Fig. 1.

In vitro viral fitness of 14x-SIVmac239 and 11x-SIVmac239 mutant viruses. We inoculated each mutant virus and wild-type SIVmac239 into cultures of concanavalin A-activated CD8-depleted peripheral blood mononuclear cell (PBMC) targets at the indicated ratio of mutant virus to wild-type virus (1:10, 1:1, or 10:1). We then harvested virus-containing supernatant at each time point indicated and quantified the proportion of each viral species by quantitative reverse transcription-PCR. The complete method, including primers used for quantitative PCR, has been described previously (40). Both mutant-inoculated cultures displayed relatively consistent ratios of wild-type to mutant virus over the 7 days of the assay, suggesting no in vitro fitness deficit or advantage for the introduced mutations. In vitro analysis of the 5x-SIVmac239 virus has been published previously (42).