Potent induction of long-term CD8⁺T cell memory by short-term IL-4 exposure during T cell receptor stimulation

Abstract

An important goal of vaccination is to achieve long-term survival of functional memory T cells. Using a MHC-compatible adoptive transfer system, we show here that a short, 3-day IL-4 but not IL-2 or IL-12 exposure during in vitro T cell receptor stimulation of naive CD8 + T cells induced long-lasting in vivo memory. Such long-term memory CD8 + T cells expressed antigen-specific cytotoxicity and the potential for IFN-γ and IL-4 production. Our results support the concept that functional T cell longevity can be regulated by cytokines during initial antigen encounter and provide a rational foundation for vaccine development. They also may have implications in formulating optimal therapeutic regimens of ex vivo expanded autologous cancer- and HIV-specific CD8 + T cells. In addition, the availability of large numbers of memory CD8 + T cells generated through our high-efficiency system should facilitate progress in the molecular dissection of CD8 + T cell memory development.