Macropinocytosis refers to the formation of primary large endocytic vesicles of irregular size
and shape, generated by actin-driven evaginations of the plasma membrane, whereby cells
avidly incorporate extracellular fluid. Macropinosomes resemble “empty” phagosomes and
show no difference with the “spacious phagosomes” triggered by the enteropathogenic
bacteria Salmonella and Shigella. Macropinosomes may fuse with lysosomes or regurgitate
their content back to the extracellular space. In multiple cell types, macropinocytosis is a …