MIMM 214 Lecture Notes - Lecture 24: Lymph Node, B-Cell Receptor, Clonal Selection
17 Apr 2017
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Document Summary
B cell activation: signal 1, signal 2 & linked recognition. Humoral immunity (hmi: abs promote pathogen neutralization, opsonization, complement activation. Type of lymphocyte: arise in the bone-marrow, key role in adaptive immunity, antigen specific, b cells are clonotypic, progenitors of antibody- producing plasma cells. Identified by expression of b cell receptor (bcr) complexes on the cell surface = membrane bound ig. Take home messages: process of clonal selection and expansion, activated b cells undergo proliferation & differentiation, one outcome: plasma cell that secretes antibodies, another is the production of memory b cells. Signal i: bcr binds antigen: b cells enter lymph node, na ve b cells circulating in the periphery pass through the lymph nodes and spleen regularly, enter lymph node through hev. If don"t encounter ag after a few months, dies via apoptosis - finite lifespan, constant regeneration in bone marrow. If b cell does encounter antigen: provides survival signal (signal i, retained in lymph node.
