Ameobal Pathogen Mimivirus Infects Macrophages through Phagocytosis
Figure 4
Role of clathrin in APMV internalization.
(A) RAW 264.7 macrophages were pretreated with 50 µM chlorpromazine for 30 min and incubated with 50 µg/ml Alexa 488-conjugated transferrin for 15 min. The intracellular distribution of fluorescent transferrin was studied in control macrophages (left panels) and in chlorpromazine-pretreated macrophages (right panels). (B) Macrophages were pretreated with different concentrations of chlorpromazine and incubated with fluorescent transferrin. The results, expressed as the percentage of transferrin uptake relative to the control, are the mean±SD of 3 experiments. (C) Macrophages were pretreated with 50 µM chlorpromazine for 30 min before a 6-hour infection with APMV (50 PFU/cell) in the presence of 20 µM monensin to limit chlorpromazine toxicity. APMV particles were revealed by indirect immunofluorescence. Their intracellular distribution was studied in control macrophages (left panels) and in chlorpromazine-pretreated macrophages (right panels). (D) Macrophages were treated with different concentrations of chlorpromazine and incubated with APMV particles. Viral particles were visualized by immunofluorescence. The results, expressed as the percentage of APMV uptake relative to the control, are the mean±SD of 5 experiments. Scale bars represent 50 µm.