Figure 5.

Vaccination with rAd leads to the induction of tumor-reactive CTL activity directed against the HPV16 E7, H-2D^b-restricted CTL epitope. B6 mice were left nonimmunized, were immunized with rAd-1, harboring minigene 1, or were immunized with rAd-2, harboring minigene 2. Two weeks later, spleen cells of these animals were taken and restimulated with HPV16-transformed tumor cells to propagate H-2D^b-restricted, HPV16 E7-specific CTL. Lytic activity of bulk CTL cultures was tested 6 days later on HPV16 MEC, untransformed B6 MEC loaded with the Sendai-virus encoded control CTL epitope FAPGNYPAL, the E1A-encoded CTL epitope, the E1B-encoded CTL epitope, or the HPV16 E7-encoded CTL epitope. Mice immunized with rAd-1 recognize the HPV16 E7-encoded CTL epitope as well as tumor cells endogenously presenting the HPV16 E7 epitope. Nonimmunized mice and mice immunized with rAd-2 do not display reactivity against HPV16 E7 peptide positive target cells. Percent specific lysis at different effector to target cell ratios is shown.