A17 Cellular Immune Response

Question 1

Steps

Answer 1

1) T-cell receptor (CD4/8) binds to MHC on APC
2. a) CD8 cell gets activated with MHC-I=> Tc-cells activate
2. b) CD$ cell activated y MHC-II=> Th-cells release cytokines
3) activated T cells multiply and differentiate in blood

Question 2

Cellular immunity

Answer 2

immune response that does not involve the production or use of antibodies, but rather the activation of macrophages, natural killer (NK) cells, antigen specific cytotoxic T lymphocytes and the release of various cytokines in response to an antigen. • It is called cellular because the protective function of immunisation can be associated with the cells.

Question 3

members

Answer 3

CD4 cells or T helper cells provide protection against the pathogens, whereas Cytotoxic T cells cause death by apoptosis without using cytokines – therefor cell-mediated cytokines are not always present.

Question 4

Function

Answer 4

o To protect the body by:
▪ T cell mediated immunity,
▪ Activating macrophages and NK cells,
▪ Stimulating cells to secrete cytokines which influence other immune cells.
o Play a role in tissue rejection.
o Most effective in removing virus-infected cells.

Question 5

Mechanism:

Answer 5

1. Cells displaying foreign antigens bind to T cells.
2. Interleukins secreted by APCs or T helper cells costimulate activation of T cells.
3. T cells proliferate, producing T helper cells.
4. T helper cells release interleukins and other cytokines which activate effector cells (cytotoxic T cells, NK cells, macrophages) that destroy the antigen/pathogen.