Human Metapneumovirus Is Capable of Entering Cells by Fusion with Endosomal Membranes
Fig 5
Chlorpromazine treatment prevents HMPV internalization and significantly impairs fusion.
(A-C) BEAS-2B cells were pretreated with DMSO or chlorpromazine hydrochloride (CPZ) before virus binding (MOI ~1). (A) HMPV internalization after 30 min at 37°C was measured. Representative Z-stack projections are shown. Actin is shown in white, green particles are on the cell surface, and red only particles are internal. White bar in image indicates 10μm. (B) Quantification of the percentage of internalized HMPV particles for each treatment. (C) HMPV sensitivity to neutralizing antiserum at the cell surface was determined and is reported as the percentage of infected cells relative to a no antibody control. (D-F) R18-MPV (MOI ~1) was bound to cells before the addition of DMSO or CPZ. HMPV binding (D), fusion (E and F), and infectivity (G) was measured. Results (mean ± SEM) are for ≥ 3 experiments. * p <0.05, ANOVA with Dunnett’s test using DMSO as the reference.