[P] Lec 03: Complement

Question 1

Three pathways of the complement system

Answer 1

Classical, Lectin, Alternative

Question 2

Refers to:

• Activated by Ag-Ab reaction
• It is part of specific immune response (3rd line of defense)
• The pathway primarily requires activation from IgM or IgG antibodies

Answer 2

Classical pathway

Question 3

1. Classical
2. Lectin
3. Alternative

A. Primary line of defense
B. Secondary line of defense
C. Third line of defense

Answer 3

1. C
2. B
3. B

Question 4

Classical pathway

1. It is activated by _____ complex
2. When the antibody that attaches is either IgG or IgM, it will trigger the activation of the _____ complex
3. C1q attaches to the antibody, whereas C1 r and C1s will activate ___ and ___.
4. When ___ is activated, it will cleave and become C4a and C4b.
5. ____ is activated simultaneously with C4. .

Answer 4

1. Ag-Ab complex
2. C1
3. C2 and C4
4. C4
5. C2

Question 5

1. C4a
2. C3a
3. C5a

A. Anaphylatoxin
B. Chemotactic factor
C. Both
D. Neither

Answer 5

1. A
2. A
3. C

Question 6

Classical pathway

6. Upon activation of C2, it will become ____ and ____
7. C4b can either bind to C2a or C2b but NOT BOTH, forming the ________.
8. C3 Convertase activates the ____. Once it is activated, there would be C3a or C3b
9. ___ can bind to complex in C3 convertase forming the C5 convertase.
10. C5 Convertase activates the ____. Once activated, there would be C5a or C5b

Answer 6

6. C2a and C2b
7. C3 convertase
8. C3
9. C3b
10. C5

Question 7

1. In the classical pathway, this results in lysis of the cells presented
2. The end effect of complement system

A. Lysis
B. Membrane Attack Complex

Answer 7

1. B
2. A

Question 8

What is the C3 Convertase of the Classical Pathway?

Answer 8

C4bC2a or C4bC2b

Question 9

What is the C5 Convertase of the Classical Pathway?

Answer 9

C4bC2aC3b or C4bC2bC3b

Question 10

What is the Membrane Attack Complex (of Classical Pathway)?

Answer 10

C5bC6C7C8C9 or C5b6789

Question 11

Also known as Mannose Binding Lectin (MBL) from gram positive cocci stimulates Mannose Associated Serine Protease (MASP).

Answer 11

Lectin Pathway

Question 12

This resembles C1 and is similar to the function of C1qrs.

Answer 12

Mannose Associated Serine Protease (MASP)

Question 13

T or F: Lectin pathway has C1 because C1 needs an antibody and Lectin provides this

Answer 13

False (gawa-gawa ko lang ‘te)

Question 14

What activates C2 and C4 in Lectin Pathway?

Answer 14

MASP

Question 15

End effect of Lectin Pathway

Answer 15

Lysis

Question 16

T or F: The C4 convertase of the Lectin and Classical Pathway are the same

Answer 16

False (C3 convertase)

Question 17

C3 convertase of Lectin Pathway

Answer 17

C4b2a or C4b2b.

Question 18

C5 convertase of the Lectin Pathway

Answer 18

C4b2a3b or
C4b2b3b.

Question 19

What is the Membrane Attack Complex of Lectin Pathway?

Answer 19

C5bC6C7C8C9 (C5b6789),

Question 20

This pathway is activated by microbial surface, Lipopolysaccharide, Zymosan, aggregated IgA

Answer 20

Alternative Pathway

Question 21

What activates the Alternative Pathway?

Answer 21

Microbial surface, Lipopolysaccharide (LPS),
Zymosan, aggregated of IgA

Question 22

3 factors needed in Alternative Pathway

Answer 22

Factor D, B, P

Question 23

In the alternative pathway, this can activate Factor B in the presence of C3 and Mg

Answer 23

Factor D

Question 24

Alternative Pathway

1. Factor D in the presence of _____ and __ will activate Factor B
2. Factor Bb can activate ___ and once activated, it will become C3a and C3b.
3. Factor Bb can adhere to C3b to form _____ (C3 Convertase).
4. For the C3 Convertase to become stabilized, it needs the _____.
5. C3 Convertase activates____ and once C3 is activated it will become C3a and C3b.

Answer 24

1. Magnesium and C3
2. C3
3. C3bBb
4. Factor P
5. C3

Question 25

Properdin

Answer 25

Factor P

Question 26

Alternative Pathway 6. C3b will bind to C3bBb which results to the formation of ________ 7. Once ___ is activated, it will become C5a and C5b. 8. C5b leads to the activation of ____________ which is the C5b6789 which then results to lysis.

Answer 26

6. C2bBb3b 7. C5 8. Membrane Attack Complex

Question 27

What is the C5 Convertase of the Alternative Pathway?

Answer 27

C3b Factor Bb 3b (C3bBb3b)

Question 28

What is the C3 Convertase of the Alternative Pathway?

Answer 28

C3b Factor Bb (C3bBb)

Question 29

What is the Membrane Attack Comple of Alternative Pathway?

Answer 29

C5bC6C7C8C9 or C5b6789

Question 30

Complement is inactivated in what conditions?

Answer 30

56*C for 30 minutes

Question 31

Anaphylatoxin components of the pathways

Answer 31

C4a, C3a, C5a

Question 32

Referred as opsonins

Answer 32

C4b, C3b, C5b and IgG

Question 33

Most abundant/common complement

Answer 33

C3

Question 34

Most common deficiency

Answer 34

C2 Deficiency

Question 35

Most severe deficiency

Answer 35

C3 Deficiency