immune system
• failure of positive selection in the thymus
|
• normal numbers of both double negative (DN) and double positive (DP) thymocytes in homozygous mutant mice, despite near-absence of both CD4+ CD8- and CD4- CD8+ single positive (SP) T cells in peripheral blood, indicates a block at the transition from the DP to the SP stage, in turn indicating failure of positive selection in the thymus
• the block in mutant T cell develoopment was shown to be cell-intrinsic, not due to the thymic microenvironment
• T cells of mutant mice are unable to pass through thymic selection steps
• T cells of mutant mice fail to up-regulate their TCRs
|
• although total T cell counts are very low and alpha/beta T cells are virtually absent, gamma/delta T cell numbers are elevated in the peripheral blood of mutant mice
|
• homozygous mutant mice are characterized by a severe reduction in the number of T cells in their blood; both CD4+ CD8- and CD4- CD8+ single positive (SP) T cells are almost entirely absent
|
• alpha/beta T cells are absent in the peripheral blood of mutant mice
|
hematopoietic system
• failure of positive selection in the thymus
|
• normal numbers of both double negative (DN) and double positive (DP) thymocytes in homozygous mutant mice, despite near-absence of both CD4+ CD8- and CD4- CD8+ single positive (SP) T cells in peripheral blood, indicates a block at the transition from the DP to the SP stage, in turn indicating failure of positive selection in the thymus
• the block in mutant T cell develoopment was shown to be cell-intrinsic, not due to the thymic microenvironment
• T cells of mutant mice are unable to pass through thymic selection steps
• T cells of mutant mice fail to up-regulate their TCRs
|
• although total T cell counts are very low and alpha/beta T cells are virtually absent, gamma/delta T cell numbers are elevated in the peripheral blood of mutant mice
|
• homozygous mutant mice are characterized by a severe reduction in the number of T cells in their blood; both CD4+ CD8- and CD4- CD8+ single positive (SP) T cells are almost entirely absent
|
• alpha/beta T cells are absent in the peripheral blood of mutant mice
|