Alpha tumor necrosis factor contributes to CD8+ T cell survival in the transition phase

Cytokine and costimulation signals determine CD8+ T cell responses in proliferation phase. In this study, we assessed the potential effect of cytokines and costimulations to CD8+ T cell survival in transition phase by transferring in vitro ovalbumin (OVA)-pulsed dendritic cell-activated CD8+ T cells derived from OVA-specific T cell receptor transgenic OT I mice into wild-type C57BL/6 mice or mice with designated gene knockout. We found that deficiency of IL-10, IL-12, IFN-γ, CD28, CD40, CD80, CD40L, and 41BBL in recipients did not affect CD8+ T cell survival after adoptive transfer. In contrast, TNF-α deficiency in both recipients and donor CD8+ effector T cells significantly reduced CD8+ T cell survival. Therefore, our data demonstrate that the host- and T cell-derived TNF-α signaling contributes to CD8+ effector T cell survival and their transition to memory T cells in the transition phase, and may be useful information when designing vaccination.