Figure 5. PbVIT functions in iron detoxification by reducing the LIP.

(a) The LIP of P. berghei wt and Pbvit⁻ iRBCs analysed by flow cytometry. ΔMFI was determined by evaluating the change in mean fluorescence intensity of PhenGreen-loaded iRBCs (SYTO 61-positive subset), after incubation with 100 μM DFO (ΔMFI=MFI_{DFO treated}−MFI_{DFO untreated}). For each independent experiment, the MFI of Pbvit⁻ iRBCs was normalized to the mean MFI of wt-iRBCs. Shown is a pool of four independent experiments (N=14), **P=0.0028 (unpaired, two-tailed Student's t-test; wt mean±s.e.m.=100±6, Pbvit⁻ mean±s.e.m.=137.1±10). (b) Liver-stage parasite load in HepG2 cells 45 h post infection with P. berghei wt and Pbvit⁻ sporozoites in the absence or presence of FeSO₄ and ascorbic acid in the growth medium, normalized to internal untreated control. Liver stage parasite load was determined by reverse transcription PCR quantification of parasite 18s expression normalized to human hypoxanthine-guanine phosphoribosyltransferase expression (shown is a pool of five independent experiments). (c) Parasite load in HepG2 cells 45 h post infection in the absence or presence of DFO added to the growth medium, determined as in b and normalized to internal untreated control (shown is a pool of five independent experiments). In b and c the asterisks denote significant differences using the two-tailed, unpaired Student's t-test: *P<0.05.