Self-enabling T cells.

摘要

In this issue of Blood, Pospori and colleagues demonstrate that T cells genetically modified to express a receptor specific for a self-peptide derived from the tumor antigen Wilms Tumor 1 are not deleted in the thymus and undergo activation in the periphery, thus acquiring functionality without vaccination.Central tolerance to self is mediated in the thymus by deletion of T cells bearing receptors capable of high-affinity recognition of self-peptides (reviewed in Klein et al). However, the presence of T cells outside the thymus that are reactive against self-antigens (such as those expressed on tumors) indicates that this mechanism is not complete. In addition, low-level TCR signaling by self-antigens in the periphery serves to "tune" the TCR. so that T cells respond optimally to foreign antigens.