logging in or signing up immune tolerance aSGuest14064 Download Post to : URL : Related Presentations : Let's Connect Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Copy embed code: Embed: Flash iPad Dynamic Copy Does not support media & animations Automatically changes to Flash or non-Flash embed WordPress Embed Customize Embed URL: Copy Thumbnail: Copy The presentation is successfully added In Your Favorites. Views: 3638 Category: Education License: All Rights Reserved Like it (2) Dislike it (0) Added: March 03, 2009 This Presentation is Public Favorites: 1 Presentation Description No description available. Comments Posting comment... Premium member Presentation Transcript Immune tolerance : Immune tolerance The other side of the coin. Slide 2: cattle of dizygotic twin Immune tolerance : Definition: A type of specific unresponsiveness to an antigen induced by the exposure of specific lymphocytes to that antigen, but response to other antigens normally. Tolerogens: antigens that induce tolerance Immune tolerance : General features of Immunologic tolerance Tolerance is antigenic specific and results from the recognition of antigens by specific lymphocytes. Normal individuals are tolerant of their own antigens(self antigen)----- Self-tolerance. Foreign antigens may be administered in ways that preferentially inhibit immune response by inducing tolerance in specific lymphocytes---antigen induction. Difference of Immuologic tolerance & immunodeficiency, immunosuppression : Difference of Immuologic tolerance & immunodeficiency, immunosuppression Immunodeficiency: any condition in which there is deficiency in the production of humoral and /or cell-mediated immunity---non-specificity to Ag Immunosuppression: The suppression of immune responses to antigens. This can be achieved by various means, including physical, chemical----non-specificity to Ag Slide 6: Experiment of Medawar on immunologic tolerance Mechanism of Immunologic Tolerance : Mechanism of Immunologic Tolerance Central tolerance Peripheral tolerance Central tolerance : Central tolerance Central tolerance occurs in the central lymphoid organs as a consequence of immature self-reactive lymphocytes recognizing ubiquitous self-antigen. Peripheral tolerance : Peripheral tolerance Peripheral tolerance was induced in peripheral organs as a result of mature self-reactive lymphocytes encountering tissue-specific self antigens under particular conditions Central tolerance : Central tolerance Clonal deletion (apoptotic cell death) During maturation of lymphocytes in the thymus for T cell or in the bone marrow for B maturation, immature lymphocytes that recognize ubiquitous self-antigen with high affinity are deleted by negative selection Clonal deletion:negative selection of T cells in the thymus : Clonal deletion:negative selection of T cells in the thymus Negative selection of B cells inbone marrow : Negative selection of B cells inbone marrow Peripheral tolerance : Peripheral tolerance Clonal anergy functional inactivation without cell death: lack co-stimulatory signal To induce immunologic tolerance : To induce immunologic tolerance Prevent the rejection of organ allografts and xenografts Treat autoimmune diseases Treat allergic diseases To terminate immunologic tolerance : To terminate immunologic tolerance To treat tumor enhance first signal or second signal To treat infection diseases You do not have the permission to view this presentation. In order to view it, please contact the author of the presentation.