FIG. 2.

Confocal laser scanning microscopic images of transiently stained promastigotes (top row) or of the macrophage cell line U937 (CFSE stain) or human monocytes (CM-DiI and CMTMR stains) infected with fluorescently labeled promastigotes (bottom row). Promastigotes were stained with 5 μM CFSE (green), 5 μM CM-DiI (red), or 5 μM CMTMR (red) as indicated. Differentiated adherent U937 cells were allowed to phagocytose promastigotes for 30 min and then stained with fluorescent phalloidin to mark the cytoskeletal actin. Actin stains were either tetramethyl rhodamine isocyanate-phalloidin (red) as a counterstain for green CFSE-labeled promastigotes or fluorescein isothiocyanate-phalloidin (green) as a counterstain for red CM-DiI- or CMTMR-labeled promastigotes.