FIG. 3.

Infectivity analysis of NC mutant and wild-type HIV-1 samples. (A) Single-round infectivity titers were obtained by infecting HCLZ cells as described in Materials and Methods and corrected for a constant level of RT activity within an assay series. The titer levels of the mutants are reported as the percentage of the wild-type sample for a particular assay series with the wild-type sample (WT) set to 100%. The percentage of wild-type HCLZ titers presented is representative of the average infectivity of samples from four independent transfections. Error bars, indicating the standard deviation from the mean, are also presented. (−)-Control samples are from 293T cells transfected with sheared salmon sperm DNA. (B) Long-term H9 replication assays of NC mutant and wild-type HIV-1 viruses are presented. RT activities of the starting inoculum, corrected for background (in counts per minute of [³H]TMP incorporated/ml) are as follows: (CNBP-3), 2.1 × 10⁶; (CNBP-5), 1.8 × 10⁶; and (wild-type), 0.4 × 10⁶. Symbols: ♦, undiluted; ▪, 1/20; ▴, 1/400; ▾, 1/8,000; •, 1/160,000; ⋄, (−)-Control (supernatants from 293T cells transfected with sheared salmon sperm DNA).