T-lymphocyte activation

Question 1

How are T-helper cells activated

Answer 1

1. pathogen with antigens is engulfed by macrophage during phagocytosis, so the macrophage is now an APC
2. T helper cell with a specific CD4 receptor binds the APC
3. this activates T-helper cells to produce cytokines which stimulates T-helper cells to undergo mitosis and produce activated T-helper cells

Question 2

How are T-killer cells activated

Answer 2

1. pathogen infects a host cell and causes host cell to become an APC
2. T-helper cell binds to APC and releases cytokines causing T-killer cells with complementary receptors attached to APC to undergo mitosis into T-killer memory cells and activated T-killer cells
3. active T-killer cell binds to APC which destroys host cell y releasing enzymes causing cell lysis