Activation of T Cells

Question 1

What happens after the macrophage engulfs biological material?

Answer 1

Protein fragments (peptides) from the material become attached to proteins in the cell.

Question 2

Where are the protein fragments added to?

Answer 2

Protein fragments are added to the macrophages cell surface membrane, displayed as ‘non-self’ antigens

Question 3

What do the antigens on the cell surface of macrophages act as?

Answer 3

Antigens presented on the surface of macrophages act as a signal to alert the immune system to the presence of foreign antigens in the body.

Question 4

What is the name given when macrophages present with non-self peptides on it’s cell surface membrane?

Answer 4

Macrophages display non-self peptides are antigen present cells (APCs)

Question 5

What are T helper cells with a complementary shape called?

Answer 5

CD4 receptor

Question 6

What do the CD4 receptors bind to?

Answer 6

Binds to the antigen on the surface of the antigen-presenting cells

Question 7

How is the CD4 activated? What does it do once it is activated?

Answer 7

activated by this binding, each T helper cell divides to produce a clone of active T helper cells and clone of T memory cells

Question 8

How long do the Second Clones remain the body for? What are the benefits of this?

Answer 8

→ Second Clone remains for years or months in the blood → If individual is exposed to the same antigen in the future, their immune system responds more quickly.

Question 9

Activation of T Cells (6)

Answer 9

1. Bacterium with antigens on surface 2. Bacterium engulfed by macrophage 3. Macrophage presents antigens on it’s surface and becomes an antigen-presenting cell (APC) 4. APC bind to T helper cell with complementary CD4 receptors 5. T helper cell is activated and divides 6. Clone of T memory cells is produced + Clone of active T helper cells