affinity maturation

affinity maturation - that ds breaks occur 1 st and...

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Affinity Maturation Affinity Maturation : The increase in the average affinity of antisera that occurs during the course of an immune response or with successive immunizations Somatic Hypermutation : The increased rate of mutation that occurs over the background mutation rate in and around rearranged Ig genes. The mutation rate in this region can be up to 100,000x greater. Affinity maturation correlates with Somatic Hypermutation (SHM). Antibodies produced late in an immune response have point mutations clustered within CDR regions. Sequence alignments of IgG isolated from B cells late in an immune response. Somatic Hyper Mutation SHM increases during the course of an immune response SHMs manifest themselves as point mutations in the CDRs Mechanism unknown, but it is believed
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Unformatted text preview: that ds breaks occur 1 st , and mutations get introduced during repair ● Mutations found within the V promoter and the intronic enhancer ● ACTIVATION-INDUCED CYTIDINE DEAMINSE IS REQUIRED FOR SHM ● AID also has effect on Class switching Selection ● SHM is an important player in affinity maturation, but affinity maturation is not possible with out selection of these SHM B cells ● SHM and selection occurs in the germinal centers, on follicular dendritic cells ● Follicular dendritic cells display the antigen on its surface ● The B Cells with highest affinity outcompete the cells with poor affinity ● These surviving cells also give rise to memory B cells: more specific B cells, high affinity, more isotypes, SHM...
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This note was uploaded on 05/06/2008 for the course MCB 150 taught by Professor Coscey during the Spring '08 term at Berkeley.

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