EG - Immune System II

Question 1

What are Dendritic Cells?

Answer 1

A bridge between the innate and adaptive immune systems

• Able to collect huge amounts of material from the environment and digest it
• They then present this information on their surface and show it to T cells

Question 2

What is an antigen?

Answer 2

Any non-self substance which causes an immune response

Question 3

How are antigens presented to T cells?

Answer 3

Via MHC molecules

Question 4

What are T-cells?

Answer 4

White blood cells

• Act to proliferate and activate upon recognition of an antigen

Question 5

What are the 2 types of T cells?

Answer 5

1) CD4+ helper T cells
* Release cytokines which attract and activate other immune cells

2) CD8+ cytotoxic T cells
* Release cytokines and substances like granzymes which kill infected cells

Question 6

How are T cell responses generated?

Answer 6

1. Dendritic cells swallow antigens by phagocytosis
2. DCs move to T cell zones
3. T cells interact with specific DCs and bind tightly
4. The specific T cell proliferates and develops
5. Activated T cells move into the inflamed tissues

Question 6

What are B cells?

Answer 6

Respond to a soluble or cell-surface antigen which binds to receptors on the surface of the B cells
* Release millions of antibodies

Question 7

How are B cells activated?

Answer 7

1. Interact with T cells
2. Activated B cells move and proliferate
3. Mature into plasma cells
4. Produce millions of antibodies

Question 8

What is Opsonisation?

Answer 8

An immune process which uses opsonins to tag foreign pathogens for elimination by phagocytes