PHGY 313 Lecture Notes - Lecture 20: Clonal Deletion, Clonal Anergy, Autoimmune Disease
24 May 2016
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Document Summary
A state of functional unresponsiveness for a particular pathogen. Breaking tolerance is making the immune system responsive to an antigen. Signal 2 is b7 and cd28 = mechanism for breaking tolerance against pathogen. Mechanisms that protect an individual from potentially self-reacting lymphocytes. Subclass of cd4+ t cells known as tregs can mediate antigen-specific silencing of t cell responses. Layers of self-tolerance: central tolerance o o. Site of action: thymus, bone marrow: peripheral anergy o o. Mechanism: cellular inactivation by weak signaling without co-stimulus. Site of action: 2nd lymphoid tissues: regulatory cells o o. Site of action: 2nd lymphoid tissues and sites of inflammation: clonal deletion o o. Site of action: 2nd lymphoid tissues and sites of inflammation. Deletion of t and b cell clones before cells are allowed to mature. For cells that possess receptors that have high affinity for self antigens. Deletion or anergizing of lymphocytes that possess receptors reacting with self antigens.
