Early endosomal markers are recruited to tPCs. (a and b) tPCs fuse with endocytic compartments acquiring features of mature phagolysosomes. Representative confocal imaging of RAW macrophages ingesting filamentous bacteria (blue) 5 min (a) and 30 min (b) after onset of phagocytosis. Images illustrate the recruitment of EEA1 (left set), GFP-Rab5 (center set), and LAMP1 (right set) to the tPC. Actin jackets, denoted by F-actin accumulation (red), delineate the top border of the tPCs. Images in main panels show merged z-stacks, and images to the right of main panels show magnified single planes from framed regions showing recruitments of early endosomal markers to the tPCs. RAW cells were either transiently expressing GFP-Rab5 or immunolabeled for EEA1 or LAMP1. (c) Number of tPCs positive for EEA1, Rab5, and LAMP1 recruitment over time from panels a and b. tPCs were scored positive for markers if labeling was observed along the entirety of the cup. Data shown are means ± SEMs of percentages from three independent experiments (n = 50 at each time point). Bars: 5 µm; (enlarged areas) 1 µm.