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Unformatted text preview: B Cell Tolerance Main Idea : It is important that B and T Cells be inactivated or eliminated during its development, otherwise autoimmune response would ravage the organism. Tolerance : A state of immunological unresponsiveness to self-antigens. Mechanisms (1) Clonal Deletion Immature B-Cells with self-reactive BCRs undergo apoptosis. (2) Receptor-Editing The antigen-specific V region of a self-reactive, immature B Cell can V region can also get replaced by another V segment via VDJ recombination. This has only been shown to occur in the light chain, NOT the heavy chain. (3) Anergy The biochemical inactivation of self-specific B Cells. This inactivation includes the inability to migrate to the germinal center or illicit a T Cell dependent response. (4) Ignorance A state in which self-reactive B cells are present and functional, but self proteins are too low to stimulate an autoimmune response....
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- Spring '08