FIG. 6.

Levels of CD8 T-cell responses in DNA-immunized or TC-MCMV-infected mice on day 5 after challenge with SG-MCMV. Three BALB/c mice were immunized three times in 2 weeks with either empty vector or plasmid DNA expressing either IE1, M54, or M105. Another group of mice was i.p. infected with TC-MCMV as described in the Fig. 4 legend. Seven weeks after the last DNA immunization or 6 weeks after MCMV infection, the mice were i.p. challenged with 1.2 × 10⁵ PFU of SG-MCMV, and an ICS assay was performed on the splenocytes of these mice on day 5 postchallenge, as described in Materials and Methods. The bars and symbols are as described in the Fig. 5 legend.