Complement- Lecture 10/5/21

Question 1

Complement

Answer 1

A series of proteins working in a cascading manner to generate defense mechanisms

Question 2

Three different pathways of complement activation

Answer 2

• Classical
• Alternative
• Mannan binding ligand

Question 3

C1q

Answer 3

First protein to bind to the Fc site of antibody, recruits C1r and C1s

Question 4

What activated C1 cleaves

Answer 4

C4, making C14b

Question 5

What C14b cleaves

Answer 5

C2, making C14b2b

Question 6

What C14b2b cleaves

Answer 6

C3, making C14b2b3b

Question 7

What C14b2b3b cleaves

Answer 7

C5

Question 8

Membrane attack complex

Answer 8

C5b through C9

Question 9

C9 function

Answer 9

Creates channel in the cell membrane to allow lysis

Question 10

Complement proteins responsible for opsonization

Answer 10

C3b

Question 11

C3a and C5a function

Answer 11

Chemotaxis and Anaphylatoxin production

Question 12

Anaphylatoxins

Answer 12

Involved in Mast cell degranulation

Question 13

C1-inhibitor

Answer 13

Important regulator of the primary pathway

Question 14

Alternative complement pathway initiation

Answer 14

Factor B, D and properdin combine with residual C3b in blood in response to lipopolysaccharide creating C3bBbP, initiates membrane attack complex

Question 15

Inhibitors of the alternative pathway

Answer 15

Factor H and Factor I

Question 16

Lectin Pathway

Answer 16

Activated by organisms with mannose on their surface

Question 17

Proteins important in Lectin Pathway (3)

Answer 17

• MBL
• MASP1
• MASP2

Question 18

Absence of C1q, C2, or C4

Answer 18

Associated with SLE (lupus)

Question 19

Absence of C3

Answer 19

Severe recurrent bacterial infections

Question 20

Absence of C5

Answer 20

Bacterial infections, like C3 but not quite as bad

Question 21

Absence of C6,7, and 8

Answer 21

Overwhelming Neisserial infections (N. Meningitidis, N. gonorrhea)

Question 22

Absence of alternative/lectin pathway components

Answer 22

Recurrent bacterial infections

Question 23

Absence of C1-INH

Answer 23

Hereditary angioedema

Question 24

Hereditary angioedema

Answer 24

Autosomal dominant, episodes of angioedema without urticaria or pruritis, can lead to asphyxiation