Lec 03: Complement Flashcards
Three pathways of the complement system
Classical, Lectin, Alternative
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
Classical pathway
- Classical
- Lectin
- Alternative
A. Primary line of defense
B. Secondary line of defense
C. Third line of defense
- C
- B
- B
Classical pathway
- It is activated by _____ complex
- When the antibody that attaches is either IgG or IgM, it will trigger the activation of the _____ complex
- C1q attaches to the antibody, whereas C1 r and C1s will activate ___ and ___.
- When ___ is activated, it will cleave and become C4a and C4b.
- ____ is activated simultaneously with C4. .
- Ag-Ab complex
- C1
- C2 and C4
- C4
- C2
- C4a
- C3a
- C5a
A. Anaphylatoxin
B. Chemotactic factor
C. Both
D. Neither
- A
- A
- C
Classical pathway
- Upon activation of C2, it will become ____ and ____
- C4b can either bind to C2a or C2b but NOT BOTH, forming the ________.
- C3 Convertase activates the ____. Once it is activated, there would be C3a or C3b
- ___ can bind to complex in C3 convertase forming the C5 convertase.
- C5 Convertase activates the ____. Once activated, there would be C5a or C5b
- C2a and C2b
- C3 convertase
- C3
- C3b
- C5
- In the classical pathway, this results in lysis of the cells presented
- The end effect of complement system
A. Lysis
B. Membrane Attack Complex
- B
- A
What is the C3 Convertase of the Classical Pathway?
C4bC2a or C4bC2b
What is the C5 Convertase of the Classical Pathway?
C4bC2aC3b or C4bC2bC3b
What is the Membrane Attack Complex (of Classical Pathway)?
C5bC6C7C8C9 or C5b6789
Also known as Mannose Binding Lectin (MBL) from gram positive cocci stimulates Mannose Associated Serine Protease (MASP).
Lectin Pathway
This resembles C1 and is similar to the function of C1qrs.
Mannose Associated Serine Protease (MASP)
T or F: Lectin pathway has C1 because C1 needs an antibody and Lectin provides this
False (gawa-gawa ko lang ‘te)
What activates C2 and C4 in Lectin Pathway?
MASP
End effect of Lectin Pathway
Lysis
T or F: The C4 convertase of the Lectin and Classical Pathway are the same
False (C3 convertase)
C3 convertase of Lectin Pathway
C4b2a or C4b2b.
C5 convertase of the Lectin Pathway
C4b2a3b or
C4b2b3b.
What is the Membrane Attack Complex of Lectin Pathway?
C5bC6C7C8C9 (C5b6789),
This pathway is activated by microbial surface, Lipopolysaccharide, Zymosan, aggregated IgA
Alternative Pathway
What activates the Alternative Pathway?
Microbial surface, Lipopolysaccharide (LPS),
Zymosan, aggregated of IgA
3 factors needed in Alternative Pathway
Factor D, B, P
In the alternative pathway, this can activate Factor B in the presence of C3 and Mg
Factor D
Alternative Pathway
- Factor D in the presence of _____ and __ will activate Factor B
- Factor Bb can activate ___ and once activated, it will become C3a and C3b.
- Factor Bb can adhere to C3b to form _____ (C3 Convertase).
- For the C3 Convertase to become stabilized, it needs the _____.
- C3 Convertase activates____ and once C3 is activated it will become C3a and C3b.
- Magnesium and C3
- C3
- C3bBb
- Factor P
- C3
Properdin
Factor P
Alternative Pathway
- C3b will bind to C3bBb which results to the formation of ________
- Once ___ is activated, it will become C5a and C5b.
- C5b leads to the activation of ____________ which is the C5b6789 which then results to lysis.
- C2bBb3b
- C5
- Membrane Attack Complex
What is the C5 Convertase of the Alternative Pathway?
C3b Factor Bb 3b (C3bBb3b)
What is the C3 Convertase of the Alternative Pathway?
C3b Factor Bb (C3bBb)
What is the Membrane Attack Comple of Alternative Pathway?
C5bC6C7C8C9 or C5b6789
Complement is inactivated in what conditions?
56*C for 30 minutes
Anaphylatoxin components of the pathways
C4a, C3a, C5a
Referred as opsonins
C4b, C3b, C5b and IgG
Most abundant/common complement
C3
Most common deficiency
C2 Deficiency
Most severe deficiency
C3 Deficiency
