Thymic requirement for clonal deletion during T cell development

Science  24 Nov 1989:
Vol. 246, Issue 4933, pp. 1044-1046
DOI: 10.1126/science.2511630


During T cell differentiation, self tolerance is established in part by the deletion of self-reactive T cells within the thymus (negative selection). The presence of T cell receptor (TCR)-alpha beta + T cells in older athymic (nu/nu) mice indicates that some T cells can also mature without thymic influence. Therefore, to determine whether the thymus is required for negative selection, TCR V beta expression was compared in athymic nu/nu mice and their congenic normal littermates. T cells expressing V beta 3 proteins are specific for minor lymphocyte stimulatory (Mlsc) determinants and are deleted intrathymically due to self tolerance in Mlsc+ mouse strains. Here it is shown that V beta 3+ T cells are deleted in Mlsc+ BALB/c nu/+ mice, but not in their BALB/c nu/nu littermates. Thus, the thymus is required for clonal deletion during T cell development.