Persistence of vaccine-induced immune responses, not the initial magnitude, best correlates with protective antitumor immunity. In mice, oligonucleotide aptamer-targeted siRNA inhibition of mammalian target of rapamycin (mTOR) activity in activated CD8+ T cells promotes their differentiation into functionally competent memory cells leading to enhanced antitumor immunity, a protective effect superior to that of non-targeted administration of the mTOR inhibitor rapamycin.
Keywords: 4-1BB costimulation; T cell memory; Tumor immunity; aptamers; mTOR.