PSL301H1 Lecture Notes - Lecture 4: Cell-Mediated Immunity, B Cell, Passive Immunity
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PSL301H1 Full Course Notes
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Antigen speci c - body recognizes a particular foreign substance and selectively reacts to it: mediated by lymphocytes. 1. different b and t cells have different receptors. 3. memory - remembers the any antigen it has encountered. 1. some activated b and t cells are long lasting: tolerance - responds to foreign substances but. All lymphocytes secrete cytokines that act on immune cells, other cells and pathogens. Antigens - recognized by immune cells and cause an immune response. Antibodies - a protein complex that recognizes one of those antigens (we make the ones) Acquired immunity can be subdivided into active and passive immunity. Active immunity: occurs when the body is exposed to a pathogen and produces its own antibodies. May occur naturally (like when a pathogen invades the body) or arti cially (like when we are given vaccinations) Passive immunity: occurs when we acquire antibodies made by another organism. Transfer from mother to fetus or injections are examples.
