The Role of Killer T Cells

Question 1

What happens to the antigen on the surface of a bacterium or virus when it invades a body cell?

Answer 1

Bacterium or virus infects a body cell, a fragment of the antigen is presented on the cell surface membrane, in the same way it occurs in a macrophage.

Question 2

What do body cells bind to?

Answer 2

T killer cells with complementary receptors bind to the antigen presented on the body cell

Question 3

What do T killer cells divide to form? What is this division stimulated by?

Answer 3

T killer cells divide to form an active clone; this division is stimulated by the cytokines from T helper cells.

Question 4

What happens if there is not enough cytokines?

Answer 4

Without cytokines, not enough T killer cells produced to fight a viral infection.

Question 5

What do T killer cells release?

Answer 5

T killer cells release enzymes that create pores in the membrane of the infected cell.

Question 6

What do the pores that the T killer cells create do to the cell?

Answer 6

Enables ions + water to flow into the infected cell, which swells + bursts (lysis) Pathogens within the cell are released

Question 7

What happens when the cell bursts?

Answer 7

Once the cell can be burst, pathogens are out of the cell + labelled by antibodies from B cells as targets for destruction by macrophages.

Question 8

T Killer Cell (6)

Answer 8

1. Bacterium infects cell of host. 2. The cell product, presents the antigens + become APC 3. T killer cell with complementary receptor binds to the APC 4. T killer cell divides to form two clones: active + memory T killer cells. Cytokines from T helper cells differentiate stimulate differentiation. 5. The active T killer cells bid to infected cells presenting antigens 6. T killer cell releases chemicals that cause pores to form in the infected cell, causing lysis. Infected cell is destroyed