PHED-2507EL Lecture Notes - Lecture 4: Adaptive Immune System, Humoral Immunity, Cell-Mediated Immunity
28 Feb 2019
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Document Summary
Adaptive defenses: antigens, b and t lymphocytes, humoral immunity, cellular immunity. Adaptive immune system: specific defensive system that eliminates almost any pathogen or abnormal cell in body. It is specific: recognizes and targets specific antigens. It is systemic: not restricted to initial site. It has memory: mounts an even stronger attack to known antigens (second and subsequent exposures. 2 main branches of adaptive system: humoral (antibody-mediated) immunity, antibodies, produced by lymphocytes. Substances that can mobilize adaptive defenses and provoke an immune response. Most are large, complex molecules not normally found in body (non-self) Characteristics of antigens: can be complete antigen or hapten (incomplete, complete antigens have two important functional properties: Immunogenicity: ability to stimulate proliferation of specific lymphocytes: reactivity: ability to react with activated lymphocytes and antibodies released by immunogenic reactions. Immunocompetent b and t cells not yet exposed to antigen are called na ve: exported from primary lymphoid organs (bone marrow and thymus) to.
