Evaluation of PD 404,182 as an Anti-HIV and Anti-Herpes Simplex Virus Microbicide

ABSTRACT PD 404,182 (PD) is a synthetic compound that was found to compromise HIV integrity via interaction with a nonenvelope protein viral structural component (A. M. Chamoun et al., Antimicrob. Agents Chemother. 56:672–681, 2012). The present study evaluates the potential of PD as an anti-HIV microbicide and establishes PD9s virucidal activity toward another pathogen, herpes simplex virus (HSV). We show that the anti-HIV-1 50% inhibitory concentration (IC 50 ) of PD, when diluted in seminal plasma, is ∼1 μM, similar to the IC 50 determined in cell culture growth medium, and that PD retains full anti-HIV-1 activity after incubation in cervical fluid at 37°C for at least 24 h. In addition, PD is nontoxic toward vaginal commensal Lactobacillus species (50% cytotoxic concentration [CC 50 ], >300 μM), freshly activated human peripheral blood mononuclear cells (CC 50 , ∼200 μM), and primary CD4 + T cells, macrophages, and dendritic cells (CC 50 , >300 μM). PD also exhibited high stability in pH-adjusted Dulbecco9s phosphate-buffered saline with little to no activity loss after 8 weeks at pH 4 and 42°C, indicating suitability for formulation for transportation and storage in developing countries. Finally, for the first time, we show that PD inactivates herpes simplex virus 1 (HSV-1) and HSV-2 at submicromolar concentrations. Due to the prevalence of HSV infection, the ability of PD to inactivate HSV may provide an additional incentive for use as a microbicide. The ability of PD to inactivate both HIV-1 and HSV, combined with its low toxicity and high stability, warrants additional studies for the evaluation of PD9s microbicidal candidacy in animals and humans.