Cell mediated and Humoral

Question 1

What are the steps of cell-mediated response?

Answer 1

• APC presents the foreign antigen to the immature T-cells
• An antigen presenting cell reaches the immature T cells in the lymph
• The APC will bind to the immature T-cells with the most complementary receptor to the foreign antigen clonal selection.
• This triggers the selected T-cell to divide rapidly by mitosis - clonal expansion
• The mature T -cells produced via clonal expansion differentiate to form 4 distinct types, T-helpers, T-regulators, T-killers and perforin
• T-killers bind to the infected body cells and destroy them by making holes in their plasma membrane
• T-helpers help to activate the humoral response by binding to complementary immature B-cell and secrete cytokines to attract phagocytes

Question 2

What are the steps of the humoral response?

Answer 2

• An APC or pathogen reaches the immature B lymphocytes
• The B-cell with the most complementary receptor to the antigen engulfs the pathogen and presents its antigens
• an activated T-helper cell binds to the antigen presenting B-cell. - Clonal selection
• The selected B-cell divides, cell divides rapidly by mitosis - clonal expansion
• The cloned cells differentiate to become either plasma or memory cells
• Plasma cells produce antibodies at a rate of 2000 molecules per second
• memory cells remain in the blood stream ready to proliferate again if you are infected with the same pathogen again.