Fig. 5. Kinetics of endocytic `marker' association with phagosomes containing initially L. amazonensis metacyclic promastigotes. Macrophages pre-exposed (A,B) or not exposed (C) to IFN- were infected at a multiplicity of four parasites/host cell. Association of the following molecules with parasite-containing phagosomes was examined as a function of time: transferrin receptor, EEA1, rab7p, macrosialin, lamp-1, cathepsin B, cathepsin D and MHC class II molecules. At the time points indicated, cell preparations were fixed, permeabilized and incubated with immunological reagents before analysis by fluorescence microscopy. For each experiment and at each time point, the percentages of parasite-containing compartments displaying the molecules listed above were determined after counting about 100 to 200 organelles. Each value represents the mean+s.d. of two to eight experiments (A,B) or is from a single experiment representative of two separate experiments (C).