BIOL 115 Lecture Notes - Lecture 23: Hiv, Cytotoxic T Cell, Passive Immunity
Document Summary
Many copies of the activated t cell are produced. Occurs when a macrophage presents an antigen to a t cell that has the specific tcr that will bind this particular antigen. This activates the t cell, causing it to undergo clonal expansion. Some t cells become cytotoxic t cells, and some will become helper t cells. Has storage vacuoles that contain perforins and enzymes called granzymes. After binding to a virus-infected cell or tumor cell, it releases perforins, which punch holes in the plasma membrane, forming a pore. Cytotoxic t cells then deliver granzymes into the pore, causing the cell to undergo apoptosis. Secrete cytokines that enhance the response of all types of immune cells. B cells cannot be activated without t-cell help. The human immunodeficiency virus (hiv), which causes aids, infects helper t cells, thus inactivating the immune response. Can be brought about naturally through an infection or artificially through medical intervention.
