Clonal deletion, tolerance

SCT includes autologous and allogeneic transplants and the choice is dependent on the end result desired as well as the risks and benefits of each procedure. Autologous transplants after immunoablative therapy function on the premise of T-cell suppression versus clonal deletion as a cause of tolerance induction in autoimmunity. 

Tolerance following the intake of a large dose of antigen develops through clonal deletion of specific Thl lymphocytes or increase in the number of antigen nonspecific... 

Clonal deletion of self-reactive T- and B-ceUs during development, which removes lymphocytes with high-avidity receptors for ubiquitous self-antigen present in the thymus and marrow. This is known as central tolerance. 

The mechanisms most often proposed for tolerance are (i) clonal deletion (elimination of the tolerogen-specific clone) and, (ii) excessive activation of Ts cells. 

Clonal deletion. Elimination (e.g. by apoptosis, receptor editing) of self-reacting B or T cells during their maturation in central or peripheral lymphoid tissues. Primary mechanism involved in the induction and maintenance of - self-tolerance. 

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