Complement activation

Question 1

What are the three pathways of complement activation?

Answer 1

classical pathway
lectin pathway
alternative pathway

Question 2

how does the complement system protect against pathogens?

Answer 2

Act as chemoattractants to promote chemotaxis of phagocytes, opsonize pathogens for phagocytosis by binding them, kill microbes by creating pores in their membranes

Question 3

How does complement help adaptive immunity?

Answer 3

opsonization of microbes allows them to be taken up by antigen presenting cells (APC)
Can enhance B cell response when bound to a microbe

Question 4

How is the classical pathway initiated?

Answer 4

binding of C1-q to the antigen-antibody complex of a pathogen

Question 5

How is the lectin pathway initiated?

Answer 5

binding of carbohydrate-binding proteins to carbohydrates on pathogens (mannose binding protein to microbial sugar residues)

Question 6

How is the alternative pathway initiated?

Answer 6

binding of C3b to pathogen surface

Question 7

What are potent activators of the classical pathway?

Answer 7

IgM, IgG

Question 8

Which complement pathways utilize C3?

Answer 8

All of them

Question 9

What is the terminal membrane attack complex?

Answer 9

construction of a protein complex to make a hole in the target membrane and kill the microbe