Specific Response - Cell Mediated

Question 1

What is the cell mediated response used for?

Answer 1

When pathogens enter body cells, the cell mediated response helps remove them

Question 2

What cells are involved in the cell mediated response?

Answer 2

• Body cells become antigen presenting cells when infected
• T helper cells with CD4 surface receptors bind to APCs and are activated
• Specific T Killer cells also bind to surface antigens
• Activated T helper cells produce cytokines to activate T Killer cells
• Activated T killer cells become cytotoxic
• T memory cells remain

Question 3

What are similarities of cell mediated and humoral responses?

Answer 3

• Both are specific to a particular antigen
• Both require forming APCs and major histocompatibility complex
• Both involve clonal selection, activating only cells that recognise antigen
• Both involve clonal expansion, proliferation of cells needed
• Both involve differentiation of cells to produce effector cells

Question 4

Outline the cell mediated response

Answer 4

• Virus/Cancer/Bacteria infected cell
• Body cell becomes APC
• T killer cells with complementary receptors bind to infected cells
• T killer cells stimulated by cytokines from helper cells
• Memory T killer cell clones produced
• Active T killer cell clones
• T killer releases chemicals to form pores. Water and ion uptake causes swelling. Cell bursts and pathogens dealt with by B cells

Question 5

What is the role of T helper cells?

Answer 5

• Stimulates B cells to divide and become capable of producing antibodies