Replication kinetics of various mutant constructs in CEMx174 cells and primary rhesus PBMC. Cells were infected with 10 ng viral equivalents and viral replication was monitored by RT assay of culture supernatant at multiple time points. Mock denotes infection with heat-denatured wild-type virus. All replication experiments were conducted in triplicate. A. Representative growth curves of viruses deleted between the DIS and the SD (i.e. nt +424-462) in CEMx174 cells. B. Replication of viruses deleted between the SD and the Gag AUG (nt +471-530) in CEMx174 cells. Viral replication was assessed in activated rhesus PBMCs using viral inocula normalized on the basis of p27-CA Ag. Growth curves were determined by p27-CA Ag ELISA of culture supernatant taken at multiple time points. All results are the average of duplicates. C. Growth curves of variants deleted within the nt region +424-462. D. Growth curves of variants deleted within the region +471-530. Mock infection denotes exposure of cells to heat-inactivated wild-type virus as a negative control. Note that the scales of the ordinates are logarithmic. The dashed line representing 0.01 ng of p27/ml indicates the threshold of sensitivity of the assay.