CONTROL OF NEONATAL TOLERANCE TO TISSUE ANTIGENS BY PERIPHERAL T-CELLTRAFFICKING

Self tolerance is acquired by the developing immune system. As reporte d here, particular properties of the neonatal tissue contribute to thi s process. Neonatal skin, but not adult skin, was accessible for naive CD8 T cells. In mouse bone marrow chimeras generated at different age s, recent thymic emigrants were tolerized to a skin-expressed major hi stocompatibility complex class I antigen only during a neonatal period but not during adulthood. Blockade of T cell migration neonatally pre vented tolerance induction. Thus, T cell trafficking through nonlympho id tissues in the neonate is crucial for the establishment of self tol erance to sessile, skin-expressed antigens.