Persistence of memory CD8 T cells in MHC class I-deficient mice

An understanding of how T cell memory is maintained is crucial for the rati onal design of vaccines. Memory T tells were shown to persist indefinitely in major histocompatibility complex (MHC) class I-deficient mice and retain ed the ability to make rapid cytokine responses upon reencounter with antig en. In addition, memory CD8 T cells, unlike naive cells, divided without MH C-T cell receptor interactions. This "homeostatic" proliferation is Likely to be important in maintaining memory T cell numbers in the periphery. Thus , after naive CD8 T cells differentiate into memory cells, they evolve an M HC class I-independent "life-style" and do not require further stimulation with specific or cross-reactive antigen for their maintenance.