P. falciparum humanized NOD-scid IL2Rγnull mouse model.

The P. falciparum humanized NOD-scid IL2Rγ^null mouse model was adapted from the procedure described by Jiménez-Díaz et al. (39). Briefly, NOD-scid IL2Rγ^null mice, continually engrafted with human erythrocytes, were infected intravenously with 2 × 10⁷ P. falciparum 3D7^0087/N9-infected erythrocytes from a humanized donor mouse on day 0. Compounds were prepared in a vehicle consisting of 70% Tween 80 and 30% ethanol, followed by a 10-fold dilution in H₂O. Experimental mice (2 per cohort) were left untreated (control mice) or treated at days 3, 4, 5, and 6 postinfection with an oral dose of the WEB-485 (compound 2; 50 mg/kg) or chloroquine (catalog number C6628; Sigma). Peripheral blood samples were taken on days 3, 4, 5, and 6 postinfection, and parasitemia was measured by microscopic analysis of Giemsa-stained blood smears. Parasitemia values were averages for 2 mice per group and are expressed as percent parasitemia at days 3, 4, 5, and 6.