The Complement System

Question 1

Best antibodies to activate complement?

Answer 1

IgM and IgG3 (multiple IgG3) required

Question 2

Match ligand, cells, and function to receptor

Receptor: CR1 / CD35

Answer 2

Ligand: C3b
Cells: Macrophages, neutrophils, RBCs
Function: Phagocytosis, clearance of immune complexes

Question 3

Match ligand, cells, and function to receptor

Receptor: CR2 / CD21

Answer 3

Ligand: C3d
Cells: FDCs, B cells
Function: Antigen trapping, B cell activation

Question 4

Match ligand, cells, and function to receptor

Receptor: CR3, CD11b/CD18 integrin

Answer 4

Ligand: iC3b
Cells: Macrophages, neutrophils
Function: Phagocytosis

Question 5

Match ligand, cells, and function to receptor

Receptor: CR4, CD11c/CD18 integrin

Answer 5

Ligand: iC3b
Cells: Macrophages, neutrophils
Function: Phagocytosis

Question 6

C4 haplotype

Absence of C4A gives increased susceptibility to:
Absence of C4B gives increased susceptibility to:

Answer 6

Systemic lupus erythematosus

Infections

Question 7

C3 convertase for Alternative pathway?

Answer 7

C3bBb

Question 8

C3 convertase for Lectin / Classical pathways?

Answer 8

C4bC2a

Question 9

C5 convertase for Alternative pathway?

Answer 9

C3b(little 2)Bb

Question 10

C5 convertase for Lectin / Classical pathways?

Answer 10

C4bC2aC3b