Harnessing negative T-cell costimulatory pathways to promote engraftment.

The authors reflect on the activation of lymphocyte in the context of allo- and auto-immunity in the U.S. They note that on account of the increasingly sophisticated molecular and immunological tools, their knowledge of the complexities of cell-cell interaction continues to evolve. Moreover, examination of the molecular interaction that occurs when a lymphocyte encounters an antigen-presenting cell (APC) has revealed that T cells require multiple signals to become fully activated.