PSL201Y1 Chapter Notes - Chapter 23: T Helper Cell, Cytotoxic T Cell, Natural Killer Cell
Document Summary
B/t cells respond to and bind to antigens (antibody generators) Each antigen has a unique structure with different recognition sites called epitopes (or antigenic determinants) B/t cells have antigen receptors, similar to how there are receptors on antibodies. Features of a typical antibody: y-shaped molecule, 4-protein chins (2 heavy, 2 light), has variable and constant regions: each antibody can bind to 2 epitopes. Early in the development of a lymphocyte, particular antigen receptor molecules are produced, creating diversity of antigen receptors of varying specificity. In the presence of a pathogen, only lymphocytes with corresponding antigens are activated to proliferate and differentiate (clonal section) Lymphocyte differentiation fives rise to clones; effector cells (ex. plasma cells) and memory cells (long-lived, all have receptors for the same antigen) Primary response is activated at first antigen exposure (10 17 days later: antigen-selected b/t cells proliferate/differentiate (by then person shows symptoms of sickness, acquired immunity: immunity from further infection by the same microorganism.
