Characterization of heme uptake in B. malayi.
A) B. malayi females were cultured in RPMI-1640 medium containing 2 μM GaPPIX and increasing hemin (0, 10, 20, or 50 μM). Motility was assessed as described in Materials and Methods on a scale from 0 (nonmotile) to 4 (highly motile). Each data point represents motility from a single experiment where worms were scored as a group (6 adult worms/treatment group) (A, B). The control groups (negative control: 0 μM GaPPIX/0 μM heme; positive control: 2 μM GaPPIX/0 μM heme) are taken from Fig. 4A as a reference. B) GaPPIX-induced immotility in female B. malayi is attenuated in the presence of heme. B. malayi females (6 worms/treatment group) were cultured in RPMI-1640 medium containing 2, 5, or 20 μM GaPPIX and increasing hemin (0, 10, 20, or 50 μM). C) Fluorescent labeling of female B. malayi worms incubated with 40 μM ZnMP for 18 h followed by a chase with 40 μM heme (hemin chloride). Worms were analyzed by epifluorescence microscopy at the indicated time points throughout the chase period (6 worms/time point) Scale bars, 100 μm. Representative images are shown.