fighting infection- virus'

Question 1

virus’ enter host cells and

Answer 1

replicate

Question 2

host cells will release

Answer 2

IFN-alpha

Question 3

IFN-alpha released by host cells causes

Answer 3

host cells to diplsay part of the viral peptide on their surface MHC 1 molecule.

Question 4

IFN-alpha also

Answer 4

prevents neighbouring cells from getting infected

Question 5

when virus kills infected cell

Answer 5

viral particles are released and activate dendritic cells, which engulf particle
- dendritic cells transport particles to the local lymph nodes via lymphatic system

Question 6

dendritic cells enter the lymph system and cause

Answer 6

naive T cells to enter

Question 7

interaction between dendritic cells and naive t cell

Answer 7

dendritic cells present viral peptides to T helper cells on their MHC II molecules which activate T cells

Question 8

dendritic cells can activate

Answer 8

Th1 and Th2 cells

Question 9

activated Th2 cells

Answer 9

cause B cells to become plasma cells and release antibodies

Question 10

how are B cells activated by T cells

Answer 10

via co-stimulatory molecules and the release of cytokines

Question 11

Th1 cells activate..

Answer 11

cytotoxic T cells

Question 12

how are cytotoxic T cells activated

Answer 12

by Th1 cells which release cytokines - IFN-gamma and IL-2)

Question 13

Th1 and cytotoxic T cells leave

Answer 13

the lymph node and of to the site of infection

Question 14

virally infected cells are killed by

Answer 14

cytotoxic T cells –> they used MHC I molecules which present on virally infected cells to be recognised

Question 15

NK cells get activated by

Answer 15

IFN-alpha released by infected cells and IL-2 and IFN-gamma, released by T helper 1 cells –> once activated NK cells kill virally infected cells

Question 16

antibodies and viral infection

Answer 16

• neutralise viral proteins b binding to them

- or bound antibodies may guide NK cells to recognise infected cells and kill them