Figure 1.

Antiretroviral drugs inhibit Plasmodium hepatic infection in vitro. (A,B) HuH7 cells were infected with green fluorescent protein (GFP)-expressing P. berghei sporozoites. The culture medium of HuH7 cells was replaced by medium containing the IC50 concentration of selected drugs 1 hour prior to infection or 2 hpi, for invasion and development assays, respectively. (A) Cell invasion was quantified by flow cytometry by determining the percentage of GFP⁺ cells at 2 hpi. (B) Percentage of infected cells (dots) and parasite development (bars) were assessed by determining the percentage and fluorescence intensity of GFP⁺ cells at 48 hpi, respectively. (C) Parasite development in cells treated with EFV, ETV and NFV was also assessed by quantification of EEF area by immunofluorescence microscopy. (D) Representative immunofluorescence microscopy images show P. berghei hepatic forms treated with the IC50 concentrations of EFV, ETV and NFV or with DMSO (control) from 2 to 48 hpi. Immunofluorescence microcopy employed antibodies against PbUIS4 (a parasitophorous vacuole membrane (PVM) protein, in red), PbHSP70 (a heat shock protein that localizes to the parasite soma, in green), and the nuclear stain Hoechst (in blue). Scale bars, 10 μm. Plots represent the mean values of at least three independent experiments with error bars indicating SEM. One-way ANOVA with post-test Dunnett. ns, not significant, ^* p < 0.05, ^** p < 0.01, ^*** p <0.001. Light gray bars or circles in panels (A–C) correspond to solvent controls, blue bars or circles correspond to NNRTIs, and red bars or circles correspond to PIs.