The Dual Role of IL-2 in the Generation and Maintenance of CD8+ Memory T Cells

• Published in: The Journal of immunology (1950) 2000-09, Vol.165 (6), p.3031-3036
• Main Authors: Dai, Zhenhua, Konieczny, Bogumila T, Lakkis, Fadi G
• Format: Article
• Language: English
• Subjects: Adoptive Transfer; AIDS/HIV; Animals; CD8-Positive T-Lymphocytes - cytology; CD8-Positive T-Lymphocytes - immunology; CD8-Positive T-Lymphocytes - transplantation; Cell Survival - immunology; Epitopes, T-Lymphocyte - immunology; Immunologic Memory - immunology; Immunophenotyping; Injections, Intravenous; Interleukin-2 - deficiency; Interleukin-2 - genetics; Interleukin-2 - pharmacology; Interleukin-2 - physiology; Lymphocyte Activation - immunology; Lymphocyte Count; Lymphocyte Transfusion; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, Knockout; Mice, Transgenic; T-Lymphocyte Subsets - cytology; T-Lymphocyte Subsets - immunology; T-Lymphocyte Subsets - transplantation
• ISSN: 0022-1767; 1550-6606
• DOI: 10.4049/jimmunol.165.6.3031

The mechanisms responsible for the generation and maintenance of T cell memory are unclear. In this study, we tested the role of IL-2 in allospecific CD8+ T cell memory by analyzing the long-term survival, phenotype, and functional characteristics of IL-2-replete (IL-2+/+) and IL-2-deficient (IL-2-/-) CD8+ TCR-transgenic lymphocytes in an adoptive transfer model. We found that IL-2 is not essential for the in vivo generation, maintenance, or recall response of CD8+ memory T cells. However, IL-2 increased the size of the CD8+ memory pool if present at the time of initial T cell activation but reduced the size of the pool if present during memory maintenance by inhibiting the proliferation of CD8+ memory T cells. Thus, IL-2-based vaccine strategies or immunosuppressive regimens that target IL-2 should take into account the divergent roles of IL-2 in CD8+ T cell immunity.