title: Actin-based phagosome motility.
abstract: Despite abundant evidence of actin's involvement at the particle internalization stage of phagocytosis, little is known about whether phagosomes undergo the same type of actin-based motility as observed with endocytic vesicles or such intracellular pathogens as Listeria and Shigella. By employing video microscopy to follow the fate of latex bead-containing phagosomes within the cytoplasm of bone marrow macrophages, we have made the novel observation of actin-based phagosome motility. Immunofluorescence microscopy confirmed that phagosomes containing IgG-opsonized, bovine serum albumin (or BSA) -coated or uncoated latex beads all formed actin-rich rocket tails that persisted only during a brief, 1-2 min period of actin-based motility. Average speeds of actin-based phagosome motility were 0.13 +/- 0.06 microm/s for IgG-coated beads, 0.14 +/- 0.04 microm/s for BSA-coated beads, and 0.11+/- 0.03 microm/s for uncoated beads. Moreover, the speeds and motile-phase duration of each type of phagosome were comparable to the behavior of pinosomes [Merrifield et al., 1999: Nat. Cell Biol. 1:72-74.]. Determination of optimal conditions for observing and analyzing actin-based phagosome motility should facilitate future investigations of phagocytosis and phagosome maturation.
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Florida College of Medicine, Health Science Center, Gainesville, FL 32610-0245, USA.
authors.forename: Fangliang
authors.initials: F
authors.lastname: Zhang
authors.forename: Frederick S
authors.initials: FS
authors.lastname: Southwick
authors.forename: Daniel L
authors.initials: DL
authors.lastname: Purich
mesh_terms: D000199:Actins / Q000378:metabolism*; D000818:Animals; D001854:Bone Marrow Cells / Q000502:physiology; D002417:Cattle; D002478:Cells, Cultured; D005260:Female; D005456:Fluorescent Dyes / Q000378:metabolism; D007074:Immunoglobulin G / Q000378:metabolism; D008264:Macrophages / Q000502:physiology* / Q000648:ultrastructure; D051379:Mice; D008810:Mice, Inbred C57BL; D008856:Microscopy, Fluorescence; D018715:Microscopy, Video; D008863:Microspheres; D009068:Movement; D010587:Phagocytosis; D010588:Phagosomes / Q000502:physiology*; D012710:Serum Albumin, Bovine / Q000378:metabolism
chemical_list: D000199:Actins; D005456:Fluorescent Dyes; D007074:Immunoglobulin G; D012710:Serum Albumin, Bovine