Feasibility of Repurposing the Polyanionic Microbicide, PPCM, for Prophylaxis against HIV Transmission during ART

Figure 2

Evidence for irreversibility of HIV-1 BaL by PPCM. PPCM was added to either virus and PBMCs (present during viral infection and replication) at the indicated concentrations, or only to virus, followed by a 1 : 100 dilution prior to inoculation into PBMC suspensions. Other conditions are presented in Section 2. Values are levels of viral p24 (pg/mL). Errors are SEM. For incubations in which PPCM was present throughout the experiment at the indicated concentrations, data were fit to transitional curves described by the general equation for a log-normal cumulative distribution, 𝑌=𝑎+0.5𝑏(erf)𝑐(−ln(𝑥/𝑐)/(2^0.5𝑑)); 𝑎=0.00853042, 𝑏=497.99247, 𝑐=0.023779, and 𝑑=−0.764206 (𝑟²=0.9995). For incubations in which PPCM was added only to virus, followed 1 h later by a 1 : 100 dilution before inoculation into PBMC suspensions, data were fit to a curve described by the equation 𝑌=𝑎exp(−𝑥/𝑏), where 𝑎=498.29049 and 𝑏=0.0526604 (𝑟²=0.9995). IC₅₀ values of PPCM when added only to virus and when present throughout the procedure were 36 (48.6–51.4% inhibition) and 23 (33.7–66.3% inhibition) μg/mL, respectively.