BIOL 2005 Lecture Notes - Thymocyte, Apoptosis, Clonal Deletion
30 Jan 2013
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Tolerance-state of the immune system characterized by unresponsiveness to a particular antigen. Ability to distinguish self from non self (unique and important to is) Dizygotic twins sharing a placenta will therefore share rbc"s (hematopoitic chimera [share stem cells] Developing/immature lymphocytes are subject to clonal deletion in presence if self-antigens are recognized. Self tolerance learned by developing immune system occurs during fetal and neonatal development. If receptor of immature lymphocyte engages a self-antigen deletion of that clone. T-cells more important than b-cells for tolerance. Central tolerance generated during lymphocyte development, involves clonal deletion. Peripheral tolerance generated after lymphocytes have matured involves anergy (inactivation) T cell development (occurs in thymus in 3 stages: tcr gene rearrangements resulting in productive a. /b dimers on cell surface have many more v/j segments than g /d. /b is located within a (between j and v) this prevents a.
