answer 2

fragment becomes covalently attached to the microbial surface and serves as a opsonin to promote phagocytosis of the microbes

Question 3

C5A

Answer 3

-soluble C5a is a potent chemoattractant that also induces changes in permeability of blode

Question 4

The AP can be intiated as an _____ when C3B is generated by either CP or LP

Answer 4

amplification loop

Question 5

The mechanism of MAC formation is identical for the

Answer 5

AP, CP, LP

Question 6

c1r AND c1s are

Answer 6

serine proteases

Question 7

The LP is triggered by what

Answer 7

a plasma protien called: manose binding lectin

Question 8

C1 inhibitor (C1-INH)

Answer 8

inactivates C1R, C1S, MASP1, MASP 2

Question 9

MCP

Answer 9

Cofactor for factor 1, mediates cleavage for C3b and C4b

Question 10

DAF

Answer 10

destabilizes c3 and c5 convertase in the CP and AP (decay accelarting activity)

Question 11

CR1

Answer 11

cofactor for factor 1, mediates cleavage of c3b and c4 b, ALSO DOES DECAY ACC ACTIVITY FOR C3/c5 convertases

Question 12

C4 binding protein

Answer 12

binds to C4B, decay accelerating and cofactor activity

Question 13

Factor H

Answer 13

binds to C3b, has decay acc activity of AP c3 and 5 converases and cofactor activity

Question 14

Factor 1

Answer 14

degrades c3b and c4b with aid of cofactors

Question 15

cd59

Answer 15

blocks c9 association with c5b -c8 to prevent MAC to form on host cells

Question 16

s-protein (vitronectin)

Answer 16

binds to c5b -7 and ihibits c9 poly

Question 17

clusterin

Answer 17

binds to c5b-7 and ihibits gernation of c5b -9

Question 18

C5a

Answer 18

• anaphylatoxin
• causes contraction of SM
• INCERASES permability of blood vessels
• degranulation of basophils
• chemotaxis and relase of o2 radicals and lysomomal enzymes

Question 19

c3a

Answer 19

• anaphylatoxin
• causes contraction of SM
• INCERASES permability of blood vessels
• degranulation of basophils

Question 20

Glomerular dz

Answer 20

• activates immune complexes of the classical pathway of complement
• c5a is a chemoattractant for neutrophils
• c5b -9 forms membrane attack complex (causes protease release)
• production of ROS and inflammatory cytokines by attracted inflammatory cells and production of proteases which will lead to lesions and tissue fibrosis

Question 21

Hereditary angioedema

Answer 21

• edema in airway, feet, hands, face
• pts have defect in C1 INH gene
• causes continous activation of plasma complement
• C1 INH usually inhibits the porduction of bradykin but now it doesnt thus that increase vasodilation, capillary permability, and fluid edema

Question 22

Paroxysmal Nocturnal hemogolobin

Answer 22

• PNH cell lacks all proteins linked trough GPI anchor to their cell membranes
• DAF (cd55) and cd59 are complement regulatory proteins (daf ihibits c5 converase and c3 convertase)

Question 23

DAF (cd55) and CD 559 ARE WHAT

Answer 23

COMPLEMENTARY REGULATORY PROTIENS

Question 24

CD59 inhibits what

Answer 24

Formation of MAC

Question 25

How do you treat PNH

Answer 25

Immunotherapy: compstatin and ecluzumab