Initial Antigen Encounter Programs CD8+ T Cells Competent to Develop into Memory Cells That Are Activated in an Antigen-Free, IL-7- and IL-15-Rich Environment

• Published in: The Journal of immunology (1950) 2004-06, Vol.172 (12), p.7315-7323
• Main Authors: Carrio, Roberto, Bathe, Oliver F, Malek, Thomas R
• Format: Article
• Language: English
• Subjects: Adoptive Transfer; Animals; Antigen Presentation; CD8-Positive T-Lymphocytes - cytology; CD8-Positive T-Lymphocytes - drug effects; CD8-Positive T-Lymphocytes - immunology; Cell Differentiation; Gene Expression Regulation - immunology; Immunologic Memory - drug effects; Immunologic Memory - immunology; Immunophenotyping; Interleukin-15 - pharmacology; Interleukin-7 - pharmacology; Kinetics; Mice; Mice, Transgenic; T-Lymphocytes, Cytotoxic - cytology; T-Lymphocytes, Cytotoxic - drug effects; T-Lymphocytes, Cytotoxic - immunology
• ISSN: 0022-1767; 1550-6606
• DOI: 10.4049/jimmunol.172.12.7315

Although much is known concerning the immunobiology of CD8+ T memory cells, the initial events favoring the generation of CD8+ T memory cells remain poorly defined. Using a culture system that yields memory-like CD8+ T cells, we show that 1 day after Ag encounter, Ag-activated T cells developed into memory-like T cells, but this optimally occurred 3 days after Ag encounter. Key phenotypic, functional, and molecular properties that typify central memory T cells were expressed within 48 h when the activated CD8+ T cells were cultured with IL-7 or IL-15 in the absence of Ag or following transfer into normal mice. These data support a model whereby Ag activation of naive CD8+ T cells not only programs effector cell expansion and contraction but the potential to develop into a memory cell which ensues in an Ag-free environment containing IL-7 or IL-15.