Time-course analysis of the effects of a NERT-stimulating cocktail on HIV-1 stability and NERT-altering agents on HIV-1 infectivity at different temperature conditions. (a) HIV-1NL4-3 virion preparations (1 ng of HIV-1 p24 antigen equivalents) were either pretreated with the NERT-stimulating cocktail, or left untreated. Subsequently, the virion preparations were incubated in RPMI-1640 medium at 37 °C for different time periods. Infectivity was assessed on initially quiescent PBLs, via HIV-1 p24 antigen expression on day 10 post-infection. The 0 h represents prompt re-isolation of virions after mixing with media containing, or not containing the NERT-stimulating cocktail. (b) HIV-1NL4-3 virion preparations (4 ng of HIV-1 p24 antigen equivalents) were pretreated with 4 μM of AZT-TP in the presence or absence of the NERT-stimulating cocktail (100 nM dNTPs, 3 mM spermine and 0.1 mM spermidine) for 15 h at different temperature conditions (37 °C and 4 °C). After re-isolation by ultracentrifugation, the virion preparations were used to infect initially quiescent human PBLs. Viral production was assessed via HIV-1 p24 antigen expression (ELISA) by day 10 post-infection.