FIG. 7.

Lipopeptides elicit potent CD8 T-cell memory responses. (A) Cytolytic effector cells were generated in vitro from spleen cells of mice that had been primed 15 months previously with 9 nmol of the indicated constructs emulsified in CFA. The cells were cultured for 5 days with Mem 71 virus-infected autologous spleen cells and then tested in the ⁵¹Cr release assay. For each immunogen, the background lysis measured on uninfected P815 targets was <15% at an effector/target ratio of 100:1. (B) CTL determinant-specific IFN-γ-secreting cells were enumerated in the spleens of mice inoculated 3 months previously with 9 nmol of the indicated immunogens emulsified in CFA. The data are presented as the number of ELISPOTS per 10⁶ spleen cells, with backgrounds in cultures lacking antigen subtracted. The results are expressed as the mean value obtained from three individual mice, and the error bars represent one standard deviation of the mean.