Combined TLR/CD40 Stimulation Mediates Potent Cellular Immunity by Regulating Dendritic Cell Expression of CD70 In Vivo

This is the authors' abstract. We don't add key points for this paper.

We previously showed that immunization with a combination of TLR and CD40 agonists (combined TLR/CD40 agonist immunization) resulted in an expansion of Ag-specific CD8 T cells exponentially greater than the expansion observed to immunization with either agonist alone. We now show that the mechanism behind this expansion of T cells is the regulated expression of CD70 on dendritic cells. In contrast to previous results in vitro, the expression of CD70 on dendritic cells in vivo requires combined TLR/CD40 stimulation and is not significantly induced by stimulation of either pathway alone. Moreover, the exponential expansion of CD8(+) T cells following combined TLR/CD40 agonist immunization is CD70 dependent. Thus, the transition from innate stimuli (TLRs) to adaptive immunity is controlled by the regulated expression of CD70.