FIG. 4.

The SARKLM variant displays the highest replication capacity in the presence of KK10-specfic CTL. CEM-GXR cells stably expressing HLA-B2705 were inoculated with WT NL4-3 or KK10 variants (MOI = 0.0015). KK10-specific CTL were added to one replicate well at an effector-to-target cell ratio of 1:10. Viral replication was measured using FACS at days 2 through 7, as described in the legend for Fig. 1, and the proportion of GFP⁺ CEM-GXR cells at each time is shown. Replication of WT virus was substantially inhibited in the presence of CTL (A), but the SARKLM variant was largely resistant to the effects of CTL (B). Replication capacity was highly variable for the different KK10 variants in the absence and presence of KK10-specific CTL, as demonstrated by the proportion of virus-infected cells present at day 7 using this in vitro coculture assay. Overall, however, the SARKLM virus exhibited the highest level of replication in either the absence or presence of CTL (C).