Vaginal HIV-1 Challenge in Mouse Model

Vaginal drug administration was carried out as described previously^{25 ,27 (link)} and summarized in Fig. 1. The employed drug concentrations in the single- and multiple drug dosing groups are provided in Supplementary Data S1–S4. Stocks of HIV-1 JR-CSF were prepared as previously described^{28 (link),37 (link)} and standardized by p24 ELISA using the Alliance HIV-1 P24 ANTIGEN ELISA Kit (96 Test) (Perkin Elmer, Waltham, MA), according to the manufacturer’s instructions. Prior to inoculation, mice were anesthetized with isoflurane. Aliquots (5 μL) of drug solutions in PBS were applied vaginally through a pipet tip. The rear half of the mouse remained elevated during the procedure to reduce chance of back-flow from the vaginal cavity during the recovery. Within 30 min (typically 15–25 min) post-drug application, mice were vaginally challenged with HIV-1 (5 µL, corresponding to 200 ng of p24). This inoculum is a standard high viral load for successful vaginal infection (1 ng of p24 corresponds to ca. 10 infectious units). Methods used for the atraumatic vaginal HIV-1 challenge are described elsewhere^{38 (link),41 (link)–44 (link)}.