Cellular response

Question 1

What are T lymphocytes/ T cells?

Answer 1

• These are white blood cells involved in specific immune response.

Question 2

What are antigen-presenting cells?

Answer 2

• Any cell that presents non-self antigen on its surface.

Question 3

Different examples of antigen-presenting cells?

4 examples!

Answer 3

1.) Cells infected with virus will present viral antigens on their surface.
2.) Macrophage (phagocyte that has enguled pathogen) will present pathogen antigens on surface.
3.) Cells from organ transplant will have different antigens compared to your self-antigens.
4.) Cancer cells will have antigens different to your own self antigens.

() - extra info clarification.

Question 4

Why is response T cells are involved in known as “cellular response?”

Answer 4

• T cells response = cellular because T cells will only respond to antigens which are present on antigen-presenting cells (not antigens on pathogens that are floating around in the blood!!)

() - extra info for clarification

Question 5

What is another name for cellular response?

Answer 5

• Cell-mediated response.

Question 6

Steps of cellular response?

Answer 6

1.) Macrophage will present destroyed pathogen’s antigens on its cell-surface membrane - becoming APC.
2.) Helper T cells’ specific antigen receptor site (on surface) will bind to antigens on APC.
3.) Binding stimulates T-helper cells to divide by mitosis - making clones.
4.) Cloned helper T cells will differentiate into cytotoxic T cells/ stimulate B cells and phagocytes.

Question 7

What do cytotoxic T cells do?

Answer 7

• Destroy abnormal/ infected cells (ie. cancer cells/ viral-infected cells.)
• Release perforin protein –> perforin embedds in cell surface membrane/ makes pores so enzymes can enter the cell. This destroys cell.

Question 8

What 3 cells do T-helper cells stimulate?

Answer 8

• Cytotoxic T cells
• B cells
• Phagocytes/ macrophages.

Question 9

What are Helper - T cells and cytotoxic T cells sometimes abbreviated as?

Answer 9

• Helper- T cells: T (subscript h.)
• Cytotoxic T cells: T (subscript c.)