IL-15Rα expression on CD8~+ T cells is dispensable for T cell memory

摘要

The generation and maintenance of immunological memory requires the activation, expansion, and persistent proliferation of antigen-specific T cells. Recent work suggests that IL-15 may be important for this process. Surprisingly, we now find that expression of the high-affinity receptor for IL-15, IL-15Rα, on T cells is dispensable for the generation or maintenance of memory CD8~+ T cells. By contrast, IL-15Rα expression on cells other than T cells is absolutely critical for this function. These findings may be related to IL-15Rα's ability to present IL-15 in trans to low-affinity IL-15Rβ/γ_c receptors on memory CD8~+ T cells. These unexpected results provide insights into how IL-15Rα supports memory CD8~+ T cells.