BIOC39H3 Lecture Notes - Lecture 5: B-Cell Receptor, Affinity Maturation, Somatic Hypermutation
26 Mar 2020
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Document Summary
1: stages of b cell development, gene rearrangements, role of the pre-bcr during b cell development, allelic exclusion, b cell tolerance. Importance of bcr co-receptor in activation: antigen binding initiates intracellular signaling, thymus-dependent vs thymus-independent antigen, b cell activation in secondary lymphoid tissue, somatic hypermutation and class-switch recombination, affinity maturation. Phase 1: generation of v, d, j recombination + clonally expressed b-cell receptor [ each b cell has unique bcr of single specificity] B cell-precursors in the bone marrow acquire functional antigen receptors through immunoglobulin gene rearrangements. Each mature b cell expresses immunoglobulin of just one antigen specificity as its b cell receptor. The b cell population as a whole represents a vast repertoire of immunoglobulins w/ different binding specificities. Phase 2: test if the bcr dont bind to self-tissue/antigen. Prevents the emergence of mature b cells bearing receptors that bind to normal constituents of human body.
