Requirements for CD8 T-cell priming, memory generation and maintenance.

Immunological memory is characterized by the ability to provide protection from secondary exposure to pathogens. CD8(+) memory T cells provide protection from cell-associated antigens owing to their elevated frequency, rapid response and localization to sites of infection. Events occurring during primary exposure to antigen can impact not only the magnitude and quality of the initial cytotoxic T lymphocyte response but also the efficacy and longevity of the ensuing CD8(+) memory pool. Recent advances shed light on the relative roles of TCR signals and environmental cues in guiding the development of CD8(+) effector T cells into CD8(+) memory T cells and supporting CD8(+) memory T-cell maintenance.