Question

1. Cleavage products of two different complement factors act similarly to recruit and activate cells. What is one of these cleavage products?

a. C1

b. C2

c. C3a

d. C5b

e. None of the above

Question 2

One of the stimuli for overall complement activation is generated when one of the complement factors undergoes a spontaneous fragmentation. This spontaneous breakdown is enhanced under what circumstance?

a. In the presence of bacteria

b.	Early in the morning

c. After a meal

d. Prior to birth

e.	Upon cantact with chemokines.

Question 3

What drives complement activation?

a.	Antigen bound to antibody

b. Direct contact with microbes

c. Soluble lectin receptors bound with pathogen carbohydrate structures

d.	All of the above

e. None of the above

Question 4

Some complement factors have the ability to opsonize pathogen via covalent linking to the surface of pathogen cells. Indicate one of these factors.

a. C3a

b. C4a

c.

C3b

d.

C5b

e. None of the above

Question 5

Which of the following statements is true regarding your own cells and complement?

a. The molecules on the surface of your own cells cannot be covalently linked with complement.

b. Complement proteins are repelled from the surface of your own cells by the negative charge of the resting membrane potential.

c. Your cells are targetted by complement, but because they are so much bigger than microbe cells there is negligible impact.

d. Your cells are targetted by complement, but only the necrotic and apoptotic ones.

Question 6

Which one of the following locations is NOT a location for toll-like receptors in your cells?

a. On the plasma membrane.

b. In the membranes of endocytotic vessicles.

c.	In the cytosol.

Question 7

This cytokine is secreted by phagocytic cells and T cells. It coordinates inflammation locally, and can also act as a hormone. It stimulates recruitment of cells to the site of infection, and it enhances the activation state of macrophage. What cytokine is this?

a.

IL-4

b. TNF

c. IL-12

d.

IL-10

e. IFN-gamma

Question 8

This cytokine is produced by regulatory T cells to reduce the activation state of immune cells. This results in lower levels of inflammatory cytokine production and lower expression of MHC proteins. What cytokine is this?

a. IL-4

b.

TNF

c.

IL-12

d.

IL-10

e. IFN-gamma

Question 9

This cytokine is associated with type 1 responses. It is produced only by lymphocytes, and it enhances the activation state of macrophages. The production of this cytokine is enhanced by IL-12 and IL-18. What is this cytokine?

a.

IL-4

b. TNF

c.

IL-12

d. IL-10

e.

IFN-gamma

Question 10

This cytokine is associated with type 2 responses. It is produced by lymphocytes, mostly. It inhibits the activation of macrophages in favor of eosinophils which are activated by IL-5, a cytokine produced at the same time. What cytokine is this?

a.

IL-4

b.

TNF

c. IL-12

d.

IL-10

e. INF-gamma

Answer 1

1. answer is 'c' - C3a

There are 3 pathways to activate immune system, in all pathways, C3-convertase cleaves and activates component C3, creating C3a and C3b, and causes a cascade of further cleavage and activation events.

2. answer is 'a' - in the presence of bacteria

Complement is a central part of the innate immunity that serves as a first line of defense against foreign and altered host cells. The complement system is composed of plasma proteins produced mainly by the liver or membrane proteins expressed on cell surface.

3. answer is 'd' - all of the above

any foreign particles enters into the body, it triggers the innate immune system and eliminate the pathogens or foreign particles from the body

4. answer is 'c' - C3b

The alternative pathway that opsonize and kill pathogens. The pathway is triggered when the C3b protein directly binds a microbe. It can also be triggered by foreign materials and damaged tissues.

5. answer is 'd'

complement can clear only the apoptotic cells and necrotic cells from our body.