Suppression of Drug Resistance in Dengue Virus

Mateo, Roberto; Nagamine, Claude M.; Kirkegaard, Karla

All mice were bred and housed under specific-pathogen-free condi-tions in a Stanford University AAALAC-accredited vivarium. The 129 IFNAR Ϫ/Ϫ IFNGR Ϫ/Ϫ and C57BL/6 IFNAR Ϫ/Ϫ IFNGR Ϫ/Ϫ mouse colonies are monitored for adventitious viral, bacterial, and parasitic pathogens by dirty-bedding sentinels. The sentinels are tested every 4 months and were found to be free of mouse parvovirus, Minute virus of mice, mouse hepatitis virus, mouse rotavirus (EDIM), Theiler's murine encephalomyelitis virus, murine norovirus, Sendai virus, mouse adenovirus 1 and 2, ectromelia (mousepox), lymphocytic choriomeningitis virus, pneumonia virus of mice, respiratory enterovirus III (Reo3), Mycoplasma pulmonis, Helicobacter spp., Pasteurella pneumotropica, fur mites, lice, and pinworms. All mice were housed in individually ventilated cages and provided with irradiated cages and bedding, irradiated food, and UVirradiated and acidified water. All experiments were approved by Stanford's Institutional Animal Care and Use Committee, Administrative Panel of Laboratory Animal Care. Age-matched mice 7 to 11 weeks of age were used for all experiments. A total of 10 7 FFU of virus was injected retro-orbitally into anesthetized mice in a volume of 100 l, and mice were housed under animal biosafety level 2 conditions. Drug treatments were performed orally. Drug treatments in C57BL/6 IFNAR ؊/؊ IFNGR ؊/؊ mice. Stocks of MK-0608 (Carbosynth, San Diego, CA) were prepared by drug resuspension in saline at a 4.4-mg/ml concentration to achieve doses of 40 mg/kg. ST-148 (ChemBridge Corporation, San Diego, CA) was prepared at a 5.5-mg/ml concentration in an aqueous solution containing 32% 2-hydroxylpropyl-␤-cyclodextrin (HP-␤-CD; Sigma, St. Louis, MO); this resulted in a dose of 50 mg/kg. Both drugs were delivered by oral gavage (200 l of drug solution or vehicle/mouse) every 12 h for 96 h, after which spleen samples were collected.