Fitness measurements for viable HIV-1 CA mutants.

aInfectivity measurement in which MT-4 cells were inoculated with supernatant from 293T cells (equivalent to MOI = 1 for WT virus) that had been transfected with single residue CA mutant proviral plasmids. Dextran sulfate was added approximately 16 h after infection to restrict replication to a single cycle. Values are reported as the percentage of the number of infected (GFP+) cells obtained with the WT virus.bFitness measurement in which MT-4 cells were inoculated with supernatant from 293T cells (equivalent to MOI = 0.01 for WT virus) that had been transfected with single residue CA mutant proviral plasmids. Multiple cycles of replication were permitted over 72 h. Values are reported as the percentage of the number of infected (GFP+) cells obtained with the WT virus.cThe frequency at which the indicated mutant residue occurs in 1000 HIV-1 subtype B sequences.*Abbreviation for cyclophilin binding loop.Mutants were considered viable if they maintained or 2% of WT fitness in the spreading replication assay.