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

Figure 1

Inhibition of HIV-1 BaL by PPCM is independent of added Ca²⁺. Values are levels of p24 (pg/mL); Errors are SEM (𝑁=3). Media contained 100 mg/mL Ca(NO₃)₂–4(H₂O), either throughout the procedure (added Ca²⁺) or only after washing PBMCs to remove unbound virus and PPCM (i.e., during PBMC incubation to allow for viral replication). 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)). In the absence of added Ca²⁺, 𝑎=2.38408, 𝑏=491.6185, 𝑐=0.03921, and 𝑑=−0.82000 (𝑟²=0.9999); in the presence of added Ca²⁺, 𝑎=0.00853, 𝑏=497.99248, 𝑐=0.02378, and 𝑑=−0.76421 (𝑟²=0.9995). The IC₅₀ values of PPCM with and without added Ca²⁺ are 24 (90% confidence limits = 33.7–66.3% inhibition) and 39 (46.8–53.2% inhibition) μg/mL, respectively.