Effect of virion production on proliferation of CD4 ⁺ T cells. (A) Fold increase in cell number from single infected CD4⁺ T cells with either an intact or defective provirus following anti-CD3/CD28 stimulation. Black dots represent median values. For this analysis, we have excluded wells with more than one provirus type detected by IPDA because some defective proviruses can give rise to virions, and we cannot be certain which provirus type is responsible for the virion production. (B) Fold increase in uninfected cells in culture wells from A for which virus in the supernatant was detected or not detected. (C–F) Relationship between virion production and infected cell proliferation. For wells with detectable supernatant virions, the number of virions/well is plotted versus the fold increase in infected cells harboring (C) intact, 3′ defective, or 5′ defective proviruses by IPDA, (D) only intact proviruses, (E) only 3′ defective proviruses, or (F) only 5′ defective proviruses. Each dot represents a well starting with a single infected cell. (G) Density plot depicting infected cell proliferation in wells with no detectable supernatant virus. The relative number of culture wells with the indicated fold increase in infected cells is shown for wells with intact, 3′ defective, or 5′ defective proviruses by IPDA. (H) Density plot depicting infected cell proliferation in wells with an intact provirus by IPDA. The relative number of culture wells with the indicated fold increase in infected cells is shown for wells with and without detectable supernatant virus. Pairwise comparisons were performed with a Wilcoxon test. * P < 0.05, *** P < 0.001, ns = not significant (P > 0.05).